Coronary artery fistula presenting as unstable angina.

c t a A 74-year-old man, with a history of heavy smoking, presented with unstable angina (Figure 1). Dobutamine stress echocardiography showed ischemia in the right coronary artery territory. Coronary angiography revealed no obstructive epicardial disease in the left dominant circulation (Figure 2A); the right coronary artery (RCA) was a small caliber and tortuous vessel, with only minor atheroma. However, an abnormal vessel arising from the proximal RCA was noted (Figure 2B and C), confirmed as a fistulous connection to the left atrium by multislice computed tomography, which also excluded other vascular anomalies (Figure 3). This was deemed to be causing a coronary steal phenomenon. Exercise myocardial perfusion imaging under anti-ischemic therapy excluded residual ischemia and the patient was successfully conservatively managed (Figure 4). Coronary-pulmonary artery fistulas (CPAF) are rare, often incidental findings of coronary angiography, thought to