A systemic review of endocardial left ventricular pacing

Abstract

Background: Endocardial left ventricular pacing is an alternative technique used in cardiac resynchronization therapy (CRT), when placement of a left ventricular lead is not possible via the coronary sinus or in non-responders to conventional CRT.

Objectives: To review the evidence regarding the efficacy and safety of endocardial left ventricular pacing.

Methods: Systematic research on Medline (PubMed), ClinicalTrials.gov and Embase with the terms "endocardial left ventricular pacing", "biventricular pacing" or "endocardial left pacing" was performed with the identification of 1038 results. Eleven studies with endocardial left ventricular pacing patients were included, independent of the technique being applied to naïve CRT patients or con non-responders to conventional CRT. The end-point of this analysis was the impact of endocardial left ventricular pacing techniques regarding New York Heart Association (NYHA) functional classification, left ventricular ejection fraction (LVEF) and QRS width, and the occurrence of complications Mean differences (MD) and confidence interval (CI) was used as a measurement of treatment.

Results: A total of 560 patients were included, with different techniques used (trans-atrial septal technique, trans-ventricular septal technique and transapical technique). Significant improvement was registered in NYHA class (MD 0.73, CI 0.48-0.98, p<0.00001, I² = 87%), LVEF (MD -7.63, CI -9.93 - -5.33, p<0.00001, I² = 69%) and QRS width (MD 29.25, CI 9.99-48.50, p<0.00001, I² = 91%). Several complications were reported after the procedure, 11 pocket infections, 22 transient ischemic attacks, 18 ischemic strokes, 41 thromboembolic events, among other complications. The mortality rate during the follow-up was 20.54%.

Conclusion: Left ventricular endocardial pacing is a feasible alternative to conventional CRT, with clinical, electrocardiographic and echocardiogrphic improvement. However, first data regarding this procedure was associated with significant complications rates.

Keywords: Cardiac resynchronization therapy; Endocardial left ventricular pacing; Left ventricular ejection disfunction; NYHA class.