Images in cardiovascular medicine. Cardiac sarcoidosis presenting as heart block.

A 47-year-old man without prior cardiac disease presented with lightheadedness, nausea, and fatigue while golfing. The initial 12-lead ECG demonstrated a first-degree atrioventricular delay, a transthoracic echocardiogram revealed normal myocardial thickness and left ventricular function, and stress nuclear imaging studies showed no ischemia; however, atrioventricular block was noted during the stress test. Within 2 months, complete heart block with junctional escape rhythm (Figure 1) developed. Laboratory testing that included thyroid studies and Lyme titers was unrevealing. Magnetic resonance imaging demonstrated 2 focal regions of late gadolinium enhancement (Figure 2) in a pattern suggestive …