This document provides information on atrial septal defects (ASD), including: - ASD is the second most common congenital heart defect, accounting for 15-20% of cases. It involves a deficiency in the atrial septum. - Types of ASD include ostium secundum (70% of cases), ostium primum, and sinus venosus defects. - ASD causes a left-to-right shunt that can lead to enlargement of the right atrium and ventricle over time if left unrepaired. Closure is generally recommended for symptomatic patients or those with evidence of pulmonary hypertension. - Diagnosis involves echocardiogram,

1. DR J P SONI
Professor and Head of the Department Paediatrics
Division of Pediatric Cardiology
DR S N Medical College
Jodhpur
Doc_jpsoni@yahoo.com

2. Acyanotic CHD’s
ACYANOTIC
CHDS
PURE
ACYANOTIC
POTENTIALLY
CYANOTIC

3. Acyanotic
CHD
Without shunt(normal
or decreased flow)
Right side of heart
PULMONARY
STENOSIS
Left side of heart
AORTIC STENOSIS
COARCTATIONOF
AORTA
L-> R SHUNT ↑ PBF
ASD
VSD
P.D.A.
Aorto-pulmonary
Window

4. A.S.D.
An atrial septal defect (ASD) is a deficiency of the atrial septum.
It is the second most common congenital heart defects seen in pediatric cardiology.
ASDs account for about 15-20% of all congenital cardiac anomalies in all CHDs . With
prevalence of 56/100,000. . Spontaneous closure of the defect is rare if defect is >8
mm at birth and after 2–3 years of age. Very rarely, an ASD can enlarge on follow-up
while in 14% of patients & develop the serious complication of pulmonary vascular
disease, usually between 20 and 40 years of age. However, in a series from India,
pulmonary vascular disease developed in the first decade in 7% of patients with
secundum ASD.
Females : males ratio is = 2:1

5. Type of A.S.D.
1-Ostium Secondum defect→70% of ASDs.
2-Ostum primum defect→20% of ASDs.
3-sinus venosus defect.→10%of ASDs.
4-coronary sinus septal defect→ < 1% of ASDs .
Patent foramen ovale : Echocardiographic detection of a small defect in fossa ovalis region with a
flap with no evidence of right heart volume overload (dilatation of right atrium and right ventricle
[RV]). Patent foramen ovale is a normal finding in newborns.

6. Foramen Ovale
• Remnant of fetal circulation
• Behaves like flap valve
• Opens during increased intra-
thoracic pressure

9. Ostium Secondum :
• Associated with structurally normal AV valves.
• It may be single or multiple
( fenestrated atrial septum)
• Female: male 3 : 1 incidence.
• Associated lesions :
Partially anomalous pulmonary venous return
Holt - Oram-syndrome.

10. posterior
rim
ASD Secondum
with rims

11. Ostium Primum
• Next most common type A S D
• Located in the lower portion of the atrial
septum.
• Will often have a mitral valve defect
associated with it called a mitral valve
cleft.
• A mitral valve cleft is a slit-like or
elongated hole usually involves the
anterior leaflet of the mitral valve.

12. Sinus Venosus
• Least common type of ASD
• Located in the upper portion of the
atrial septum.
• May be Association with an abnormal
pulmonary vein connection
• Four pulmonary veins, two from the
right lung and two from the left lung,
normally return red blood to the left
atrium.
• Usually with a sinus venosus ASD, a
pulmonary vein from the right lung
will be abnormally connected to the
right atrium instead of the left
atrium.
• This is called an anomalous pulmonary
vein.

14. ASD sinus venosus

15. ASD sinus venosus

16. Coronary sinus ASD
This is caused by a defect in the embryonic left-
arteriovenous fold which forms a common wall
between coronary sinus and the left atrium.
A coronary sinus defect results in a communication
of variable size between the coronary sinus (CS)
and the left atrium (LA).
It is in most cases associated with a persistent
left superior vena cava (l-SVC) and an atrial septal
defect of the coronary sinus type and often part
of a more complex cardiac malformation. unroofing
of coronary sinus is described as
Type I presence of PLSVC
Type II absence of PLSVC Partial unroofing is
Type III partial unroofing and
Type IV when the mid or terminal portion of the
coronary sinus is involved.

