OPTIMAL AV DELAY IS NOT PREFERRED TOSPONTANEOUS AV CONDUCTION IN PATIENTS WITHPACEMAKER

摘要

Atrio-ventricular (AV) delay (AVD) optimization provides hemodynamic improvement in patients with dual-chamber pacemaker (DPM). However, spontaneous AV conduction produces more synchronized ventricular contraction than pacing. The purpose of this study was to evaluate if optimal-AVD (O-AVD) pacing preserved heart function superiorly than long-AVD (L-AVD) allowing spontaneous AV conduction. This study included 16patients with DPM having prolonged PR interval (PR>200msec, 5males, mean age 72+-10years). Patients were divided to patients with mildly-prolonged PR interval (group I: PR<250msec, n=10) and significantly-prolonged PR interval (group II: PR>250msec, n=6). AVD was adjusted to L-AVD for the first 6months and O-AVD for the next6 months. Echocardiographic measurements and NYHA classification were compared between each setting in group I and II. No differences were found on LVEDD (group I: 47.6+-7.2mm vs 47.7+-8.3mm, group II: 42+-5.5mm vs 45.2+-4.4mm), LVESD (group I: 30.7+-6.3mm vs 31.2i8.6mm, group II: 25.8+-3.7mm vs 26.5+-3.1mm), LVEF (group I: 63.5+-9.5% vs 63+-13.3%, group II: 70.3+-3.7% vs 71.7+-3.8%) and NYHA classification (group I: 1.3+-0.5 vs 1.3+-0.5, group II: 1.2+-0.4 vs 1.2+-0.4).Conclusions: There was no significant difference on heart function between L-AVD and O-AVD regardless of spontaneous PR interval. It is suggested that O-AVD does not provide significant benefit in patients with spontaneous AV conduction.