C ongenital coronary artery anomalies (CCAs) are important causes of sudden cardiac arrest (SCA).1-3 We report the case of a patient in whom the mode and pathophysiology of SCA were documented to a thorough degree. The details of this case add to our knowledge of CCAs and the mechanisms of SCA in young athletes who have these rare conditions.
Case ReportA 26-year-old woman, a well-trained and accomplished runner (body mass index, 16.7 kg/m 2 ), collapsed 200 meters from the finish line of a 26.2-mile marathon after running for 3 hours 27 minutes. She was rushed to a nearby medical tent and was found to be pulseless. A rhythm strip revealed ventricular fibrillation. After undergoing brief chest compressions, she was given 1 mg of intravenous epinephrine followed by 2 direct-current cardioversions. Sinus rhythm was restored, and a pulse was palpable.The patient was intubated and transported to a nearby hospital, where a 12-lead electrocardiogram showed sinus tachycardia with inferolateral ST-segment depression. She was rushed to our tertiary center. A peak troponin I level of 1.88 ng/mL and a creatine kinase level of 6,426 U/L were noted. Thirty-six hours after the SCA and after hypothermia was discontinued, she made a full neurologic recovery. She was soon weaned from mechanical ventilation.On day 6 after the SCA, echocardiograms showed normal left ventricular (LV) wall thickness and motion. Cardiac magnetic resonance images revealed that the left main coronary artery (LMCA) originated ectopically from the right coronary sinus (Fig. 1) and that the proximal left main (LM) trunk probably had an intramural course, inside the aortic wall. The LMCA ran between the aorta and pulmonary artery (pursuing an interarterial or "preaortic" course) before branching into the left anterior descending coronary artery (LAD) and left circumflex coronary artery. A viability study showed only small focal areas of intramural hyperenhancement, suggesting a small scar, at the mid-anteroseptal LV wall. On day 9, coronary angiograms revealed an anoma-