Ryuji Okamoto, MD; Kimimasa Saito, MD*; Masatoshi Miyahara, MD*; Shinya Okamoto, MD*; Katsutoshi Makino, MD*; Ryuji Hirano, MD**; Makoto Kimura, MD**; Tsutomu Ohi, MD**; Takakazu Kouji, MD*; Naoki Isaka, MD; Takeshi Nakano, MD

Abstract
Anomalous left main coronary artery (LMCA) originating from the right coronary sinus and running between the aorta and pulmonary trunk is a rare congenital condition. Although this disease is known to be associated with myocardial infarction and sudden death, the precise mechanism is uncertain. A 14-year-old male with this anomaly developed myocardial infarction during exercise complicated by primary antiphospholipid syndrome. He was admitted to hospital with persistent chest pain and sudden cardiac collapse that occurred while he was running. Cardiac catheterization demonstrated a narrowed segment in the LMCA and impaired blood flow, prompting a diagnosis of extensive anterior myocardial infarction. Emergency bypass surgery was performed using a single saphenous vein graft to the left anterior descending artery. Postoperative angiography showed the presence of an anomalous LMCA arising from the right sinus of Valsalva and running between the great vessels. The aortic samples were pathologically normal. He was discovered to also have primary antiphospholipid syndrome and was discharged without symptoms after warfarin therapy. Complicated primary antiphospholipid syndrome may trigger myocardial infarction in asymptomatic patients with this type of coronary anomaly.
(Jpn Circ J 2000; 64: 214-217)

Key Words: Antiphospholipid syndrome; Congenital heart disease; Coronary vessel anomalies; Myocardial infarction; Coronary artery bypass grafting

Mailing address: Ryuji Okamoto, MD, First Department of Internal Medicine, Mie University, 2-174 Edobashi, Tsu, Mie 514-8507, Japan. E-mail: ryuji@clin.medic.mie-u.ac.jp