Atrial Septal Defect in Children- a common congenital heart disease.

1. ATRIAL SEPTAL DEFECT
Presenter:
Dr. Archana Shrestha Yadav
Resident Phase A

2. OBJECTIVES
 Introduction
Embroyology
Incidence and Genetic Associations
Pathophysiology
Types of ASD
Natural History
 Evaluation and Management

3. INTRODUCTION
ASD is an acyanotic CHD characterized by defect
in the interatrial septum causing a left to right
flow between the atria
Severity depends on :
- size of defect
- size of shunt
- associated anomalies
Resulting in spectrum
from : asymptomatic to
right sided overload, PAH , even atrial arrhythmias

4. EMBROYOLGY OF HEART

6. Septum formation in primitive
atrium

7. INCIDENCE
ASD constitutes 8-10% of congenital heart
defects in children.
Incidence = 56 per 100,000 live births
Recent estimates are much higher (100 per
100,000 live births), likely due to increased
recognition in the era of common use of
echocardiography
female: male ratio for secundum ASD = 3:1
For sinus venosus ASD= 1:1

8. ETIOLOGY
Actual etiology of this congenital defect is
unknown.
Some factors may play role as there are some
evidences of being association with ASD.
Factors include:
- Genetic factor
- Environmental factor including antenatal
use of teratogenic drugs, congenital infection

9. GENETICS
The genetic basis of ASD is not completely
understood.
In the majority of cases this is a sporadic
lesion, yet some homeobox gene defects have
been found to explain some of the well known
familial cases of ASDs, such as NKX2-
chromosome-5, which has an autosomal
dominant inheritence and AV conduction
defect.

10. Other genetic syndromes with skeletal
abnormalities HOLT-ORAM Syndrome, which is
accused by mutations in the transcription factor
TBX5, essential in development of both the
heart and upper limbs.
ASD can be part of many other syndromes like
DOWN syndrome and Noonan syndrome

11. HEMODYNAMICS
Desaturated blood enters
the right atrium from the
vena cava at a volume of 3
L/min/m2 and mixes with
an additional 3 L of fully
saturated blood shunting
left to right across the ASD

12. Results in :
increase in oxygen saturation
in the right atrium.
 Six liters of blood flows
through the tricuspid valve
and causes a mid-diastolic
flow rumble.
Oxygen saturation may be
slightly higher in the right
ventricle because of
incomplete mixing at the
atrial level.

13. The full 6 L flows across
the right ventricular
outflow tract and causes a
systolic ejection flow
murmur.
Six liters returns to the left
atrium, with 3 L shunting
left to right across the
defect and 3 L crossing the
mitral valve to be ejected
by the left ventricle into
the ascending aorta.

14. PATHOPHYSIOLOGY

16. TYPES
Ostium Secundum (75-85%)
Ostium Primum (10-15%)
Sinus Venosus (5-10%)
Coronary Sinus septal
defect (1%)

17. Ostium Secundum
• Most common type.
• Defect in the region of
fossa ovalis.
• Single or Multiple.
• May be associated with
partial anomalous venous
return most commonly of
the right upper pulmonary
vein.

19. Ostium Primum
• Situated in the lower
portion of the artrial
septum and overlies the
mitral and tricuspid valve.
• Often associated with
clefts in the anterior mitral
and septal tricuspid valve
leaflets and small VSDs.

20. Sinus Venosus
• Least common type.
• Situated in the upper
part of atrial septum in
close relation to the
entry of the Superior
venacava.
• Abnormal fusion
between embryologic
sinus venosus and
atrium.

23. ACCORDING TO SIZE:
In younger children – In older children
Small defect: <3 mm Small defect: <6 mm
Moderate defect: Moderate defect:
3 – 8 mm 6 – 12mm
Large defect: >8 mm Large defect: >12 mm

24. ASSOCIATIONS
Associated malformations are nearly 30% of Cases. Like:
Secundum ASD
● Pulmonic stenosis
● Mitral valve prolapse
● Partial anomalous pulmonary venous connection
Primum ASD
● Cleft mitral valve
● Discrete subaortic stenosis
Sinus Venosus septal defect
● Partial anomalous pulmonary venous return
Coronary Sinus septal defect
● Partial and total anomalous pulmonary venous return
● Persistent left superior vena cava

25. SYMPTOMS AND SIGNS
Vary with the size of defect.
Small defect: Asymptomatic and is usually
diagnosed during a routine health check up.
Large defect: Symptomatic and patients
usually present with
 Failure to thrive.
 Easy fatigability.
 Increased perspiration
 Recurrent Pulmonary infections.
 Platypnea
 Orthodeoxia

26. On examination
General examination
 Appearance: Usually normal
 Heart rate: Normal
 Respiratory rate: Normal
 Weight and height: may be less than 10th centile.

