[Assessment of postsystolic shortening of left ventricle in dilated cardiomyopathy using tissue velocity imaging].

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 (V(IC)), systolic phase (V(S)), and PSS (V(PSS)), the time of V(PSS) (T(PSS)) was measured and the ratio of V(PSS) to V(IC) (V(PSS)/V(IC)), and ratio of V(PSS) to V(S) (V(PSS)/V(S)) were calculated. The active and passive PSS were compared by the standard of V(PSS)/V(IC).

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 V(PSS), V(PSS)/V(IC), and V(PSS)/V(S) of the pathological PSS were increased and the T(PSS) of pathologic velocity of PSS (V(PSS)) were prolonged. Compared with the passive PSS segments, the V(PSS) and V(PSS)/V(S) of active PSS were increased and the T(PSS) of active V(PSS) 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.