Other Congenital Cardiac Anomalies

Pulmonary atresia with an intact ventricular septum, in which the pulmonary valve is not properly formed, thus impeding blood flow from the heart to the lungs, frequently occurs together with hypoplasia of the tricuspid valve and right ventricle hypoplasia. This association is easily understood based on the fact that normal ventricular growth in fetal life depends on adequate inflow and outflow of that ventricle.

Coronary arterial abnormalities, particularly fistulous connections of the coronary arteries to the hypoplastic right ventricle and coronary artery stenoses, are common and have a major impact on prognosis and surgical options; surgery is inevitably required. Immediate postnatal survival is dependent on patency of the ductus arteriosus. Infants present with cyanosis, and auscultatory findings may include a murmur of tricuspid regurgitation or a patent ductus arteriosus. If not previously diagnosed on prenatal ultrasound, postnatal diagnosis is through echocardiography.

Pulmonic valve stenosis (see also Pulmonic Stenosis) as an isolated finding is a common congenital defect (7 to 10% of congenital heart defects) and leads to obstruction of outflow from the right ventricle. This obstruction results in right ventricular hypertrophy and eventually right ventricular failure. The pathology may be commissural fusion of a bileaflet or trileaflet valve or leaflet dysplasia.

Clinical findings include a prominent early systolic ejection click and a normal or wide split second heart sound (S2) with a soft pulmonary component and a harsh systolic ejection murmur (intensity varying directly with severity of stenosis), which is loudest at the upper left sternal border. In neonates with critical pulmonary stenosis, cyanosis is present due to right-to-left atrial shunting through a patent foramen ovale.

Treatment is usually transcatheter balloon dilation. If the stenosis is moderate to severe, surgical relief of the stenosis is very effective, but surgery is usually reserved for those valves that are not amenable to transcatheter balloon dilation.

These anomalies include any complex lesion with only one functional ventricle and include a hypoplastic right ventricle (RV) or left ventricle (LV) and, less commonly, a true undifferentiated single ventricular chamber. Timing of postnatal presentation depends upon the presence of an atrial septal defect, pulmonary stenosis, and a patent ductus arteriosus; infants may display heart failure or cyanosis. If not previously diagnosed on prenatal ultrasound, postnatal diagnosis is through echocardiography.

Surgical management involves ensuring adequate pulmonary blood flow via a systemic to pulmonary artery anastomosis (eg, modified Blalock-Taussig-Thomas shunt [see Tetralogy of Fallot]) for patients with decreased pulmonary blood flow, or protecting the pulmonary vascular bed and limiting pulmonary blood flow via pulmonary artery banding or some other intervention (such as a modified Norwood type reconstruction of the aortic and pulmonary roots, sometimes called a Damus-Kaye-Stansel anastomosis) if pulmonary overcirculation exists. Later, the Fontan procedure can be used as definitive treatment to make the functioning single ventricle solely a systemic ventricle.