应用组织多普勒成像技术评价右心室起搏室壁收缩功能

目的：应用组织多普勒成像（TDI）技术检测组织运动速度、应变与应变率等参数，评价其在右室心尖起搏（VVI）与房室顺序起搏（DDD）的改变规律对节段性心肌功能的影响。方法：选择近期安装永久起搏器行VVI起搏的患者30例归入VVI组，房室顺序起搏的患者32例归入DDD组，年龄匹配的正常人32例归入对照组，分析3组之间TDI指标的变化及其变化规律。结果：正常组、DDD组及VVI组各节段的PSV、PSS及PSSR测值均依次降低，但PSSR在3组之间无显著性下降，而PSV与PSS显著下降的节段数多为右心室壁节段。起搏组左心室节段PSVT、PSST及PSSRT显著延长，右心室壁则显著缩短。结论：TDI可以作为起搏后早期评价患者节段心肌收缩运动的无创指标。起搏后患者心肌运动速度与应变下降早于应变率下降。早期的右心室心尖起搏，左室节段收缩功能较正常并无显著性差异；而VVI起搏患者的右心室壁节段收缩功能较正常及房室顺序起搏显著减低。

Evaluation of the myocardial contractile function of right ventricular pacing by tissue Doppler imaging

Objective: To investigate the change of TDI parameters after right ventricular pacing, and to reveal the effects of VVI and DDD on myocardial contractile function. Methods:The study included 3 groups, VVI group(30 patients receiving single-chamber pacing), DDD group(32 patients receiving dual-chamber pacing),control group(32 healthy human). TDI parameters of regional myocardium were observed. Results:PSV, PSS and PSSR were lowest in VVI group, followed by DDD group and control group. The number of the segments with significantly decreased PSSR was less than that of the segments with decreased PSV and PSR. In the two pacing groups, PSVT, PSST and PSSRT of left ventricle prolonged significantly, but those of right ventricle were shortened. Conclusion:TDI is a noninvasive method to evaluate the regional myocardium contraction after recent pacing. After pacing, there is no significant change in strain rate, and the decrease of velocity and strain are most in left ventricle. It is suggested that there is no significant change of the left ventricular contraction after pacing, but the contraction of the right ventricle in VVI mode is decreased compared with DDD mode.