Functional abnormalities in patients with permanent right ventricular pacing: the effect of sites of electrical stimulation

J Am Coll Cardiol. 2002 Oct 16;40(8):1451-8. doi: 10.1016/s0735-1097(02)02169-1.

Abstract

Objectives: We sought to evaluate the long-term effects of alternative right ventricular pacing sites on myocardial function and perfusion.

Background: Previous studies have demonstrated that asynchronous ventricular activation due to right ventricular apical (RVA) pacing alters regional myocardial perfusion and functions.

Methods: We randomized 24 patients with complete atrioventricular block to undergo permanent ventricular stimulation either at the RVA (n = 12) or right ventricular outflow (RVOT) (n = 12). All patients underwent dipyridamole thallium myocardial scintigraphy and radionuclide ventriculography at 6 and 18 months after pacemaker implantation.

Results: After pacing, the mean QRS duration was significantly longer during RVA pacing than during RVOT pacing (151 +/- 6 vs. 134 +/- 4 ms, p = 0.03). At six months, the incidence of myocardial perfusion defects (50% vs. 25%) and regional wall motion abnormalities (42% vs. 25%) and the left ventricular ejection fraction (LVEF) (55 +/- 3% vs. 55 +/- 1%) were similar during RVA pacing and RVOT pacing (p > 0.05). However, at 18 months, the incidence of myocardial perfusion defects (83% vs. 33%) and regional wall motion abnormalities (75% vs. 33%) were higher and LVEF (47 +/- 3 vs. 56 +/- 1%) was lower during RVA pacing than during RVOT pacing (all p < 0.05). Patients with RVA pacing had a significant increase in the incidence of myocardial perfusion defects (p < 0.05) and a decrease in LVEF (p < 0.01) between 6 and 18 months, but patients with RVOT pacing did not (p > 0.05).

Conclusions: This study demonstrates that preserved synchronous ventricular activation with RVOT pacing prevents the long-term deleterious effects of RVA pacing on myocardial perfusion and function in patients implanted with a permanent pacemaker.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Aged, 80 and over
  • Cardiac Pacing, Artificial*
  • Coronary Circulation
  • Dipyridamole
  • Electrocardiography
  • Female
  • Heart Block / diagnostic imaging
  • Heart Block / physiopathology*
  • Heart Block / therapy*
  • Humans
  • Male
  • Middle Aged
  • Pacemaker, Artificial
  • Prospective Studies
  • Radionuclide Ventriculography
  • Thallium Radioisotopes
  • Tomography, Emission-Computed, Single-Photon
  • Vasodilator Agents

Substances

  • Thallium Radioisotopes
  • Vasodilator Agents
  • Dipyridamole