不同房室间期对右室起搏比例影响的研究

Effect on percentage of right ventricular pacing with different AV dalai

目的探讨不同AV间期对右室起搏比例的影响，以及如何进一步进行AV间期的优化。方法2012年9月至2015年12月，选择在我院接受圣犹达双腔起搏器植入患者，根据病因分为“病窦综合征（SSS）”组38例及“房室传导阻滞（AVB）”组41例。所有患者均为DDD起搏模式，植入时默认AV间期PV／AV为150／170ms（5286型）及150／200ms（5816、5826型）。植入2个月后，AV间期设为PV／AV325／350ms；植入4个月后，打开自动自主传导搜索功能（5286型）及VIPTM功能（5816、5826型），PV／AV按照5286型起搏器固定参数设置，即每间隔5min搜索3个心动周期，并设置搜索时间120ms。每次随访时记录心室起搏比例，以秩和检验比较不同设置对起搏比例的影响。结果SSS组一例患者因持续性心房颤动终止研究。两组患者默认设置、最长AV间期设置及自主传导搜索设置时起搏比例中位数分别为37％、3％、5％（ssS组），83％、50％、54％（AVB组），三种设置间差异具有统计学意义（P〈0．05），SSS组差异更显著。结论通过延长AV间期可减少右室起搏，但对起搏器治疗患者，首先推荐个体化设置。

Objective Several studies have shown that not only unnecessary right ventricular pacing but also inappropriate AV delay could have detrimental effects on heart function. The purpose of this study was to compare the percentage of right ventrieular pacing of different AV delay in sick sinus syndrome （SSS） and Mobitz type Ⅱ or complete atrioventricular block （AVB）, and to study how to set AV delay individually. Methods Patients who accepted dual chamber pacemaker implantation, were divided into SSS or AVB group from September 2012 to December 2015. All of these pacemakers could work with Automatic Intrinsic Conduction Searching（AICS） or Ventricular Intrinsic Preferencc（VIP）. AV delay was changed and the percentage of right ventricular paeing（VP%） was recorded every two months after implantation. The AV delay for atrial paced/sensed events was 150/170 ms（5286） or 150/200 ms（5816 and 5826）at baseline respectively. After two months, it was extension to maximum delay with 325/350 ms, and was working for two months since that time. After another two months, the pacemakers worked with AICS or VIP. AICS and VIP were set to search automatically for intrinsic R-wave conduction every 5 minutes for 3 cycles, with another 120ms added to the baseline AV delay. The VP%s with each AV delay was compared. Results 79 patients were included this study. 38 of them were diagnosed SSS, and 41 were in AVB group. 1 patient in SSS group was excluded because of permanent atrial fibrillation was occurred. In SSS group, medians of VP% at 2nd, 4th and 6th month were 37%, 3% and 5% respectively. While in AVB.group, the medians were 83%, 50% and 54%. Maximum delay and AICS/VIP reduced VP% significantly in both groups（P〈0.05）, and the VP% with maximum delay was lesser than that with AICS/VIP （P〈0.05）. Compared to AVB group, VP% in SSS group was reduced more significantly. Conclusion VP% can be reduced by longer AV delay. The AV delay should be set individually. It is recommended to implant the pacemakers with AICS/VIP. But it needs more studies to evaluate how to set the AV delay individually.