Abstract
Long QT2 (LQT2) syndrome is characterized by bifid (or notched) T waves, whose mechanism is not understood. The purpose of this study was to test whether increased interventricular dispersion of repolarization induces bifid T waves. We simultaneously recorded surface ECG and unipolar electrograms at baseline and after dofetilide in a canine model of dofetilide-induced LQT2 (6 male mongrel dogs). Standard ECG variables, T-wave duration, and moments of peaks of bifid T waves (Tp1 and Tp2) were correlated with moments of local repolarization. Epicardial electrograms were recorded over the left ventricular (LV) and right ventricular (RV) anterior walls (11 × 11 electrode grid, 5-mm interelectrode distance). In 5 of the 6 hearts, we also recorded intramural unipolar electrograms (n = 4-7 needles per heart). In each unipolar recording, we determined activation time, repolarization time (RTs), and activation-recovery interval. In addition, we studied RT response to heart rate changes. Dofetilide prolonged QT and QTc, induced bifid T waves in 4 of 6 animals, and prolonged RT heterogeneously in LV and RV, resulting in increased interventricular and LV intraventricular RT dispersion. Dofetilide did not induce a disparate response in acti...Continue Reading
References
Sep 1, 1988·Progress in Cardiovascular Diseases·W M JackmanR Lazzara
Apr 1, 1968·Circulation·K Millar, J A Abildskov
Nov 1, 1983·Journal of the American College of Cardiology·G N KayA L Waldo
Nov 15, 1995·Circulation·A J MossM H Lehmann
Apr 21, 1995·Cell·M C SanguinettiM T Keating
Mar 10, 1995·Cell·M E CurranM T Keating
Oct 10, 1997·Circulation·W Shimizu, C Antzelevitch
Nov 3, 1998·Circulation·G X Yan, C Antzelevitch
Jan 20, 1999·Circulation·P G VoldersM A Vos
Jul 22, 1999·Annals of the New York Academy of Sciences·M C Sanguinetti
Nov 22, 2000·Circulation·J P Mounsey, J P DiMarco
Jan 11, 2000·Circulation·L ZhangA Medina
Sep 3, 2002·Computer Methods and Programs in Biomedicine·Mark PotseCornelis A Grimbergen
May 21, 2003·Circulation·Paul G A VoldersMarc A Vos
Oct 1, 1959·British Heart Journal·W EVANS
Feb 6, 2004·Journal of Cardiovascular Electrophysiology·Michael R Franz
Apr 27, 2005·Heart Rhythm : the Official Journal of the Heart Rhythm Society·Jørgen K KantersMichael Christiansen
Sep 15, 2005·Circulation·Michiel J JanseMichael R Rosen
Feb 21, 2006·Journal of the American College of Cardiology·David J TesterMichael J Ackerman
Aug 29, 2006·Medical & Biological Engineering & Computing·J J StruijkE Toft
Sep 2, 2006·Heart Rhythm : the Official Journal of the Heart Rhythm Society·Ruben CoronelMichiel J Janse
Feb 9, 2007·Annals of Noninvasive Electrocardiology : the Official Journal of the International Society for Holter and Noninvasive Electrocardiology, Inc·Norbert JostAndrás Varró
Jul 8, 2008·British Journal of Pharmacology·T M HaushalterA S Bass
Jun 30, 2009·Italian Journal of Pediatrics·Maria Pia CalabròGiuseppe Oreto
Apr 23, 2011·Circulation. Arrhythmia and Electrophysiology·Hitoshi HorigomeMasao Yoshinaga
Citations
Jun 5, 2016·Cardiac Electrophysiology Clinics·Fatemah Shenasa, Mohammad Shenasa
May 26, 2016·Progress in Biophysics and Molecular Biology·Bas J BoukensRuben Coronel
Dec 31, 2016·PloS One·Lars JohannesenDavid G Strauss
Jul 15, 2017·Acta Physiologica·O E Osadchii
Nov 8, 2018·Annals of Noninvasive Electrocardiology : the Official Journal of the International Society for Holter and Noninvasive Electrocardiology, Inc·Jason A ThomasLarisa G Tereshchenko
Mar 4, 2020·PloS One·Daniel RomeroAlfredo I Hernández
Sep 10, 2020·Frontiers in Physiology·Marianna MeoRémi Dubois
Oct 9, 2020·Heart Rhythm : the Official Journal of the Heart Rhythm Society·Mathilde R RivaudRuben Coronel
May 14, 2021·Frontiers in Physiology·Valerie Y H van WeperenMarc A Vos
Oct 29, 2021·Medical & Biological Engineering & Computing·Daniel RomeroAlfredo Hernández