Spontaneous Iliac Arteriovenous Fistula Leading to High-Output Heart Failure and Cardiac Arrest

We report a case of a 70-year-old male who complained to family members of the sudden onset of groin pain. He then collapsed, and emergency medical services were called. The patient arrived at the ED with a return of spontaneous circulation after cardiac arrest. The patient was diagnosed with a spontaneous iliac arteriovenous (AV) fistula secondary to aneurysmal rupture. This is a rare but potentially life-threatening condition that can result in high-output heart failure and, as described here, cardiac arrest. The differential diagnosis of groin pain is vast, but in the setting of cardiac arrest, vascular causes must be considered. Treatment is most often operative intervention, as was the case with the patient presented. It is predictable that as the population ages and invasive vascular surgeries become more common, the incidence of iliac AV fistulas will increase, resulting in more presentations of high-output heart failure or cardiac arrest in the emergency department.