| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
(Circulation. 2002;105:1247.)
© 2002 American Heart Association, Inc.
Basic Science Reports |
From the Heart and Vascular Research Center and Departments of Medicine and Biomedical Engineering (F.G.A., D.S.R.), MetroHealth Campus, Case Western Reserve University, Cleveland, Ohio, and Masonic Medical Research Laboratory (G.-X.Y., C.A.), Utica, NY.
Correspondence to David S. Rosenbaum, MD, Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, 2500 MetroHealth Dr, Hamann 322, Cleveland, OH 44109-1998. E-mail drosenbaum{at}metrohealth.org
Background Specific ion channel mutations underlie the congenital long-QT syndrome (LQTS). However, the mechanisms by which dysfunction at the molecular level translates into functional electrical instability leading to torsade de pointes (TdP) in LQTS are poorly understood.
Methods and Results The cellular basis of TdP was investigated using a novel approach of transmural optical imaging in the canine wedge preparation (n=14). The spatial organization of repolarization and arrhythmogenesis were determined in a surrogate model of LQT2. Action potentials were recorded simultaneously from 128 sites spanning the transmural wall of the left ventricle. In LQT2, QT interval prolongation was paralleled by an abrupt rise in transmural dispersion of repolarization (DOR) from 2.7±0.9 ms/mm (controls) to 12.2±2.1 ms/mm (LQT2). Islands of midmyocardial (M) cells formed zones of increased refractoriness in LQT2, producing steep spatial gradients of repolarization that were directly responsible for conduction block and self-sustained intramural reentrant circuits underlying TdP.
Conclusions These data provide direct evidence supporting the functional expression of M cells in intact myocardium and a central role for M cells in the development of reentrant TdP arrhythmias in LQTS.
Key Words: torsades de pointes action potentials arrhythmia ion channels mapping
This article has been cited by other articles:
![]() |
S. Poelzing and D. S. Rosenbaum The Modulated Dispersion Hypothesis Confirmed in Humans Circ Arrhythmia Electrophysiol, April 1, 2009; 2(2): 100 - 101. [Full Text] [PDF] |
||||
![]() |
C. Antzelevitch Role of spatial dispersion of repolarization in inherited and acquired sudden cardiac death syndromes Am J Physiol Heart Circ Physiol, October 1, 2007; 293(4): H2024 - H2038. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Michailova, W. Lorentz, and A. McCulloch Modeling transmural heterogeneity of KATP current in rabbit ventricular myocytes Am J Physiol Cell Physiol, August 1, 2007; 293(2): C542 - C557. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. G. Akar, R. D. Nass, S. Hahn, E. Cingolani, M. Shah, G. G. Hesketh, D. DiSilvestre, R. S. Tunin, D. A. Kass, and G. F. Tomaselli Dynamic changes in conduction velocity and gap junction properties during development of pacing-induced heart failure Am J Physiol Heart Circ Physiol, August 1, 2007; 293(2): H1223 - H1230. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Jeyaraj, L. D. Wilson, J. Zhong, C. Flask, J. E. Saffitz, I. Deschenes, X. Yu, and D. S. Rosenbaum Mechanoelectrical Feedback as Novel Mechanism of Cardiac Electrical Remodeling Circulation, June 26, 2007; 115(25): 3145 - 3155. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. N. Sabir, M. J. Killeen, C. A. Goddard, G. Thomas, S. Gray, A. A. Grace, and C. L.-H. Huang Transient alterations in transmural repolarization gradients and arrhythmogenicity in hypokalaemic Langendorff-perfused murine hearts J. Physiol., May 15, 2007; 581(1): 277 - 289. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. T. Morita, D. P. Zipes, H. Morita, and J. Wu Analysis of action potentials in the canine ventricular septum: No phenotypic expression of M cells Cardiovasc Res, April 1, 2007; 74(1): 96 - 103. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. R. Mills, N. Mal, F. Forudi, Z. B. Popovic, M. S. Penn, and K. R. Laurita Optical mapping of late myocardial infarction in rats Am J Physiol Heart Circ Physiol, March 1, 2006; 290(3): H1298 - H1306. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Jespersen, M. Grunnet, and S.-P. Olesen The KCNQ1 Potassium Channel: From Gene to Physiological Function Physiology, December 1, 2005; 20(6): 408 - 416. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Shah, F. G. Akar, and G. F. Tomaselli Molecular Basis of Arrhythmias Circulation, October 18, 2005; 112(16): 2517 - 2529. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. M. Nerbonne and R. S. Kass Molecular Physiology of Cardiac Repolarization Physiol Rev, October 1, 2005; 85(4): 1205 - 1253. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Schimpf, C. Wolpert, F. Gaita, C. Giustetto, and M. Borggrefe Short QT syndrome Cardiovasc Res, August 15, 2005; 67(3): 357 - 366. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. D. Spragg, F. G. Akar, R. H. Helm, R. S. Tunin, G. F. Tomaselli, and D. A. Kass Abnormal conduction and repolarization in late-activated myocardium of dyssynchronously contracting hearts Cardiovasc Res, July 1, 2005; 67(1): 77 - 86. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. G. Akar, R. C. Wu, G. J. Juang, Y. Tian, M. Burysek, D. DiSilvestre, W. Xiong, A. A. Armoundas, and G. F. Tomaselli Molecular mechanisms underlying K+ current downregulation in canine tachycardia-induced heart failure Am J Physiol Heart Circ Physiol, June 1, 2005; 288(6): H2887 - H2896. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Pathak, D. Curnier, J. Fourcade, J. Roncalli, P. K. Stein, P. Hermant, M. Bousquet, P. Massabuau, J.-M. Senard, J.