Objectives Long-term right ventricular apical pacing (RVAP) is associated with impaired cardiac function. This study aims to investigate the predictability of paced QRS duration (pQRSd) in heart-failure events among patients receiving RVAP.
Methods 194 patients with complete atrioventricular block receiving pacemaker treatment were enrolled and stratified to group 1: pQRSd <160 ms, n = 53; group 2: 160 ≤ pQRSd < 90 ms, n = 97; and group3: pQRSd ≥ 190 ms, n = 44. Study outcomes were heart-failure events, changes in pQRSd and changes of left ventricular ejection fraction (LVEF).
Results During the 3-year follow-up, the incidence of heart-failure events were 9.4%, 27.8% and 56.8% in group 1, 2, 3 respectively (P < 0.001). Among the patients without heart-failure events, the pQRSd at 3 years remained longer than that at baseline (162.1 ± 22.6 vs. 160.9 ± 22.1 ms, P < 0.05). While among patients who experienced heart-failure events, the prolonged pQRSd at 3 years seem more pronounced as compared with baseline (184.1 ± 21.1 vs. 179.8 ± 21 ms, P < 0.001). Linear regression demonstrated that decrease of LVEF was positively correlated with pQRSd over time (RR: 0.423; P < 0.05). Receiver operation curve showed that the cut-off value of pQRSd was 165 ms with a sensitivity of 0.789.
Conclusions A prolonged pQRSd has a detrimental effect on long-term cardiac function during RVAP in patients with complete atrioventricular block. pQRSd could be a useful predictor to identify patients who are at risk for heart-failure events during RVAP.