| We study longitudinal motion characteristics during isovolumic contraction , ejection , isovolumic relaxation , early relaxation , atrial systole phases in left ventricular total and regional myocardium of myocardial infarction patients with three vessels lesions by Quantitative Tissue Velocity Imaging ( QTVI) , assess systolic and diastolic function in left ventricular regional myocardium, discuss postsystolic shortening in isovolumic relaxation phase and its clinical meanings.MethodsWe used QTVI for assessing left ventricular regional myocardium of 30 myocardial infarction patients ( MI group) and 30 normal persons ( Control group). After having collected dynamic images and analyzed information off - line, we acquired left ventricular velocity profiles along long axis asynchronously in basal, mid segments of different walls, measured peak velocities (VIC VS VIR VE VA) during isovolumic contraction, ejection, isovolumic relaxation, early relaxation, atrial systole phases. We acquired left ventricular strain rate and strain profiles along long axis asynchronously in regional segments of different walls, measured peak systolic strain rate (SRS)and strain (max) in regional myocardium. We acquired left ventricular time - velocity integral profiles along long axis asynchronously in mitral, basal, mid, apical segments of different walls, measured maximum time velocity integral (TVImax). Furthermore, we measured maximum displacement along long axis asynchronously in basal , mid and apical segments of different walls with Tissue Tracking, and calculated left ventricularwall motion score indexes(TT Score indexes). We also acquired maximum dis-placement( Dmax) of 6 mitral annular sites.ResultsPeak velocities( VIC VS VIR VE VA) in different segments of left ventricular regional myocardium were lower in MI group than Control group, especially in infarcted segments. What should be paid attention to was; peak velocity amplitude in ejection declined, but it had positive velocity spike; abnormal positive velocity in isovolumic relaxation phase suggested postsystolic shortening. Peak systolic strain rate in different segments of normal persons were relative similar, strain rate curve was regular. However, in MI group, strain rate curve was irregular. Systolic peak strain rate in MI group were apparently lower than Control group. Maximum strain( max.) and strain rate(SRs) were lower in MI group than Control group. Time velocity integrals in different segments of left ventricle were lower were MI group than Control group, especially in infarcted segments. What' s more , time velocity integrals in some segments of Ml group had two wave crests, reached maximum in isovolumic relaxation phase, but still lower than maximum TV I of Control group. Maximum displacements in different segments of left ventricular regional myocardium by Tissue Tracking were lower in Ml group than Control group, especially in infarcted sements. TT Score indexes were lower in MI group than Control group (6. 23 1.93 vs 9.71 1. 08, P < 0.01). In Control group, TT Score indexes were related with age, decreasing with age ( r = -0. 49 , P <0. 01). In MI group , TT Score indexes were related with mean systolic peak velocity, time - velocity intergral of different mitral annular sites, left ventricular ejection fraction, ( r = 0. 62, 0. 59, 0.67 ,P<0. 01 ). In MI group , TT Score indexes were related with left ventricular wall motion indexes by eyes ( r = -0.63, P<0.01).ConclusionsSystolic and diastolic function in MI patients with three vessels lesions areimpaired apparently; abnormal movement in isovolumic relaxation phase suggests existence of postsystolic shortening, abnormal wall motion and ventricular dyssynchrony in regional myocardium; VIR is a marker of abnormal regional wall motion and ischemic myocardium. Of those, time - velocity integral and maximum displacement (Dmax) of 6 mitral annular sites with tissue tracking to assess left ventricular systolic function are valuable, reproducible, accurate markers. QTVI can qui... |
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