Effect of epicardial or biventricular pacing to prolong QT interval and increase transmural dispersion of repolarization

Medina‐Ravell, Victor; Lankipalli, Ramarao S.; Yan, Gan‐Xin

doi:10.1016/s1062-1458(03)00205-8

Cited by 15 publications

(11 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, increased transmural heterogeneity of APD and the resultant dispersion of repolarization have been reported as important factors in arrhythmogenesis under a range of pathophysiological circumstances (2). In experiments using intracellular microelectrodes to record from the endo-and epicardium of rabbit ventricular wedge preparations, no difference in APD was detected between endo-and epicardial stimulation at a cycle length of 2,000 ms (27). Similar results have been reported in canine ventricular wedge preparations (14).…”

Section: Effect Of Activation Sequence On Apd 90 and Repolarizationsupporting

confidence: 77%

Effect of activation sequence on transmural patterns of repolarization and action potential duration in rabbit ventricular myocardium

Myles

Bernus

Burton

et al. 2010

American Journal of Physiology-Heart and Circulatory Physiology

View full text Add to dashboard Cite

Myles RC, Bernus O, Burton FL, Cobbe SM, Smith GL. Effect of activation sequence on transmural patterns of repolarization and action potential duration in rabbit ventricular myocardium. Am J Physiol Heart Circ Physiol 299: H1812-H1822, 2010. First published October 1, 2010; doi:10.1152/ajpheart.00518.2010.-Although transmural heterogeneity of action potential duration (APD) is established in single cells isolated from different tissue layers, the extent to which it produces transmural gradients of repolarization in electrotonically coupled ventricular myocardium remains controversial. The purpose of this study was to examine the relative contribution of intrinsic cellular gradients of APD and electrotonic influences to transmural repolarization in rabbit ventricular myocardium. Transmural optical mapping was performed in left ventricular wedge preparations from eight rabbits. Transmural patterns of activation, repolarization, and APD were recorded during endocardial and epicardial stimulation. Experimental results were compared with modeled data during variations in electrotonic coupling. A transmural gradient of APD was evident during endocardial stimulation, which reflected differences previously seen in isolated cells, with the longest APD at the endocardium and the shortest at the epicardium (endo: 165 Ϯ 5 vs. epi: 147 Ϯ 4 ms; P Ͻ 0.05). During epicardial stimulation, this gradient reversed (epi: 162 Ϯ 4 vs. endo: 148 Ϯ 6 ms; P Ͻ 0.05). In both activation sequences, transmural repolarization followed activation and APD shortened along the activation path such that significant transmural gradients of repolarization did not occur. This correlation between transmural activation time and APD was recapitulated in simulations and varied with changes in intercellular coupling, confirming that it is mediated by electrotonic current flow between cells. These data suggest that electrotonic influences are important in determining the transmural repolarization sequence in rabbit ventricular myocardium and that they are sufficient to overcome intrinsic differences in the electrophysiological properties of the cells across the ventricular wall. action potential remodeling; electrophysiology TRANSMURAL DIFFERENCES in cellular electrophysiology are known to exist in mammalian ventricular myocardium (13,47). In studies of isolated ventricular myocytes, endocardial cells display an action potential duration (APD) that is consistently longer than that of epicardial cells (9,26,28,51). Furthermore, ventricular M cells with distinct electrophysiological characteristics have been identified in the midmyocardium of some mammals, including rabbit (26), dog (40), and human (10,19). At slow stimulation rates, M cells display an APD that is much longer than cells isolated from either epi-or endocardial regions. The dominant influence of these cellular electrophysiological heterogeneities in intact myocardium has been suggested by studies using microelectrode recordings from three regions on the transmural surface of isolated canine ve...

show abstract

Section: Effect Of Activation Sequence On Apd 90 and Repolarizationsupporting

confidence: 77%

Effect of activation sequence on transmural patterns of repolarization and action potential duration in rabbit ventricular myocardium

Myles

Bernus

Burton

et al. 2010

American Journal of Physiology-Heart and Circulatory Physiology

View full text Add to dashboard Cite

show abstract

“…4) in our series presented with polymorphic VT, and such an arrhythmia has been described in case reports. 22 Our retrospective observational study suggests that ventricular proarrhythmia after CRT is a rare but potentially serious problem. In contrast to prior studies, most of our patients had monomorphic rather than polymorphic VT.…”

Section: Discussionmentioning

confidence: 90%

“…Proarrhythmic effects of RV apical pacing have been described, 19 and there are few case reports of occurrence of polymorphic VT after biventricular pacing. 21,22 To our knowledge, this is the first case series describing precipitation of ventricular tachyarrhythmias, primarily monomorphic VT, after initiation of biventricular pacing.…”

Section: Discussionmentioning

confidence: 91%

Potential proarrhythmic effect of biventricular pacing: Fact or myth?

et al. 2005

View full text Add to dashboard Cite

“…The mechanism triggering ventricular arrhythmias might involve a reversal of the normal sequence of activation of the ventricular myocardium: this alteration prolongs the QT interval and increases the transmural dispersion of repolarisation, creating a substrate for re-entrant arrhythmias [10,11]. Another hypothesis is that the CS (coronary sinus) lead may be located close to the critical isthmus of the VT circuit, resulting in the possibility of sustained re-entry.…”

Section: Discussionmentioning

confidence: 99%

The beneficial effect of biventricular pacing on ventricular tachycardia in a patient with non-ischemic cardiomyopathy

Nicoletti

Tomei

Zanotto

et al. 2008

International Journal of Cardiology

View full text Add to dashboard Cite

Effect of epicardial or biventricular pacing to prolong QT interval and increase transmural dispersion of repolarization

Cited by 15 publications

References 22 publications

Effect of activation sequence on transmural patterns of repolarization and action potential duration in rabbit ventricular myocardium

Effect of activation sequence on transmural patterns of repolarization and action potential duration in rabbit ventricular myocardium

Potential proarrhythmic effect of biventricular pacing: Fact or myth?

The beneficial effect of biventricular pacing on ventricular tachycardia in a patient with non-ischemic cardiomyopathy

Contact Info

Product

Resources

About