组织多普勒超声评价急性心肌梗死患者的收缩后收缩

目的 评价急性心肌梗死患者和健康人在等容舒张期出现的收缩后收缩（PSS）现象及临床意义。方法 利用组织多普勒超声检测36例急性心肌梗死患者和36例正常人的局部心肌，获得不同节段射血期、等容舒张期的峰值速度（VS、VIR）、应变率（SRS、SRIR）、应力（εS，εIRn）等。结果 正常组的生理性PSS多位于室间隔、前壁的基底、心尖段。梗死组的病理性PSS等容舒张期峰值速度增大，持续的时间延长。梗死组有92个节段VIR〉VS，结合应变率和应力分析，39个节段在等容舒张期主动收缩；12个节段为矛盾运动，其中8个节段是主动与被动活动的混合。结论 病理性和生理性PSS有明显差别。利用组织多普勒超声各项指标，有助于理解病理性PSS的机制，并指导临床的诊断、治疗。

Assessment of postsystolic shortening in acute myocardial infarction patients by tissue Doppler echocardiography

Objective To assess postsystolic shortening(PSS) and its clinical meanings during isovolumic relaxation phase in regional myocardium of acute myocardial infarction patients and normal persons.Methods Left ventricular regional myocardia of 36 acute myocardial infarction patients(MI group) and 36 normal persons(control group) were assessed by tissue Doppler echocardiography.Left ventricular velocity profiles along long axis asynchronously in basal,mid and apical segments of different walls were acquired,mean peak velocities,peak strain rate,peak strain during systolic,isovolumic relaxation phase in regional myocardium were measured.Results In control group,PSS could be seen in 144 segments,especially at basal and apical segment of ventricular septum,anterior wall.In MI group,analyzed with strain rate and strain,V_(IR) were bigger than V_S in 92 segments.Thirty-nine segments actively shortened in isovolumic relaxation phase;12 segments were dyskinesis.Among 12 segments,8 segments relaxed during ejection,but actively shortened in isovolumic relaxation phase,mixing actively and passively motion.Conclusions Physiologic PSS are different from pathologic PSS.Different indexes of tissue Doppler echocardiography can be useful in understanding mechanism of PSS and guide clinical diagnosis and therapy.