Left Ventricular Volumes and Systolic Function After Long-term Right Ventricular Pacing May be Predicted by Paced QRS Duration, but not Pacing Site

BackgroundLong-term right ventricular apical (RVA) pacing causes adverse left ventricular (LV) remodelling and clinical outcomes.MethodsForty-one patients (19 men, mean age 70.9 ± 14.2, 23 right ventricular septal and 18 RVA pacing) underwent pacemaker implantation for atrioventricular block. LV volumes and left ventricular ejection fraction (LVEF) were assessed by echocardiography 39.3 ± 17.2 months after implantation. Predictors of left ventricular systolic volume (LVESV), left ventricular diastolic volume (LVEDV) and LVEF were analysed.ResultsNo difference was found between RVA pacing and right ventricular septal pacing groups in LVESV (40.6 ± 22.6 vs 33 ± 14.4 ml; p = 0.199), LVEDV (88.2 ± 31.2 vs 73.7 ± 23.9 ml; p = 0.102) and LVEF (56.1 ± 8.6 vs 56 ± 6.6%; p = 0.996). With multivariate stepwise regression, only pQRSd and renal impairment independently predicted LVESV (β = 0.522, 95% CI: 0.242–0.802; p = 0.001 and β = 40.3, 95% CI: 17.6–62.9; p = 0.001 respectively), LVEDV (β = 0.786, 95% CI: 0.338–1.235; p = 0.001 and β = 42.8, 95% CI: 6.6–79; p = 0.022 respectively) and LVEF (β = −0.161, 95% CI: −0.283 to −0.04; p = 0.011 and β = −14.8, 95% CI: −24.6 to −5.0; p = 0.004 respectively).ConclusionspQRSd and renal impairment, but not pacing site or baseline LVEF, may be predictors for LV volumes and systolic function after long-term RV pacing. pQRSd may be target for pacing site optimisation.