Ventricular Pacing Site Selection (V-PASS)

A Randomized, Prospective Multicenter Pilot Study to Determine the Influence of the Ventricular Pacing Site on the Incidence of Atrial Fibrillation and Heart Failure in Patients With Indication for Permanent Pacemaker Stimulation Therapy.

The purpose of this study is to determine whether there is a relationship between ventricular lead position and the incidence of heart failure and atrial fibrillation in patients with indication for permanent pacemaker stimulation.

AV-Block of higher degree is the primary indication for pacing therapy for about 20% of pacemaker patients. Pacing systems with only ventricular stimulation (VVI and VDD) have a fraction of about 40% of all pacemakers in Germany. About 50% of the implanted pacemakers in Germany are dual-chamber pacemakers and one half of them is used for treatment of AV blocks.

Picture 1: Fractions of pacing indications in Germany Picture 2: Fractions of used pacing modes in Germany /1/

A lot of studies proved in the past that the pacing site influenced the development of hemodynamics, heart failure (HF) and atrial fibrillation (AF). Unfortunately, the results are not commonly applicable or statistically assured. Due to this, further examinations are required in order to get explicit statements regarding application of alternative, nonapical ventricular lead positioning.

1. Pilotphase It shall be determined whether a randomized positioning of ventricular leads at 2 defined positions (either Group A: Positioning at right ventricular apex or Group B:. Positioning at right ventricular high septum) is feasible. Included patients will already by examined and followed according to protocol. After having proved feasibility of randomized positioning, the data of these patients shall be used for evaluation of the V-PASS study.
2. Study Phase It shall be evaluated how far 2 defined different ventricular lead positions for permanent pacemaker therapy can influence the combined study endpoint mortality and clinically relevant symptoms of heart failure. Further more the development of hemodynamics and the incidence of atrial fibrillation shall be studied.

Inclusion Criteria:

Patients with an expected ventricular stimulation rate of >60% in planned pacing therapy. This will be the following pacing indications

• Symptomatic first-degree AV block, PQ time >250ms
• Second-degree Av block with permanent 2:1 conduction
• Permanent third-degree AV block
• Paroxysmal first-degree to third-degree Av block, with an anticipated rate of ventricular stimulation >60%
• Symptomatic bradyarrhythmia absoluta with permanent atrial fibrillation, with an anticipated rate of ventricular stimulation >60%

Exclusion Criteria:

• heart failure acc. NYHA III or IV
• Intra-atrial conduction delay (P-wave > 150ms)
• Myocardial infarction less then 6 months before pacemaker implant
• hypertrophic obstructive cardiomyopathy
• Cardiogenic shock
• pregnancy
• Lactation period
• Patients under 18 years of age