Figure 1: Atrioventricular Reciprocating Tachycardia and Tachycardia-induced Cardiomyopathy.

A 62-year-old man without significant past medical history presented with new onset heart failure symptoms. His electrocardiogram on presentation revealed a wide complex tachycardia and an echocardiogram demonstrated a left ventricular ejection fraction (LVEF) of 10–15 % with normal left ventricular (LV) wall thickness and a moderately dilated LV cavity. An electrophysiology study was performed, which made the diagnosis of atrioventricular reciprocating tachycardia (AVRT) with a concealed left lateral accessory pathway, which was successfully abated. A follow-up echocardiogram one month later demonstrated an improved LVEF to 35–40 % and an echocardiogram performed one year later demonstrated normal LV wall thickness, cavity size and systolic function.