We report a case of a 19-year-old man presenting with an acute myocardial infarction. Coronary arteries were free from atherosclerotic disease. A patent foramen ovale (PFO) was detected on contrast echocardiography with right-to-left shunting during Valsalva maneuver. No other embolic source was identified. We closed the patient's PFO with a 23-mm PFO occluder. No residual intracardiac shunt was found on contrast transthoracic echocardiography at 1-year follow-up and no recurrent paradoxical embolization occurred.