Common atrioventricular canal defect or complete atrioventricular septal defect
- There is congestive heart failure in infancy. There may be cyanosis commonly.
- Isolated ASDs result from abnormal development of the septa that partition the common atrium of the developing heart into right and left chambers.
- There may be Down’s syndrome.
- There is marked parasternal heave or right ventricular apical impulse.
- Atrioventricular (AV) canal defects result primarily from mal development of the partitioning of the AV canal by the endocardial cushions.
- There is murmur of mitral regurgitation radiating to left sternal edge.
- There is mid diastolic flow murmur of tricuspid valve . There is wide fixed splitting of second heart sound and P2 is loud.
- shows left axis deviation and right ventricular hypertrophy.
- shows increased pulmonary vascularity and cardiomegaly.
- Note: All may be associated with PR prolongation.
- Ostium secundum: Rightward axis, right ventricular hypertrophy, rSR’ pattern in V1
20 echocardiography :
- shows common atrioventricular valve above the ventricular septum.
TREATMENT OF ASD
- To prevent thrombus formation after device deployment, aspirin 325 mg daily for 6 months and clopidogrel 75 mg for a month
- Surgical or non-surgical closure of the defect at appropriate age before pulmonary hypertension develops and reversal of shunt (right to left) occurs.
- Closure is usually delayed until preschool age (2–4 years), except for large defects to be repaired earlier.
- Secundum ASDs that are suitable for percutaneous closure should be 35 mm or less in stretched balloon diameter and should have a sufficient (>5 mm) rim of surrounding atrial tissue.