Predictors of left ventricular function deterioration in patients with left bundle branch block and ejection fraction >50%.

Resynchronization therapy has become standard of care in patients with left bundle branch block (LBBB), congestive heart failure (CHF), and low ejection fraction (EF). In order to characterize the left ventricular (LV) function evolution in patients with LBBB and baseline preserved LVEF, records of all patients who visited an academic echocardiography laboratory during a period of 4 years were retrospectively investigated. Patients were included if they had a baseline EF >50%, LBBB on surface electrocardiography, and at least one follow-up echocardiogram no earlier than 3 months after the baseline study.

Accelerated junctional rhythm and nonalternans repolarization lability precede ventricular tachycardia in Casq2-/- mice.

Background: Calsequestrin-2 (CASQ2) is a Ca(2+) 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.