Spontaneous acquired left descending coronary artery to left ventricle fistula in a patient with an apical saddle thrombus.

Coronary artery fistulas are a rare anomaly. The majority are congenital in origin, although they may be acquired due to invasive cardiac procedures or trauma. The most common course is between the right coronary artery and the right ventricle. The authors describe the case of an acquired left anterior descending coronary artery to left ventricle fistula, associated with a saddle thrombus, in a patient with a previously normal coronary angiogram and none of the predisposing factors mentioned above. Spontaneous formation of acquired coronary fistulas is reported as a very rare event in the literature.