目的：应用三维斑点追踪技术对比分析左束支起搏与右室流出道起搏对左心室收缩的影响。方法：对25例左束支起搏和25例右室流出道起搏术后的患者进行观察性研究，入选者均为病态窦房结综合征患者。用三维斑点追踪技术于术前、术后1个月、术后6个月采集患者左心室舒张和收缩末容积、射血分数，左心室壁总体纵向、径向、周向应变，计算心动周期标化的左心室壁16节段达最小收缩容积时间标准差，同期采集NT-proBNP和QRS波宽度。结果：左束支起搏状态下左心室应变与同步性与生理传导无统计学差异(P 0.05)。结论：左束支起搏是一种生理性起搏方式，左束支起搏状态下的心功能参数优于右室流出道起搏，三维斑点追踪技术可早期发现左心室收缩功能的变化。 Objective: The purpose of this study is to compare the effects of left bundle branch pacing and right ventricular outflow tract pacing on left ventricular systole using 3D speckle tracking technique. Methods: Twenty-five patients with left bundle branch pacing and twenty-five patients with right ventricle outflow tract pacing were enrolled in an observational study. All of them were diagnosed with sick sinus syndrome. Three-dimensional speckle tracking imaging technology was taken to obtain left ventricular end-diastolic volume, end-systolic volume, ejection fraction, global longitudinal strain, radial strain and circumferential strain, before and one or six months after operation. Then percentage of standard deviation of time, when the left ventricular sixteen segments reached minimum end-systole in cardiac cycle, would be calculated. Meanwhile, the information about the plasma NT-proBNP levels and QRS complex duration were detected. Results: Compared with the self‐conduction status, no significant difference was found in parameters of left ventricular strain and systolic synchrony when the mode was left bundle branch pacing (P