Journal of Nippon Medical School: Vol.69 No.3 page.218

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ArticleTitle Torsades de Pointes: Unanswered Questions

AuthorList Borys Surawicz

Affiliation Krannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis, Indiana

Language EN

Volume 69

Issue 3

Year 2002

Page 218-223

Received February 12, 2002

Accepted February 20, 2002

Keywords dispersion of repolarization, early after depolarizations, long QT, gender gap of repolarization

Abstract
Torsade de pointes (Tdp) is a polymorphic ventricular tachycardia (VT) in which the axis of the QRS complex changes direction after a certain number of complexes as if the complex rotated around the baseline. Tdp is usually associated with QT prolongation, and dispersion of ventricular repolarlization (DR). Experimental models of tdp are usually associated with induction of early after depolarizations (EADs). Several aspects of the pathogenesis of tdp are incompletely understood. The purpose of this article is to propose the directions in research that may increase our current understanding of the factors responsible for tdp.

The most plausible hypotheses requiring further supporting evidence are: 1. The occurrence of tdp requires the presence of DR i.e. tdp does not occur in the absence of DR. 2. EADs appear to play an important role as a trigger to tdp in the animal models, but more evidence are needed at the clinical level. 3. EADs may be responsible for arrhythmias other than tdp. 4. The greater incidence of tdp in the females than in tha males may be attributed to differences in the duration of the QT interval and different morphology of the ST-segment and the T-wave. The above gender differences may be caused by the effects of gonadal hormones which modulate some of the membrane currents flowing during early ventricular repolarization.

Correspondence to Borys Surawicz, M.D., M. A. C. C., 8333 Naab Rd, Suite 400. Indianapolis, IN 46260
tscott@thecaregroup.com

ArticleTitle	Torsades de Pointes: Unanswered Questions
AuthorList	Borys Surawicz
Affiliation	Krannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis, Indiana
Language	EN
Volume	69
Issue	3
Year	2002
Page	218-223
Received	February 12, 2002
Accepted	February 20, 2002
Keywords	dispersion of repolarization, early after depolarizations, long QT, gender gap of repolarization
Abstract	Torsade de pointes (Tdp) is a polymorphic ventricular tachycardia (VT) in which the axis of the QRS complex changes direction after a certain number of complexes as if the complex rotated around the baseline. Tdp is usually associated with QT prolongation, and dispersion of ventricular repolarlization (DR). Experimental models of tdp are usually associated with induction of early after depolarizations (EADs). Several aspects of the pathogenesis of tdp are incompletely understood. The purpose of this article is to propose the directions in research that may increase our current understanding of the factors responsible for tdp. The most plausible hypotheses requiring further supporting evidence are: 1. The occurrence of tdp requires the presence of DR i.e. tdp does not occur in the absence of DR. 2. EADs appear to play an important role as a trigger to tdp in the animal models, but more evidence are needed at the clinical level. 3. EADs may be responsible for arrhythmias other than tdp. 4. The greater incidence of tdp in the females than in tha males may be attributed to differences in the duration of the QT interval and different morphology of the ST-segment and the T-wave. The above gender differences may be caused by the effects of gonadal hormones which modulate some of the membrane currents flowing during early ventricular repolarization.
Correspondence to	Borys Surawicz, M.D., M. A. C. C., 8333 Naab Rd, Suite 400. Indianapolis, IN 46260 tscott@thecaregroup.com