Part one of my book Principles of Cardiology revised)

1. Principles of Cardiology pages 1-61
ELECTROCARDIOGRAPHY
Prof. Samir Rafla
The electrocardiogram (ECG) is a graphic representation of the electrical activity
generated by the heart during the cardiac cycle. The electrical activity starts from the
SA node, bundle of His, right and left bundles, Purkinje fibers to stimulate the
ventricles.
Waveforms: The waveforms and intervals of the ECG are: The P wave = atrial
depolarization. The QRS complex = ventricular depolarization. The Q wave is the initial
downward deflection, the R wave is the initial upward deflection, and the S wave is the
second downward deflection. The interval from the beginning of the P wave to the
beginning of the Q wave is the PR interval.
The T wave = ventricular repolarization. The interval from the end of ventricular
depolarization to the beginning of the T wave is termed the ST segment. The interval
from the onset of ventricular depolarization to end of T is the QT interval.
STANDARD APPROACH TO THE ECG: Normally, standardization is 1.0 mV
per 10 mm, and paper speed is 25 mm/s (each horizontal small box = 0.04 sec)
Heart Rate: divide 1500 by number of small boxes between each QRS.
Rhythm: Sinus rhythm is present if every P wave is followed by a QRS, PR interval >
0.12 s, and the P wave is upright in leads I, II, and III.
Intervals: PR (0.12 - 0.20 s). QRS (0.06 - 0.10 s).
QT 0.43 s;
ST-T WAVES: ST elevation : Acute MI, coronary spasm, pericarditis (concave
upward), LV aneurysm.
ST depression: Digitalis effect, strain (due to ventricular hypertrophy), ischemia, or
nontransmural MI.
Tall peaked T: Hyperkalemia; acute MI ("hyperacute T").
Inverted T: Non-Q-wave MI, ventricular "strain" pattern, drug effect (e.g., digitalis),
hypokalemia, hypocalcemia, increased intracranial pressure (e.g., subarachnoid
bleeding).

2. 2
FIG: The magnified ECG wave is presented with the principal time intervals indicated.
Fig: The pathways of Conduction.

3. 3
RHEUMATIC FEVER
Introduction. Classified as a connective tissue or collagen vascular disease, rheumatic
fever (RF) is the leading cause of acquired heart disease in children and young adults.
a. In many developing countries the incidence of acute RF approaches or exceeds 100
per 100.000, whereas in the Unites States it is estimated to be less than 2 per 100.000.
b. Rheumatic fever is more common among population at high risk for streptococcal
pharyngitis, those in close contact with school age children, and persons of low
socioeconomic status. It occurs commonly between the ages of 5 and 18 years and is
rare before 5. Rheumatic fever affects both sexes equally, except for Sydenham’s
chorea, which is more prevalent in females after puberty.
The clinical manifestations of RF develop after a silent period of approximately 3 weeks
following a tonsillopharyngitis caused by a group A streptococcal infection (GAS).
Diagnostic criteria
1. The Jones criteria, are designed to aid in the diagnosis of the first episode of RF.
Rheumatic fever can be diagnosed when a previous upper airway infection with GA-
Streptococci is detected in conjunction with either two major manifestations, or one
major and two minor manifestations. Major manifestation includes arthritis, carditis,
chorea, erythema marginatum, and subcutaneous nodules.
Minor manifestations include: fever, arthralgias, history of tonsillitis 1-3 weeks before
the arthralgia, history of rheumatic heart disease;
high C-reactive protein, high erythrocyte sedimentation rate, raised antistreptolysin O
titer above 200 Todd’s units or prolonged PR interval on electrocardiogram (ECG).
Major manifestations:
1. Carditis: affecting 41% to 83% of patients. It can be defined as pancarditis affecting
the endocardium, myocardium, and pericardium: The main clinical manifestations
include increased heart rate, murmurs, cardiomegaly, rhythm disturbances, pericardial
friction rub, and heart failure. Congestive heart failure is rare in the acute phase; if
present, it usually results from myocarditis. The most characteristic component of
rheumatic carditis is a valvulitis (endocarditis) involving the mitral and aortic valves.
Pericarditis may cause chest pain, friction rubs, and distant heart sounds.

4. 4
2. Arthritis. This is the most common manifestation of RF. It is present in around 80%
of the patients and has been described as painful, asymmetric, migratory, and transient;
it involves large joints, such as knees, ankles, elbows, wrists, and shoulders. It improves
markedly with the use of salicylates within 48 hours of treatment. Monoarthritis,
oligoarthritis, and involvement of small joints of the extremities are less common. The
arthritis of RF is benign and self- limiting (Lasting 2 to 3 weeks) and does not result in
permanent sequelae.
3. Sydenham’s chorea. This extrapyramidal disorder is characterized by purposeless and
involuntary movements of face and limbs, muscular hypotonia, and emotional lability.
4. Subcutaneous nodules.
5. Erythema marginatum.
Minor manifestations:
1. Fever is encountered during the acute phase of the disease.
2. Arthralgia is defined as pain in one or more large joints without objective findings of
inflammation on physical examination.
3. Other clinical manifestations of RF include abdominal pain, epistaxis, acute
glomerulonephritis. These are not included as diagnostic criteria for the diagnosis of
RF.
Laboratory examination and diagnostic testing.
1. Neither throat culture nor rapid antigen test, if positive; differentiate
between recent infection associated with RF and chronic carriage of
pharyngeal GAS.
2. Antistreptolysin O is the most commonly available test. Elevated or rising ASO titers
provide solid evidence for recent GAS infection. A greater than two-fold rise in ASO
titers compared with convalescent titers is diagnostic.
3. Increased sedimentation rate.
4. Increased C reactive protein CRP/
5. The most common finding in the electrocardiogram is the presence of P-R
prolongation and sinus tachycardia.
Therapy:

5. 5
Patient with the diagnosis of rheumatic activity should initially receive a full course of
antibiotic to ensure proper eradication of the organism.
A. Arthritis: Anti-inflammatory medications are generally recommended for 3 weeks
for symptomatic relief.
1. Pain resolves within 24 hours of starting therapy with salicylates.
2. If pain persists after salicylate treatment, the diagnosis of RF is questionable.
3. The recommended dose of salicylate is 100 mg/kg per day, given in 4 divided doses.
Toxic effects such as anorexia, nausea, vomiting, and tinnitus should be avoided.
B. Carditis
1. Strenuous physical activity should be avoided.
2. Congestive heart failure should be treated with appropriate therapy.
3. In patients with significant cardiac involvement, corticosteroids are preferred over
salicylates. The recommended dose is 1 to 2 mg/kg per day, (maximum of 60 mg/day as
Prednisolone). Commonly, therapy is needed for more than one month in patients with
cardiac involvement. Therapy should be continued until there is sufficient clinical and
laboratory evidence of disease inactivity.
4. The gradual reduction in steroid doses is important to avoid relapses. Use of
salicylates (75 mg/kg per day) while tapering corticosteroids may reduce the likelihood
a relapse.
Summary: Jones Criteria of Rheumatic Fever
Major Criteria Minor Criteria
Migratory polyarthritis Fever
Carditis Arthralgia
Chorea High sedimentation rate
Subcutaneous nodules Positive C reactive protein
Erythema Marginatum Prolonged PR interval
Prevention:
The most important step in the treatment of RF is the eradication of GAS infection.
Penicillin is the agent of choice. A. best results are achieved with a single intramuscular
dose of penicillin G benzathine. b. The oral antibiotic of choice is penicillin V
(phenoxymethyl penicillin) (see Table for dosage information). Patients allergic to

6. 6
penicillin: oral erythromycin can be used. The recommended dosage is erythromycin for
10 days. The maximal dose of erythromycin is 1 g/day.
Table: Duration of therapy for secondary prevention of rheumatic fever
Disease state Duration of therapy
RF + carditis + residual valvular
disease
At least 10 years post episode and at least
until age 40. Lifelong prophylaxis may be
required
RF + carditis without valvular
disease
10 years or beyond adulthood, whichever
is longer.
RF without carditis 5 years or until age of 21, whichever is
longer.
RF, rheumatic fever.
VALVULAR HEART DISEASE
MITRAL STENOSIS
ETIOLOGY AND PATHOLOGY: Two-thirds of all patients with mitral stenosis (MS)
are females. MS is generally rheumatic in origin. Pure or predominant MS occurs in
approximately 40% of all patients with rheumatic heart disease. The valve leaflets are
diffusely thickened by fibrous tissue and/or calcific deposits. The mitral commissures
fuse, the chordae tendineae fuse and shorten. The valvular cusps become rigid, and
these changes in turn, lead to narrowing at the apex of the funnel-shaped valve.
Other rare causes of mitral stenosis: Atrial myxoma, ball valve thrombus, congenital
and calcific-atherosclerortic disease.
PATHOPHYSIOLOGY: In normal adults the mitral valve orifice is 4 to 6 cm2
. When
the mitral valve opening is reduced to 1 cm2
, a left atrial pressure of approximately 25
mmHg is required to maintain a normal cardiac output. The elevated left atrial pressure,
in turn, raises pulmonary venous and capillary pressures, reducing pulmonary
compliance and causing exertional dyspnea.
Pulmonary hypertension results from (1) the passive backward transmission of the
elevated left atrial pressure, (2) pulmonary arteriolar constriction, (reactive pulmonary

7. 7
hypertension), and (3) organic obliterative changes in the pulmonary vascular bed. In
time, the resultant severe pulmonary hypertension results in tricuspid and pulmonary
incompetence as well as right-sided heart failure.
SYMPTOMS AND COMPLICATIONS: - Dyspnea, hemoptysis. - Orthopnea and
paroxysmal nocturnal dyspnea. Pulmonary edema develops when there is a sudden
surge in flow across a markedly narrowed mitral orifice.
The cardiac cycle: Simultaneous electrocardiogram and pressure obtained from the left
atrium, left ventricle, and aorta, and the jugular pulse during one cardiac cycle.
When moderately severe MS has existed for several years, atrial arrhythmias as flutter
and fibrillation occur.
Hemoptysis results from rupture of pulmonary-bronchial venous connections
(apoplexy) secondary to pulmonary venous hypertension. Frank hemoptysis must be
distinguished from the bloody sputum that occurs with pulmonary edema, pulmonary

8. 8
infarction, and bronchitis, three conditions that occur with increased frequency in the
presence of MS.
Recurrent pulmonary emboli, sometimes with infarction are an important cause of
morbidity and mortality late in the course of MS, occurring most frequently in patients
with right ventricular failure. Pulmonary infections, i.e., bronchitis, broncho-
pneumonia, and lobar pneumonia, commonly complicate untreated MS. Infective
endocarditis is rare in pure MS but is not uncommon in patients with combined stenosis
and regurgitation.
Summary: Causes of hemoptysis in mitral stenosis:
- Bronchitis
- Congestion
- Pulmonary edema
- Pulmonary embolism, infarction
- Pulmonary apoplexy
Thrombi and emboli: Thrombi may form in the left atrium, particularly in the enlarged
atrial appendage of patients with MS. If they embolize, they do so most commonly to
the brain, kidneys, spleen, and extremities. Embolization occurs much more frequently
in patients with atrial fibrillation. Rarely, a large pedunculated thrombus or a free-
floating clot may suddenly obstruct the stenotic mitral orifice. Such “ball valve”
thrombi produce syncope, angina, and changing auscultatory signs with alterations in
position, findings that resemble those produced by a left atrial myxoma.
PHYSICAL FINDINGS: Inspection: In advanced cases there is a malar flush. When
fibrillation is present, the jugular pulse reveals only a single expansion during systole
(c-v wave) (systolic venous pulse).
Palpation: Left parasternal lift along the left sternal border signifies an enlarged right
ventricle. In patients with pulmonary hypertension, the impact of pulmonary valve
closure can usually be felt in the second and third left intercostal spaces just left of the
sternum (Diastolic shock). A diastolic thrill is frequently present at the cardiac apex,
particularly if the patient is turned into the left lateral position.
Auscultation: The first heart sound (S1) is generally accentuated and snapping. In
patients with pulmonary hypertension, the pulmonary component of the second heart