17. Age of presentation:
• ASD, is present at birth; however, in most cases, a murmur is not audible until the
child is a few months old. Symptoms usually do not occur in individuals with ASD
until late childhood, adolescence, or adulthood.
• Secondum type, sinus venosus, and unroofed coronary sinus defects sometimes are
not diagnosed until the third decade of life.
• Ostium primum ASDs usually are diagnosed in the first few years of life because of
the presence of a mitral regurgitation murmur.

18. Patho-physiology:
The degree of left to right shunt depends on :
1. The size of the defect –
3 – 6 mm Small ASD
 6 – 12 Moderate
 12 Large Qp : Qs between 2:1 and 4:1
2. Pressure difference between both atria
< 5 <8

19. 3. Compliance of right (Diastolic) and left ventricle
4. vascular resistance in pulmonary and systemic circulation.
•
ASD in infants is asymptomatic : Right atrial muscular wall is thick & less
compliant thus limiting the left to right shunt as infant becomes older,
PVR drops, right ventricular wall becomes thinner and left to right shunt
increases .

20. • Large blood flow through the right side of the heart cause enlargement of right
atrium and ventricle, dilatation of the pulmonary artery but pulmonary atrial
pressure is usually normal ( absence of high pressure communication between Pulm.
and Sys. Circulation.)
• PVR may increase in adulthood and result either reduction in left to right shunt or
right to left shunt.

21. ASD shunting
RV enlarge &
hypertrophy
PA enlarge
Pul. Circulation congestion
Pul. Arterial Hypertension
Right side CHF
Oxygenated blood in PVs
LA
LV
Aorta Ejection ↓
Systemic circulation
insufficiency
FTT
SVC IVC
RA enlarge
Haemo-dymamics of ASD
Obstructive PAH
Eisenmanger’s syndrome

22. Sign & Symptoms ->
• Generally asymptomatic
• Pulmonary plethora: frequent chest infections
• Systemic Circulation Insufficiency ：Failure to thrive、poor weight
gain、feeding difficulty、fatigue, shortness of breath、sweating
• Cyanosis：Cyanosis in large lesions with severe Pul Hypertension.
Clinical findings of ASD

23. Sign of ASD
Heart sound:
. S1 accentuated - loud
• S2 fixed & widely split ( Volume in RV ↑-
Prolonged ejection phase- Pul.Valve closes late）
• P2 accentuated Loud.

24. Sign of ASD
Murmurs
• Shunt Murmur: Absent
• Flow Murmurs:
• (a) A grade Ⅰ-Ⅲ/Ⅵ ejection systolic murmur is heard
best at LSB2-3 which widely transmitted all over the
chest. No thrill. (relative Pul. Valve stenosis)
(b) Delayed Diastolic Murmur at LLSB
( relative Tricuspid stenosis）

26. Diagnosis:
• X-Ray Chest PA view:
*Variable degrees of right ventricle and atrial
enlargement.
* Enlargement of pulmonary artery.
*Increase pulmonary vascularity .

27. ECG
Sinus Venosus defects: P wave  0; Negative P in Inferior leads (ASD SV
below SVC)
QRS Axis: RAD (90 to 180)
LAD 0-30 Primum Defect
LAD 30- 60 – incomplete Endocardial cushion defect
LAD >60 Complete A V canal defect
rsR or rSR, incomplete RBBB, R in right precordial 10 – 15 mm >  PVD

28. RSR
Left axis deviation - 0 to -30᷁ suggest
A.S.D. Primum defect

29. RSR
Left axis deviation - 30 t0 -60᷁ suggest
A.S.D. Incomplete endocardial
cushion defect
Between -30 to - 60

30. LEFT TO RIGHT SHUNT
RSR
Left axis deviation > -60᷁ suggest
Complete Atrio-Ventricular Canal defect

31. Left axis deviation > -60᷁ suggest
Complete atrio-ventricular canal defect
Associated Right Ventricular Hypertrophy suggest
Lesion is associated with Pulmonary arterial
hypertension(PAH)
Or Pulmonary Stenosis
Associated left Ventricular Hypertrophy suggest
Lesion is associated with
Mitral regurgitation
Rupture of Sinus of Vasalva into Right Atrium
Shunt from Left Ventricle to Right Atrium
LEFT TO RIGHT SHUNT

