**5.1.1 Symptoms**

Isolated ASD patients are usually asymptomatic and are usually detected at the time of preschool physical examination. Sometimes these defects are detected when echocardiographic studies are performed for some unrelated reason. A few patients do present with heart failure in infancy, although this is uncommon.

#### **5.1.2 Physical examination**

The right ventricular and right ventricular outflow tract impulses are increased and hyperdynamic. No thrills are usually felt. The second heart sound is widely split and fixed (splitting does not vary with respiration) and is the most characteristic sign of ASD. Ejection systolic clicks are rare with ASDs. The ejection systolic murmur of ASD is soft and is of grade I-II/VI intensity and rarely, if ever, louder. The murmur is secondary to increased flow across the pulmonary valve and is heard best at the left upper sternal border. A grade I-II/VI mid-diastolic flow rumble is heard (with the bell of the stethoscope) best at the left lower sternal border. This is due to large volume flow across the tricuspid valve. There is no audible murmur because of flow across the ASD.

#### **5.1.3 Noninvasive evaluation**

#### **5.1.3.1 Chest x-ray**

Chest film usually reveals mild to moderate cardiomegaly, prominent main pulmonary artery segment and increased pulmonary vascular markings.

#### **5.1.3.2 Electrocardiogram**

16 Congenital Heart Disease – Selected Aspects

should be two or more times the size of the coarcted segment, but no larger than the diameter of the descending aorta at the level of diaphragm. The immediate (Figures 8) and intermediate-term results of balloon coarctation angioplasty have been good although long-

When there is a defect in the partition between left and right heart structures, the oxygenated blood is shunted from left-to-right because of generally lower pressure and/or resistance in the right heart than in the left. The physical findings are either a manifestation of flow across the defects or due to effects of excessive flow across the cardiac chambers (volume overload) and valves. The magnitude of the shunt determines the clinical

There are three major types of atrial septal defects (ASDs) and these include ostium secundum, ostium primum and sinus venosus defects. The clinical features are essentially similar but I will mainly concentrate on ostium secundum ASDs. Atrial septal defects constitute 8% to 13% of all CHDs. Pathologically, there is deficiency of the septal tissue in the region of fossa ovalis. These may be small to large. Most of the time, these are single defects, although, occasionally multiple defects and fenestrated defects can also be seen. Because of left-to-right shunting across the defects, the right atrium and right ventricle are dilated and somewhat hypertrophied. Similarly, main and branch pulmonary arteries are also dilated. Pulmonary vascular obstructive changes are not usually seen until adulthood.

Isolated ASD patients are usually asymptomatic and are usually detected at the time of preschool physical examination. Sometimes these defects are detected when echocardiographic studies are performed for some unrelated reason. A few patients do

The right ventricular and right ventricular outflow tract impulses are increased and hyperdynamic. No thrills are usually felt. The second heart sound is widely split and fixed (splitting does not vary with respiration) and is the most characteristic sign of ASD. Ejection systolic clicks are rare with ASDs. The ejection systolic murmur of ASD is soft and is of grade I-II/VI intensity and rarely, if ever, louder. The murmur is secondary to increased flow across the pulmonary valve and is heard best at the left upper sternal border. A grade I-II/VI mid-diastolic flow rumble is heard (with the bell of the stethoscope) best at the left lower sternal border. This is due to large volume flow across the tricuspid valve. There is no

Chest film usually reveals mild to moderate cardiomegaly, prominent main pulmonary

present with heart failure in infancy, although this is uncommon.

audible murmur because of flow across the ASD.

artery segment and increased pulmonary vascular markings.

term follow-up is limited (Rao 1999).

presentation and symptoms.

**5.1 Atrial septal defect** 

**5.1.1 Symptoms** 

**5.1.2 Physical examination** 

**5.1.3 Noninvasive evaluation** 

**5.1.3.1 Chest x-ray** 

**5. Ayanotic heart defects: Left-to-right shunts** 

**The ECG** shows mild right ventricular hypertrophy; the so-called diastolic volume overload pattern with rSR' pattern in the right chest leads.
