Ventricular tachycardia induced by biventricular pacing in patient with severe ischemic cardiomyopathy

Transseptal Left Ventricular Endocardial Pacing Reduces Dispersion of Ventricular Repolarization

“…However, despite its beneficial effects on left ventricular (LV) function, it is unclear whether it reduces sudden cardiac death or the occurrence of ventricular arrhythmias (VAs) 2,3 . Furthermore, there is evidence that in some cases CRT may be proarrhythmic 4 . The conventional approach for CRT is simultaneous pacing from the LV epicardium, via the coronary sinus (CS) or a surgically placed epicardial lead, and the right ventricular (RV) endocardium.…”

Prevalence of ventricular arrhythmias in patients with cardiac resynchronization therapy without back-up ICD

“…Cases documented increased ventricular arrhythmia following CRT-P implantation due to a potential proarrhythmic effect; 17,18 assuming this point of view, CRT should be preferable only with a defibrillator back-up. 19 However, large clinical studies have suggested that CRT-P could contribute by itself to a reduction in mortality by decreasing the incidence of lethal ventricular arrhythmias, 20 supported by the fact that biventricular cardiac pacing produces reverse remodeling with a favorable impact on outcome and can reduce frequency of ventricular arrhythmias.…”

Successful Catheter Ablation of Two Types of Ventricular Tachycardias Triggered by Cardiac Resynchronization Therapy: A Case Report

“…First, epicardial left ventricular pacing reverses the course of activation of the myocardial wall (activating it from epicardium to endocardium), which prolongs the QT interval, increases the transmural dispersion of repolarization and creates the substrate and trigger for reentrant polymorphic VTs, similar to arrhythmias in long QT syndrome 6 . Second, left ventricular pacing significantly modifies the activation pattern within the scar areas and thus may, under certain circumstances, create an unidirectional block and reentry 4 . This may result in easier induction of monomorphic VTs.…”

“…Recent studies have also shown reduction in all‐cause mortality 1 . However, anecdotal reports have described proarrhythmic effect of CRT, leading to recurrent ventricular tachycardias (VTs) either following an implantation of CRT device 2, 3 or after an upgrade from standard dual chamber pacing to CRT 4 …”