Unstable angina with coronary to pulmonary artery fistulae.

Three patients presenting with chest pain were found at cardiac catheterization to have fistulae between the left anterior descending coronary and the main pulmonary artery. Two patients presented with unstable angina, the third with atypical chest pain. Of the two patients presenting with unstable angina both had concomitant coronary artery disease. One was successfully treated with percutaneous transluminal coronary angioplasty. The other underwent successful double aorto-coronary bypass grafting and fistulae ligation. The remaining patient's symptoms resolved after informing him that he did not have atheromatous coronary artery disease. In no patient was the presence of the fistula felt to be related to the patients presenting complaint. In the two patients with unstable angina, a coronary steal phenomenon was postulated as a possible contributing factor.