Other Congenital Cardiac Anomalies
Other structural congenital cardiac anomalies include the following:
Rare nonstructural cardiac anomalies include
Long QT syndrome and other genetic arrhythmia syndromes with risks of severe and possibly fatal ventricular arrhythmias are discussed elsewhere. (See also Overview of Congenital Cardiovascular Anomalies.)
Aortopulmonary window is an abnormal connection between the aorta and the main pulmonary artery. It is very rare and accounts for < 0.6% of all cardiac malformations. Aortopulmonary window can be isolated or occur with other cardiovascular abnormalities such as atrial septal defect, coarctation of the aorta, or tetralogy of Fallot.
In patients with an isolated aortopulmonary window, examination reveals a continuous murmur. Symptoms are those of left to right shunt. Large left-to-right shunts cause excess pulmonary blood flow and left ventricular volume overload, which may lead to signs of heart failure (eg, tachypnea, poor feeding, diaphoresis). During infancy, these symptoms often result in failure to thrive. A large left-to-right shunt also leads to lower lung compliance and higher airway resistance, which leads to pulmonary hypertension.
Diagnosis is by physical examination findings and imaging, usually echocardiography, CT, or cardiac angiography.
Surgical repair of aortopulmonary window should be done as soon as possible after diagnosis.
Bicuspid aortic valve is the most common congenital cardiovascular abnormality. It is present in 1 to 2 % of live births.
Patients with bicuspid aortic valve are predisposed to developing infective endocarditis, aortic regurgitation, and/or aortic stenosis. Bicuspid aortic valve can also be associated with dilation of the ascending aorta and coarctation of the aorta.
Children with bicuspid aortic valve may be asymptomatic if there is little or no valve dysfunction. Symptoms depend on the type of complication and can include fever in infective endocarditis or dyspnea, fatigue, syncope, palpitations, and exercise intolerance due to valvular regurgitation or stenosis. Examination reveals an early systolic click, a systolic ejection murmur and, if aortic regurgitation is present, a diastolic decrescendo murmur.
Diagnosis is by physical examination findings and echocardiography. Echocardiography shows the characteristic finding of fusion of two of the three aortic valve leaflets. Fusion of the right coronary and left coronary leaflets is the most common morphology. Children with fusion of the right coronary and noncoronary leaflets are more likely to have progression of valve dysfunction and to require intervention during childhood.
Treatment of bicuspid aortic valve is indicated if severe valve dysfunction develops and if symptoms occur. Treatment consists of balloon dilation or surgical repair of stenotic valves. Regurgitant valves are treated with surgery.
There is a genetic predilection for bicuspid aortic valves, so first-degree relatives of patients with a bicuspid aortic valve should undergo screening echocardiography.
Congenitally corrected transposition (levo-transposition) is relatively rare and accounts for about 0.5% of congenital cardiac anomalies. The normal embryologic looping of the fetal heart tube is reversed, resulting in atrioventricular and ventriculoarterial discordance. The result is the right atrium connects to a right-sided morphologic left ventricle (LV) and the left atrium connects to a left-sided morphologic right ventricle (RV). In almost all cases, the morphologic LV connects to the pulmonary artery and the morphologic RV connects to the aorta. The circulation is thus physiologically “corrected,” but associated anomalies are present in the majority of patients, including ventricular septal defect, pulmonic stenosis, Ebstein anomaly or other dysplasia of the left-sided tricuspid valve, congenital atrioventricular block, mesocardia or dextrocardia, and heterotaxy syndromes.
These anomalies result in a wide range of clinical manifestations. As patients reach adulthood, a common concern is the development of dysfunction of the morphologic RV, which serves as the systemic ventricle. This dysfunction may be subclinical or manifest as severe cardiomyopathy and heart failure, leading to consideration of heart transplantation.
Double outlet right ventricle can result in a very wide spectrum of anatomy and physiology depending on the size and location of the ventricular septal defect (VSD), as well as the presence and degree of pulmonic stenosis. In the most common variety with a subaortic VSD, a complete repair is possible with closure of the VSD in such a way as to direct left ventricular outflow to the aorta.
Ebstein anomaly consists of variable apical displacement and dysplasia of the septal and inferior leaflets of the tricuspid valve with dysplasia, but normal origin, of the anterior leaflet as well. These abnormalities displace the effective valve orifice downward, resulting in compromise of the function of the right ventricle with an atrialized portion that is proximal to the valve opening. This anomaly has been associated with maternal use of lithium during pregnancy. Associated abnormalities include atrial septal defect, pulmonic stenosis, and Wolff-Parkinson-White syndrome.
There is a remarkably wide spectrum of presentation, ranging from severely cyanotic newborns to cardiomegaly with mild cyanosis in childhood to a previously asymptomatic adult presenting with atrial arrhythmias or reentry supraventricular tachycardia. The onset of symptoms depends on the degree of tricuspid valve anatomic and functional derangement and presence of accessory pathways (eg, Wolff-Parkinson-White syndrome). When symptoms result from a severely dysfunctional tricuspid valve, surgical repair should be considered.
Pulmonary atresia frequently occurs together with hypoplasia of the tricuspid valve and right 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.
These anomalies include any complex lesion with only one functional ventricle and include hypoplastic right ventricle (RV) and left ventricle (LV) and, less commonly, a true undifferentiated single ventricular chamber. Surgical management involves ensuring adequate pulmonary blood flow via a systemic-to-pulmonary artery anastomosis (eg, modified Blalock-Taussig shunt [see Tetralogy of Fallot]) for patients with decreased pulmonary blood flow or protecting the pulmonary vascular bed via pulmonary artery banding if pulmonary overcirculation exists. Later, the Fontan procedure can be used as definitive treatment to make the functioning single ventricle solely a systemic ventricle.
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