9. 9
sound (P2) is often accentuated, and the two components of the second heart sound are
closely split. The opening snap (OS) of the mitral valve is most readily audible in
expiration at, or just medial to, the cardiac apex but also may be easily heard along the
left sternal edge. This sound generally follows the sound of aortic valve closure (A2) by
0.05 to 0.12; that is, it follows P2; the time interval between A2 closure and OS varies
inversely with the severity of the MS. It tends to be short (0.05 to 0.07 s) in patients
with severe obstruction, and long, (0.10 to 0.12 s) in patients with mild MS. The
intensities of the OS and S1 correlate with mobility of the anterior mitral leaflet.
The OS usually precedes a low-pitched, rumbling, diastolic murmur, heard best at the
apex with the patient in the left lateral recumbent position. In general, the duration of
the murmur correlates with the severity of the stenosis. In patients with sinus rhythm,
murmur often reappears or becomes accentuated during atrial systole, as atrial
contraction elevates the rate of blood flow across the narrowed orifice (presystolic
accentuation).
Associated lesion: With severe pulmonary hypertension, a pansystolic murmur
produced by functional tricuspid regurgitation may be audible along the left sternal
border. Characteristically, this murmur is accentuated by inspiration, and should not be
confused with the apical pansystolic murmur of mitral regurgitation.
In the presence of severe pulmonary hypertension and right ventricular failure, a third
heart sound may originate from the right ventricle. The enlarged right ventricle may
rotate the heart in a clockwise direction and form the cardiac apex, giving the examiner
the erroneous impression of left ventricular enlargement. Under these circumstances, the
rumbling diastolic murmur and the other auscultatory features of MS become less
prominent or may even disappear and be replaced by the systolic murmur of functional
tricuspid regurgitation which is mistaken for mitral regurgitation. When cardiac output
is markedly reduced in a patient with MS, the typical auscultatory findings, including
the diastolic rumbling murmur, may not be detectable (silent MS).
ECG findings: The P wave is wide and may be notched which suggests left atrial
enlargement. It becomes tall and peaked in lead II and upright in lead V1 when severe
pulmonary hypertension.

10. 10
Echocardiogram: Two-dimensional echo-Doppler echocardiography for estimation of
the transvalvular gradient and of mitral orifice size, the presence and severity of
accompanying mitral regurgitation, the extent of restriction of valve leaflets, their
thickness, and the subvalvular changes. Transthoracic and transesophageal echo are
needed to verify presence of atrial thrombi.

11. 11
X-Ray chest: Straightening of the left border of the cardiac silhouette, prominence of
the main pulmonary arteries, dilatation of the upper lobe pulmonary veins, and
backward displacement of the esophagus by an enlarged left atrium.
Summary of signs of mitral stenosis:
- Mid-diastolic rumbling murmur with presystolic accentuation;
- Snappy first sound;
- Opening snap;
- Diastolic thrill.
DIFFERENTIAL DIAGNOSIS: The apical middiastolic murmur associated with aortic
regurgitation (Austin Flint murmur) may be mistaken for MS. However, in a patient
with aortic regurgitation, the absence of an opening snap or presystolic accentuation if
sinus rhythm is present points to the absence of MS.
Tricuspid stenosis, a valvular lesion that occurs very rarely in the absence of MS, may
mask many of the clinical features of MS.
MANAGEMENT: Penicillin prophylaxis of beta-hemolytic streptococcal infections and
prophylaxis for infective endocarditis are important. In symptomatic patients, some
improvement usually occurs with restriction of sodium intake and maintenance doses of
oral diuretics. Digitalis glycosides usually do not benefit patients with pure stenosis and
sinus rhythm, but they are necessary for slowing the ventricular rate of patients with
atrial fibrillation and for reducing the manifestations of right-sided heart failure in the
advanced stages of the disease.
Small doses of beta-blockers (e.g., atenolol 25 mg/d) may be added when cardiac
glycosides fail to control ventricular rate in patients with atrial fibrillation. Particular
attention should be directed toward detecting and treating any accompanying anemia
and infections. Hemoptysis is treated by measures designed to diminish pulmonary
venous pressure, including bed rest, the sitting position, salt restriction, and diuresis.
Anticoagulants should be administered continuously in those with atrial fibrillation.
If atrial fibrillation is of relatively recent origin in a patient who’s MS is not severe
enough to warrant surgical treatment, reversion to sinus rhythm pharmacologically or

12. 12
by means of electrical countershock is indicated. Usually this should be undertaken
following 3 weeks of anticoagulant treatment. Conversion to sinus rhythm is rarely
helpful in patients with severe MS, particularly those in whom the left atrium is
especially enlarged or in whom atrial fibrillation is chronic.
Mitral valvotomy by balloon or surgical mitral valvotomy, is indicated in the
symptomatic patient with pure MS whose effective orifice is less than approximately
1.3 cm2
(or 0.8 cm2
/ m2
of body surface area). Mitral valve replacement by prosthetic
valve is resorted to only if the valve is heavily calcified and associated with
incompetence.
Percutaneous balloon valvuloplasty is an alternative to surgical mitral valvuloplasty in
patients with pure or predominant rheumatic stenosis (it is now the first choice). Young
patients without extensive valvular calcification or thickening or subvalvular deformity
are the best candidates for this procedure.
Contraindications of balloon mitral valvotomy:
1. presence of left atrial thrombi,
2. presence of combined mitral incompetence and stenosis, and
3. heavily calcified mitral cusps.
MITRAL REGURGITATION
ETIOLOGY:
1- Chronic rheumatic heart disease is the cause of severe mitral regurgitation (MR).
2- MR also may occur as a congenital anomaly.
3- MR may occur in patients with infarction involving the base of a papillary muscle.
4- MR may occur with marked left ventricular dilatation.
5- Massive calcification of the mitral annulus of unknown cause, presumably
degenerative, which occurs most commonly in elderly women.
6- Systemic lupus erythematosus, rheumatoid arthritis, are less common cause.
7- Mitral prolapse.

13. 13
Acute MR occur 1- secondary to infective endocarditis involving the cusps or chordae
tendineae, 2- in acute myocardial infarction with rupture of a papillary muscle or one of
its heads, 3- as a consequence of trauma, 4- or following apparently spontaneous
chordal rupture.
MITRAL REGURGITATION: SYMPTOMS: Fatigue, exertional dyspnea, and
orthopnea are the most prominent complaints in patients with chronic, severe MR.
Hemoptysis and systemic embolism also occur less frequently in MR than in MS.
Right-sided heart failure, with painful hepatic congestion, ankle edema, distended neck
veins, ascites, and tricuspid regurgitation, may be observed in patients with MR who
have associated pulmonary vascular disease and marked pulmonary hypertension. In
patients with acute, severe MR, left ventricular failure with acute pulmonary edema and
/or cardiovascular collapse is common.
PHYSICAL FINDINGS: Palpation: A systolic thrill is often palpable at the cardiac
apex, the left ventricle is hyperdynamic, and the apex beat is often displaced laterally.
Auscultation: The first heart sound is generally absent, soft (muffled), or buried in the
systolic murmur. A low-pitched third heart sound (S3) occurring 0.12 to 0.17 sec after
aortic valve closure, i.e. at the completion of the rapid-filling phase of the left ventricle,
is an important auscultatory feature of severe MR.
A fourth heart sound is often audible in patients with acute, severe MR of recent onset
who are in sinus rhythm. A systolic murmur of at least grade III/VI intensity is the most
characteristic auscultatory finding in severe MR. It is usually holosystolic (pansystolic).
In MR due to papillary muscle dysfunction or mitral valve prolapse, the systolic
murmur commences in midsystole. In patients with ruptured chordae tendineae the
systolic murmur may have a cooing or “sea gull” quality; in patients with a flail leaflet
the murmur may have a musical quality.
Summary: Signs of mitral incompetence:
- Harsh pansystolic murmur over apex propagated to axilla.
- Muffled first heart sound.
- Systolic thrill over apex.

14. 14
Electrocardiogram: In patients with sinus rhythm there is evidence of left atrial
enlargement (P mitrale), but right atrial enlargement also may be present when
pulmonary hypertension is severe. Chronic, severe MR with left atrial enlargement is
generally associated with atrial fibrillation.
Echocardiogram: Doppler echocardiography and color Doppler flow echocardiography
imaging are the most accurate noninvasive techniques for the detection and estimation
of MR. The left atrium is usually enlarged. Findings which help to determine the
etiology of MR can often be identified; these include vegetations associated with
infective endocarditis, incomplete coaptation of the anterior and posterior mitral leaflets,
and annular calcification, as well as left ventricular dilation, aneurysm, or dyskinesia.
The echocardiogram in patients with mitral valve prolapse is described below.
Roentgenogram: The left atrium and left ventricle are the dominant chambers; in
chronic cases, the former may be massively enlarged and forms the right border of the
cardiac silhouette. Pulmonary venous congestion, interstitial edema, and Kerly B lines
are sometimes noted.
TREATMENT: Medical: The non surgical management of MR is directed toward
restricting those physical activities that regularly produce dyspnea and excessive
fatigue, reducing sodium intake, and enhancing sodium excretion with the appropriate
use of diuretics. Vasodilators and digitalis glycosides increase the forward output of the
failing left ventricle. Angiotensin-converting enzyme inhibitors are given in chronic
MR. The same considerations as in patients with MS apply to the reversion of atrial
fibrillation to sinus rhythm. Surgical treatment should be offered to patients with severe
MR whose limitations do not allow them to perform normal household activities despite
optimal medical management. Surgery is indicated when the end systolic diameter of
the left ventricle by echo exceeds 50 mm.
MITRAL VALVE PROLAPSE
Mitral valve prolapse (MVP), also termed the systolic click-murmur syndrome, is a
common, but highly variable, clinical syndrome. It is a frequent finding in patients who
have the typical features of the Marfan syndrome. The posterior leaflet is usually more
affected than the anterior, and the mitral valve annulus is often greatly dilated.

