Right ventricular pacing increases tricuspid regurgitation grade regardless of the mechanical interference to the valve by the electrode.

AIMS: The effect of right ventricular (RV) pacing on tricuspid regurgitation (TR) is debatable and is presumed to be related to an interference with valve closure by the electrode. The aim of the study was to determine the impact of pacing per se on TR grade. METHODS AND RESULTS: The study group included 23 clinically stable patients (13 males; mean age 78 +/- 12 years) with a permanent pacemaker at the RV apex (83% DDD mode) and normal left ventricular function. They were all non-dependent on pacing and were otherwise in sinus rhythm. None had a primary dysfunction of the tricuspid valve. TR grade and RV size were assessed in two consecutive echo studies with and without active RV pacing. Results showed that active RV pacing was associated with an increase in TR severity (TR vena contracta: 0.4 +/- 0.2 vs. 0.2 +/- 0.2 cm, P < 0.001; TR jet area: 4.1 +/- 2.3 vs. 2.3 +/- 1.8 cm(2), P < 0.001). This was also reflected in a significant decrease in the number of patients with mild TR (P = 0.003) and increase in the number with moderate regurgitation (P = 0.02). There was no change in RV areas with pacing. CONCLUSION: Active RV pacing is associated with a significant increase in TR grade. This effect is not induced by acute changes in the RV area and is unrelated to an interference with leaflet closure by the electrode.