Coronary Artery Fistula: An Unexpected Cause of Heart Failure in a 58-Year-Old Woman.

Coronary artery fistula (CAF) is an abnormal connection between a coronary artery and a heart chamber resulting in left-to-right shunt. A large CAF was an unexpected cause of heart failure in a 58-year-old woman who underwent transcatheter closure of the CAF with improvement in symptoms but complicated by myocardial infarction. (Level of Difficulty: Beginner.).