The patient is a 23-year-old man with a history of aortic stenosis, status post modified Ross procedure at age 9, complicated by complete heart block requiring a pacemaker, which was subsequently converted to a biventricular pacemaker 6 years ago and a battery change 2 years ago. His only complaints have been that he fatigues easily and experiences occasional light-headedness with an increase in activity such as power walking.

Six years ago, a small fistula was found near his left ventricular outflow tract (LVOT). A recent cardiac catheterization demonstrated that his left ventricular outflow fistula had enlarged (Fig. 3-1).