Many reports of marijuana-associated myocardial infarct (MI) are limited by incomplete evaluation of the toxicologic exposure, a lack of definitive anatomic findings, and the potential for comorbid coronary atherosclerosis inherent in an adult population. We report a 16-year-old adolescent boy who presented with chest pain after smoking marijuana and was found to have acute MI. Electrocardiogram showed diffuse ST-segment elevations. Exhaustive toxicologic testing confirmed the presence of Δ-9-tetrahydrocannabinol metabolite and ruled out other drugs of abuse. Echocardiography demonstrated moderate global left ventricular systolic dysfunction. Coronary angiography demonstrated no focal coronary lesions or obstruction. Right ventricular septal endomyocardial samples biopsied 36 hours after the onset of pain showed a subendocardial acute MI with a sparse neutrophilic infiltrate. One month after the event, magnetic resonance imaging showed a severely dilated left ventricle and moderately to severely depressed global systolic function. Late gadolinium enhancement consistent with myocardial fibrosis was seen in nearly all myocardial segments. Our unusually well-documented findings strengthen the potential association between marijuana and MI. Furthermore, we demonstrate a disease distribution supporting a process that affects the coronary circulation globally, likely at the distal, small-vessel level.
Keywords: cardiac magnetic resonance imaging; marijuana; myocardial infarct.