Effects of right ventricular pacing on left ventricular ejection fraction in a pacemaker clinic

The aim of this study was to evaluate whether a change of left ventricular ejection fraction (LVEF) depending on percentage of right ventricular pacing is found in a real-life setting of a pacemaker clinic.

269 patients with either a pacemaker or an ICD and who are regularly followed at the pacemaker clinic of the Luzerner Kantonsspital participated in the study. We tested whether LVEF measured by echocardiography between the first measurement at the time of the pacemaker implantation and the last measurement at the time of the last pacemaker control is dependent on the extent of ventricular pacing. Mean follow-up was 3.9 +/- 2.9 years. Mean LVEF most significantly decreased in the group of patients with baseline LVEF > or = 45% and an extent of right ventricular pacing > or = 66% (from 57.6 +/- 7.2% to 53.1 +/- 10.2%, P < 0.001). In patients with an extent of right ventricular pacing < 66% no decrease of LVEF was observed. Analysis of variance showed that LVEF decrease between the first measurement at the time of the pacemaker implantation and the last measurement at the time of the last pacemaker control was dependent on the extent of right ventricular pacing, even if other factors such as age, gender and previous myocardial infarction are incorporated in the analysis.

In a real-life population of a pacemaker clinic right ventricular pacing was associated with a decrease in LVEF.