Limitation of fractional flow reserve in evaluating coronary artery myocardial bridge.

Symptomatic myocardial bridge is treated with medical therapy, but in refractory cases, percutaneous revascularization has been used. We describe two cases to highlight differences in coronary compression and flow pattern, which make the luminal narrowing associated with a myocardial bridge anatomically and physiologically different from the fixed stenosis of atherosclerotic epicardial disease. Due to these characteristics, evaluating the functional severity of a myocardial bridge using fractional flow reserve as a guide to revascularization may be of limited value.