"発作性上室性頻拍"例における塩酸ジルチアゼム静注の効果

Effect of diltiazem on patients with paroxysmal reentrant supraventricular tachycardia

　Ca拮抗薬のうち，ベラパミルは，Vaughan Williamsの抗不整脈剤分類のIV群に位置しており，主に上室性頻拍症に有効であることが報告_1〜8）されている。

　一方，本邦で開発されたCa拮抗薬であるジルチアゼムにも，ベラパミルと同様の抗不整脈作用のあることが実験的には確認されているが，ジルチアゼムの臨床例に対する検討はいまだ少ない_9〜11）。

To evaluate the efficacy diltiazem, a potent slow channel blocker, in the termination and prevention of tachycardia, we performed electrophysiological study before and after the intravenous administration of diltia-zem in 20 patients with paroxysmal reentrant supra-ventricular tachycardia. In 10 patients dual AV nodal pathways were proved. In the other 10 patients a con-cealed accessory atrio-ventricular pathway was demon-strated. Diltiazem in amount of 10 or 20 mg were given intravenously in all 20 patients during sustained AV nodal reentrant tachycardia (AVNRT) or AV reentrant tachycardia (AVRT). AVNRT was successfully termi-nated in 9 out of 10 patients. In 5 patients antegrade slow AV nodal pathway was blocked and retrograde fast AV nodal pathway was blocked in other 4 patients. Intravenous diltiazem administration increased tachy-cardia cycle lengths from 346±24 msec (mean±SD) to 405±28 msec by prolonging mainly antegrade AH conduction. Initiation of tachycardia was not successful after diltiazem administration in all patients with AVNRT. Diltiazem administration successfully termi-nated in S of 10 patients by blocking antegrade AH conduction. Tachycardia cycle lengths were increased from 313±48 msec to 394±49 msec. After diltiazem administration, it was unable to initiate tachycardia in 7 patients. No overt adverse effects were noted with diltiazem administration. Diltiazem seems to be clini-cally useful for termination and prevention of paroxy-smal reentrant supraventricular tachycardia.