15. 15
MVP may be associated with thoracic skeletal deformities.
MVP is common in females between the ages of 6 and 30 years. Most patients are
asymptomatic and remain so for their entire lives. Arrhythmia, most commonly
ventricular premature contractions and paroxysmal supraventricular and ventricular
tachycardia, have been reported and may cause palpitations, light-headedness, and
syncope. Many patients have chest pain which is difficult to evaluate.
PHYSICAL EXAMINATION: Auscultation: the most important finding is the mid-or
late (nonejection) systolic click, which occurs 0.14 s or more after the first heart sound.
Systolic clicks may be followed by a high-pitched late systolic murmur, heard best at
the apex. A useful echocardiographic definition of MVP is systolic displacement (in the
parasternal view) of the mitral valve leaflets into the left atrium > 3 mm. Thickening of
the mitral valve leaflets is present. Doppler studies are helpful in revealing and
evaluating accompanying MR.
Treatment: The management of patients with MVP consists of reassurance of the
asymptomatic patient without severe MR or arrhythmias; prevention of infective
endocarditis with antibiotic prophylaxis in patients with a systolic murmur and the relief
of the atypical chest pain by beta blockers.
AORTIC STENOSIS
Aortic stenosis (AS) occurs in one-fourth of all patients with chronic valvular heart
disease; approximately 80 percent of adult patients with symptomatic valvular AS are
male.
Etiology: 1. AS may be congenital in origin, 2. secondary to rheumatic inflammation of
the valve, 3. degenerative calcification of the aortic cusps of unknown cause.
PATHOPHYSIOLOGY: A peak systolic pressure gradient exceeding 50 mmHg or an
effective aortic orifice less than approximately 0.5 cm2
/m2
of body surface area i.e., less
than approximately one-third of the normal orifice, is generally considered to represent
critical obstruction to left ventricular outflow.
SYMPTOMS: AS is rarely of hemodynamic or clinical importance until the valve
orifice has narrowed to approximately one-third of normal, i.e., to 1 cm2
in adults.
Exertional dyspnea, angina pectoris, and syncope are the three cardinal symptoms.
Angina pectoris reflects an imbalance between the augmented myocardial oxygen

16. 16
requirement by the hypertrophied myocardium and the un-accompanying increase in
coronary blood flow. Orthopnea, paroxysmal nocturnal dyspnea, and pulmonary edema,
i.e., symptoms of left ventricular failure, also occur only in the advanced stages of the
disease.
PHYSICAL FINDINGS: A palpable double systolic arterial pulse the so-called
bisferiens pulse, excludes pure or predominant AS and signifies dominant or pure aortic
regurgitation or obstructive hypertrophic cardiomyopathy.
Palpation: The apex beat is usually sustained and displaced laterally, reflecting the
presence of left ventricular hypertrophy. A systolic thrill is generally present at the base
of the heart in the suprasternal notch, and along the carotid arteries.
Auscultation: Harsh ejection systolic murmur over aortic area propagated to carotids.
The sound of aortic valve closure, the second sound is very weak or even absent with
tight aortic stenosis.
Frequently, a fourth heart sound is audible at the apex in many patients with severe
AS and reflects the presence of left ventricular hypertrophy and an elevated left
ventricular enddiastolic pressure; a third heart sound generally occurs when the left
ventricle dilates and fails.
The murmur of AS is characteristically an ejection systolic murmur loudest at the
base of the heart, most commonly in the second right intercostal space. It is transmitted
along the carotid arteries. Occasionally, it is transmitted downward and to the apex and
may be confused with the systolic murmur of MR.
Summary: Signs of aortic stenosis:
1. Harsh ejection systolic murmur over aortic area propagated to carotids.
2. Weak or absent second heart sound (aortic component)
3. Systolic thrill over aortic area, suprasternal notch and carotids.
4. Strong sustained apex,
Electrocardiogram: This reveals left ventricular hypertrophy in the majority of patients
with severs AS.
Echocardiogram: The key findings are left ventricular hypertrophy. The transaortic
valvular gradient can be estimated by Doppler echocardiography.
Congestive heart failure was considered to be the cause of death in one-half to two-
thirds of patients. Among adults dying with valvular AS sudden death, which

17. 17
presumably results from an arrhythmia (ventricular tachycardia or fibrillation) occurred
in 10 to 20 percent and at an average age of 60 years.
TREATMENT: All patients with moderate or severe AS require careful periodic
follow-up. In patients with severe AS, strenuous physical activity should be avoided
even in the asymptomatic stage. Digitalis glycosides, sodium restriction, and the
cautious administration of diuretics are indicated in the treatment of congestive heart
failure, but care must be taken to avoid volume depletion.
In the majority of adults with calcific AS and critical obstruction, replacement of the
valve is necessary. Percutaneous balloon aortic valvuloplasty is an alternative to
surgery in children and young adults with congenital aortic stenosis. It is not commonly
employed in elderly with severe calcific aortic stenosis because of a high restenosis rate.
Electrocardiogram (ECG), left ventricular, and aortic pressure curves in a patient with
aortic stenosis. There is a pressure gradient across the aortic valve during systole

18. 18
Fig. Abnormal sounds and murmurs associated with valvular dysfunction displayed
simultaneously with left atrial (LA), left ventricular (LV), and aortic pressure tracings.
AVO, aortic valve opening; E, ejection click; MVO, mitral valve opening; OS, opening
snap of the mitral valve.
.
AORTIC REGURGITATION
ETIOLOGY: Approximately three-fourths of patients with pure or predominant aortic
regurgitation (AR) are males; females predominate among patients with AR who have
associated mitral valve disease.
Causes:
1- In approximately two-thirds of patients with AR the disease is rheumatic in origin,
resulting in thickening, deformation and shortening of the individual aortic valve cusps,
changes which prevent their proper opening during systole and closure during diastole.
2- Acute AR also may result from infective endocarditis, which may attack a valve
previously affected by rheumatic disease, a congenitally deformed valve, or rarely a
normal aortic valve, and perforate or erode one or more of the leaflets.
3- Patients with discrete membranous subaortic stenosis often develop thickening of the
aortic valve leaflets, which in turn leads to mild or moderate degrees of AR.
4- AR also may occur in patients with congenital bicuspid aortic valves.
5- Aortic dilatation, i.e., aortic root disease, widening of the aortic annulus and
separation of the aortic leaflets are responsible for the AR.
6- Syphilis and ankylosing rheumatoid spondylitis may lead to aortic dilatation,
aneurysm formation, and severe regurgitation.

19. 19
7- Cystic medial necrosis of the ascending aorta, associated with other manifestations
of the Marfan syndrome, idiopathic dilatation of the aorta, and severe hypertension all
may widen the aortic annulus and lead to progressive AR.
8- Occasionally, AR is caused by retrograde dissection of the aorta involving the aortic
annulus.
History: Patients with severe AR may remain asymptomatic for 10 to 15 years.
Sinus tachycardia during exertion may produce particularly uncomfortable palpitations.
Exertional dyspnea is the first symptom of diminished cardiac reserve. This is followed
by orthopnea, paroxysmal nocturnal dyspnea, and excessive diaphoresis. Chest pain
occurs frequently, even in younger patients, due to diminished coronary filling during
diastole.
Nocturnal angina may be a particularly troublesome symptom. The anginal episodes can
be prolonged and often do not respond satisfactorily to sublingual nitroglycerin. Late in
the course of the disease, evidence of systemic fluid accumulation, including congestive
hepatomegaly, ankle edema, and ascites, may develop.
PHYSICAL FINDINGS: Peripheral signs: Arterial pulse: A rapidly rising “water-
hammer” pulse, which collapses suddenly as arterial pressure falls rapidly during late
systole and diastole, and capillary pulsations, an alternate flushing and paling of the root
of the nail while pressure is applied to the tip of nail, are characteristic of free AR. A
booming, “pistol-shot” sound can be heard over the femoral or brachial arteries, and a to
- fro murmur is audible if the femoral artery is lightly compressed with a stethoscope.
The arterial pulse pressure is widened, with an elevation of the systolic pressure and a
depression of the diastolic pressure. The severity of AR does not always correlate
directly with the arterial pulse pressure, and severe regurgitation may exist in patients
with arterial pressures in the range of 140/60.
Palpation: The apex beat is strong and displaced laterally and inferiorly. The systolic
expansion and diastolic retraction of the apex are prominent and contrast sharply with
the sustained systolic thrust characteristic of severe AS. In many patients with pure AR
or with combined AS and AR, palpation or recording of the carotid arterial pulse reveals
it to be bisferiens, i.e., with two systolic waves separated by trough.

20. 20
Auscultation: A third heart sound is common, and occasionally, a fourth heart sound
also may be heard. The murmur of AR is typically a high-pitched, blowing, decrescendo
early diastolic murmur which is usually heard best in the third left intercostal space.
Unless it is trivial in magnitude, the AR is usually accompanied by peripheral signs
such as a widened pulse pressure or a collapsing pulse. On the other hand, with the
Graham steel murmur of pulmonary regurgitation, there is usually clinical evidence of
severe pulmonary hypertension, including a loud and palpable pulmonary component to
the second heart sound.
A midsystolic ejection murmur is frequently audible in AR. It is generally heard best
at the base of the heart and is transmitted to the carotid vessels. This murmur may be
quite loud without signifying organic obstruction; it is often higher pitched, shorter,
than the ejection systolic murmur heard in patients with predominant AS.
A third murmur which is frequently heard in patients with AR is the Austin Flint
murmur, a soft, low-pitched, rumbling middiastolic or presystolic bruit. It is probably
produced by the displacement of the anterior leaflet of the mitral valve by the aortic
regurgitant stream. Both the Austin Flint murmur and the rumbling diastolic murmur of
MS are loudest at the apex, but the murmur of MS is usually accompanied by a loud
first heart sound and immediately follows the opening snap of the mitral valve, while
the Austin Flint murmur is often shorter in duration than the murmur of MS, and in
patients with sinus rhythm the latter exhibits presystolic accentuation.
Summary: Signs of aortic incompetence over the heart:
- Soft blowing early diastolic murmur over aortic area propagated to apex.
- Austin-Flint murmur (diastolic murmur over mitral area).
Echocardiogram: Essential for detection of severity and cause of AR.
TREATMENT: Although operation constitutes the principal treatment of aortic
regurgitation, and should be carried out before the development of heart failure, the
latter usually respond initially to treatment with digitalis, salt restriction, diuretics, and
vasodilators, especially angiotensin-converting enzyme inhibitors.

21. 21
In patients with severe AR, careful clinical follow-up and noninvasive testing with
echocardiography at approximately 6-month intervals are necessary. Operation is to be
undertaken at the optimal time, i.e., after the onset of left ventricular dysfunction but
prior to the development of severe symptoms. Valve replacement is indicated if the LV
dilates to 50 mm in systole and 65 to 70 mm in diastole.
ACUTE AORTIC REGURGITATION: Infective endocarditis, aortic dissection, and
trauma are the most common causes of severe, acute AR.
TRICUSPID STENOSIS
It is generally rheumatic in origin and is more common in women than in men. It does
not usually occur as an isolated lesion or in patients with pure MR but is usually
observed in association with MS. Hemodynamically significant TS occurs in 5 to 10
percent of patients with severe MS; rheumatic TS is commonly associated with some
degree of regurgitation.
SYMPTOMS: Since the development of MS generally precedes that of TS, many
patients initially have symptoms of pulmonary congestion. Amelioration of the latter
should raise the possibility that TS may be developing. Fatigue secondary to a low
cardiac output and discomfort due to refractory edema, ascites, and marked
hepatomegaly are common in patients with TS and / or regurgitation.
Severe TS is associated with marked hepatic congestion, often resulting in
cirrhosis, jaundice, serious malnutrition, anasarca, and ascites. The jugular veins are
distended, and in patients with sinus rhythm there may be giant “a” waves.
On auscultation, the pulmonic closure sound is not accentuated, and occasionally, an OS
of the tricuspid valve may be heard approximately 0.06 s after pulmonic valve closure.
The diastolic murmur of TS has many of the quality of the diastolic murmur of MS, and
since TS almost always occurs in the presence of MS, the less common valvular lesion
may be missed. The murmur is augmented during inspiration, and it is reduced during
expiration.
Surgical treatment of the tricuspid valve is not ordinarily indicated at the time of
mitral valve surgery in patients with mild TS. On the other hand, definitive surgical
relief of the TS should be carried out, preferable a the time of mitral valvotomy, in
patients with moderate or severe TS who have mean diastolic pressure gradients

