组织多普勒评价双腔起搏器不同房室间期对心功能的影响

Influence of atrioventricular delay of dual chamber pacemaker on cardiac function:evaluation by tissue Doppler enchocardiography

目的观察双腔起搏器以房室全能型方式起搏在不同房室间期(AVD)时心功能的变化,以探讨最佳 AVD,指导临床程控起搏器 AVD 参数的设定。方法 30例房室传导阻滞患者,均植入双腔起搏器,男18例,女12例。利用组织多普勒速度-时间曲线分别测量程控不同 AVD 时室间隔及左室各壁基底段的收缩峰值速度和收缩达峰时间(从收缩期开始至收缩峰值的时间),在常规二维超声切面上测量心排出量(CO)、心脏指数(CI)、每搏输出量(SV)、左室射血分数(LVEF)、左室收缩末期内径(LVESd)和舒张末期内径(LVEDd)。AVD 自100 ms 起以30 ms 步长依次递增至250 ms。结果程控不同的 AVD 对心功能的影响不同,AVD 程控为160 ms 时的血流动力学指标:CO(5.5 L/min±1.1 L/min,P<0.05)、CI(3.5 L·min^(-1)·m^(-2)±0.8 L·min^(-1)·m^(-2),P<0.05)、SV(78 ml±13 ml,P<0.05)、LVEF(67%±7%,P<0.05)、LVEDd(121 mm±29 mm,P<0.05)均达最大值,LVESd 达最小值(37 mm±16 mm,P<0.05);室间隔及左室各壁基底段的收缩峰值速度最快,收缩达峰时间最短,各室壁运动的同步性最好(P<0.05)。结论选择最佳的 AVD(160 ms)双腔起搏器程控时.对患者心功能改善有显著的影响。

Objective To investigate the optimal atrioventricular delay （AVD） in using dualchamber pacemaker. Methods Thirty patients with atrioventricular conduction block, aged 62 ± 12, implanted for were implanted with DDD pacemakers. Program controller was used to program the AVD. Two-dimensional echocardiography was used to measure the hemodynamic parameters： cardiac output （ CO）, cardiac output index （CI）, stroke volume （SV）, left ventricular ejection fraction （LVEF）, left ventricular end-systolic diameter （LVESd）, left ventricular end-diastolic diameter （LVEDd）, peak systolic velocity （ Vs）, and peak systolic time of the basic segment at inter-ventricular septum and left ventricular under the pattern of tissue velocity imaging at different values of AVD. For each patient, the AVD was prolonged to 250 ms stepwise by 30 ms starting from 100 ms. Results Cardiac function changed with different AVD. When the AVD was 160 ms, the maximal values were reached for CO （5.5 L/min ± 1.1 L/min,P 〈0.05）, CI （3.5 L ·min^-1 · m^-2 ＋0. 8 L ·min^-1 · m^-2,P 〈0. 05）, SV （78 ml ± 13 ml,P 〈0.05）, LVEF （67% ± 7%, P 〈 0.05 ）, LVEDd （ 121 mm ± 29 mm, P 〈 0, 05 ）, and Vs. LVESd reached its minimal value （37 mm±16 mm, P 〈0.05） and the Vs values of different ventrieular walls reached the minimal too （ all P 〈 0. 05）, Conclusion When the optimal AVD is selected the cardiac function can be significantly improved. Tissue Doppler echocardiography is useful in evaluating cardiac function and determining the ootimal AVD.