2. CARDIOVASCULAR SYSTEM
Properties of Cardiac Muscle
1. Autorhythmicity
2. Conductivity
3. Contractility
4. Excitability
5. All or none law
6. Long refractory period
11. ο Diagnosis of arrhythmias & heart
blocks.
ο Diagnosis of hypertrophy.
ο Diagnosis of IHD.
ο Diagnosis of other diseases like
electrolyte imbalance, pericarditis
etc.
12. NERVE SUPPLY OF HEART
Autonomic Nervous System
Sympathetic supply( T1 to T5 )
Effects of stimulation
(Due to Noradrenalin and Adrenalin )
1. Increase in Heart rate
2. Increase in Force of contraction
3. Increase in Excitability
4. Increase in Conductivity
(Effects blocked by alpha & beta blockers)
13. PARA SYMPATHETIC SUPPLY
(Lt. & Rt. Vagus)
Effects of Stimulation :
(Due to Acetyl Choline )
1. Decrease in Heart rate
2. Decrease in Force of contraction
3. Decrease in Excitability
4. Decrease in Conductivity
(All effects reverted by Atropine
which blocks muscarinic 2 receptors)
15. VENTRICULAR SYSTOLE
(contraction)
Events :
1. Isovolumetric contraction phase
2. Maximum ejection phase
3. Reduced ejection phase
(First Heart sound occurs at beginning
of Iso-volumetric contraction phase)
16. VENTRICULAR DIASTOLE
(relaxation)
Events :
1. Protodiastole
2. Isovolumetric relaxation phase
3. First rapid filling phase
4. Diastasis
5. Last rapid filling phase
(Second heart sound occurs at beginning
of Isovolumetric relaxation phase )
17. FIRST HEART SOUND
Causes :
1. Closure of A-V valves
2. Contraction of Ventricles
3. Ejection of blood in big vessels
Peculiarities
1. Like LUBB
2. Intensity high & pitch low
3. More duration
4. Best heard at apex
5. Best heard with diaphragm
6. Coincides with carotid pulse
18. SECOND HEART SOUND
Causes :
1. Closure of S-L valves
2. Relaxation of Ventricles
3. Regurgitation of blood in big vessels
Peculiarities :
1. Like DUP
2. Intensity low & pitch high
3. Short duration
4. Best heard at base
5. Best heard with bell
6. Comes after carotid pulse
19. REGULATION OF HEART RATE
1. Nervous factors
2. Hormonal factors
3. Local factors
4. Reflexes : Cardio acceleratory reflex
Cardio inhibitory reflex
5. Miscellaneous factors like body temp.
20. CLINICAL EXAMINATION OF
ARTERIAL PULSE
1. Rate
2. Rhythm
3. Volume
4. Force
5. Tension
6. Equality
7. Condition of vessel wall
8. Peripheral pulsations
9. Apexβpulse co-relation
21.
22. CARDIAC OUTPUT
1. Stroke Volume (70 ml)
2. Minute volume=S.V x H.R.(5 litres/min.)
3. End systolic volume (60 ml)
4. End diastolic volume (130 ml)
5. Ejection systolic fraction (0.55)
=Stroke volume/End diastolic volume
(Criterion of cardiac fitness )
28. (Preferably with hospitalization)
1. Treat the basic cause
2. Oxygenation
3. Salt restricted diet
4. Cardiotonic drugs like digitalis
5. Drugs to reduce load on heart like
diuretics
TREATMENT OF CARDIAC FAILURE
32. FACTORS AFFECTING B.P.
Systolic B.P. depends upon Cardiac output
Diastolic B.P. depends upon Peripheral
Resistance, which depends upon-
β Diameter of blood vessel
β Elasticity of blood vessel
β Viscosity of blood
β Velocity of blood
β Length of blood vessel
33. REGULATION OF B.P.
Short term regulation :
Nervous regulation
1. Baroreceptors
2. Chemoreceptors
3. CNS ischemic response
Hormonal regulation
1. Renin angiotensin
2. Catecholamines
3. ADH
34.
35.
36. REGULATION OF B.P.(cont.. )
Intermediate :
1. Vascular stress relaxation
2. Capillary fluid shift mechanism
Long term :
1. Role of aldosterone
2. Role of kidney
37. HYPERTENSION
Definition :
Types : 1. Primary
2. Secondary
Predisposing factors for primary hypertension :
1. Age
2. Sex
3. Heredity
4. Life style(Diet,sedentary work,stress,habits)
5. D.M. and obesity
39. TREATMENT OF PRIMARY
HYPERTENSION
β Mild hypertension :
Life style modification
Salt, fat and sugar restriction
Tranquillizers if required
β Moderate hypertension :
All above
Diuretics
β Severe hypertension:
All above
Anti hypertensives
42. STAGES OF HYPOVOLEMIC
SHOCK
1. Compensatory : Blood loss upto 500ml
(All B.P.regulating mechanisms working to maximum)
2. Progressive : Blood loss upto 1 litre
(External help in form of fluid or blood transfusion )
3. Irreversible : Blood loss more than 1 litre
(Harmful positive feedback sets in )
43. PRINCIPLES OF TREATMENT
1. Hospitalization
2. Replacement therapy
3. Drugs e.g dopamine
4. Treatment of complications
e.g renal failure
44. PECULARITIES OF CORONARY
CIRCULATION
(Normal flow β250 ml per min )
1. End arteries
2. Filled in diastole
3. High capillary density
4. A-V difference of oxygen is high
5. Local factors regulate blood flow
6. Presence of beta receptors
7. Energy derived from fatty acids
45. PECULARITIES OF PULMONARY
CIRCULATION
( Normal flow β5lits per min )
1. Low pressure system
2. No tissue fluid formation
3. Distensible
4. Nerves and hormones have no effect
5. Hypoxia causes vasoconstriction
6. Less blood flow to apex and more to base
7. Rich lymphatic supply