冠攣縮性狭心症例において病変形態と冠攣縮の関係を血管内エコーにて評価しえた1例

A Case of Vasospastic Angina in which the Relationship between Plaque Morphology and Spams is Assessed by Intravascular Ultrasound

　症例は68歳，男性．冠攣縮性狭心症にて入退院を繰り返していた．入院後のアセチルコリン負荷冠動脈造影ではV_1-4誘導のST上昇と前下行枝の閑塞を認め，血管内エコーでは攣縮部位に全周性のプラークとその一部に高輝度のプラークを認め，攣縮にてプラークの収縮による内腔狭小化を認め，特にその反応は高輝度プラーク部で大であった．攣縮遠位部では中膜からの血管全体の収縮により内腔は虚脱していた．以上，血管内エコーは動脈壁性状と攣縮の関係を評価するのに有用であった．

Intravascular ultrasound imaging was performed in a patient with variant angina undergoing coronary angio-graphy. Vasospasms were provoked by Achetilcholine.ECG showed ST elevation in V_1-4 lead and left ascend-ing artery obstruction was showen by coronary angio- graphy. Non-calcific circumferential lesions with high and soft echo densities were observed by IVUS. Lumen diameters were decreased by thickened lesions, espe-cially those with high echo density after Achetilcholine. In distal lesions, thin and soft circumferential plaques were observed and the lumen was obstructed due todecrease in total vessel constriction. IVUS was a useful method for documenting the relationship between plaque morphology and vasomotion. This suggests that mixed stages of atherosclerosis are associated with vasospasms in variant angina.