Cellular Biology Local -Adrenergic Stimulation Overcomes Source-Sink Mismatch to Generate Focal Arrhythmia
نویسندگان
چکیده
junction uncoupling with carbenoxolone (25 mol/L) increased focal activity (2.18 1.43 versus 1.33 1.46 PVCs per injection, P<0.05), which further supports source-sink balance as a critical mediator of Ca -induced PVCs. Conclusions: These data provide the first experimental demonstration that localized -adrenergic receptor stimulation produces spatiotemporal synchronization of sarcoplasmic reticulum Ca overload and release in the intact heart
منابع مشابه
Local β-adrenergic stimulation overcomes source-sink mismatch to generate focal arrhythmia.
RATIONALE β-Adrenergic receptor stimulation produces sarcoplasmic reticulum Ca(2+) overload and delayed afterdepolarizations in isolated ventricular myocytes. How delayed afterdepolarizations are synchronized to overcome the source-sink mismatch and produce focal arrhythmia in the intact heart remains unknown. OBJECTIVE To determine whether local β-adrenergic receptor stimulation produces spa...
متن کاملSodium Current Reduction Unmasks a Structure-Dependent Substrate for Arrhythmogenesis in the Normal Ventricles
BACKGROUND Organ-scale arrhythmogenic consequences of source-sink mismatch caused by impaired excitability remain unknown, hindering the understanding of pathophysiology in disease states like Brugada syndrome and ischemia. OBJECTIVE We sought to determine whether sodium current (INa) reduction in the structurally normal heart unmasks a regionally heterogeneous substrate for the induction of ...
متن کاملSynchronous systolic subcellular Ca2+-elevations underlie ventricular arrhythmia in drug-induced long QT type 2.
BACKGROUND Repolarization delay is a common clinical problem, which can promote ventricular arrhythmias. In myocytes, abnormal sarcoplasmic reticulum Ca(2+)-release is proposed as the mechanism that causes early afterdepolarizations, the cellular equivalent of ectopic-activity in drug-induced long-QT syndrome. A crucial missing link is how such a stochastic process can overcome the source-sink ...
متن کاملRemodeling of cardiac passive electrical properties and susceptibility to ventricular and atrial arrhythmias
Coordinated electrical activation of the heart is essential for the maintenance of a regular cardiac rhythm and effective contractions. Action potentials spread from one cell to the next via gap junction channels. Because of the elongated shape of cardiomyocytes, longitudinal resistivity is lower than transverse resistivity causing electrical anisotropy. Moreover, non-uniformity is created by c...
متن کاملSource-Sink Mismatch Causing Functional Conduction Block in Re-Entrant Ventricular Tachycardia
Ventricular tachycardia (VT) caused by a re-entrant circuit is a life-threatening arrhythmia that at present cannot always be treated adequately. A realistic model of re-entry would be helpful to accurately guide catheter ablation for interruption of the circuit. In this review, models of electrical activation wavefront propagation during onset and maintenance of re-entrant VT are discussed. In...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2012