Authors: Mikayla B. Troughton, MD – Northwestern University Feinberg School of Medicine, Chicago, IL and Destiny F. Chau, MD - Arkansas Children’s Hospital/University of Arkansas for Medical Sciences, Little Rock, AR.


A previously healthy 10-year-old female child sustains a cardiac arrest while playing soccer. Return of spontaneous circulation was achieved with cardiopulmonary resuscitation. Upon hospital admission, an electrocardiogram demonstrated Q-waves and ST segment depression with inversion in the anterolateral leads. An echocardiogram revealed depressed left ventricular function, mild to moderate mitral valve regurgitation, lack of left ventricular outflow tract obstruction and the presence of abnormal collateral connections between the right and left coronary systems. A cardiac MRI was completed and demonstrated the following (Source credit: authors): Figure 1. Cardiac MRI image: Ao = Aorta; PA = Pulmonary Artery


Which of the following is the MOST LIKELY etiology for the cardiac arrest?