The use of isoproterenol in electrophysiologic drug testing in patients with sustained ventricular tachycardia : the mechanism of action and clinical significance of isoproterenol 持続型心室頻拍の薬効判定におけるイソプロテレノールの有用性についての研究 : イソプロテレノールの作用機序と臨床的意義
The use of isoproterenol in electrophysiologic drug testing in patients with sustained ventricular tachycardia : the mechanism of action and clinical significance of isoproterenol
持続型心室頻拍の薬効判定におけるイソプロテレノールの有用性についての研究 : イソプロテレノールの作用機序と臨床的意義
学位の種類: 博士（医学）. 報告番号: 乙第1307号. 学位記番号: 新大院博（医）乙第1215号. 学位授与年月日: 平成4年4月23日
Acta Medica et Biologica. 1992, 40(1), 35-41.
Isoproterenol has been used in electro-physiologic studies to facilitate the induction of ventricular tachycardia (VT) as well as in drug testing. However, the mechanism of the induction of VT and the clinical significance of the VT induced with isoproterenol have yet to be deternlined. The present study assessed the effects of isoproterenol in the induction of VT during drug testing in 23 patients (34 drug testings), and analyzed the patients'characteristics and electrophysiologic parameters. The standard protocol for inducing VT was used. Sustained monomorphic VT was induced in 15 testings after the use of isoproterenol (ineffective drug testing). In the other 19 testings, sustained VT was not induced even after the use of isoproterenol (effective drug testing). Isoproterenol altered the electrophysiologic parameters in a similar manner in the two testings. However, nonsustained VT was more frequently induced before isoproterenol in the ine汀ective drug testings: 60% vs 16% (P<0.05). This indicates that isoproterenol converted nonsustained VT into sustained VT, implying that isoproterenol improved the conduction within the slow conduction zone, resulting in VT which did not termi-nate spontaneously. Facilitated conduction outside the reentry circuit, namely, the intervening tissue between the stimulation site and the reentry circuit, likely, played a minor role. The majority of patients treated with an effective drug showed no recurrence of VT during the follow-up period.