Accelerated Junctional Rhythm and Nonalternans Repolarization Lability Precede Ventricular Tachycardia in Casq2−/− Mice...Calsequestrin-2
Repolarization Lability in Casq2−/− Mice. Background: Calsequestrin-2 (CASQ2) is a Ca2+ buffering protein of myocardial sarcoplasmic reticulum. CASQ2 mutations underlie a form of catecholaminergic polymorphic ventricular tachycardia (CPVT). The CPVT phenotype is recapitulated in Casq2 −/− mice. Repo...
| Publicado en: | Journal of Cardiovascular Electrophysiology Vol. 23; no. 12; pp. 1355 - 1364 |
|---|---|
| Autores principales: | , , , , , |
| Formato: | equations & formulas research tables/charts tracings Journal Article |
| Publicado: |
Wiley-Blackwell
Dec2012
|
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=84362911&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 84362911 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 10453873 GSB jtl: Journal of Cardiovascular Electrophysiology issn: 10453873 maglogo: Y pubinfo: dt: Dec2012 vid: 23 iid: 12 pid: 480 pub: Wiley-Blackwell place: Malden, Massachusetts artinfo: ui: 84362911 104397804 104397804 10.1111/j.1540-8167.2012.02406.x 84362911 ppf: 1355 ppct: 9 formats: fmt: – @attributes: type: T – @attributes: type: P tig: atl: Accelerated Junctional Rhythm and Nonalternans Repolarization Lability Precede Ventricular Tachycardia in Casq2−/− Mice...Calsequestrin-2 aug: au: MEZU, URE L. SINGH, PRABHPREET SHUSTERMAN, VLADIMIR HWANG, HYUN‐SEOK KNOLLMANN, BJORN C. NĚMEC, JAN affil: Heart and Vascular Institute, School of Medicine, University of Pittsburgh, Pennsylvania, USA sug: subj: Tachycardia, Ventricular Pathology Tachycardia, Ventricular Familial and Genetic Electrocardiography Calcium Binding Proteins Mutation Animal Studies Mice Heart Rate Descriptive Statistics Isoproterenol Administration and Dosage Fisher's Exact Test T-Tests Heart Conduction System Pathology Funding Source Data Analysis Software ab: Repolarization Lability in Casq2−/− Mice. Background: Calsequestrin-2 (CASQ2) is a Ca2+ buffering protein of myocardial sarcoplasmic reticulum. CASQ2 mutations underlie a form of catecholaminergic polymorphic ventricular tachycardia (CPVT). The CPVT phenotype is recapitulated in Casq2 −/− mice. Repolarization lability (RL)-beat-to-beat variability in the T wave morphology-has been reported in long-QT syndrome, but has not been evaluated in CPVT. Methods and Results: ECG from Casq2 −/− mice was evaluated with respect to heart rate (HR) and RL changes prior to onset of ventricular tachycardia (VT) to gain insight into arrhythmogenesis in CPVT. Telemetry from unrestrained mice (3-month-old males, 5 animals of each genotype) and ECG before and after isoproterenol administration in anesthetized mice was analyzed. Average HR in sinus rhythm (SR), occurrence of nonsinus rhythm and RL were quantified. HR was slower in Casq2 −/− animals. Accelerated junctional rhythm (JR) occurred more frequently in Casq2 −/− mice and often preceded VT. In Casq2 −/− mice, HR increased prior to VT onset, prior to onset of JR and on transition from JR to VT. RL increased during progression from SR to VT and after isoproterenol administration in Casq2 −/−, but not in Casq2+/+ animals. Isoproterenol did not increase repolarization alternans in either genotype. Conclusions: Accelerated JR, likely caused by triggered activity in His/Purkinje system, occurs frequently in Casq2 −/− mice. The absence of CASQ2 results in increased RL. The increase in HR and in RL precede onset of arrhythmias in this CPVT model. Nonalternans RL precedes ventricular arrhythmia in wider range of conditions than previously appreciated. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1355-1363, December 2012) pubtype: Academic Journal doctype: equations & formulas research tables/charts tracings Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
|---|