Phidippides was a Greek messenger who experienced sudden death after running more than 175 miles in two days. In today's world, marathon running and other endurance sports are becoming more popular and raising concern about sudden deaths at these events. Once etiologies such has hypertrophic cardiomyopathy, anomalous coronary arteries, and coronary atherosclerosis have been excluded, there is now an additional consideration termed Phidippides cardiomyopathy. Because endurance sports call for a sustained increase in cardiac output for several hours, the heart is put into a state of volume overload. It has been shown that approximately one-third of marathon runners experience dilation of the right atrium and ventricle, have elevations of cardiac troponin and natriuretic peptides, and in a smaller fraction later develop small patches of cardiac fibrosis that are the likely substrate for ventricular tachyarrhythmias and sudden death. Cardiac magnetic resonance imaging is emerging as the diagnostic test of choice for this condition. This review and case report summarizes the key features of this newly appreciated disorder. © 2012 Wiley Periodicals, Inc.

The authors have no funding, financial relationships, or conflicts of interest to disclose.