组织速度成像评估原发性扩张型心肌病左心室心肌收缩后收缩

Assessment of postsystofic shortening of left ventricle in dilated cardiomyopathy using tissue velocity imaging

目的探讨组织速度成像评估原发性扩张型心肌病(DCM)左室心肌收缩后收缩(PSS)的意义。方法获取14例 DCM 患者和22例正常人左室18节段组织速度曲线,测量等容收缩期峰速(V_(IC))、射血期峰速(V_S)、PSS 峰速(V_(PSS))和 PSS 波持续时间(T_(PSS)),计算 V_(PSS)与 V_(IC)比值(V_(PSS)/V_(IC))、V_(PSS)与 V_S 比值(V_(PSS)/V_S)。以 V_(PSS)/V_(IC)作为判定主动性与被动性 PSS 的标准并对其参数进行比较。结果正常人仅少数节段出现生理性 PSS,而 DCM 各节段均出现病理性 PSS。与生理性 PSS 相比,病理性 PSSV_(PSS)、V_(PSS)/V_(IC)、V_(PSS)/V_S 增大,T_(PSS)延长。与被动性 PSS 相比,主动性 PSS 的 V_(PSS)、V_(PSS)/V_S 增大,T_(PSS)延长。结论 DCM 左室心肌存在病理性 PSS,可能与心肌"类缺血"状况有关。生理性和病理性 PSS、主动性和被动性 PSS 差异明显。

Objective To evaluate the postsystolic shortening （PSS） of different segments of left ventricle （LV） and its meanings in dilated cardiomyopathy （DCM）. Methods Twenty-two normal controls and 14 DCM patients underwent tissue velocity imaging （TVI） to obtain the regional velocity profiles of 18 segments of LV. The peak velocities of isovolumic contraction phase（ VIC ）, systolic phase （ VS ）, and PSS （VPSS） ,the time of VPSS （TPSS） was measured and the ratio of VPSS to VIC （VPSS/VIC）, and ratio of VPSS to VS （ VPSS/VS ） were calculated. The active and passive PSS were compared by the standard of VPSS/VIC. Results Physiologic PSS was detected only in minority segments of normal subjects and pathologic PSS was detected in all segments of DCM patients. Compared with the physiologic PSS, The VPSS, VPSS/VIC, and VPSS/VS of the pathological PSS were increased and the TPSS of pathologic velocity of PSS （ VPSS ） were prolonged. Compared with the passive PSS segments, the VPSS and VPSS/Vs of active PSS were increased and the TPSS of active VPSS segments were prolonged. Conclusion PSS exists in LV, probably having relation with ischemia-like condition of myocardium in DCM patients. There are significant differences between physiologic and pathologic PSS, and between active and passive PSS.