1.INTRODUCTION
cardiac pacing technology as a therapy has been used for over a half century and it remains the most effective therapy for bradycardia and cardiac conduction dysfunction.Traditionally, the pacing site at the apex of the right ventricle has been chosen because of the ease of placement of transvenous pacing leads. Several studies conducted over the past two decades have shown that right ventricular pacing (RVP)has adverse effects on clinical outcomes because of ventricular mechanical asynchrony which is secondary to electrical asynchrony1–3. The Pursuit of alternate pacing sites has been widely studied but no definitive conclusion is reached4. In 2000, Deshmukh conducted the pioneering investigation of permanent direct His bundle pacing(HBP)5.Since then, more and more studies showed that HBP is superior in preserving electrical synchrony and left ventricular(LV)function compared to right ventricular pacing (RVP)6,7. However, lead placement for HBP is a technically challenging due to its anatomic location, and long-term capture thresholds of HBP have been found to be significantly higher than those of RVP. In 2017, Huang Weijian proposed left bundle branch area pacing (LBBAP) firstly8. Some clinical trials have demonstrated that left bundle branch area pacing exhibited the feasibility for patient with left bundle branch block (LBBB)/heart failure and showed more stable and reliable pacing parameters,but these trials mostly were small sample,short-term studies. LBBAP may be a potential physiological pacing method that can replaces HBP, but it lacks of clinical application and requires to investigate the electrocardiogram characteristics, pacing parameters ,the safety and the effectiveness .
So we systematically reviewed currently available literature and carried out this meta-analysis: (i) to investigate the electrocardiogram characteristics change (ii)to report the stability of pacing parameters and (iii)to summuerize the successful rate of LBBAP from kinds of articles. The reporting of this systematic review follows current standards.