Brief Discussion on Atrial Septal Defects in Children, Clinical features, management and Complications

1. Atrial Septal Defects
Dr. VANNALA RAJU
Consultant Pediatrician
Hyderabad

2. • Introduction
• An atrial septal defect (ASD) is a hole of variable size in the atrial septum.
• ASD is detected in 1 child per 1500 live births, and accounts for 5-10% of congenital heart
defects.
• ASDs make up 30-40% of all congenital heart disease detected in adults (second only to
bicuspid aortic valve).
• ASDs occur in women 2-3 times more common than men.

3. • ASDs can occur in different anatomic portions of the atrial septum.
• ASDs can be isolated or occur with other congenital cardiac anomalies.
• Functional consequences of ASDs are related to the anatomic location of the defect, its
size, and the presence or absence of other cardiac anomalies.

4. Embryology

5. • Types of ASD
• Primum ASD
• Secundum ASD
• Sinus venosus defects
• Coronary sinus defects
• Patent foramen ovale

6. • Primum ASD
• • Make up ~15% of all ASDs.
• • Occur if the septum primum does not fuse with the endocardial cushions, leavinga defect at the base of the
interatrial septum that is usually large.
• • Usually not isolated – primum ASDs are typically associated with anomalies of the AV valves (such as cleft
mitral valve) and defects of the ventricular septum
• (VSDs) or a common AV canal.

7. Secundum ASD
• Make up ~70% of all ASDs.
• Occur twice as often in females.
• Typically located within the area bordered by the limbus of the fossa
ovalis.
• Defects vary in size, from <3 mm to >20 mm.

8. • Secundum ASD
• • May be associated with other ASDs.
• • Multiple defects can be seen if the floor of the fossa ovalis (AKA valve of the foramen
ovale) is fenestrated.
• • Ten to twenty percent have a functional mitral valve prolapse.
• • May be related to changing LV geometry associated with RV volume overload

9. Sinus venosus ASD
• Make up ~10% of ASDs.
• Characterized by malposition of the insertion of the SVC or IVC
straddling the atrial septum.
• Often associated with anomalous pulmonary venous return the
RUL/RMLpulmonary veins may connect with the junction of the SVC and
RA in the setting of a superior sinus venosus ASD.

10. • Coronary Sinus Septal Defects
• • Less than 1% of ASDs
• • Defects in the inferior/anterior atrial septum region that
• includes the coronary sinus orifice.
• • Defect of at least a portion of the common wall separating the coronary sinus and the left
atrium – AKA “unroofed coronary sinus”
• • Can be associated with a persistent left SVC draining into the coronary sinus.

11. • 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

12. • Patent Foramen Ovale
• •Not truly an “ASD” because no
• septal tissue is missing.
• •Oxygenated blood from the IVC
• crosses the foramen ovale in utero.
• •At birth, the flap normally closes
• due to Reduced right heart pressure and PVR
• • Elevated LA pressure.
• • Flap fusion is complete by age two
• in 70-75% of children; the
• remainder have a PFO.

13. LEFT-TO-RIGHT SHUNT
• In early infancy, when pulmonary resistance is high, left and right ventricular
compliances are similar, and net shunting through an ASD is typically slight.
• As the left ventricle matures, it becomes less compliant in diastole than the
right, and left atrial pressure rises. This drives a left-to-right shunt at the atrial
level in the presence of an ASD.
• With age, the disparity between systemic and pulmonary resistance, and in
turn between left and right ventricular compliance, results in increased left-to-
right shunting and advancing right ventricular volume loading.
HEMODYNAMICS

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

15. 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.

16. 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.

17. • PATHOPHYSIOLGY

18. • Over time, right ventricular
volume load results in dilation
and hypertrophy, eventually
affecting the function of both
ventricles.
• Atrial enlargement may
contribute to the late incidence
of atrial fibrillation. Right
ventricular volume overload is
noted to occur as a rule when
ASDs are larger than 6 mm in
diameter
• Volume-induced
hypertrophy of the right
ventricle produces a loss
of coronary reserve and
eventual impairment of
right ventricular systolic
and diastolic function.
• Left ventricular
functional reserve is
diminished by adulthood
in most patients with ASD.

19. • • Although left ventricular systolic function may be normal at rest, the left ventricle
exhibits a subnormal diastolic dimension, and a loss of functional reserve at exercise.
•
• • In general, the functional loss in the left and right ventricles is normalized 6 months
following ASD closure in children and young adults.

20. • 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.

21. • Natural History of ASDs
• • Most ASDs <8mm close spontaneously in infants.
• • Spontaneous closure is unusual in children and adults; defects often become progressively larger.
• • Most patients with a significant shunt flow ratio (Qp:Qs > 2:1) will be symptomatic and require closure by age40.
• • Increasing size of the ASD may preclude percutaneous closure.
• • Weight is more affected then height
• Association
• • Holt oram syndrome
• • Patau’s syndrome
• • Edward’s syndrome

22. • • 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.
• • Cerebrovascular accident, resulting from paradoxical embolization through an ASD, is a
rare complication.
Infective endocarditis does not occur in patients with isolated ASDs.
Mitral stenosis may occur as a result of rheumatic fever in a case of
ASD (Lutembacher syndrome).

23. • 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

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

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

26. 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.

27. 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

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

29. • 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.

30. 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

31. 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.
Exception:
an older patient, in whom pulmonary vascular
resistance may be a concern.

32. 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.

33. 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

34. 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

35. 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 and anticoagulants.

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

37. .
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

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

39. 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.

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

41. 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

42. 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

43. Surgical management
• Surgical closure has been the “gold standard” formof 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.

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

46. Indications:
• 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)
Contraindications:
• Patients with severe irreversible PAH & reverse shunt
SPO2 < 90%

47. 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

48. 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

49. 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

50. 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.

51. 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

52. THANK YOU