Comparative study of the effect of left ventricular pacing versus right ventricular pacing on left ventricular function

Abstract

Abstract Background: Pacing from the apex of the RV is not considered optimal. This work aimed to assess and compare RV and LV pacing concerning LV function and dyssynchrony. Thirty-six patients who presented with indications for pacemakers were divided into three groups: 12 had LV pacing (lead was inserted from coronary sinus to lateral vein, the same procedure used in resynchronization pacing); 12 had RV pacing group (apical pacing only, not septal or outflow). 12 had Dual-chamber pacing. Control group: Twelve healthy subjects were included in this study. Results: RV pacing group: During the post-implantation period, the distance of the 6-MWT improved significantly, P= 0.006. The cardiac output (COP) during the preimplantation period and at the six-month follow-up (P= 0.003). The t-IVT (Total isovolumic time) variables at the pre-and post-implantation periods at six months (P= 0.005). LV pacing group: The comparison of the 6-MWT distance and the quality of life (QOL) score in the post-implantation period and at six months revealed a highly significant difference (improvement) Also in the median values of the PAP (RAP = Right atrial pressure), COP, MPI (MPI = Myocardial performance index), t-IVT, and Z (Z ratio = sum of the left ventricular ejection and filling times divided by RR interval) (P= 0.000). Conclusions: RVP seems to have less detrimental effects on LV synchrony and LV function. For those patients indicated for conventional pacemaker indications with normal or mildly impaired LV function with EF > 35%, RVA (right ventricular apical) pacing is still the gold standard pacing site.