27. Precordium
 Inspection:
 Slight prominence of
precordium
 Palpation:
 Apex beat may be shifted to left
 P2 may be palpable
 Left parasternal heave may be
present

28. Auscultation:
 S1 is normal
 S2 is widely splitted and
fixed
Ejection systolic murmur
,medium pitched, soft, grade
1-3/6 & best heard at left 2nd
& 3rd ICS
 A diastolic flow rumble
across the tricuspid valve
region.

29. INVESTIGATIONS
Routine tests :(CBC, septic screening, s.electrolyte, s.
creatinine, blood grouping, coagulation profile, etc)
should be done before management.
Diagnostic Investigations includes-
-X-ray
-Ecg
-Echocardiography
-Sometimes cardiac catheterization

30. Xray Findings
Cardiomegaly
RA enlargement
RV enlargement
Full pulmonary conus
Increased pulmonary
vascular markings
Plethoric lung fields

31. ECG
Enlarged ‘p’
wave
indicating
Right atrial
hypertrophy
rsR’ seen and tall R
wave
Indicating RBBB and
RVH
Also note that the aVF
is predominantly
upwards as compared
to Lead I indicating
Right Axis Deviation
LAD with rSR’ in V1 is suggestive
of Ostium primum defect

32. Associated lesions-
-Right atrial and RV enlargement with diastolic
flattening and paradoxical IVS motion are
evidence of RV volume overload and a significant
left- to-right shunt,
- mitral valve prolapse,
-cleft mitral valve,
-anomalous pulmonary veins.
 Contrast echocardiography with intravenous
agitated saline may be used to confirm the
presence of a shunt if color Doppler are not
conclusive.

33. RA
LA
RV
Echocardiogram
 Primary diagnostic
imaging modality for ASD.
 Provides:
- exact localization of ASD
- size of ASD
- measurement of septal
rims
- Confirmation of the shunt
- Abnormal motion of
ventricular septum.
- Associated lesions can be
identified

34. Cardiac catheterization
 Patients with the classic features of a
hemodynamically significant ASD on physical
examination and chest radiography, in whom
echocardiographic identification of an isolated
secundum ASD is made, need not undergo diagnostic
catheterization before repair, with the
Exception:
an older patient, in whom pulmonary vascular
resistance may be a concern.

35. NATURAL HISTORY
 In patients with an ASD <3 mm in size
diagnosed before 3 months of age,
spontaneous closure occurs in 100% of
patients at 1½ years of age.
 Spontaneous closure occurs more than 80%
in patients with defects between 3-8 mm
before 1½ years of age.
 An ASD with a diameter > 8 mm rarely closes
spontaneously.

36.  Most children with an ASD remain active and
asymptomatic. Rarely, congestive heart failure
(CHF) can develop in infancy.
 If untreated, pulmonary hypertension and
subsequent CCF may develop during or after
third decade, and reversal of shunt may occur
(rare), it may be progressive with pregnancy
 With or without surgery, atrial arrhythmias
(flutter or fibrillation) may occur in adults.

37.  Infective endocarditis does not occur in
patients with isolated ASDs.
Cerebrovascular accident, resulting from
paradoxical embolization through an ASD, is a
rare complication.
Mitral stenosis may occur as a result of
rheumatic fever in a case of ASD (Lutembacher
syndrome).

38. COMPLICATIONS OF ASD
Right sided heart failure
Frequent pulmonary infections
Flow-related PAH
Pulmonary vascular obstructive disease
Paradoxical embolism
Tricuspid and mitral insufficiency
Atrial arrhythmias—atrial flutter, atrial fibrillation,
and Sick Sinus Syndrome.

39. MANAGEMENT
Patients with small shunts and normal RV size are
generally asymptomatic and require no therapy
but need longtime follow up for spontaneous
closure.
Moderate to large shunt and/or symptomatic ASD
should be managed with following strategies:
- Medical therapy
- Interventional therapy
- Surgical therapy

40. Medical management
Aim to reduce volume overload and to
strengthen functions of heart muscles.
Symptomatic children :
 Diuretics:
-These agents relieve ventricular overload,
peripheral and pulmonary congestion
 Digoxin:
-Helps to strengthen the heart muscle, enabling it
to pump more efficiently

41.  Afterload reducers:
- Enalapril
- Captopril
Exercise restriction is no necessary
Prophylaxis for infective endocarditis is not
indicated
Atrial arrythmias : Appropriate Antiarrhythmic
drugs.
Atrial fibrillation : Antiarrhythmic drugs +
anticoagulants.

42. Irreversible PAH :dobutamine, calcium channel
blockers (high dose), diuretics, prostacycline,
sildenafil or oxygen therapy.
Treatment of Other complications, like-
pulmonary infections, thrombo- embolic events or
heart failure should also be treated accordingly.

