Torsades de pointesの3例

Three cases of Torsades de pointes

　Torsades de Pointes （TDP）は，1966年フランスのDessertenne^1）により初めて報告された心室性頻拍症（VT）で，QRS波形群が基線を中心にtwistするように見えるため命名された。TDPは致死的不整脈となりうるため，その臨床的特徴について最近注目されている^2,3）。今回我々は，Disopyramide，および低K血症により誘発されたTDP 3例（表1）を経験したので，その臨床的特徴，心電図所見および治療法について若干の文献的考察を加えて報告する。

Torsades de Pointes is an atypical ventricular tachycardia, a characteristic sinusoidal twisting of QRS complex around the base line, first described by Dessertenne et al in 1966.

Since their orginal description, many literatures including both reviews and case reports have been issued. However, the exact causes, mechanism and its true relation to usual ventricular tachycardia and fibrillation remain to be elucidated. In the present report, three cases of Torsades de Pointes (TDP) were described. All these patients revealed a prolonged QT and QTc interval as has been re-cognized at the occasion of TDP attacks together with low serum potassium concentration. In addi-tion, one had hypertrophic cardiomyopathy (case 1), cholelithiasis (case 2) and uterus cancer (case 3), respectively. Regarding to the treatment, direct current counter shock was applied to terminate the TDP in all 3 cases, the correction of low serum potassium concentration was also done in each case. Lidocaine was ineffective in case 3 to terminate the TDP, while verapamil was effective in case 3 to convert TDP to normal sinus rhythm. In case 2, no antiarrhythmic drugs were applied, however, cardiac massage and normalization of serum potas-sium concentration succeeded to recover normal sinus rhythm.

The diversity of the causes and treatments of TDP in these three cases was discussed in relation to the genesis of TDP.