22. 22
exceeding 4 to 5 mmHg and tricuspid orifices less than 1.5 to 2.0 cm2
. TS is almost
always accompanied by significant tricuspid regurgitation.
TRICUSPID REGURITATION
Most commonly, tricuspid regurgitation (TR) is functional and secondary to
marked dilatation of the right ventricle and the tricuspid annulus. Functional TR may
complicate right ventricular enlargement of any cause, including inferior wall infarcts
that involve the right ventricle, and is commonly seen in the late stages of heart failure
due to rheumatic or congenital heart disease with severe pulmonary hypertension, as
well as in ischemic heart disease, cardiomyopathy, and cor pulmonale. It is in part
reversible if pulmonary hypertension is relieved. Rheumatic fever may produce organic
TR, often associated with TS. Endomyocardial fibrosis, infective endocarditis may
produce TR.
The clinical features of TR result primarily from systemic venous congestion and
reduction of cardiac output. The neck veins are distended with prominent V waves, and
marked hepatomegaly, ascites, pleural effusions, edema, systolic pulsations of the liver
and positive hepato-jugular reflux are common. A prominent right ventricular pulsation
along the let parasternal region and a blowing holosystolic murmur along the lower left
sternal margin which may be intensified during inspiration and reduced during
expiration or the Valsalva maneuver are characteristic findings; AF is usually present.
Summary: Signs of tricuspid regurgitation
- Pansystolic murmur over tricuspid area increases with inspiration.
- Systolic neck vein pulsations
Echocardiography and Doppler: for detection of severity of TR, estimation of
pulmonary pressure and search for vegetations of infective endocarditis.
Treatment of the underlying cause of heart failure usually reduces the severity of
functional TR. In patients with mitral valve disease and TR due to pulmonary
hypertension and massive RV enlargement, effective surgical correction of the mitral
valve abnormality results in lowering of the pulmonary vascular pressure and gradual

23. 23
reduction or disappearance of the TR. Tricuspid valvuloplasy by De Vega procedure
and Carpentier ring can be done.
Pulmonary Stenosis: See congenital pulmonary stenosis
Pulmonary Regurgitation
Dilatation of the pulmonary artery in cases of pulmonary hypertension may produce
pulmonary regurgitation. This is called Graham Steel murmur. It is differentiated
from the early diastolic murmur of aortic regurgitation by the associated signs of
pulmonary hypertension, and by Doppler study.
CONGENITAL HEART DISEASE
Congenital heart malformations remain one of the most frequent birth defects, with a
live-born prevalence of about 8 per 1000 live-born infants in western countries.
Etiology of congenital heart disease:
It is generally an abnormal form of cardiac development in the first 6-8 weeks of
intrauterine life. It is either due to exposure of the fetus in this period to injurious
teratogenic factor or to abnormal chromosomal structure.
Some causes could be identified as:
1- Drugs e.g. thalidomide, excess alcohol intake, anticonvulsant drugs.
2- Exposure to radiation e.g. X-rays and gamma rays.
3- Hereditary diseases: Diseases caused by chromosomal abnormalities eg Turner
syndrome, Down syndrome or mongolism.
4- Maternal infections e.g. German measles in the first trimester of pregnancy.
Congenital heart diseases in the adults could be classified into:
I- Left or right ventricular outflow obstruction: Aortic stenosis, pulmonary stenosis,
coarctation of aorta.
II- Left to right shunts: ASD, VSD and PDA.
III- Cyanotic heart disease: Fallot’s tetralogy and other cyanotic congenital diseases.

24. 24
LEET TO RIGHT SHUNT
When there is a congenital communication between both sides of the heart, e.g. atrial or
ventricular septal defects or patent ductus arteriosus the blood always flows from the
left side (left atrium, left ventricle or aorta) to right side (right atrium, right ventricle or
pulmonary artery). This is because the pressure in all left-sided chambers is higher than
in right-sided chambers.
EFFECTS:
1- Left to right shunt results in pulmonary plethora (increased vascularity in the lung). If
the shunt is very big heart failure may occur but this is rare.
2- In mild to moderate cases the pulmonary vessels dilate to accommodate the excessive
blood flow. Mild cases are well tolerated but if the shunt is excessive the pulmonary
vessels react by vasoconstriction. Pulmonary arteriolar vasoconstriction causes
pulmonary hypertension which results in right ventricular hypertrophy.
3- Pulmonary hypertension causes rise of pressure in the chambers of the right side of
heart. Ultimately the pressure in the right side exceeds that of the left side and the blood
starts to flow across the defect in the reverse direction, i.e. right to left shunt (reversed
shunt). The patient becomes cyanosed. Emboli originating in the venous side may be
shunted across the defect to the arterial side and settle in organs such as the brain or
limbs. This is paradoxical embolism.
Closure of the defect at this stage is useless and dangerous. This situation of a
congenital defect + reversed shunt is called Eisenmenger’s syndrome. Eisenmenger’s
syndrome is not an independent congenital heart disease. It is the end result of big left to
right shunt. At this stage the clinical picture is that of central cyanosis with severe
pulmonary hypertension.
ATRIAL SEPTAL DEFECT
In the presence of a defect in the atrial septum the right atrium receives blood both from
the normal venous return and the left atrium, the right atrium dilates. This results in:
Dilatation and hypertrophy of the right ventricle (volume overload), dilatation of the
pulmonary artery, and pulmonary plethora. If the defect is big and uncorrected
pulmonary arteriolar vasoconstriction progressively occurs and results in pulmonary
hypertension usually at age 20-30 years. When the pressure in the right atrium exceeds

25. 25
that in the atrium the shunt becomes reversed (Eisenmenger’s syndrome) and the patient
becomes cyanosed.
Clinical features:
1- Atrial septal defect is more common in females. When the left to right shunt is very
big pulmonary plethora may predispose to repeated chest infections in infancy.
Otherwise there are no symptoms for many years. Ultimately heart failure occurs.
2- Atrial fibrillation occurs in late cases.
3- Right ventricular dilatation and hypertrophy cause a hyperdynamic impulse in the
third and fourth spaces to the left of the sternum and precordial bulge.
4- Excessive flow across the tricuspid valve may produce a third heart sound and short
mid-diastolic murmur at the tricuspid area.
5- Excessive blood flow at the pulmonary valve may produce pulsations, dullness and
an ejection systolic murmur in the pulmonary area.
6- The specific auscultatory sign of atrial septal defect is wide fixed splitting of the
second heart at the pulmonary area. The pulmonary component of the second sound is
delayed because the right ventricle takes a long time o empty the excessive volume of
blood it receives. The splitting dose not vary with respiration because: although
inspiration causes increase in venous return, yet the resulting rise in right a trial pressure
causes proportionate decrease in the left to right shunt so that the right ventricular
output is constant and the time relation between aortic and pulmonary components of
the second sound remains constant.
7- Progressive pulmonary hypertension occurs in big defects and result in Eisenmenger
syndrome. At this stage the clinical picture consists of: Central cyanosis, signs of
pulmonary hypertension, and signs or right ventricular hypertrophy.
X-RAY PICTURE:
1- Plethoric lung fields. 2- Dilatation of the right atrium, right ventricle and pulmonary
artery. 3- Marked pulsation of the pulmonary artery and its branches seen during
screening (hilar dance).
ELECTROCARDIOGRAPHIC FEATURES: The characteristic sign is incomplete right
bundle branch block with rSr' pattern in V1 lead. Signs of right ventricular hypertrophy
also appear when pulmonary hypertension develops. Atrial fibrillation occurs in late
cases.
ECHOCARDIOGRAPHY WITH DOPPLER: Must be done for every patient with
suspected congenital heart disease. In A.S.D. it shows the septal defect and dilated right

26. 26
ventricle and abnormal movement of the interventricular septum characteristic of
volume overload on the right ventricle. Cardiac catheterization may be done in some
cases.
COMPLICATIONS:
1- Pulmonary hypertension and reversal of shunt.
2- Right ventricular failure. 3- A trial fibrillation.
TREATMENT: Small defects can be left alone. Large defects should be closed
surgically or by percutaneous insertion of occluder (device that occludes the ASD) .
VENTRICULAR SEPTAL DEFECT
1- In the presence of a defect in the septum, the right ventricle receives both the normal
venous and the shunted blood. If the defect is big right ventricular hypertrophy occurs.
2- This excessive blood flows in the pulmonary artery and the pulmonary circulation
and then returns to the left atrium and the left ventricle. This causes: Dilatation of the
pulmonary artery, pulmonary plethora, dilatation of the left atrium, dilatation and
hypertrophy of the left ventricle.
3- If the shunt is very big excessive flow may cause heart failure in infancy.
4- If the shunt is large the pulmonary vessels react by vasoconstriction causing
pulmonary hypertension and reversal of shunt (Eisenmenger syndrome).
5- Small V.S.D. does not cause pulmonary hypertension and may close spontaneously.
Clinically, the murmur is very loud (Roger’s disease).
CLINICAL PICTURE: The specific signs of V.S.D. are: 1- A characteristic
pansystolic murmur best heart in the third and fourth left intercostal spaces just lateral
to the sternum, usually accompanied by a thrill. 2- With large shunts the increased flow
across the mitral valve may cause a third sound and a mid-diastolic flow murmur at the
apex.
The clinical course depends upon the size of the defect:
1- Small ventricular septal defect: many defects close spontaneously.
2- Moderately large defect:

27. 27
1st- Progressive pulmonary hypertension and low cardiac output e.g. fatigue,
syncope on exercise, pulsations and palpable loud second heart sound in the pulmonary
area, right ventricular hypertrophy, etc.
2nd- When the pressure in the right ventricle equals that in the left ventricle no blood
will flow across the defect and the murmur diminishes disappears. The patient becomes
cyanosed on crying.
3rd- When the shunt is reversed the patient becomes cyanosed.
X-RAY PICTURE: Is normal in cases with small defects. Large defects result in:
pulmonary plethora (overfilled large and tortuous pulmonary arteries), large main
pulmonary artery, left and right ventricular enlargement, left atrial enlargement.
ECHOCARDIOGRAPHY WITH DOPPLER: Can show the size of cardiac chambers.
The defect can sometimes be shown by two-dimensional echo. Color Doppler is very
helpful in showing the blood flow through the defect. Detection of the site of the defect,
the magnitude of the shunt and the degree of pulmonary hypertension can be assessed
by this non-invasive method.
CARDIAC CATHETERISATION AND ANGIOGRAPHY: Is done in some cases.
COMPLICATIONS: Infective endocarditis, pulmonary hypertension, and heart failure.
DIFFERENTIAL DIAGNOSIS: A pansystolic murmur at the sternal border can be
caused by tricuspid or mitral incompetence in addition to the ventricular septal defect.
Sometimes the murmur of pulmonary stenosis is heard at the third intercostal space but
it is usually ejection in type and its maximal intensity is in the second space. Other
causes of systolic murmur at left sternal border are hypertrophic obstructive
cardiomyopathy, subaortic membrane and aortic stenosis.
TREATMENT:
1- To prevent infective endocarditis all patients must receive an antibiotic prophylaxis
before performing minor procedures that may causes bacteremia, e.g. dental extraction,
delivery, etc.
2- Small ventricular septal defects should be left alone. Many of them close
spontaneously.
3- Surgical closure is indicated if the defect is moderate or large in size, provided that
the pulmonary pressure is normal or moderately elevated. Surgical closure is
contraindicated if pulmonary pressure is severe (Eisenmenger’s syndrome).
PATENT DUCTUS ARTERIOSUS

28. 28
The ductus arteriosus is normally present in the fetus. It connects the aorta (at the
junction of the arch with the descending aorta) with the pulmonary artery (at the
junction of the main pulmonary artery with its left branch). It normally closes. During
the first month after birth:
Effects:
1- The blood flows through the duct from the aorta to the pulmonary artery, i.e. left to
right shunt.
2- As the pulmonary artery receives blood both from the shunt and the right ventricle,
pulmonary artery dilatation and pulmonary plethora occur.
3- If the shunt is big pulmonary vasoconstriction and hypertension occurs. When the
pressure in the pulmonary artery equals that of the aorta the shunt will first become
confined to the systole only and then ceases altogether. The murmur, accordingly, will
first become only systolic and finally will be completely inaudible.
5- When the pressure in the pulmonary artery exceeds that of the aorta, the shunt will be
reversed and cyanosis occurs (Eisenmenger’s syndrome).
CLINICAL FEATURES: Patent ductus arteriosus is commoner in females. Its
characteristic signs are:
1- A continuous (machinery) murmur that occupies both systole and diastole because
the pressure in the aorta exceeds that of the pulmonary artery all through the cardiac
cycle. It is best heard in the first and second left intercostal spaces. There may be
continuous thrill in the same area.
2- With large ductus, the increased flow across the mitral may cause a mid-diastolic
murmur.
When the pressure in the pulmonary artery exceeds that of the aorta, right to left shunt
occurs and cyanosis appears (Eisenmenger’s syndrome). The deoxygenated blood will
flow from the pulmonary artery across the ductus down the descending aorta. The lower
limbs will be cyanosed while the upper limbs remain pink (differential cyanosis).
X-RAY PICTURE: X-ray is normal in cases with small ductus. In moderate to large
ductus the following signs appear: Pulmonary plethora, enlargement of the left atrium,
left ventricle and the aorta. Hilar dance seen in the hilum by screening.
Differential diagnosis: Other causes of continuous murmur as aorto-pulmonary window,
in coarctation of the aorta, mammary softle, rupture sinus of Valsalva, venous hum...

