实时三维超声心动图评价右心室不同部位起搏对左心房同步性的影响

目的 采用实时三维超声心动图(RT-3DE)评价右心室心尖部(RVA)和间隔部(RVS)起搏对缓慢性心律失常患者左心房同步性的影响.方法 将51例高度或Ⅲ度房室传导阻滞患者分为RVA组(n=31)和RVS组(n=20),采用RT-3DE分别测算患者安置埋藏式心脏起搏器术前和术后1、3、6、12个月的左心房主动射血分数(LAAEF)、左心室射血分数(LVEF)及左心房16节段、12节段、6节段QRS波起点到左心房收缩最小收缩容积的时间标准差(Tmsv-16-SD、Tmsv-12-SD、Tmsv-6-SD)及最大时间差(Tmsv-16-Dif、Tmsv-12-Dif、Tmsv-6-Dif)的变化.并对以上参数进行统计学分析.结果 两组术后3、6、12个月的Tmsv-16-SD、Tmsv-12-SD及Tmsv-6-SD和两组术后各时间点的Tmsv-16-Dif、Tmsv-12-Dif、Tmsv-6-Dif均分别较各组术前增高(P均 <0.05),RVS组术后3、6、12个月Tmsv-16-SD、Tmsv-12-SD、Tmsv-6-SD和Tmsv-16-Dif、Tmsv-12-Dif、Tmsv-6-Dif均小于同时点RVA组(P <0.05).RVS组6、12个月的LAAEF、LVEF均大于同时点RVA组(P <0.05).结论 采用RT-3DE检测的左心房各节段达最小容积的最大时间差可较时间标准差更敏感地评价右心室不同部位起搏对左心房同步性的影响.持续RVA和RVS起搏均可导致缓慢性心律失常患者左心房收缩运动失同步化,但RVS起搏的不良影响较小.

Real-time three-dimensional echocardiographic evaluation of left atrial synchronicity in patients with different selective site pacing

Objective To evaluate the effects of right ventricular apex (RVA) pacing and right ventricular septum (RVS) pacing on left atrial synchronicity by real-time three-dimensional echocardiography (RT-3DE) in patients with atrioventricular block. Methods RVA pacing was conducted in 31 patients with atrioventricular block (RVA group) and RVS pacing in 20 patients (RVS group). The left atrium active ejection fraction (LAAEF), the left ventricular ejection fraction (LVEF), the standard deviation and maximal difference of the time to minimal systolic volume (Tmsv) of 16, 12, and 6 left atrial segments (Tmsv-16-SD, Tmsv-12-SD, Tmsv-6-SD, Tmsv-16-Dif, Tmsv-12-Dif, Tmsv-6-Dif) were measured and calculated at preoperation, the first month, 3rd month, 6th month, and 12th month after pacemaker implantation by RT-3DE. The statistical analysis was performed. Results The Tmsv-16-SD, Tmsv-12-SD, Tmsv-6-SD on the 3rd month, 6th month, 12th month, and the Tmsv-16-Dif, Tmsv-12-Dif, Tmsv-6-Dif at all time points after pacemaker implantation in both groups were significantly longer than those at preoperation (all P <0.05). Compared with RVA group, the Tmsv-16-SD, Tmsv-12-SD, Tmsv-6-SD, as well as Tmsv-16-Dif, Tmsv-12-Dif, and Tmsv-6-Dif on the 3rd month, 6th month, 12th month after implantation were shortened in RVS group (all P <0.05), the LAAEF and LVEF on the 6th month and 12th month were elevated (P <0.05). Conclusion For RT-3DE assessment of left atrial asynchrony in patients with RVA and RVS pacing, the maximum difference of Tmsv is more sensitive than the standard deviation of Tmsv. Although RVA and RVS pacing produce the left atria mechanical asynchrony during 12-month follow-up, RVS pacing reduces the unfavourable effects.