心筋梗塞を併発した単冠状動脈症の1例

A case of single coronary artery complicated with myocardial infarction

　単冠状動脈症は冠動脈の起始異常の1つで，冠状動脈造影検査上の基礎知識として知っておくことにより，判読の誤りを防止することができるものと考えられる^1）。また臨床的には，心不全^2,3），不整脈や突然死^4〜5）の報告，また心筋梗塞の併発の報告^6〜8）もみられる。

　今回，著者らは心筋梗塞を併発した単冠状動脈症の1例を経験したので報告する。

The single coronary artery may be defined as a congenital cardiac vascular anomaly in which the entire heart is supplied by an artery that arises by one ostium from an aortic trunk. Single coronary artery has been considered a minor coronary anomaly without clinical importance. However, sudden death, myocardial infarction and anginal syndrome have been reported recently in patients with this anomaly. We report a patient with single coronary artery complicated with myocardial infarction.

A 53 year old woman experienced exertional chest pain of 13 months' duration. She had sufferedfrom acute myocardial infarction 27 months prior to admission. An electrocardiogram revealed a QS pattern in V₁ to V₄ and an inverted T wave in V₁ to V₅, compatible with anterior myocardial infarc-tion. Left ventriculogram showed akinesis in the anterolateral, apical and partially diaphragmatic wall. Ascending aortogram suggested that the left coronary artery arose from the left sinus of valsalva. An injection into right sinus of valsalva revealed no coronary ostium. A selective left coronary angio-gram demonstrated that the left main coronary artery bifurcated into the left anterior descending artery (LAD) and circumflex artery (LCX). The LAD had a 90% obstruction at segment 7. The LCX, which had a moderate cariber and no segmental stenosis, supplied the area of the heart normally maintained by the right coronary system. The present case was an example of type 1 by Smith's classification. The patient's condition remained stable on medical treatment.

The case of Smith's type 1 of single coronary artery myocardial infarction was reported.