29. 29
TREATMENT: Prophylaxis against endocarditis. Closure either surgical or with a
device introduced with percutaneous, transvenous catheter.
CYANOTIC HEART DISEASE
- Tetralogy of Fallot.
- Ebstein anomaly.
- Transposition of the great arteries.
- Total anomalous pulmonary venous drainage.
- Truncus arteriosus.
- Pulmonary arterio-venous malformation.
Acquired cyanotic disease: Eisenmenger Syndrome.
FALLOT’S TETRALOGY
PATHOLOGY AND EFFECTS: Fallot’s tetralogy consists of:
1- Severe pulmonary stenosis which causes right ventricular hypertrophy. The
pulmonary stenosis is usually infundibular but sometimes it is both valvular and
infundibular.

30. 30
2- Large ventricular septal defect which makes the pressure equal in both ventricles.
3- The origin of the aorta is abnormally deviated to the right (dextroposed, dextro =
right) so that it lies partly over the right ventricle (the aorta overrides both ventricles).
4- Due to the severe pulmonary stenosis and the large ventricular septal defect, the
pressure in both ventricles is equal. There is rush of blood across the defect and the
ventricular septal defect produces no murmur.
5- Part of the blood pumped by the right ventricle passes in the aorta (right to left
shunt) causing central cyanosis.
In summary Fallot’s tetralogy consists of four components (tetra =4).
1- Pulmonary stenosis.
2- Ventricular septal defect.
3- Dextroposed and overriding aorta.
4- Right ventricular hypertrophy.
CLINICAL FEATURES:
1- The patient is cyanosed since birth, (usually after birth by few weeks); the degree of
cyanosis depends on the severity of the pulmonary stenosis.
2- When the patient exercises, cyanosis is increased. In order to increase the blood flow
to the head and brain, the child usually squats to compress the lower limbs against the
abdomen and to deviate the blood from the lower to the upper half of the body. It also
increases the systemic arterial resistance. As the pressure in the aorta rises, more blood
will be deviated across the pulmonary stenosis to the lungs. Thus more oxygenated
blood returns to the heart.
3- Chronic cyanosis and tissue anoxia results in: Dyspnea, fatigue, angina, retarded
growth, polycythemia, clubbing of fingers.
4- Sometimes the muscle surrounding the outflow tract of the right ventricle goes into
spasm, especially after excitement and exercise. The blood flow to the lungs decreases
markedly and the oxygenation decreases resulting in attacks of severe cyanosis:
cyanotic spells. If prolonged they may lead to death.
5- The characteristic cardiac signs are:
A- Murmur of pulmonary stenosis (ejection systolic murmur in second left
space, usually accompanied by a thrill.

31. 31
B- The second heart sound is single and consists only of the aortic component.
C- Right ventricular hypertrophy.
X-RAY PICTURE:
4. Right ventricular hypertrophy causes the apex to be displaced outwards and
becomes separated from the diaphragm.
5. Right-sided aortic arch in some cases.
6. Pulmonary oligemia (the pulmonary artery and its branches are diminished in size
due to the pulmonary stenosis. All the above factors result in a characteristic cardiac
shadow: Coeur en sabot (sabot = wooden shoe).
ELECTROACARDIOGRAPHIC FEATURES: Show moderate right ventricular
hypertrophy.
ECHOCARDIOGRAPHY WITH DOPPLER: Delineates the abnormal anatomy.
Cardiac catheterization and angiography is needed for differential diagnosis.
COMPLICATIONS:
1- Polycythemia causes increased viscosity of blood resulting in a tendency towards
thrombosis, e.g. cerebral thrombosis.
2- Infective endocarditis
3- Brain abscess results when bacterial emboli are shunted from the venous to the
arterial side and lodge in the brain (paradoxical embolism).
TREATMENT:
1- Surgical correction is indicated in all cases by: Resection of the excessive stenotic
infundibular muscle splitting of the fused pulmonary valve leaflets, and closure of the
ventricular septal defect.
2- If he patient is too young, or the condition is too severe, an anastomosis is performed
to allow blood to reach the lungs by: implanting the subclavian artery in the
corresponding pulmonary artery (Blalock-Taussig operation).
3- Cyanotic attacks result from infundibular spasm and constitute an emergency. The
are treated by: Put the patient in the squatting position or compress the flexed lower
limbs against the abdomen, sedation, propranolol (inderal) intravenously. Propranolol is
a beta-adrenergic blocker. It depresses the contractility of the infundibular muscle.
LEFT VENTRICULAR OUTFLOW TRACT OBSTRUCTION
- Valvular aortic stenosis: 70% of patients with valvular AS a malformation of the
valve (usually a bicuspid valve).

32. 32
- Discrete subvalvular aortic membrane:
Represents 8-10% of congenital AS. The magnitude of obstruction is variable. Most
membranes are eventually associated with progressive aortic regurgitation and their
presence may be an absolute indication for excision. There is a high recurrence rate
after excision (approximately 30% and septal myotomy is often performed).
COARCTATION OF THE AORTA
Narrowing of the aorta usually just distal to the left subclavian artery. Coarctation may
affect other parts of the aorta or the renal arteries.
EFFECTS:
1- Because of the narrowing, pressure rises in the ascending aorta and the aortic arch
and its branches. This results in hypertension in the upper limbs.
2- Pressure and flow decreases in the descending aorta and its branches producing
ischemia in the abdominal organs and the limbs.
3- Ischemia of the kidneys results in release of renin which raises the blood pressure.
4- Hypertension results in left ventricular hypertrophy and it severe results in left
ventricular failure.
5- Anastomosis form between the branches of the aorta proximal and distal to the
obstruction. The most important of these connect the subclavian artery through its
internal mammary branch to the intercostal arteries which arise from descending aorta.
The intercostal arteries become enlarged and tortuous and erode the lower border of the
ribs causing rib notching. Appreciable anastomosis develops gradually by time. That is
why rib notching is not detectable except after the age of 10. Other anastomosis
develops around the scapula and another connects the superior and inferior epigastric
arteries.
CLINICAL FEATURES:
1- In the majority of cases there are no symptoms and the essential diagnostic feature of
coarctation is that the blood pressure in the upper limbs exceeds that in the lower limbs.
2- The pulse in the upper limbs, neck and suprasternal notch is strong. Pulse in the
lower limbs is weak and delayed or absent.

33. 33
3- Hypertension in the upper half of the body may produce headache, epistaxis while
ischemia of the lower half may produce thin, underdeveloped lower limbs and
claudication in the calf.
4- Visible and palpable pulsations of dilated collateral may be felt in the intercostal
areas.
5- A late systolic murmur may be heard on the back due to blood flow in the collaterals.
The murmur is sometimes continuous.
6- The cardiac signs are nonspecific and include: left ventricular hypertrophy, an
ejection systolic murmur heard at the aortic area.
X-RAY PICTURE:
1- Signs of left ventricular hypertrophy.
2- Rib notching is the most specific sign.
ELECTROCARDIOGRAPHIC SIGNS: Left ventricular hypertrophy and strain.
COMPLICATIONS:
1- Hypertension in the upper half of the body may result in: cerebral or subarachnoid
hemorrhage, left ventricular failure, dissection of the aorta.
2- Infective endocarditis.
TREATMENT: surgical resection of the narrowed segment is indicated in moderate and
severe cases preferably during childhood. Balloon dilation with expandable stent is a
feasible method of treatment. All patients must have prophylaxis against endocarditis.
PULMONARY STENOSIS
Pulmonary stenosis may be caused by: Congenital fusion of pulmonary valve cusps
(congenital valvular pulmonary stenosis).
EFFECTS:
1- In both valvular and infundibular stenosis the pressure in the right ventricle rises,
this causes hypertrophy of the right ventricle (pressure over-load). Consequently the
right atrium hypertrophies. When the stenosis is severe the output of the right ventricle
and the cardiac output are reduced. The pulmonary blood flow is reduced, i.e.
pulmonary oligemia.
CLINICAL FEATURES:

34. 34
1. Mild cases are as asymptomatic, in severe cases low cardiac output occurs and
results in fatigability, syncope on effort, small volume pulse, cold extremities, etc.
2. An ejection systolic murmur is caused by passage of blood through the stenosed
valve. It is best heard over the pulmonary area. It may be preceded by an ejection click.
3. The pulmonary component of the second heart sound is faint and delayed due to
prolonged contraction of the right ventricle.
4. There is usually a systolic thrill over the pulmonary area.
5. Right ventricular hypertrophy produces a sustained impulse in the third and fourth
intercostal spaces just to the left of the sternum and pulsation in the epigastrium.
Forceful right atrial contraction causes a large wave in the neck veins (the a wave).
X-RAY PICTURE: 1. Pulmonary oligemia occurs in moderate to severe cases and
results in reduced pulmonary vascular markings). 2- Right ventricular enlargement is
proportional to the severity of the stenosis. Right atrial enlargement may also occur. 3.
Post-stenosis dilatation of the pulmonary artery is seen.
ECG FEATURES: Right ventricular hypertrophy.
ECHO FEATURES: Right ventricular hypertrophy, the stenosed pulmonary valve.
TREATMENT: Either percutaneous transvenous balloon dilatation (the standard
treatment, first option) or surgical removal of the valve by open-heart surgery.
Interventions In Congenital Heart Diseases (therapeutic procedures that are used in
treatment without surgery but through catheterization):
- Pulmonary stenosis balloon dilatation.
- Aortic stenosis balloon dilatation.
- Coarctation of the aorta balloon dilatation and stent insertion.
- Atrial septal defect insertion of Amplatzer occluder through catheter.
- Patent ductus arteriosus occlusion by insertion of coil.
- Other procedures.
DIAGNOSIS AND MANAGEMENT OF SYNCOPE AND HYPOTENSION

35. 35
Syncope is a sudden and transient loss of consciousness with associated loss of
postural tone. The occurrence of syncope is 3% in men ad 3.5% in women in the
general population. As a general role, the incidence of syncope increases with age.
Hypotension: When systolic blood pressure (SBP) is less than 90 mmHg or reduction
of SBP of 30 mmHg or more from baseline.
Patients with transient episode of altered consciousness (presyncope) and those with
complete loss of consciousness (syncope) are classified into 3 broad categories: cardiac
syncope, noncardiac syncope, and syncope of undetermined etiology. Among all
patients with syncope associated with cardiac disease, sudden cardiac death is extremely
high.
Table: Causes of Syncope
Circulatory (reduced cerebral blood flow)
A. Inadequate vasoconstrictor mechanisms
1. Vasovagal (vasodepressor)
2. Postural hypotension
3. Primary autonomic insufficiency
4. Sympathectomy (pharmacologic, due to antihypertensive medications such as
methyldopa and hydralazine, or surgical )
5. Carotid sinus syncope
6. Diseases of the central and peripheral nervous system, including autonomic nerves)
B. Hypovolemia
1. Blood loss – gastrointestinal hemorrhage.
2. Addison’s disease
C. Mechanical reduction of venous return
1. Valsalva maneuver. 2. Cough; Micturition.
3. Atrial myxoma, ball valve thrombus.
D. Reduced cardiac output
1. Obstruction to left ventricular outflow: aortic stenosis, hypertrophic subaortic
stenosis.
2. Obstruction to pulmonary flow: pulmonary stenosis, primary pulmonary
hypertension, pulmonary embolism.
3. Myocardial: massive myocardial infarction with pump failure.
4. Pericardial: cardiac tamponade
E. Arrhythmias

