Primary Outcome Measures:
- Calculation of reduction in % VP when RVP algorithm is ON versus OFF, recording % VP at 4 and 8 weeks after randomization
Secondary Outcome Measures:
- Occurrence of possible undesired consequences of the RVP algorithm (e.g. retrograde conduction; AF burden) and adverse events in the periods with the algorithm switched ON versus OFF, 4 and 8 weeks after randomization
- Patient’s opinion about treatment (on a six-point scale), at 4 and 8 weeks after randomization
- explorative subanalysis on patients with different arrhythmias and/or conducting system defects to investigate in which type of patients the RVP algorithm will have the largest impact on %VP
- Reproducibility of the %VP assessment, comparison %VP during Baseline periode and 4-week study period with RVP OFF
Electrical stimulation in the apex of the right ventricle ( ventricular pacing) usually improves the heart function of patients with a pacemaker and can even be life-saving. However, evidence is accumulating that ventricular pacing may also have undesired long-term cardiac effects. Therefore, it makes sense to limit ventricular pacing to the absolute required minimum. The functionality RVP (Refined Ventricular Pacing) in the C-series 2nd generation pacemakers of Vitatron B.V. Arnhem, the Netherlands is designed to reduce ventricular pacing.
After implantation of the Vitatron C50 D model C50A2 (pacemaker) or Vitatron C60 DR model C60A2 (pacemaker) and a 4-6 weeks stabilization period, proper functioning of pacemaker and leads (stimulation- and sensing parameters) is checked. The pacemakers will be programmed according to predefined settings.
In the following 4-weeks Baseline period diagnostic data (atrial fibrillation burden and percentage of ventricular pacing (% VP)) are collected in the pacemaker memory. Based on these data, patients will be excluded from further participation (patients with more than 15% atrial fibrillation) or subdivided into three groups: (a) < 30% VP (30- VP group), (b) >30% VP, Sick Sinus Syndrome and normal conductivity (SSS group), (c) >30% VP, 1st or 2nd degree AV block. Patients in these three groups will be treated for 4 weeks alternatively with the RVP functionality switched ON or OFF. The order will be determined by randomization. At the end of these two cross-over periods the % VP and the judgment of the patients of the last period will be assessed. Adverse events will be recorded from the moment of study enrolment.