不同部位起搏对心室间电机械同步性的对比观察

Comparative study of interventricular electrical and mechanical synchrony at different cardiac pacing sites

目的比较右室心尖部（RVA）、右室流出道间隔部（RVS）和左室流出道间隔部（LVS）起搏对心室间电机械同步性的差异，评价出保持心室间电机械同步的理想起搏部位。方法选择2008年1—12月在我院行射频消融术（左侧隐性旁道）后患者30例，术后分别将标测电极放置于左室后侧壁（LVPLw）及右室前侧壁（RVALW），大头消融电极依次放置于RVA、RVS、LVS起搏。通过测量起搏点至LVPLW及至RVALW的传导时间差来反映心室间电激动的同步性，不同部位起搏主动脉射血前间期（APEI）与肺动脉射血前间期（PPEI）差来反映心室间机械收缩同步性，并比较两者相关性。结果RVA起搏时至LVPLW及至RVALW的传导时间差为（34±7）ms，RVS起搏为（18-4-4）ms，LVS为（12±4）ms，差异有统计学意义（P〈0．01）。RVA起搏APEI—PPEI绝对值为（25±5）ms；RVS起搏为（13±4）ms，LVS为（11±3）ms，差异有统计学意义（P〈0．01）。心室起搏后，LVPLw—RVALW差值变化与APEI—PPEI绝对值增加呈正相关（r=0．993，P〈0．01）。LVS起搏后主动脉压[（127±23）mmHg]和左室收缩末压[（142-4-22）mm Hg]明显增加（P〈0．05），左室舒张压显著降低[（9±3）mmHg，P〈0．05]。结论LVS起搏对心室间电机械同步性影响小，更符合生理性的起搏，心室间电激动与机械收缩同步相一致。

Objective To compare the different impacts of fight ventricular apex, fight ventrieular outflow tract septum and left ventricular outflow tract septum region on interventricular electro-mechanical synchronization and assess the ideal pacing sites for maintaining the interventricular electro-mechanical synchronization. Methods A total of 30 patients without organic heart disease were operated with radiofrequency ablation at our hospital. The mapping electrodes were implanted post-operatively on the left ventricular posterior wall （LVPLW） and fight ventricular anterior lateral wall （RVALW） respectively. And the ablation electrodes were placed subsequently in fight ventricular apex, right ventricular outflow tract septum region and left ventricular outflow tract septum. The difference values were measured between transmission time from pacemaker to LVPLW, from pacemaker to RVALW and between aortic pre-ejection interval （APEI） and pulmonary artery pre-ejection interval （PPEI）. Then their correlations were compared. Results When pacing at fight ventricu]ar apex, the difference value between transmission time from pacemaker to LVPLW and from pacemaker to RVALW was （34 ± 7）ms. And it was （18 ± 4）ms while pacing at fight ventricular outflow tract septum region and （12 ±4）ms at left ventricular outflow tract septum region. There was significant difference （P 〈 0. 01 ）. The absolute value of APEI-PPEI was （25 ± 5 ） ms at fight ventricular apex, （13 ±4） ms at fight ventricular outflow tract septum region and （11 ± 3 ） ms at left ventricular outflow tract septum region. And there was significant difference （ P 〈 0. 01 ）. The absolute value of APEI-PPEI was positively correlated with the change of LVPLW-RVALW （ r = 0. 993, P 〈 0. 01 ）. Left ventricular outflow tract septum pacing showed ABp and left ventricle end-systolic pressure significantly increased [ （ 127 ± 23 ） mm Hg, （ 142 ± 22） mm Hg ,P 〈0. 05 ], left ventricular end-diastolic pressure was significantly lower [ （ 9 ± 3 ）mm Hg, P 〈 0. 05 ]. Conclusion Compared with fight ventricular apical pacing and fight ventricular outflow tract ventricular septal pacing, left ventricular outflow tract septum has a smaller impact on the electro-mechanical synchronization. It conforms more closely to the physiological pacing so that there is a higher synchronization of electrical and mechanical ventrieular contractions.