Other Congenital Cardiac 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 Atrial Septal Defect (ASD) An atrial septal defect (ASD) is an opening in the interatrial septum, causing a left-to-right shunt and volume overload of the right atrium and right ventricle. Children are rarely symptomatic... read more , coarctation of the aorta Coarctation of the Aorta Coarctation of the aorta is a localized narrowing of the aortic lumen that results in upper-extremity hypertension, left ventricular hypertrophy, and malperfusion of the abdominal organs and... read more , or tetralogy of Fallot Tetralogy of Fallot Tetralogy of Fallot consists of 4 features: a large ventricular septal defect, right ventricular outflow tract obstruction and pulmonic valve stenosis, right ventricular hypertrophy, and over-riding... read more .

In patients with an isolated aortopulmonary window, examination reveals a continuous murmur. Symptoms are those of left to right shunt Left-to-right shunts Congenital heart disease is the most common congenital anomaly, occurring in almost 1% of live births ( 1). Among birth defects, congenital heart disease is the leading cause of infant mortality... read more . Large left-to-right shunts cause excess pulmonary blood flow and left ventricular volume overload, which may lead to signs of heart failure Heart failure Congenital heart disease is the most common congenital anomaly, occurring in almost 1% of live births ( 1). Among birth defects, congenital heart disease is the leading cause of infant mortality... read more (eg, tachypnea, poor feeding, diaphoresis). During infancy, these symptoms often result in failure to thrive Failure to Thrive (FTT) in Children Failure to thrive in children is weight consistently below the 3rd to 5th percentile for age and sex, progressive decrease in weight to below the 3rd to 5th percentile, or a decrease in 2 major... read more . 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 Pulmonary Hypertension Pulmonary hypertension is increased pressure in the pulmonary circulation. It has many secondary causes; some cases are idiopathic. In pulmonary hypertension, pulmonary vessels may become constricted... read more 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 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 Ventricular Septal Defect (VSD) A ventricular septal defect (VSD) is an opening in the interventricular septum, causing a shunt between ventricles. Large defects result in a significant left-to-right shunt and cause dyspnea... read more , pulmonic stenosis Pulmonic Stenosis Pulmonic stenosis (PS) is narrowing of the pulmonary outflow tract causing obstruction of blood flow from the right ventricle to the pulmonary artery during systole. Most cases are congenital... read more , Ebstein anomaly Ebstein anomaly Other structural congenital cardiac anomalies include the following: Aortopulmonary window Congenitally corrected transposition Double outlet right ventricle Ebstein anomaly read more 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 Overview of Cardiomyopathies A cardiomyopathy is a primary disorder of the heart muscle. It is distinct from structural cardiac disorders such as coronary artery disease, valvular disorders, and congenital heart disorders... read more and heart failure Heart failure Congenital heart disease is the most common congenital anomaly, occurring in almost 1% of live births ( 1). Among birth defects, congenital heart disease is the leading cause of infant mortality... read more , leading to consideration of heart transplantation Heart Transplantation Heart transplantation is an option for patients who have any of the following and who remain at risk of death and have intolerable symptoms despite optimal use of drugs and medical devices:... read more .

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 Ventricular Septal Defect (VSD) A ventricular septal defect (VSD) is an opening in the interventricular septum, causing a shunt between ventricles. Large defects result in a significant left-to-right shunt and cause dyspnea... read more (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 Pulmonic Stenosis Pulmonic stenosis (PS) is narrowing of the pulmonary outflow tract causing obstruction of blood flow from the right ventricle to the pulmonary artery during systole. Most cases are congenital... read more . 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 Atrial Septal Defect (ASD) An atrial septal defect (ASD) is an opening in the interatrial septum, causing a left-to-right shunt and volume overload of the right atrium and right ventricle. Children are rarely symptomatic... read more , pulmonic stenosis Pulmonic Stenosis Pulmonic stenosis (PS) is narrowing of the pulmonary outflow tract causing obstruction of blood flow from the right ventricle to the pulmonary artery during systole. Most cases are congenital... read more , and Wolff-Parkinson-White syndrome Wolff-Parkinson-White (WPW) syndrome Reentrant supraventricular tachycardias (SVT) involve reentrant pathways with a component above the bifurcation of the His bundle. Patients have sudden episodes of palpitations that begin and... read more .

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 Reentrant Supraventricular Tachycardias (SVT) Including Wolff-Parkinson-White Syndrome Reentrant supraventricular tachycardias (SVT) involve reentrant pathways with a component above the bifurcation of the His bundle. Patients have sudden episodes of palpitations that begin and... read more . 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 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.

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 Definitive management Tetralogy of Fallot consists of 4 features: a large ventricular septal defect, right ventricular outflow tract obstruction and pulmonic valve stenosis, right ventricular hypertrophy, and over-riding... read more ]) 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 Treatment Tricuspid atresia is absence of the tricuspid valve accompanied by a hypoplastic right ventricle. Associated anomalies are common and include atrial septal defect, ventricular septal defect... read more can be used as definitive treatment to make the functioning single ventricle solely a systemic ventricle.