32. • 3 - Echocardiogram : Trans thoracic and Trans esophageal ECHO-
• * Provide exact Localize and size of ASD.
* Increased right ventricular end diastolic dimensions.
* Ventricular septum motion is normal or abnormal ( in RV overload) .
* Confirmation of the shunt, Pul. Arterial Hypertension
* Assessment of ASD margin ( particularly TEE)
* Additional defect is present or not
* Pre and Post procedural assessment of ASD for device deployment ( particularly
TEE when ASD is complicated – associated with aneurysm and number more than one )
• 4 - Cardiac catheterization:
• It is mostly performed for device closure of the defect. A diagnostic catheterization is
required in those with pulmonary hypertension and suspected pulmonary vascular disease.
• Note : in the case of classical features of ASD on physical examination , CXR ,and ECHO
which Identify isolated secondum ASD, there is no need for the cardiac cath before
surgery.

33. Where is shunt ?
What is the direction of shunt ?
What is diagnosis?
74
78
84
95
84
84
95
95

34. Where is shunt ?
What is the direction of shunt ?
What is diagnosis?
74
78
84
95
84
84
95
95
Answer : At atrial level
Left to right from to LA to RA
A S D
Qp = 1/PAO2-PVO2 X 100 = 1/84-95 X 100 = 1/11 X 100 = 9
Qs = SAO2- MVO2 X 100 = 1/95-74 X 100 = 1/21X 100 =5
QeS = 1/PVO2-MVO2 X 100 = 1/95 – 74 X 100 = 1/21 X100 = 5
Qp/Qs = 9/5 = 1.8
Left to right = Qp- QeS = 9-5 = 4
Right to left = qS- qEs = 5-5 = 0

35. Where is shunt ?
What is the direction of shunt ?
What is diagnosis?
74
78
74
85
74
74
85
85
95
95

36. Where is shunt ?
What is the direction of shunt ?
What is diagnosis?
74
78
74
85
74
74
85
85
95
95
Answer : At atrial level
Right to Left from to LA to RA
A S D
Qp= 1/74-95 x 100 = 1/21x 100 = 5L
Qs= 1/ 85-95 x 100 = 1/10 x100 = 10 L
Qp/Qs=
𝟓
𝟏𝟎
= 0.5 :1, suggestive of PAH with Eissenmanger
syndrome
QeP =1/ PVO2-MVO2 = 95-74 = 1/21x100 = 5
Left to right shunt = Qp – QeS = 5 – 5 = 0
Right to left shunt = Qs – QeS = 10 – 5 = 5

37. If QP QS < 1.5 : don’t need Closure except for paradoxical
emboli
Spontaneous closure of ASD usually occur within the 1 year of life.
ASD of < 7 mm in neonatal period may reduce in size and require no intervention

38. Significant or Large ASD
QP / QS > 1.5 : 1
RV volume overload
P HTN : PAP > 2/3 systemic
PVR > 2/3 SVR
Challenge to O2 or No - reversibility
Lung biopsy → reversibility
- PLAN FOR ASD CLOSURE

39. The individuals with ASD are at risk of -
PV Resistance (PVR) in ASD usually is normal, 1 unit / m2
Atrial arrhythmia : Af , Flutter , PAT occurs commonly in
older patients. They are probably related to large
shunts. < 20 y 1 - 2% ; > 20 y 15 - 50%
Cardiac failure : Rare in Infancy

40. • Class I: General agreement exists that the treatment is useful and
effective.
• Class II: Conflicting evidence or divergence of opinion or both about
the usefulness/ efficacy of treatment.
• IIa: Weight of evidence/ opinion is in favour of usefulness/ efficacy.
• IIb: Usefulness/ efficacy is less well established.
• Class III: Evidence and/or general agreement that the treatment is
not useful and in some cases may be harmful.
The CHDs are classified according to management out come into
three categories :

41. Spontaneous closure is rare if defect >8 mm at birth and
rare after age 2 years.
Very rarely an ASD can enlarge on follow up .
Patent foramen ovale: Echocardiographic detection of a small
defect in fossa ovalis region with a flap with no evidence of
right heart volume over- load (dilatation of right atrium and
right ventricle). Patent foramen ovale is a normal finding in
newborns.
A.S.D.

