gms | German Medical Science

33rd International Congress on Electrocardiology

International Society of Electrocardiology

Characterization Of Electrocardiographic Phenotype In Kcnq1 Mutant Mice

Meeting Abstract

  • corresponding author presenting/speaker M. Kuwahara - University of Tokyo, Tokyo, Japan
  • T. Yagi - University of Tokyo, Tokyo, Japan
  • K. Ito - University of Tokyo, Tokyo, Japan
  • K. Nishino - Osaka Medical College, Osaka, Japan
  • K. Suzuki - Osaka Medical College, Osaka, Japan
  • H. Tsubone - University of Tokyo, Tokyo, Japan

33rd International Congress on Electrocardiology. Cologne, 28.06.-01.07.2006. Düsseldorf, Köln: German Medical Science; 2007. Doc06ice050

The electronic version of this article is the complete one and can be found online at:

Published: February 8, 2007

© 2007 Kuwahara et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Question: Long QT syndrome (LQTS) is a disorder of ventricular repolarization, characterized by ECGs with prolonged QT intervals and T-wave abnormalities. LQTS can result in syncope, seizure, and sudden death as a result of torsades de pointes cardiac arrhythmias. Kcnq1 encodes Kcnq1, which belongs to a family of voltage-dependent K+ ion channel proteins. Loss-of-function mutations in human Kcnq1 gene have been linked to one of inherited forms of LQTS so called Jervell and Lange-Nielsen Syndrome (JLNS). Although there are a few studies to targeted disruption of the Kcnq1 gene mouse model, it is still controversy of a cardiac phenotype in these animals. Because another type of mutant mouse (C3H/HeJCrl-Kcnq1vtg-2J/J mice) that disrupt the Kcnq1 gene has recently been reported, we evaluated the cardiac phenotype of this mouse with ECGs analysis.

Method-used: Wild-type, heterozygous and homozygous mutant females of similar age (2-3 months) were anesthetized with 25 mg/kg pentobarbital via i.p. injection and placed in a prone position on a heated matte. Standard limb lead ECG was recorded and analyzed with ECG processor (Softron).

Results: Homozygous mice displayed increases in most ECG parameters, although no differences in heart rate were observed. The most striking change in homozygous mice occurred in the morphology of the T-wave. The amplitude of the T-wave in homozygous mice was doubled relative to the control mice. The QT interval and QTc interval were significantly prolonged in homozygous mice. These data indicated that ventricular repolarization was altered in homozygous mice.

Conclusions: These results suggest that this mouse is a potentially valuable animal model of JLNS.