Outcome in patients undergoing upgrade to cardiac resynchronization therapy: predictors of outcome after upgrade to CRT.

The advantages of upgrade to cardiac resynchronisation therapy (CRT) have not been explored as carefully as the outcomes of de novo CRT implantations. Furthermore selection criteria for patients with the potential to benefit the most from this therapy are unknown. Therefore, we analyzed the long term outcome and its predictors in a real-world cohort receiving a CRT upgrade from previous pacemaker (PM) and defibrillator devices (ICD).

Ventriculoatrial conduction and related pacemaker-mediated arrhythmias in patients implanted for atrioventricular block: an old problem revisited.

Introduction: Ventriculoatrial (VA) conduction and related pacemaker-mediated tachyarrhythmias (PMT) have not been systematically investigated in a large cohort of patients implanted for symptomatic atrioventricular (AV) block.

Methods And Results: Two hundred fifty consecutive patients (71±14 years, 63% male) implanted for symptomatic second- or third-degree AV block were screened for retrograde VA conduction and related PMTs including endless loop tachycardia (ELT) and repetitive nonreentrant VA synchrony (RNRVAS). After a mean post-implantation period of 38±12 months, AV block was persistent in 137 (55%) and variable in 113 (45%) patients.