42. Indication for closure:
ASD associated with right ventricular volume overload
should be closed early.
Ideal age of closure:
(i) In asymptomatic child: 2-4 years (Class I).
(ii) Sinus venosus defect surgery may be delayed to 4-5
years (Class IIa).

43. ASD 21.8 mm Tricuspid regurgitation enlarge RV
Enlarge PA PA PPG 20mmHg Enlarge IVC no chage in DIA with RESPATION
Symptomatic ASD
Have Following ECHO finding-
Large ASD
Size > 20mm per sq meter
ASD Flow may be Lt-> Rt
Or RT -> Lt
Enlarge Right atrium & Ventricle
Tricuspid Regurgitation
Enlarge IVC
Enlarge Pul Artery with High PPG

44. (iii) Symptomatic ASD in infancy :
Early closure is recommended
(Class I) if associated with
congestive heart failure
Severe pulmonary artery
hypertension; which is seen in
about 8%-10% of cases.
One must Rule out associated
lesions e.g.
Aorto-pulmonary window………
RV
LV
RA
LA
ASD
MS

45. left ventricular inflow obstruction – Lutembacher syn
RV
LV
RA
LA
ASD
MS

46. COR TRIATRIUM SINSTER

47. Supra cardiac PAPVC

48. Cardiac TAPVC Coronary sinus

49. Cardiac PAPVC RUPV -> RA
RV
LV
RA
LA

50. Cardiac TAPVC – LPV TO RA

51. Infra-
diaphragmatic
TAPVC

52. Stepwise evaluation of ASD
•Determine the site of defect: fossa ovalis or others (others being not suitable for device).
•Visualize the defect from subcostal view (Sagittal and coronal).
• Initial indication is the volume overload of the chambers (RA and RV) in 4c view.
•Determine the direction of shunting of the defect.
•Look for the associated structures particularly pulmonary veins and AV valves.
•Look for the pulmonary artery pressures: TR and PR gradients.
•Determine suitability for device closure.

53. Medical management of ASD
Drug therapy is recommendation for patients with CHDs- ASD,VSD and PDA, who have
abnormal cardiac morphology or function like –
Cardiac volume over load that is dilated cardiac chamber despite preserved systolic function,
Valvular regurgitation
Pulmonary hypertension because of volume overload, but no symptoms of heart failure.

54. Digoxin is indicated in heart failure associated with reduced systolic function of heart.
Utility of Digoxin in heart failure secondary to volume overload of the ventricle, as seen
in left to right shunt lesions, is less clear, since the myocardial contractility is normal in
such cases.
Rapid digitalization is usually not indicated when using digoxin for heart failure.
Rapid digitalization may be indicated for treatment of acute tachyarrhythmias.
The maintenance dose is given in twice daily doses for children under 10 years and once daily
for children above 10 years.
Digoxin “holiday” is generally not needed in children.
The half life of digoxin is markedly prolonged in preterm babies and in those with renal
dysfunction.
Dose of digoxin should he halved when using amiadarone.

