Dynamic ventricular overdrive stimulation in atrial fibrillation: effects on ventricular rate irregularity, ventricular pacing, and fusion beats.

Aims: In pacemaker patients with preserved atrio-ventricular (AV) conduction, atrial fibrillation (AF) can lead to symptomatic ventricular rate irregularity and loss of ventricular stimulation. We tested if dynamic ventricular overdrive (DVO) as a potentially pacemaker-integrated algorithm could improve both aspects.

Methods And Results: Different settings of DVO and ventricular-ventricular-inhibited-pacing (VVI) with different base rates were tested in two consecutive phases during electrophysiological studies for standard indications.

Multicenter clinical experience with an atrial lead designed to minimize far-field R-wave sensing.

Aims: To evaluate a novel atrial lead designed to reduce far-field sensing.

Methods And Results: Sixty-three patients with standard pacing indications were randomized to receive an OptiSense 1699T (St Jude Medical, USA) or conventional pacing lead in the right atrium. Post-implant follow-up was conducted for all patients at 90 days and for a subset at 360 days.