Spontaneous Thrombosis of a Left Circumflex Artery Fistula Draining Into the Coronary Sinus.

A 28-year-old woman was referred to our institution with sudden onset chest pain at rest. Electrocardiography revealed an inferoposterior ST-segment elevation myocardial infraction. The patient proceeded to cardiac catheterization, which revealed a large ectatic left circumflex coronary artery with an apparent fistula connecting it to the coronary sinus. Follow-up angiography revealed that the fistula was no longer patent, spontaneously thrombosed, and resolved without requiring surgery.