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Other Congenital Cardiac Anomalies

By

Lee B. Beerman

, MD, Childrens Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine

Last full review/revision Dec 2020| Content last modified Dec 2020
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Other structural congenital cardiac anomalies include the following:

  • Aortopulmonary window

  • Congenitally corrected transposition

  • Double outlet right ventricle

  • Ebstein anomaly

  • Pulmonary atresia with an intact ventricular septum

  • Single ventricle with or without pulmonary stenosis

Rare nonstructural cardiac anomalies include

  • Congenital complete heart block

  • Congenital metabolic errors leading to cardiomyopathy

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

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 results in dyspnea; signs of labored breathing with flaring, grunting, or chest wall retractions; and recurrent respiratory infections. If the aortopulmonary connection is large, pulmonary hypertension equal to systemic pressure will be present.

Diagnosis is by physical examination findings and imaging, usually echocardiography, but this defect may be relatively subtle and the etiology of the pulmonary hypertension may initially be obscure. MR, CT, or cardiac angiography may be necessary to define the anatomy.

Surgical repair of aortopulmonary window should be done as soon as possible after diagnosis.

Congenitally corrected transposition (Levo-transposition) of the great arteries

Congenitally corrected transposition (levo-transposition) of the great arteries 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

Double outlet right ventricle (DORV), in which both the aorta and pulmonary artery connect to the right ventricle, is a malformation virtually always associated with a ventricular septal defect (VSD). DORV can result in a very wide spectrum of anatomy and physiology depending on the size and location of the 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

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 paroxysmal 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 with intact ventricular septum

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. 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. 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. If not previously diagnosed on prenatal ultrasound, postnatal diagnosis is through echocardiography.

Single ventricle spectrum

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 congestive 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.

More Information

The following are some English-language resources that may be useful. Please note that The Manual is not responsible for the content of these resources.

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LITHOBID
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