43. Interventional therapy

44.  Closure of ASD :
In patients with small secundum ASDs and
minimal left-to-right shunts without right
ventricular enlargement, closure is not required
Indications of ASD closure-
All symptomatic patients
Asymptomatic patients with-
• Qp : Qs ratio of at least 2 : 1
• Right ventricular enlargement
Time of closure- usually after the 1st yr and
before entry into school

45. Interventional therapy
Indication:
i. Echocardiographic evidence of ostium secundum ASD
ii. Clinical evidence of RV volume load ( i.e. 1.5:1 degree
of left to right shunt or RV enlargement )
iii. ASD diameter less than 36 mm
iv. Presence of sufficient rim of tissue( at least 5 mm)
v. Patient with fenestrated Fontan lateral tunnel if
temporary balloon occlusion is tolerated

46. Contraindication:
Sinus venosus, coronary sinus or primum ASD
Extensive congenital cardiac anomaly.
Known sepsis within one month prior to implantation or
any untreated systemic infection prior to device
placement.
Bleeding disorder, untreated ulcer or any other
contraindications to aspirin therapy.
Demonstrated intracardiac thrombi on echo.
 Any patient whose size or condition would cause to be a
poor candidate for cardiac catheterization.

47. Different ASD closure devices:
Clamshell(TM) device
Buttoned device
Angel wings(TM) device
Atrial septal defect occluder system device

49. Advantages of device closure-
It is safe and cost-effective than
surgery
 Successful implantation rates
more than 96%,
Fewer complications: Major<1%,
 Shortened hospitalization
Avoidance of pain and residual
thoracotomy scars
 Reduced need for blood products.
Disadvantages of
device closure-
Higher rate of small
residual leak

50. Complications of Device Closure:
Device misalignment/embolization
Device erosion of atrial wall or aorta
Device impingement on adjacent structures AV valve,
Coronary sinus, SVC, Pulmonary veins, Aorta
Infection including endocarditis
Thromboembolic Complication
Allergic reaction
Valvular regurgitation
Residual shunt

51. Follow– Up After Device Closure:
Clinical - assessment of symptoms of arrhythmia, chest
pain, or embolic events.
Echocardiography surveillance - device position, residual
shunting, and complications such as thrombus
formation or pericardial effusion.
Frequency of follow-up echocardiography - usually at
24 hours, 1 month, 6 months, and 1 year and at
regular intervals thereafter.

52. Surgical management

53. Surgical management
Surgical closure has been the “gold standard” form
of treatment of ASD
Surgeons need proper training and expertise in
performing operations.
The surgical approach can be by right thoracotomy or
sternotomy, and more limited incisions are feasible
with either approach.

54. Procedure- Simple suture
or patch closure
Timing-
Surgery is usually delayed
until the patient is 2 to 4
years of age because the
possibility of spontaneous
closure exists.
In infancy- If CCF not
respond to medical
management

56. Indication:
 ASD with RA and RV enlargement with / without
symptoms.
 ASD minimum diameter > 10 mm on echocardiography
 A sinus venosus, coronary sinus or primum ASD
 Chronic atrial arrythmia with ASD (concomitant Maze
 procedure)
Contraindication:
 Patients with severe irreversible PAH & reverse shunt
 SPO2 < 90%

57. Advantages of Surgery-
Can be performed in any type
of ASD
Associated anatomical
abnormality can be corrected
concurrently.
Excellent late outcome.
Disadvantages of
Surgery-
Costly
Needs expertise hands
Prolong Hospital stay
pain and residual
thoracotomy scars

58. Complications:
● Pericardial effusion / constriction
● Residual shunt
● RV systolic and diastolic dysfunction
● Pulmonary artery pressure
● Mitral regurgitation
● Pulmonary vein stenosis or caval vein stenosis
(sinus venosus defects)
● Arrhythmia
● Tricuspid regurgitation

59. Follow – Up After Surgical Closure:
Early postoperative follow-up:
-Symptoms of undue fever, fatigue, vomiting, chest pain, or
abdominal pain
( may represent post pericardiotomy syndrome with
tamponade and needs immediate evaluation with
echocardiography.)
Annual clinical F/U: (if following conditions persist or
develop)
- PAH.
- Atrial arrhythmias.
- RV or LV dysfunction.
- Coexisting valvular or other cardiac lesion

60. PROGNOSIS:
Patients generally survive up to adulthood without
surgical or percutaneous intervention mainly with
small to moderate size ASD and many patients live to
advanced age.
The results after surgical or device closure in
children with moderate to large shunts are excellent.
 Mortality is less than 2% after surgical closure of
uncomplicated ASD
Mortality and morbidity increase with pulmonary
vascular disease

61. TAKE –HOME MESSAGES
Atrial septal defects are relatively common CHD
Early symptoms are usually rare except very large
deffect.
Any kind of closure is safe and effective and
associated with improved life expectancy
A comprehensive treatment plan should include
input from the primary care provider, the
Paediatric Cardiologist and the Paediatric
Cardiovascular surgeon.

62. THANK YOU