Isolated Coronary Artery Anomalies Clinical Presentation

Updated: Dec 18, 2014
  • Author: Jamshid Shirani, MD; Chief Editor: Eric H Yang, MD  more...
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Presentation

History

Most patients with coronary artery anomaly remain asymptomatic either because the anomaly does not produce any symptoms during life or because the first manifestation is sudden death.

In infants, myocardial ischemia may manifest as episodic crying, tachypnea, or wheezing. The infant may refuse to eat, presumably in order to avoid anginal pain.

In older individuals, symptoms are reported in less than 30% of patients before a diagnosis of coronary anomaly is made. These generally include palpitation, exertional dyspnea, angina or syncope, fatigue, or fever. These symptoms rarely raise clinical suspicion for diagnosis of coronary artery anomalies.

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Physical

Most coronary artery anomalies are discovered incidentally during noninvasive imaging, coronary angiography, or at autopsy and cause no clinical symptoms. However, particular subsets of these anomalies have been associated with sudden death, myocardial ischemia, congestive heart failure, or bacterial endocarditis.

Sudden death

This presentation has been observed in association with the origin of the left main or right coronary arteries from the opposite sinus of Valsalva and the type B (ie, between the aorta and pulmonary trunk) course of the anomalous vessel. This particular anomaly often is associated with a slitlike ostium and an obtuse takeoff of the proximal portion of the aberrant coronary artery. This combination may result in ischemia during exertion due to the stretching of the affected vessel that compromises blood flow at the ostium of the vessel. Increased cardiac output during exercise may also distend the ascending aorta and the pulmonary trunk and contribute to decreased blood flow through the anomalous coronary artery.

Sudden death also has been reported with congenital coronary artery structural abnormalities such as stenosis, hypoplasia, or atresia. Such structural abnormalities of the coronary arteries interfere with normal myocardial perfusion. Sudden death also has been reported in association with high takeoff of coronary arteries. The latter may lead to impairment of diastolic coronary artery flow. Ventricular fibrillation has been identified as the terminal event in some patients with coronary artery anomaly who have died suddenly during ambulatory electrocardiographic monitoring.

Myocardial ischemia

In addition to abnormalities mentioned under sudden death, myocardial ischemia also may occur in patients with anomalous origin of the left and, occasionally, right coronary artery from the pulmonary artery or right ventricle. In this type of anomaly, myocardial ischemia primarily occurs because of low coronary perfusion pressure secondary to the relatively low pulmonary diastolic pressure.

Myocardial ischemia also may occur in the setting of a single coronary artery when the aberrantly coursing vessel terminates prematurely and the myocardium distal to the vessel is inadequately perfused.

Intramyocardial course of coronary arteries (ie, myocardial bridge) occasionally has been associated with myocardial ischemia. The mechanism of myocardial ischemia in this condition is not fully elucidated.

Large coronary artery fistulas also may reduce myocardial perfusion and, thus, cause ischemia.

Congestive heart failure

Large coronary artery fistulas may result in right- or left-sided cardiac volume overload with or without symptoms of congestive heart failure. The hemodynamic effects of coronary artery fistulas depend on their site of drainage, diameter, and length. Drainage into the right heart produces left-to-right shunt with dilation of the right heart chambers and increase in pulmonary resistance. Eisenmenger syndrome has not been reported in association with such shunts. Drainage into the left heart produces left ventricular volume overload that may mimic aortic insufficiency clinically.

Heart failure also may be the predominant presentation in infants with the origin of the left main coronary artery from the pulmonary trunk. In the latter condition, the left ventricle appears dilated and globally hypokinetic on transthoracic echocardiography.

Bacterial endocarditis

Coronary artery fistulas may result in an increased risk of infective endocarditis or endarteritis depending on the location of the fistula. The infection commonly involves the receiving chamber of the heart at the entrance site of the anomalous coronary artery.

Signs

Physical findings generally are absent in most congenital coronary artery anomalies. The following signs may be present in patients with either anomalous origin of the left coronary artery from the pulmonary artery or a large coronary artery fistula:

  • Tachypnea and respiratory distress
  • Continuous precordial murmur
  • Systolic murmur of mitral regurgitation
  • S 3 or S 4 gallop rhythms
  • Cardiomegaly
  • Hepatomegaly
  • Edema
  • Peripheral cyanosis
  • Failure to thrive (infants)
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Causes

The exact pathogenetic mechanisms for development of congenital coronary artery anomalies are not well understood. According to extensive embryologic studies, formation of a normal coronary arterial system depends on multiple morphologic features, including formation of cardiac sinusoids, development of coronary buds on embryologic aortopulmonary trunk, and selective connection between the 2 systems. Any malformation within these systems may lead to development of coronary artery anomalies.

Congenital heart diseases

Some congenital heart diseases are found in association with coronary artery anomalies. These associations are especially strong in the following:

  • Truncus arteriosus, single coronary artery, and anterior coronary trunk crossing the outflow tract of the right ventricle
  • Transposition of the great arteries and ectopic origin of coronary ostia
  • Pulmonary valve atresia with intact ventricular septum and solitary coronary artery or coronary artery fistula draining into the right ventricle
  • Double outlet right ventricle and unpredictable coronary anatomy
  • Isolated aortic valve anomalies (such as bicuspid aortic valve) and ectopic origin of ostia, left coronary artery dominance, high takeoff of the left coronary artery, and shortening of the left main trunk
  • Tetralogy of Fallot and ectopic origin of the coronary arteries or coronary artery fistula draining into the pulmonary trunk

Familial clustering

Isolated reports of specific coronary artery anomalies occurring in family members have appeared in recent years. However, to date, no definitive data on coronary inheritance pattern have been reported in humans. [19]

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