Implantation of pacemaker to monitor ventricular function and dyssynchrony

Author(s): Doaa Elkholy, Mostafa Nawar, Mohamed Ayman Abdelhay, Samir Rafla

Background: Pacing from the apex of the RV is not optimal. This study aimed to assess and compare RV and LV pacing of LV function and dyssynchrony. Methods: 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). Twelve had RV pacing group (apical pacing only, not septal or outflow). Twelve had Dual-chamber pacing. Twelve healthy participants were included in this study as Control group. Results: During the post-implantation period, the distance of the 6-MWT improved significantly, P=0.006. Cardiac Output (COP) during the preimplantation period and at the six-month follow-up (P=0.003). The IVT (Isovolumic Time) variables at six months’ pre- and post-implantation periods (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) as well as in the median values of the PAP (RAP: Right Atrial Pressure), COP, MPI (MPI: Myocardial Performance Index), 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 fewer 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.