36. 36
1. Bradyarrhythmias
a. Atrioventricular (AV) block (second and third degree), with Stokes-Adams attacks
b. Ventricular asystole
c. Sinus bradycardia, sinoatrial block, sinus arrest, sick sinus syndrome
d. Carotid sinus syncope
a. Tachyarrhythmias: Supraventricular tachycardia. Episodic ventricular tachycardia
Other causes of disturbances of consciousness
A. Hypoglycemia
B. Hypoxia
C. Hypoventilation
D. Transient cerebral ischemic attack
E. Emotional disturbances, anxiety attack, hysterical seizures.
Noncardiac Syncope
Neurocardiogenic syncope:
The syndrome of neurocardiogenic syncope, the common faint (also referred to as
neurally mediated hypotension, vasovagal syncope, and vasodepressor syncope), is one
of the most common causes of syncope.
This disorder is due to abnormality in the neuro-cardiovascular interactions responsible
for maintaining systemic and cerebral perfusion.
Diagnostic evaluation:
Head-up tilt (HUT) is essential for the diagnosis of neurocardiogenic syncope. Here
we change the position of the patient from the horizontal to the vertical position. HUT
at an angle of 60º to 90º for a time period of 20 to 60 min is the usual protocol.
Management of syncope:
First-line therapy includes counseling the patient to avoid dehydration, prolonged
period of standing motionless, and situations known to trigger syncope. Volume
expansion, fludrocortisone may be helpful in augmenting salt retention and volume
expansion.
Alpha-Agonists: Medodrine may prevent neurocardiogenic syncope due to
vasoconstrictor effect that may reduce venous pooling.
Orthostatic Syncope (orthostatic Hypotension):
Orthostatic hypotension is a disorder in which assumption of the upright posture is
associated with a fall in blood pressure. Therapy: is based on treatment of causes.

37. 37
Management of hypotension: 1- Treatment of the etiology. 2- Avoid dehydration. 3-
Medodrine. 4. Mineralocorticoids as Astonin H.
Cardiac Syncope
It is due to severe diminution of the cardiac output Either due to severe obstructive
lesion as tight mitral stenosis, atrial myxoma, aortic stenosis, obstructive
cardiomyopathy or due to arrhythmia whether tachy or brady. Obstructive lesions and
arrhythmias frequently coexist; indeed, one abnormality may accentuate the other.
Common disorders associated with cardiac syncope are listed in table.
Diagnostic evaluation of syncope associated with cardiac disease:
- History & physical examination
- Echocardiography & Doppler
- Standard ECG
- Holter monitor ( 24 h. ECG continuous recording )
- Electrophysiologic study.
- Cardiac catheterization.
Treatment of cardiac syncope: Obstructive Heart Disease, for patients with syncope
caused by obstructive heart disease, cardiac surgery is often the treatment of choice.
Arrhythmic syncope, detailed discussion of therapy for cardiac arrhythmias presented
earlier. Antiarrhythmic drugs, pacemakers and ablation are available tools of
management of arrhythmia.
Syncope of undetermined cause: Despite careful diagnostic evaluation, the cause of
syncope often cannot be defined.
Sudden Cardiac Death
Definition: Sudden cardiac death describes the unexpected natural death due to cardiac
cause within a short period from the onset of symptoms.
More recent definition focused on time interval of one hour from the symptoms leading
to collapse and then to death.
Incidence: SCD accounts for 300.000 to 400.000 deaths yearly in the United States.
SCD is the most common and often the first manifestation of coronary heart disease
(CHD) and is responsible for half the deaths from cardiovascular disease.

38. 38
Sudden Cardiac Death in the young: The most common underlying pathological
conditions in people who die of SCD in the first three decades of life are myocarditis,
hypertrophic cardiomyopathy, congenital coronary artery anomalies,
atherosclerotic coronary heart disease, conduction system abnormalities (e.g. long QT),
congenital arrhythmogenic disorders, arrhythmias associated with mitral valve
prolapse and aortic dissection. About 40% of SCD in the pediatric population occur in
patients with surgically treated congenital cardiac abnormalities.
Risk factors for Sudden Cardiac Death (SCD):
1- Left ventricular hypertrophy (by ECG)
2- Cholesterol.
3- Hypertension.
4- Cigarette smoking.
5- Diabetes.
6- Alcohol.
7- Obesity.
8- History of coronary heart disease.
9- Age.
10- Positive family history of SCD.
11- Frequent PVCs (Premature ventricular contractions, unsustained ventricular
tachycardia).
Cardiac Abnormalities Associated with Sudden Cardiac Death
I. Ischemic heart disease
A) Coronary Atherosclerosis:
- Acute myocardial infarction, - Chronic ischemic cardiomyopathy
B) Anomalous origin of coronary arteries.
II. Cardiomyopathies
A. Idiopathic dilated cardiomyopathy
B. Hypertrophic cardiomyopathy
C. Hypertensive cardiomyopathy
D. Arrhythmogenic right ventricular dysplasia
III. Valvular heart disease: Aortic stenosis
IV. Inflammatory and Infiltrative myocardial disease

39. 39
V. Congenital heart disease.
VI. Primary Electrical Abnormality.
A. Long Q-T syndrome
B. Wolf Parkinson White syndrome (WPW).
C. Idiopathic ventricular tachycardia
D. Idiopathic ventricular fibrillation
E. Brugada syndrome (right bundle block with raised ST in V1 to V3)
VII. Drug and other toxic agents
A. Proarrhythmia (Drug induced arrhythmia)
B. Cocaine and Alcohol. C. Electrolyte abnormalities
Treatment Options for Patients at Risk of Sudden Cardiac Death (SCD)
I. Pharmacologic therapy
1- Beta blockers , Angiotensin-converting enzyme inhibitors
2- Class I antiarrhythmic drugs,
3- Class III antiarrhythmic drugs: Amiodarone, sotalol
II. Device therapy
1- Automatic implantable cardioverter Defibrillator (ICD)
2- External automatic defibrillator
III. Role of surgery: Revascularization
IV. Catheter Ablation therapy.

40. 40
CARDIAC ARRHYTHMIAS
An arrhythmia is any disturbance in the normal sequence of impulse generation and
conduction in the heart.
Anatomy of the conduction system: The conduction system of the heart consists of the
sinus node, internodal tracts, atrioventricular node (AVN), bundle of His, bundle
branches (right and left), and Purkinje fibers.
Fig: The pathways of Conduction.
General considerations: Normal cardiac impulses arise from the automatic
(pacemaking) cells of the sinus node and are conducted through the atria to the AV
junction then the His-Purkinje system to the ventricular muscle. Normally the sinus
node discharges at a rate of 60-100/min.

41. 41
Mechanisms of arrhythmias
A- Disturbance of impulse formation: may result from either:
1- Disturbed normal automaticity:
2- Triggered activity: Hyper-excitable focus which discharges ectopic impulses.
B- Disturbance of Impulse conduction: e.g. heart block
Classification of arrhythmia:
Clinical classification:
- Rapid, regular. Sinus tachycardia, supraventricular tachycardia, atrial flutter,
ventricular tachycardia.
- Rapid, irregular. Sinus arrhythmia, multiple ectopic beats whether atrial or
ventricular, atrial fibrillation.
- Slow, regular. Sinus bradycardia, nodal rhythm, complete heart block.
- Slow, irregular. Slow atrial fibrillation.
Disturbances in Sinus Rhythm
Sinus tachycardia
Cardiac impulses arise in the sinus node at a rate more than 100/min.
Etiology:
A- Physiological: Infancy, childhood, exercise and excitement.
B- Pharmacological: Sympathomimetic drugs such as epinephrine and isoproterenol.
Parasympatholytic drugs such as atropine. Thyroid hormones, nicotine, caffeine,
alcohol.
C- Pathological: Fever, hypotension, heart failure, pulmonary embolism, hyperkinetic
circulatory states as anemia.
Treatment: 1- Treatment of the underlying etiology. 2- Propranolol.
Sinus Bradycardia
Cardiac impulses arise in the sinus node at a rate less than 60/min.
Etiology:
A- Physiologic: Athletes, sleep, and carotid sinus compression.
B- Pharmacologic: Digitalis, propranolol, verapamil and diltiazem.
C- Pathologic: Convalescence from infections, hypothyroidism, obstructive jaundice,
rapid rise of the intracranial tension, hypothermia and myocardial infarction
(particularly inferior wall infarction).

42. 42
Treatment:
1- Treatment of the underlying etiology is usually all that is needed.
2- If the patient is hemodynamically compromised, Atropine 0.6 – 1.0 mg IV may be
given and repeated every 3 hours (maximum 2.5 mg in two hours).
SICK SINUS SYNDROME: This term is applied to a syndrome encompassing a
number of sinus nodal abnormalities that include: 1- persistent spontaneous sinus
bradycardia not caused by drugs, and inappropriate for the physiological circumstance,
2- apparent sinus arrest or exit block, 3- combinations of SA and AV conduction
disturbances, or 4- alternation of paroxysms of rapid and slow atrial and ventricular
rates (bradycardia-tachycardia syndrome).
FIG. Normal intracardiac electrograms.
PREMATURE BEATS (EXTRASYSTOLES)
These are cardiac impulses of ectopic origin occurring earlier than expected in the
prevailing rhythm. The ectopic focus may be: 1- Atrial resulting in atrial premature
beat. 2- AV junctional (arising from bundle of His) resulting in AV junctional
premature beat. 3- Ventricular resulting in ventricular premature beat.

43. 43
Etiology:
A- Physiological: Emotions, exercise and fatigue.
B- Pharmacological: Coffee, alcohol, tobacco, catecholamines, digitalis and hypoxia.
C- Pathological: Various infections, digestive disturbances, hyperthyroidism and all
cardiovascular disorders.
SUPRAVENTRICULAR TACHYARRHYTHMIAS
All tachyarrhythmias that originate above the bifurcation of the bundle of His are
classified as supraventricular arrhythmias (SVT). The atrial rate must be 100 or more
beats per minute for a diagnosis.
SVTs may be separated into three groups based on duration: brief paroxysms,
persistent, and chronic (permanent).
Arrhythmias that are paroxysmal in onset and offset (e.g., paroxysmal SVT due to AV
nodal reentry or WPW syndrome, paroxysmal atrial fibrillation, paroxysmal atrial
flutter) tend to be recurrent and of short duration; i.e., seconds to hours.
Persistent tachycardias (e.g., sinus tachycardia, ectopic atrial tachycardia
(nonparoxysmal), multifocal atrial tachycardia, longer episodes of PSVT or atrial flutter
or fibrillation) may persist for days or weeks.
Longstanding or chronic SVTs (chronic atrial flutter, chronic atrial fibrillation) do not
revert if untreated, often fail to revert even with attempted treatment, and if reverted will
frequently recur despite therapy.
Supraventricular tachyarrhythmias include; atrial tachycardia, atrial flutter, atrial
fibrillation and AV tachycardias.
ATRIAL FLUTTER
Atrial flutter is a rapid regular atrial tachyarrhythmia that is less common than the
PSVTs or atrial fibrillation. It is observed in the presence of underlying atrial
abnormalities such as those secondary to mitral valve disease, congenital heart disease,
cardiomyopathies, and, less frequently, coronary artery disease.

