Numerous variations of normal coronary artery anatomy that are of no hemodynamic consequence may be encountered in the hearts of otherwise healthy patients. Other coronary anomalies are secondary to some other cardiac defect. Example of such abnormalities include variations in coronary origin and course in TCA and TOF. Although these anomalies have no intrinsic clinical significance, they may create difficulties in the operative correction of the underlying defect.

The most common clinically important coronary artery anomaly is the origin of a coronary from the pulmonary artery. The left coronary artery is far more frequently involved in this defect than is the right. The pathophysiology of this condition depends on the extent of collaterals between the right and left coronaries. After birth, when pulmonary artery pressure falls, thesc is shunting of blood from the right coronary into the left and then into the pulmonary artery, in essence an arteriovenous fistula. The pressure in the small coronary arteries is low when the collaterals are small and myocardial perfusion is inadequate. These patients present within the first several months of life with symptoms of angina as well as those of congestive fsihure due to ischemic myocardial dysfunction and mitral reurgitation.

Arteriographic demonstration of this anomalous origin of a coronary artery should be followed by prompt operation. Three surgical approaches, have been employed, The first approach, simple ligation of the anomalous vessel at its origin, is a relatively easy operation and may be successful when there are extensive collaterals, usually in the older patient. Coronary bypass, using the saphenous vein or subclavian artery, is another option, but patency rates of these minute anastarnoses are low. Excellent results have been obtained in some infants with inadequate collaterals by establishing a direct connection between the aorta and left coronary artery , either by direct reimplantation or by a tunnel created within the pulmonary artery.

The second most common major anomaly of the coronary arteries is coronary arteriovenou fistula. In these cases, the coronary arises from the aorta and connects with the right atrium, right ventricle, pulmonary artery, coronary sinus, or superior vena cava. Patients may present at any age and are frequently discovered during evaluation of an asymptomatic murmur. As with other left-to-right shunts, symptoms of congestive failure predominate when the fistula is large, although angina may be encountered as well. Operative treatment consists of obliterating the fistulous connection. This may be difficult, as there may be multiple fstulas. Successful operation is curative, and operative mortality should approach zero.

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