右冠動脈の解離性動脈瘤による急性心筋梗塞症の1剖検例

A autopsy case of primary dissecting aneurysm of right coronary artery

　心筋虚血を生ずる各種病態のうち，冠動脈の原発性解離性動脈瘤は極めて稀な病因とされてきた。Pretty,H．C．^1）以来文献上報告されてきた症例を56例^1〜43）見い出し得た。従来の報告^{20,29,34,35）}では若年成人で，とくに女に多く，産褥に比較的見られるとされてきたが，その原因は未だ明らかではない。著者らは高齢男性例を経験したので文献考察とともに報告する。

A eighty year old man was admitted to our hospital because of dyspnea and chest pain. He was treated as inpending myocardial infarction despite of absence of pathologic Q wave and elevated ST on the electrocardiogram. On second day he was observed signs of pulmonary edema and ECG recordings of intraventricular conduction disturb-ance. On third day he died shortly after he had showed electrocardiographic findings of acute inferior infarction.

At autopsy, his heart (320 g) was evidenced acute inferior myocardial infarction caused with primary dissecting aneurysm of right coronary artery, having advanced atherosclerosis, consisted with foam cell aggregation, cholesterin crystal and severe intimal thicking. Intramural hematoma with mural dissec-tion, being marked luminal dilatation like as aneurysm, located at subintimal to medial site in the coronary artery, and was filled with red blood cells, fibrin exudation and numerous neutrophilic leukocytes.

An isolated intramural dissecting aneurysm of the coronary artery is a very rare lesion. Approx-imately 56 caes of this lesion have been previously documented in the literatures, and eight of these cases was collected in Japanese. Most cases were women and died suddenly. Commonly, the lesion of intramural dissection located at medial to adventitial sites of the coronary artery in our review.