Association of Atrial Arrhythmia and Sinus Node Dysfunction in Patients With Catecholaminergic Polymorphic Ventricular Tachycardia

Abstract

Statistical AnalysisAll numeric data are presented as the means ± SD. Because of differences in the variables and limited sample numbers, statistic analysis was performed using Wilcoxon nonparametric analysis or chi-square analysis when necessary. A p-value less than 0.05 was considered significant. Circ J 2007; 71: 1606 -1609 (Received May 8, 2007 revised manuscript received June 14, 2007; accepted June 22, 2007 Background This study was performed to investigate the frequency and importance of supraventricular arrhythmia and sinus node (SN) dysfunction in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT). Methods and ResultsEight patients with CPVT (mean age: 16.8±8.1 years) underwent an electrophysiological study. SN recovery time (1,389±394 ms) was slightly prolonged, and 4 of 8 patients had abnormal values. Atrial flutter (AF) was induced by low-rate atrial pacing in 2 patients and by isoproterenol infusion in 1 patient. Atrial fibrillation (Af) was induced by isoproterenol infusion in 2 patients. One patient presented with Af during the follow-up period, and 2 of 4 patients with AF/Af presented with increased SN recovery time.Conclusions Patients with CPVT frequently have associated with SN dysfunction, and inducible atrial tachyarrhythmias, which indicate that the pathogenesis of CPVT is limited not only to the ventricular myocardium, but also to broad regions of the heart, including the SN and atrial muscle. (Circ J 2007; 71: 1606 -1609)

STIM1–Ca 2+ signaling modulates automaticity of the mouse sinoatrial node

“…In addition to ventricular arrhythmias, these patients also develop sinus node dysfunction and bradycardia, which frequently requires permanent pacemaker insertion. Computational studies further reinforce the idea that SAN dysfunction results from leaky RYR2-containing Ca 2+ stores (5). These studies emphasize the importance of Ca 2+ signaling in the automaticity of SANCs.…”

“…S4). Therefore, the reduction in I Ca-L may be due to the depletion of SR Ca 2+ stores in SANCs from cSTIM1 −/− mice, as has been described for SANCs harboring mutations in mouse RyR2 that cause CPVT (5,22,23). We also extended our investigation to include T-type Ca 2+ currents (I Ca-T ).…”

“…Several recent studies show that maintenance of sarcoplasmic reticulum (SR) Ca 2+ stores is critically important for SAN automaticity, as is evident from genetic studies involving patients and mice that have leaky SR Ca 2+ stores (4). Mutations in the ryanodine receptor (RYR2) or calsequestrin genes that result in spontaneous Ca 2+ release cause catecholamiergic polymorphic ventricular tachycardia (CPVT) (5,6). In addition to ventricular arrhythmias, these patients also develop sinus node dysfunction and bradycardia, which frequently requires permanent pacemaker insertion.…”

Catecholaminergic Polymorphic Ventricular Tachycardia in 2012

“…28,49,50 Indeed, CPVT patients may be at increased risk of inappropriate shocks due to CPVT-related supraventricular arrhythmias. 51,52 In 2008, the first three CPVT patients with successful prevention of adrenergically-mediated arrhythmias with left cardiac sympathic denervation (LCSD) were described, some with long-term follow-up. 53 After this, more successful experiences with LCSD in CPVT have been published.…”

From the Ryanodine Receptor to Cardiac Arrhythmias

“…52 As well as ventricular arrhythmias, patients with CPVT also show atrial arrhythmias and sinoatrial node dysfunction. 53 Work on isolated RyRs has shown that the probability that they are open at low cytoplasmic concentrations is greater than for wild-type RyRs. 54,55 It has also been shown that DADs are more likely to occur in cells that express either mutant RyRs or CSQ.…”