44. 44
Untreated atrial flutter usually has atrial rates between 240 and 340 per minute,
commonly very close to 300 per minute. The ventricular rate in atrial flutter is usually a
defined fraction of the atrial rate 2: 1 conduction generating a ventricular rate of 150 per
minute and 4:1 conduction at 75 per minute.
Clinically, atrial flutter may occur in brief, persistent, or chronic forms, and therapeutic
approaches are influenced by the clinical pattern.
Electrocardiographic Features
Atrial flutter generates a defined pattern of atrial activity in the ECG. Classically, a saw-
tooth pattern is identifiable in leads II, 111, and aVF. A narrow QRS complex
tachycardia at a rate of 150 per minute should always lead to the consideration of atrial
flutter. Carotid sinus massage will not interrupt atrial flutter but nonetheless may be
very helpful in distinguishing flutter from other mechanisms, impairment of AV nodal
conduction causes an abrupt change from a rate of 150 per minute to 75 per minute or
less.
Management of atrial flutter: - If the patient is hemodynamically compromised, D.C.
cardioversion using low energies (around 50 joules) should be instituted.
- Administering a Class IA antiarrhythmic agent (i.e., quinidine, procainamide, or
disopyramide). IC antiarrhythmic drugs, flecainide and propafenone, are as effective, if
not more effective than Class IA drugs. Class III antiarrhythmic agents (i.e.,
amiodarone, sotalol) may also be quite effective. In general, atrial flutter is difficult to
suppress completely with drug therapy. - The ventricular rate is slowed by digitalis
and/or propranolol or verapamil before antiarrhythmics are instituted to avoid very rapid
rates associated with drug induced 1:1 AV conduction.
- At present, catheter ablation provides the best hope of cure.
FIG. A 12-lead ECG of a typical case of type 1 atrial flutter.

45. 45
FIG. A 12-lead ECG of a typical case of type 1 atrial flutter.
FIG: Atrial flutter with AV block varying between 2: 1 and 4: 1.
AV Nodal Reentrant Tachycardia
Electrocardiographic Features: Paroxysmal SVT due to AV nodal reentry is
characterized by an abrupt onset and termination and usually has a narrow QRS
complex without clearly discernable P waves. The rate is commonly in the range of 150
to 250 per minute (commonly 180 to 200 bpm in adults) and with a regular rhythm.
Management of PSVT Due to AV Nodal Reentry
The acute attack: Vagal maneuvers serve as the first line of therapy. Simple procedures
to terminate paroxysmal SVT
- Carotid sinus massage: If effective the rhythm is abruptly stopped; occasionally only
moderate slowing occurs
- Cold water splash on face.
- Performance of Valsalva's maneuver (often effective).

46. 46
Intravenous adenosine, Ca channel blockers (verapamil), digoxin or B-blockers are the
choices for managing the acute episodes.
Adenosine, 6 mg given intravenously, followed by one or two 6-mg boluses if
necessary, is effective and safe for acute treatment.
A 5-mg bolus of verapamil (isoptin) , followed by one or two additional 5-mg boluses
10 min apart if the initial dose does not convert the arrhythmia, has been an effective
regimen in up to 90 percent of patients with PSVT due to AV node reentry.
Intravenous digoxin, 0.5 mg infused over 10 min and repeated if necessary may convert
the arrhythmia.
DC cardioversion: Consider DC cardioversion before digitalis or a beta blocker is
administered.
Radiofrequency catheter ablation: Should be considered early in the management of
patients with symptomatic recurrent episodes of AV node reentry.
AV Reentrant Tachycardia
PSVT Due to Accessory Pathways (The Wolff-Parkinson-White Syndrome)

47. 47
ELECTROCARDIOGRAPHIC RECOGNITION: Three basic features in the ECG of
patients with the usual form of WPW syndrome caused by an AV connection:
(1) Short P-R interval less than 120 msec during sinus rhythm;
(2) QRS complex duration exceeding 120 msec
(3) Slowly rising onset of the QRS in some leads (delta wave).
The most common tachycardia is characterized by a normal QRS, by ventricular rates of
150 to 250 beats/min and by sudden onset and termination.
Termination of the acute episode should be approached as for AV nodal reentry. In
many patients, particularly those with a very rapid ventricular response, electrical
cardioversion is the initial treatment of choice.
The Wolff-Parkinson-White Syndrome
ELECTRICAL ABLATION: Ablation of the accessory pathway is advisable for
patients with frequent symptomatic arrhythmias that are not fully controlled by drugs.
Atrial Fibrillation

48. 48
The arrhythmia is characterized by multiple electric foci in the atrium causing
disorganized atrial depolarizations without effective atrial contraction. Electrical
activity of the atrium can be detected on ECG as small irregular baseline undulations,
called f waves, at a rate of 350 to 600 beats/min. The ventricular response is grossly
irregular (irregular irregularity) and is usually between 100 and 160 beats/min.
It is a common arrhythmia, occurring in 5 – 10 % of individuals over 65 years of age. It
also occurs in a paroxysmal form in younger patients.
The hemodynamic consequences of atrial fibrillation are due to two factors:
(1) The loss of atrial systole may impair ventricular function in the noncompliant
ventricle [e.g., aortic stenosis, left ventricular hypertrophy (LVH)] or the dilated
ventricle with systolic dysfunction, and
(2) A rapid ventricular rate will encroach upon the diastolic filling period of the left
ventricle and the diastolic flow time of the coronary arteries.
(3) The risk of embolism and stroke is a long-term concern of special importance. Atrial
fibrillation may occur in paroxysmal, persistent, and chronic patterns.
Clinical expression of atrial fibrillation:
Definition Duration
- Paroxysmal Minutes/hours
- Short-lasting Seconds --<1 hour
- Long-lasting >1 hour; -- < 48 hours
- Persistent Two days -- weeks
- Permanent (Chronic) Months / years
Table: Causes of atrial fibrillation
With structural heart disease
- Rheumatic mitral valve disease
- Ischemic heart disease
- Hypertension
- Cardiomyopathy: Dilated, Hypertrophic
- Atrial septal defect, - Constrictive pericarditis, Myocarditis
Without structural heart disease

49. 49
- Alcohol. Thyrotoxicosis
- Acute pericarditis. Pulmonary embolism
- Sick sinus syndrome, Lone atrial fibrillation
Atrial Fibrillation
Clinical picture
Onset and offset are sudden in paroxysmal cases.
Symptoms: Paroxysmal AF produces symptoms similar to those of supraventricular
tachycardia. Established AF (persisting for more than two weeks) is better tolerated than
the paroxysmal variety. Congestive heart failure may occur if the attack is prolonged,
the ventricular rate is very rapid, or the underlying heart disease is severe.
Signs:
1- Arterial pulse:
a- Rate is usually 100-150/min. Slower rates may be encountered in old age and in
patients receiving digitalis or beta-blockers.

50. 50
b- Rhythm shows marked (irregular) irregularity. c- Force is irregular. d- Pulsus deficit:
The radial pulse rate is less than the cardiac rate counted at the apex beat. This is due to
inability of the week ventricular contractions following short diastolic periods to open
the aortic valve.
2- Neck veins show systolic expansion; no “a” waves are seen.
3- Auscultation reveals varying intensity of S1.
4- Exercise increases the pulse irregularity and deficit.
Electrocardiogram: The P waves are replaced by irregular f waves. The QRS
complexes are normal in shape but irregularly spaced.
Complications: 1- Atrial thrombosis due to stagnation of blood in the fibrillating atria.
The formed thrombi may embolize in the systemic and pulmonary circulations. 2- Heart
failure due to loss of the atrial contribution to contractility and the cardiac output.
Atrial fibrillation (AF) progressed to ventricular fibrillation (VF)
Treatment of Atrial Fibrillation
Pharmacologic Management of Patients with Recurrent Persistent or Permanent AF:
- Recurrent Persistent AF:
A) Minimal or no symptoms: Anticoagulation and rate control as needed.
B) Disabling symptoms in AF:
1- Anticoagulation and rate control
2- Antiarrhythmic drug therapy

51. 51
3- Electrical cardioversion as needed, continue anticoagulation as needed and therapy
to maintain sinus rhythm
- Permanent AF: Anticoagulation and rate control as needed.
AF management
Antiarrhythmic Drug Therapy to Maintain Sinus Rhythm in Patients with
Recurrent Paroxysmal or Persistent AF:
A) No or minimal heart disease:
1- Flecainide, propafenone, sotalol
2- Amiodarone, dronedarone, dofetilide, Disopyramide, procainamide, quinidine
3- Consider non-pharmacological options (ablation).
B) Heart disease present:
a- Heart failure: Amiodarone, dofetilide
1- Coronary artery disease: Sotalol, Amiodarone, dofetilide
2- Dronedarone is allowed only in HF class I or II with precaution.
3- Vernakalant I.V. for aute AF of less than 7 days duration, with many precautions
and contraindications.
C) Hypertension: With
1- With LVH (septum greater than or equal to 1.4 cm): Amiodarone
2- Without this degree of LVH: - Flecainide, propafenone.

52. 52
Drugs for Pharmacologic Cardioversion of AF (Rhythm
control)
Drug Route of Admin. And Dosage
Amiodarone Oral: 1.2 to 1.8 g /day then 200 to 400 mg /d maintenance.
IV: 1.2 g /d IV continuous or in divided doses, then 200 to 400
mg /d maintenance
Dofetilide Oral: Creatinine clearance > 60 ml/min: 500 mcg BID
Flecainide Oral 200 to 300 mg
IV: 1.5 to 3 mg /kg over 10 to 20 min
Propafenone Oral: 450 to 600 mg
IV: 1.5 to 2 mg per kg over 10 to 20 min
Orally Administered Pharmacological Agents for Heart
Rate Control in Patients with AF
Drug Maintenance dose
Digoxin 0.125 to 0.375 mg daily
Metoprolol* 25 to 100 BID
Propranolol 80 to 360 mg daily in divided doses
Verapamil 120 to 360 mg daily in divided doses
Diltiazem 120 to 360 mg daily in divided doses
Anticoagulation of Patients with Atrial Fibrillation: Indications
Rheumatic mitral valve disease with recurrent or chronic atrial fibrillation.
Dilated cardiomyopathy with recurrent persistent or chronic atrial fibrillation.
Prosthetic valves.
Prior to (>3 weeks) elective cardioversion of persistent or chronic atrial fibrillation, and
also for 3 weeks after cardioversion (because of atrial stunning).

53. 53
Coronary heart disease or hypertensive heart disease with recurrent persistent or chronic
atrial fibrillation
Atrial fibrillation in thyrotoxicosis (while awaiting long-term control; elective
cardioversion)
Chronic or persistent lone atrial fibrillation, age >60 years
Controversial; or limited data
Coronary or hypertensive heart disease with normal left atrial size, after first episode of
paroxysmal atrial fibrillation
Elective cardioversion of atrial fibrillation of short duration (2-3 days) with normal left
atrial size
Chronic or persistent lone atrial fibrillation, age <60 years
Not indicated
Lone atrial fibrillation, short paroxysms (<48 h)
Most clinical settings associated with short paroxysms (minutes to hours)
Relative contraindications
Difficulty controlling prothrombin times. Dementia
Malignancies, especially associated with bleeding risk
Prior major bleeding events. Uncontrolled hypertension
Treatment of Cardiac Arrhythmias with Catheter Ablative Techniques
Radiofrequency ablation destroys tissue by controlled heat production. Catheter ablation
is used to treat patients with four major tachyarrhythmias: atrial flutter/fibrillation, AV
nodal reentry, accessory pathways and ventricular tachycardia.
VENTRICULAR TACHYCARDIA
Specific Forms of Ventricular Tachycardia
Duration: Salvo (3-5 impulses)
Nonsustained VT: (6 impulses, up to 29 seconds)
Sustained VT: (>30 seconds)
The electrocardiographic diagnosis of ventricular tachycardia is suggested by the
occurrence of a series of three or more bizarrely shaped premature ventricular
complexes whose duration exceeds 120 msec, with the ST-T pointing opposite to the
major QRS deflection.

