α1-blockerが有効であった難治性冠攣縮性狭心症の1例

A Case of Refractory Vasospastic Angina in which α1-blocker was Effective

　症例は45歳，女性．主訴：前胸部痛．既往歴：気管支喘息．現病歴：1995年夏より，午前2時から3時頃に時々前胸部痛を感じていた．1カ月前より発作が頻発するようになったため来院した．発作時に心電図上，II,III,aV_FにST上昇を認めたため，冠攣縮性狭心症の診断で入院した．心臓カテーテル検査で，右冠動脈と左冠動脈の複数の部位に冠攣縮が出現，消褪を繰り返した．亜硝酸剤，K-channel開口薬，Ca-antagonistによる治療を試みたが無効，β₁-stimulantも併用したが発作はコントロールできなかった．更にα₁-blockerの追加投与を試みたところ，発作の頻度は減少した．本症例ではα₁-blockerの追加投与が発作の軽減に有効であった．

A 45-year-old woman had suffered from frequent anginal episodes. She was treated with isosorbide dinitrate, nicorandil and diltiazem, which were ineffective. During coronary angiography, she had an-ginal attacks with ST elevation in II, III, aV_F leads. Simultaneously her right coronary artery, # 1 was ob-structed. Intracoronary injection of isosorbide dinitrate was effective. We diagnosed her complaint as variantangina. Since prazosin therapy was initiated, freqency of the attacks diminished. Coronary artery vasoconstric-tion is mediated via adrenergic α receptors. So prazosin, α₁-blocker has possible effectivity against vasospasm. Prazosin therapy chould be tried in refractory variant angina.