Mechanisms and incidence of torsades de pointes tachycardia

NOVOTNÝ, Tomáš. Mechanisms and incidence of torsades de pointes tachycardia. In Marek Malík. Sex and Cardiac Electrophysiology: Differences in Cardiac Electrical Disorders Between Men and Women. 1st edition. Neuveden: Academic Press, 2020, p. 303-308. ISBN 978-0-12-817728-0. Available from: https://dx.doi.org/10.1016/B978-0-12-817728-0.00026-7.

Basic information

• Original name: Mechanisms and incidence of torsades de pointes tachycardia
• Authors: NOVOTNÝ, Tomáš (203 Czech Republic, guarantor, belonging to the institution).
• Edition: 1st edition. Neuveden, Sex and Cardiac Electrophysiology: Differences in Cardiac Electrical Disorders Between Men and Women, p. 303-308, 6 pp. 2020.
• Publisher: Academic Press

Other information

• Original language: English
• Type of outcome: Chapter(s) of a specialized book
• Field of Study: 30201 Cardiac and Cardiovascular systems
• Country of publisher: United Kingdom of Great Britain and Northern Ireland
• Confidentiality degree: is not subject to a state or trade secret
• Publication form: printed version "print"
• WWW: URL
• RIV identification code: RIV/00216224:14110/20:00118093
• Organization unit: Faculty of Medicine
• ISBN: 978-0-12-817728-0
• Doi: http://dx.doi.org/10.1016/B978-0-12-817728-0.00026-7
• Keywords in English: Afterdepolarization; Polymorphic ventricular tachycardia; Re-entry; Sex differences; Torsades de pointes
• Tags: rivok, topvydavatel
• Tags: International impact, Reviewed

Abstract

Torsades de pointes (TdP) is a specific polymorphic ventricular tachycardia related to specific condition – QT interval prolongation in majority of cases. Mechanisms of TdP initiation and perpetuation are still not fully understood and are discussed in detail in this article. TdP is initiated by early afterdepolarizations (EADs). The L-type Ca current (ICa,L) and the Na–Ca exchange current (INCX) are the major currents with potential to create EADs. Density and activity of these currents are influenced by sex hormones which may thus contribute to sex differences in the susceptibility to triggered activity. Female sex was confirmed as an independent risk factor for TdP. In patients with acquired atrioventricular block females developed TdP at QT intervals shorter than males. Thus, there must be other sex specific factors that increase the risk of arrhythmias. In other words, the effect of sex goes beyond the action potential duration. The incidence of TdP is difficult to estimate due to differences in the methodology of a particular study. Nevetheless, it is clearly higher in women.