BACKGROUNDIt is well known that increased cumulative ventricular pacing proportion (CumVP%) is one of the most important causes for adverse cardiovascular events. Therefore, how to reduce CumVP% has been a treatment issue in recent years. This study aimed to investigate the effects of different pacing algorithms on CumVP% in patients with pacemakers.

METHODSPacemakers with three pacing algorithms, i.e., conventional dual chamber rate adaptive pacing (DDDR), search atrioventricular conduction plus (SAV+) and managed ventricular pacing (MVP), were implanted in 42 patients including 41 with bradycardia arrhythmias and one with ventricular tachycardia. Pacemakers were programmed to work in conventional DDDR, SAV+ and MVP during the follow-up periods of the first, the second and the third month. In each pacing algorithm, the time percentages of four pacing and sense status including atrial sense-ventricular sense (AS-VS), atrial sense-ventricular pacing (AS-VP), atrial pacing-ventricular sense (AP-VS) and atrial pacing-ventricular pacing (AP-VP) were calculated. Cumulative ventricular pacing proportions were compared in the three pacing algorithms in the first, the second and the third month postoperatively.

RESULTSIn the DDDR algorithm AS-VS, AS-VP, AP-VS and AP-VP were 2.4%, 52.3%, 2.5% and 42.8% respectively, while in SAV+ they were 19.3%, 34.9%, 33.9% and 12.0%, in MVP they were 38.9%, 13.2%, 41.6% and 6.4%. In the above the DDDR, SAV+ and MVP algorithms, cumulative ventricular pacing proportions were 95.1%, 46.9% and 19.6%, respectively (P < 0.05) and the percentages of CumVP% < 40% in patients were 0, 23.8% and 95.2.0% (P < 0.05).

CONCLUSIONSCompared with the conventional DDDR algorithm, both SAV+ and MVP significantly reduced the CumVP%, especially the MVP algorithm. Patients may benefit from MVP algorithm due to reduced CumVP%.