-L. Montastruc, et al. QT dynamicity: a prognostic factor for sudden cardiac death in chronic heart failure Eur J Heart Fail, March 2, 2005; 7(2): 269 - 275. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Milberg, N. Reinsch, K. Wasmer, G. Monnig, J. Stypmann, N. Osada, G. Breithardt, W. Haverkamp, and L. Eckardt Transmural dispersion of repolarization as a key factor of arrhythmogenicity in a novel intact heart model of LQT3 Cardiovasc Res, February 1, 2005; 65(2): 397 - 404. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. E. Clancy and R. S. Kass Inherited and Acquired Vulnerability to Ventricular Arrhythmias: Cardiac Na+ and K+ Channels Physiol Rev, January 1, 2005; 85(1): 33 - 47. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. N. Healy and A. D. McCulloch An ionic model of stretch-activated and stretch-modulated currents in rabbit ventricular myocytes Europace, January 1, 2005; 7(s2): S128 - S134. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Extramiana and C. Antzelevitch Amplified Transmural Dispersion of Repolarization as the Basis for Arrhythmogenesis in a Canine Ventricular-Wedge Model of Short-QT Syndrome Circulation, December 14, 2004; 110(24): 3661 - 3666. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. J. Saucerman, S. N. Healy, M. E. Belik, J. L. Puglisi, and A. D. McCulloch Proarrhythmic Consequences of a KCNQ1 AKAP-Binding Domain Mutation: Computational Models of Whole Cells and Heterogeneous Tissue Circ. Res., December 10, 2004; 95(12): 1216 - 1224. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Ueda, D. P. Zipes, and J. Wu Functional and transmural modulation of M cell behavior in canine ventricular wall Am J Physiol Heart Circ Physiol, December 1, 2004; 287(6): H2569 - H2575. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. G. Akar, D. D. Spragg, R. S. Tunin, D. A. Kass, and G. F. Tomaselli Mechanisms Underlying Conduction Slowing and Arrhythmogenesis in Nonischemic Dilated Cardiomyopathy Circ. Res., October 1, 2004; 95(7): 717 - 725. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Poelzing and D. S. Rosenbaum Altered connexin43 expression produces arrhythmia substrate in heart failure Am J Physiol Heart Circ Physiol, October 1, 2004; 287(4): H1762 - H1770. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Burashnikov, S. Mannava, and C. Antzelevitch Transmembrane action potential heterogeneity in the canine isolated arterially perfused right atrium: effect of IKr and IKur/Ito block Am J Physiol Heart Circ Physiol, June 1, 2004; 286(6): H2393 - H2400. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. Libbus, X. Wan, and D. S. Rosenbaum Electrotonic load triggers remodeling of repolarizing current Ito in ventricle Am J Physiol Heart Circ Physiol, May 1, 2004; 286(5): H1901 - H1909. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Poelzing, F. G. Akar, E. Baron, and D. S. Rosenbaum Heterogeneous connexin43 expression produces electrophysiological heterogeneities across ventricular wall Am J Physiol Heart Circ Physiol, May 1, 2004; 286(5): H2001 - H2009. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. M. Roden Drug-Induced Prolongation of the QT Interval N. Engl. J. Med., March 4, 2004; 350(10): 1013 - 1022. [Full Text] [PDF] |
||||
![]() |
R. P. Katra, E. Pruvot, and K. R. Laurita Intracellular calcium handling heterogeneities in intact guinea pig hearts Am J Physiol Heart Circ Physiol, February 1, 2004; 286(2): H648 - H656. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Kimura, T. Kobayashi, S. Owada, K. Ashikaga, T. Higuma, S. Sasaki, A. Iwasa, S. Motomura, and K. Okumura Mechanism of ST Elevation and Ventricular Arrhythmias in an Experimental Brugada Syndrome Model Circulation, January 6, 2004; 109(1): 125 - 131. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Smetana, V. N. Batchvarov, K. Hnatkova, A. J. Camm, and M. Malik Ventricular gradient and nondipolar repolarization components increase at higher heart rate Am J Physiol Heart Circ Physiol, January 1, 2004; 286(1): H131 - H136. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. M. Roden A Surprising New Arrhythmia Mechanism in Heart Failure Circ. Res., October 3, 2003; 93(7): 589 - 591. [Full Text] [PDF] |
||||
![]() |
F. G. Akar and D. S. Rosenbaum Transmural Electrophysiological Heterogeneities Underlying Arrhythmogenesis in Heart Failure Circ. Res., October 3, 2003; 93(7): 638 - 645. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. M. Di Diego, L. Belardinelli, and C. Antzelevitch Cisapride-Induced Transmural Dispersion of Repolarization and Torsade de Pointes in the Canine Left Ventricular Wedge Preparation During Epicardial Stimulation Circulation, August 26, 2003; 108(8): 1027 - 1033. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. R. Laurita, R. Katra, B. Wible, X. Wan, and M. H. Koo Transmural Heterogeneity of Calcium Handling in Canine Circ. Res., April 4, 2003; 92(6): 668 - 675. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. D. Booker, S. D. Whyte, and E. J. Ladusans Long QT syndrome and anaesthesia Br. J. Anaesth., March 1, 2003; 90(3): 349 - 366. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Wu and D. P. Zipes Transmural reentry triggered by epicardial stimulation during acute ischemia in canine ventricular muscle Am J Physiol Heart Circ Physiol, November 1, 2002; 283(5): H2004 - H2011. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Antzelevitch Sympathetic modulation of the long QT syndrome Eur. Heart J., August 2, 2002; 23(16): 1246 - 1252. [PDF] |
||||
|
Circulation Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 2002 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |