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.

• 摘要目的：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。