Physiologic assessment of coronary artery fistula.

Coronary artery fistula is an uncommon clinical entity. The most common coronary artery fistula is from the right coronary artery to the right side of the heart, and it is less frequent to the pulmonary artery. The effect of a coronary artery fistula may be physiologically significant because of the steal phenomenon resulting in coronary ischemia. Based on published reports, it is recommended that patients with congenital coronary artery fistulas be considered candidates for elective surgical correction to prevent complications including development of congestive heart failure, angina, subacute bacterial endocarditis, myocardial infarction, and coronary aneurysm formation with rupture or embolization. A patient is presented in whom treadmill-exercise thallium imaging was effective in determining the degree of coronary steal from a coronary artery fistula, leading to successful corrective surgery.