pediatrics
Atrioventricular Septal Defect
Symptoms and Signs of Atrioventricular Septal Defect
Complete atrioventricular septal defect with a large left-to-right shunt causes signs of Heart failure (eg, tachypnea, dyspnea during feeding, poor weight gain, diaphoresis) by age 4 to 6 weeks. Pulmonary vascular obstructive disease ( Partial AV septal defects do not usually cause symptoms during childhood as long as left AV valve regurgitation is mild or absent. However, symptoms (eg, exercise intolerance, fatigue, palpitations) may develop during adolescence or early adulthood. Infants with moderate or severe left AV valve regurgitation often have signs of heart failure. Patients with transitional AV septal defects may have signs of heart failure if the ventricular septal defect is moderately restrictive with high flow or may be asymptomatic if the ventricular septal defect is highly restrictive (small). Physical examination in children with complete AV septal defects shows an active precordium due to volume and pressure overload of the right ventricle; a single, loud second heart sound (S2) due to pulmonary hypertension; a grade 2 to 3/6 systolic murmur due to increased flow across the pulmonary outflow tract; and sometimes a diastolic murmur at the apex and low left sternal border related to increased flow across the AV valves (see table). In patients with persistent elevation of pulmonary vascular resistance, especially those with Down syndrome, there may be no murmur, but a loud single S2 will be present. Most children with a partial defect have examination findings similar to patients with a Atrial Septal Defect (ASD) , wide splitting of the S2 and a midsystolic (eg, ejection systolic) murmur audible at the upper left sternal border. A mid-diastolic murmur may be present at the lower left sternal border when the atrial shunt is large. A cleft in the left AV valve results in a blowing apical systolic murmur of mitral regurgitation. 