A large arteriovenous fistula between the femoral artery and the femoral vein after cardiac catheterization manifesting as high-output cardiac failure.

Arteriovenous fistula is a potential complication of cardiac catheterization. Most of these fistulas cause no harm. We describe a case of high-output heart failure caused by an arteriovenous fistula in the groin. The heart failure was resolved by surgical closure of the fistula.