Thallium-201 myocardial SPECT in myocardial bridging.

Myocardial bridging is an uncommon condition where a major coronary artery is bridged by a band of muscle and narrows during systole, particularly during rapid heart rates. We present a patient with typical angina and angiographically proven 60% systolic bridging of the left anterior descending artery distal to the first perforator. Postexercise SPECT 201TI scanning demonstrated a severe reduction of perfusion to the septum and a moderate reduction of perfusion to the anterior wall of the left ventricle. Redistribution images demonstrated good reversibility of the perfusion defects indicating reversible myocardial ischemia. This case provides additional supportive evidence that myocardial bridging may cause myocardial ischemia.