55. Diuretics
are widely used in heart failure because of the symptomatic relief from fluid overload with in
minutes of administration - Furosemide, torsemide.
Dosages and Pharmacodynamics: Oral: 1-2 mg/kg every 12 hours, maximum of 4 mg/kg/day;
intravenous: 1 mg/kg/dose up to 3-4 times a day;
Continuous IV infusion: 1-4 mg/kg/day. Continuous infusion may be better and safer in acute
heart failure and in postoperative setting.
The onset of action starts in 10-20 minutes after an IV dose and 20-30 minutes after oral
administration. The duration of action is six hours.
The dose does not need to be adjusted in renal or hepatic impairment.
Furosemide may increase chances of digoxin toxicity by producing hypokalemia.
It activates the renin angiotensin aldosterone axis (RAAS), producing vasoconstriction, which
is detrimental in heart failure. Concomitant use of ACEi (vasodilator) is recommended,
whenever possible.

56. Vasodilators:
Angiotensin Converting Enzyme Inhibitors (ACEi)
ACEi decrease the adrenergic drive and block the heart failure induced activation of renin
angiotensin aldosterone axis (RAAS).
Increased levels of aldosterone and angiotension II have been associated with poor outcome in
heart failure.
ACEi also increase bradykinin which has natrinuretic properties.
Currently ACEi therapy is recommended as the first line treatment for heart failure, when it
is not secondary to an obstructive lesion.
Enalapril. Enalapril is useful for older children. It is longer acting and given twice daily. The
dose is 0.1- 0.5 mg/kg/dose twice a day. The initial dose may be smaller.
BP and renal parameters should be monitored when up titrating the dose

57. Beta blockers
Heart failure results in activation of sympathetic nervous system and increased levels of
circulating catecholamines. Chronic activation of sympathetic nervous system leads to worsening
of heart failure by inducing myocardial apoptosis and fibrosis. Circulating catecholamines also
induce peripheral vasoconstriction along with renal retention of salt and water. Betablockers
antagonize these deleterious effects. In addition, betablockers also have antiarrhythmic
effect.
Carvedilol is a non selective beta blocker which also has an anti-oxidant property. Due to its
alpha blocking effect, carvedilol exerts a vasodilatory effect. It improves functional class and
fractional shortening in children with ventricular dysfunction
Carvedilol: 0.1 mg/kg/day in two divided doses, increase at 1-2 weekly interval to 1 mg/kg/day
with a maximum of 2 mg/kg/day.
Metoprolol: 0.2-0.4 mg/kg/day initially, gradually increase to a maximum of 1 mg/kg/day in two
divided doses.

58. Do
• Treat the underlying cause of heart failure.
• Digoxin has a narrow safety window in
children.
• Continuous infusion of furosemide may be
better in acutely ill cases .
• A persistent tachycardia (>180) may indicate
“tachycardio-myopathy” as the cause of heart
failure.
• Rapid digitalization is not required for
majority.
drug therapy of cardiac diseases in children working group on management of congenital heart diseases in india correspondence to: dr anita saxena,
professor of cardiology, all india institute of medical sciences, new delhi 110029, india indian pediatrics 2009
Do Not
• Combine angiotensin converting enzyme
inhibitors
(ACEi) with Angiotensin receptor blockers (ARB)
(Class III).
• Avoid combining ACEi and spironolactone, if
necessary, monitor potassium levels (Class II b)
• Do not give ACEi in heart failure secondary to
pressure overload (Class III)
• Avoid using ACEi in acute decompensated heart
failure (Class II b)
• Betablockers should not be initiated in acute
decompensated stage of heart failure (Class III)
• Potassium supplements are not required in early
infancy

59. Indication for closure:
ASD associated with right ventricular volume overload should
be closed early.
Ideal age of closure:
(i) In asymptomatic child: 2-4 years (Class I).
(ii) sinus venosus defect surgery may be delayed to 4-5 years
(Class IIa).

