Induction and aggravation of atrioventricular valve regurgitation in the course of chronic right ventricular apical pacing.

Aims: Valvular regurgitation, especially on the right side of the heart, is a common finding even in patients without endocardial pacing leads. The severity of valvular regurgitation can change after permanent pacemaker (PPM) implantation. Ventricular pacing has been shown to cause ventricular dysfunction. The purpose of this study was to evaluate the mid-term effects of right ventricular (RV) apical pacing on atrioventricular (AV) valvular regurgitation in patients with a normal left ventricular function before PPM implantation.

Methods And Results: Patients who required dual-chamber pacemakers due to a high-degree AV block were enrolled in the study. Initial echocardiography was performed before PPM implantation and re-evaluation by echocardiography was performed every 24 months thereafter. A total of 125 patients (61 male; mean age: 66.57 ± 6.45 years) were included in the study, and 115 pacemaker-dependent patients were followed up (mean ± SD; 4.08 ± 0.8 years). Echocardiography demonstrated mild tricuspid regurgitation (TR) and mitral regurgitation (MR) in 70 (60.1%) and 34 (29.6%) patients before PPM implantation, respectively. Moderate TR and MR were detected in 10 (8.7%) and 1 (0.9%) patients, respectively. Thirty-six (31.6%) patients showed moderate-to-severe TR at long-term follow-up, compared with the 10 (8.7%) patients, who had the same degree of TR before RV apical pacing (P < 0.001). Mild and moderate MR were detected in 54 (47%) and 8 (7%) patients after PPM implantation on the last echocardiography(P < 0.001). Baseline systolic pulmonary artery pressure (PAP) was 29.24 ± 8.45 mmHg, which increased to 36 ± 11 mmHg on the last echocardiography (P < 0.001).

Conclusion: Considering the haemodynamic effects at mid-term follow-up, left ventricular dysfunction is rare in patients with RV apical pacing and normal baseline left ventricular function. Right ventricular apical pacing is associated with a significant increase in the prevalence and severity of TR and MR.