CORONARY STENOSIS AND STEAL PHENOMENON IN CORONARY-PULMONARY FISTULA - ASSESSMENT WITH STRESS THALLIUM TOMOGRAPHY AFTER CORONARY ANGIOPLASTY AND FISTULECTOMY

We present a 46-year-old male with unstable angina and bilateral coron ary-to-pulmonary artery fistulae in whom reversible myocardial ischemi a was detected by exercise-stress thallium-201 single-photon emission computed tomography (SPECT). Coronary angiography revealed a 99% steno sis at the proximal site of the left descending coronary artery and bi lateral coronary-to-pulmonary artery fistulae with a saccular aneurysm . Percutaneous transluminal coronary angioplasty abolished chest pain and electrocardiographic changes. However, definitely improved, but st ill present, stress-induced perfusion abnormalities were demonstrated by an exercise-stress thallium-201 SPECT study. Myocardial ischemia wa s the only serious complication related to the coronary fistulae, and after they were surgically resected, the reversible perfusion abnormal ity was no longer observed. These findings suggest that coronary-to-pu lmonary artery fistulae potentiated the myocardial ischemia in patient with coronary stenosis leading to unstable angina and prolonged the p resence of coronary perfusion abnormality on stress thallium scans pro bably through a coronary steal phenomenon.