60. (ii) Symptomatic ASD in infancy : stabilized with medical therapy and
advise early closure.
Early closure is recommended (Class I) if associated with congestive
heart failure, severe pulmonary artery hypertension; seen in about 8%-
10% of cases. Rule out associated lesions (e.g., total anomalous pulmonary
venous drainage, left ventricular inflow obstruction, aorto-pulmonary
window).
(iii) If presenting beyond ideal age: Elective closure irrespective of age
as long as there is right heart volume overload and pulmonary vascular
resistance is in operable range (Class I).
RV
LV
RA
LA
ASD
MS

61. Method of closure
Surgical:
Established mode (Class I). : ASD Secondum, Sinus venosus, Ostium primum and
Ostium Secondum not suitable for device closure because of deficient rim.
Device closure:
More recent method, used for Secondum ASDs only (Class I).
Device closure is not advised for Secondum atrial septal defect due to higher likelihood of
complications, if:
i. Deficient rims – inferior rim ii. ASD size more than (20 mm/m)
iii. High Pulmonary pressure iv. High left ventricular end diastolic pressure

62. Device size
Selection of device closure :
ASD with good rim : size of device is 2-4 mm more than size of ASD size
ASD with Aneurysm : device size is 4-6 mm more than size of ASD but decided
during procedure

63. Method of closure of ASD
Prognosis: Lesion’s diameter<3mm mostly closed
within 3months of age.
3-8 mm ASD may close spontaneously.
Lesion’s diameter>8mm rarely close without any
intervention.
Large shunt（Qp/Qs>1.5）needs operation.
Invasive cardiac catheterization：Amplazer、
cardia seal ect. device to seal the lesion

64. Amplatzer Atrial Septal Defect Occluder
• AGA Medical, Golden Valley Mn
• 2001- FDA approved for Secondum lesions
• Nitinol mesh frame work and left/right atrial
disks
• Filled with poly-fabric to promote thrombosus.
• Sinus Venosus – (cover Stent closure-
adult) Although surgery remains the first-line
treatment for SVASD, transcatheter closure is
a feasible alternative in high-risk surgical
candidates. Amplatzer-Vascular-Plug-II (St.
Jude Medical)

66. TTE and ASD Device closure
• Transthoracic echocardiogram four
chamber view to evaluate atrial
septal defect.
• Note presence of inter-atrial
communication between left and
right atrium.

67. TTE after intervention
• Transthoracic echocardiogram four
chamber view one day after Amplatzer
device placement.

68. A S D
Type of ASD location intervention
Secondum Mid portion of septum
Fossa ovalis
Elective closure -2-4 y
Device or surgery
Primum Lower portion of septum Symptomatic - MR –early surgery
Asymptomatic – elective closure –
2 -4y
Sinus venosus Region of junction of either SVC Elective surgical closure
Between 2-4y
Coronary sinus (rare) Region of ostium of coronary
sinus
Elective surgical closure
Between 2-4y

69. Recommendation for Follow Up
i. Follow-up after surgery: Clinical and echo in the 1st year only. No further follow-up is required
if no residual defect, no pulmonary hypertension, or arrhythmia. Patient/guardians should be
explained about reporting to hospital in case of any cardiac symptoms or symptoms suggestive of
arrhythmias.
ii. ii. Follow-up after device closure:
a. Antiplatelet agents: Aspirin (3–5 mg/kg/day) is given a day before or immediately after the
Procedure and then continued; •
Device ≤30 mm – Aspirin (3–5 mg/kg/day) is continued for total duration of 6 months.
Device >30 mm – Aspirin (3–5 mg/kg/day) and clopidogrel (1.5–2 mg/kg/day) are given for 3
months followed by aspirin alone for 3 more months.
b. Echocardiography: At discharge, 1 month, 6 months, 1 year, and then every 3–5 years.
iii. Infective endocarditis (IE) prophylaxis is recommended for 6 months after device or surgical
closure. However, all patients are advised to maintain good oro-dental hygiene after this period also.

70. Prognosis & Complications:
• 15% ostium Secondum in term infants close spontaneously .
• Symptoms don’t usually appear until the third decade in life or later :
• Pulmonary hypertension, atrial dysrhythmias, AV valve
• insufficiency, and heart failure , initially appears during volume
• overload in pregnancy .
• Infective Endocarditis is extremely rare and there is no
need for antibiotic prophylaxis for isolated secondum .

71. Sinus Venosus defect closure may be associated with development of : stenosis of SVC/RUPV
or loss of sinus rhythm.
Device closure of large ASD with over sized devices is associated with a risk of late device
erosion and cardiac tamponade in a very small number.