54. 54
The rates range from 70 to 250 beats/min. Ventricular tachycardia can be sustained,
defined arbitrarily as lasting longer than 30 sec or requiring termination because of
hemodynamic collapse, or nonsustained (Unsustained), when it stops spontaneously in
less than 30 sec.
Ventricular tachycardia (Wide QRS tachycardia)
Management: Intravenous lidocaine or amiodarone, followed by an infusion of the
successful drug. If the arrhythmia does not respond to medical therapy, electrical DC
cardioversion can be employed.
Ventricular tachycardia in a patient with right ventricular dysplasia.

55. 55
CONGENITAL LONG QT INTERVAL SYNDROME
The normal QT interval is .43 sec. The congenital long QT interval syndrome, which is
present persistently from childhood, is characterized by the presence of long QT
intervals on the standard 12-lead ECG. The affected patients are prone to episodes of
torsade de pointes (ventricular tachycardia with special polymorphic
configuration), which may cause transient light-headedness or syncope or sudden
cardiac death. Arrhythmias may occur at rest, under emotional stress, or with exercise.
ACQUIRED LONG QT INTERVAL SYNDROME
Causes: Antiarrhythmic drugs as quinidine. There is a growing list of other drugs that
may prolong the QT interval, and establish susceptibility to torsade de pointes. These
include the phenothiazines, certain antibiotics, pentamidine, cocaine, and terfenadine,
among others.
Management of Congenital Long QT Interval Syndrome: Long-term therapy includes
B-adrenergic blockade. Placement of an ICD should be considered for patients with
resistant arrhythmias.
CARDIOVERSION AND DEFIBRILLATION
Differences between cardioversion and defibrillation:
Cardioversion Defibrillation
Elective Emergency
Synchronized Non-synchronized
For AF, A. flutter, SVT, VT For V. fibrillation
50, 100, 150, 200 Joules Start by 200 Joules
Need sedative first Patient is unconscious
VENTRICULAR FLUTTER AND FIBRILLATION
MANAGEMENT: Immediate nonsynchronized DC electrical shock using 200 to 360
joules is mandatory treatment for ventricular fibrillation. Cardiopulmonary resuscitation
is employed only until defibrillation equipment is ready. Time should not be wasted
with cardiopulmonary resuscitation maneuvers if electrical defibrillation can be done
promptly.

56. 56
The Implantable Cardioverter Defibrillator (ICD)
Apparatus (pacemaker) that gives electric shock if the patient develops ventricular
fibrillation. The pacemaker is inserted in the sub-pectoral area.
ICD indications
A. Cardiac arrest not due to acute ischemia or infarction or reversible causes.
B. Documented sustained VT with hemodynamic compromise.
C. Syncope of unknown origin in structural heart disease patients with inducible
sustained VT.
D. Cardiomyopathy ischemic or non-ischemic with ejection fraction 30% or lower
(MADIT II results).
AV HEART BLOCK
Heart block is a disturbance of impulse conduction that can be permanent or transient,
owing to anatomical or functional impairment.
The conduction disturbance is classified by severity in three categories.
During first degree heart block, conduction time is prolonged but all impulses are
conducted (P-R interval > 0.2 sec.).
Second degree heart block occurs in three forms:
Mobitz type I (Wenckebach) and type II; and persistent 2:1 block.
Mobitz Type I heart block is characterized by a progressive lengthening of the
conduction time until an impulse is not conducted (Fig).
Mobitz Type II heart block denotes occasional (Mobitz II) or repetitive sudden block of
conduction of an impulse without prior measurable lengthening of conduction time.
When no impulses are conducted, complete or third degree block is present.
Mobitz type I (Wenckebach) block

57. 57
Mobitz Type II second degree heart block
COMPLETE AV BLOCK
ELECTROCARDIOGRAPHIC RECOGNITION: Complete AV block occurs when no
atrial activity conducts to the ventricles and therefore the atria and ventricles are
controlled by independent pacemakers. Thus, complete AV block is one type of
complete AV dissociation.
The ventricular focus is usually located just below the region of block, which can be
above or below the His bundle bifurcation. The ventricular rate of acquired complete
heart block is less than 40 beats/min but may be faster in congenital complete AV
block.
CLINICAL FEATURES. Block proximal to the His bundle generally exhibits normal
QRS complexes and rates of 40-60 beats/min because the escape focus that controls the
ventricle arises in or near the His bundle.
Causes: Surgery, electrolyte disturbances, endocarditis, tumors, Chagas' disease,
rheumatoid nodules, calcific aortic stenosis, myxedema, polymyositis, infiltrative
processes (such as amyloid, sarcoid, or scleroderma). In the adult, drug toxicity,
coronary disease, and degenerative processes appear to be the most common causes of
AV heart block.
COMPLETE AV BLOCK
MANAGEMENT: Temporary or permanent pacemaker insertion is indicated in patients
with symptomatic bradyarrhythmias. Vagolytic agents such as atropine (novatropine 15
drops every 8 hours) are useful, while catecholamines such as isoproterenol (Allupent
syrup 5 ml every 8 hours) can be used transiently to treat patients who have heart block.
The use of transcutaneous pacing is preferable.

58. 58
ELECTROPHYSIOLOGIC STUDY
EP study is an invasive procedure in which intracardiac electrode catheters are used to
evaluate cardiac arrhythmias and to select various therapeutic options.
Indications of EPS:
Diagnostic:
 Aborted SCD (sudden cardiac death). - Syncope of undetermined cause.
 Recurrent WCT (wide complex tachycardia). - Ventricular tachycardia.
 Recurrent tachycardia with WPW syndrome.
 Symptomatic refractory NCT (narrow complex tachycardia).
Therapeutic:
 Catheter ablation for AVNRT (AV nodal reentrant tachycardia), WPW (Wolff
Parkinson White syndrome), VT (Ventricular Tachycardia), Atrial fibrillation.
 Acute termination of hemodynamically unstable tachycardias.
CARDIAC PACEMAKERS
Cardiac pacemakers are devices either implanted permanently or inserted temporarily,
consisting of a pulse generator and an electrode catheter that is placed transvenously
into the right ventricle and/or atrium. Small electrical impulses, generated by the pulse
generator and delivered via the electrode catheter depolarize the heart. Pacemakers are
widely used for treating bradyarrhythmias but can also be useful for treatment of some
tachyarrhythmias.
Temporary pacing is indicated for symptomatic second or third degree heart block
caused by transient drug intoxication or electrolyte imbalance in the setting of an acute
MI, CHB, or Mobitz II second degree AV Block. Symptomatic sinus bradycardia, AF
with a slow ventricular response.
Indications for permanent pacemaker implantation:
Symptomatic bradycardia, due to either sinus node dysfunction or AV nodal block, in
absence of a reversible cause, constitutes a class I indications for permanent pacing.
Asymptomatic conditions that are also considered class I indications for permanent
pacing include:
1- 3rd
degree AV Block .

59. 59
2- Persistent advanced 2nd
degree or 3rd
degree AVB after acute MI with
demonstrated block in His-Purkinje system (BBB).
3- Chronic bifascicular or trifascicular block with intermittent type II second or third
degree AV Block.
Pacing modalities: a four-letter alphabetic code is used to identify pacing modalities.
The first initial defines the chamber that is paced (V: ventricle, A: atrium, D: dual
chamber). The second identifies the chamber that is sensed (V, A, D), the third
indicates the response to sensed event (I: inhibited, T: triggered, D: dual function), and
the fourth when present, denotes, R: rate responsive node. VVI & DDD modes are used
most commonly. VVI units pace and sense ventricle and a sensed (native) event
inhibits the ventricular stimulus. DDD units, pace and sense both chambers, events
sensed in the atrium inhibit the atrial stimulus and trigger a ventricular response after
an appropriate interval, where as ventricle-sensed events inhibit ventricular and atrial
outputs.
Antiarrhythmic Drugs
Class Mode of
Action
Drugs Indication Dose Side Effects
Class
IA
Reduces
rate of
entry of
sodium
into the
cell
Quinidine
(Quinidine)
For
supraventricular
and ventricular
arrhythmias
including
conversion of AF or
A flutter, SVT, VT
600 – 1000
mg/day
Prolongation of QT
interval, risk of
Torsade de pointes.
Quinidine syncope,
quinidine induced
sudden death.
Diarrhea, vomiting
Procainamide
(Pronestyl)
Is effective
against
supraventricular
and ventricular
arrhythmias
2-6
mg/min
IV. 350-
1000 mg q
6 h PO
SLE like
syndrome,
prolonged QT,
nausea, rash,
myalgia,
Disopyramid
e (Norpace)
Is effective
against
supraventricular
and ventricular
arrhythmias
100-400
mg q 8 h
Worsening of
heart failure,
anticholinergic
actions as urine
retention. Avoid
in pts with

60. 60
glaucoma
Class
IB
Lidocaine
(Zylocain)
Ventricular
arrhythmias only
1-4 mg/min
IV (50-150
mg IV
loading
dose)
Confusion,
convulsions
Mexiletine
(Mexitil)
Ventricular
arrhythmias only
150-300
mg q 6-8 h
Confusion,
tremor,
bradycardia,
hypotension
Class
IC
Flecainide
(Tambocor)
Is very effective
for ventricular
and
supraventricular
tachycardias
100-200
mg q 12 h
PO
Aggravation of
arrhythmia
(proarrhythmia),
negative inotropic
effect, depression
of sinus node
Propafenone
(Rytmonorm)
Has a rule in
treatment of many
types of
arrhythmias
including
supraventricular
arrhythmias
150-300 mg
q 8-12 h
Negative inotropic
effect
Class
II
Beta
adrenergi
c
blockers
e.g.
Propranolol
(Inderal),
Atenolol,
Bisoprolol,
Carvedilol
For premature
beats atrial and
ventricular, for
torsade de
pointes,
10-200 mg
q 8 h PO
Bradycardia,
hypotension, heart
failure, intermittent
claudication,
worsening of
asthma, impotence
Class
III
Prolong
action
potential
duration
Amiodarone
(Cordarone)
Life-threatening
ventricular
arrhythmias,
conversion and
slowing of atrial
fibrillation,
AVNRT,
tachycardias
associated with
WPWs
200-400
mg q 6-8 h
Corneal deposits,
photosensitivity,
skin pigmentation,
thyroid
disturbances (hypo
& hyperfunction),
alveolitis, liver
enzyme elevation
Sotalol
(Betacor)
Effective in
supraventricular
80-160 mg
x 2-3 PO
Torsade de
pointes,

61. 61
and ventricular
arrhythmias
bronchospasm in
asthmatic patients
Class
IV
Calcium
antagonis
ts
Verapamil
(Isoptin)
Diltiazem
Slow the
ventricular rate in
AF or flutter, treat
and prevent
AVNRT
0.1 Mg/kg
IV 40-160
mg q 6-8 h
PO
60-120 mg
q 6-8 h PO
Constipation,
edema of LL,
negative inotropic
effect
Unclas
sified
Activates
K+
channels
Adenosine
(Adenocore)
Is very effective
for the acute
conversion of
paroxysmal SVT
6-18 mg
IV rapidly
Contraindicated
in sick sinus s., or
2nd
or 3rd˚
heart
block. Antidote is
theophylline
Enhances
central
and
periphera
l vagal
tone
Digoxin
(Lanoxin)
Slow ventricular
rate in AF, flutter
0.5 – 1 mg
IV or
0.125 –
0.25 mg /d
PO
Bradycardias and
tachycardias
(atrial, junctional,
vent.
tachycardia),
nausea, vomiting
Note: there are new two important antiarrhythmic drugs: Dronedarone (Multaq), and
Vernakalant.