Postsystolic shortening in regional myocardium of myocardial infarction patients assessed by quantitative tissue velocity imaging / 中华超声影像学杂志

ABSTRACT

Objective By quantitative tissue velocity i maging(QTVI),to observe longitudinal wall motion characteristics during isovolumic contraction, ejection, isovolumic relaxation, early relaxation, atrial systole phases in regional myocardium of myocardial infarction patients with three diseased blood vessels, and to assess postsystolic shortening in isovolumic relaxation phase and its clinical meanings. Methods Left ventricular regional myocardium of 30 myocardial infarction patients (MI group) and 30 non-cardiac disease subjects (control group) was assessed by QTVI. After dynamic images were collected and information was analyzed off-line, left ventricular myocardial velocity and time velocity integral profiles were acquired along long axis asynchronously in basal and middle segments of different walls, peak velocities (V IC , V S, V IR , V E, V A) during different phases and maximum time velocity integral (TVI max )in regional myocardium was measured. Results Peak velocities(V IC , V S, V IR , V E, V A) in different segments of left ventricular regional myocardium in MI group were lower than those of control group, especially more obviously in infarcted segments. Peak velocity amplitude in ejection declined, but it had positive velocity spike; abnormal positive velocity in isovolumic relaxation phase suggested postsystolic shortening. What's more, time velocity integrals in some segments of MI group had two wave crests, reached maximum in isovolumic relaxation phase, but were still lower than that of control group. Conclusions Systolic and diastolic function in MI patients with three diseased blood vessels are apparently impaired; abnormal movement in isovolumic relaxation phase suggests existence of postsystolic shortening and abnormal wall motion in regional myocardium.V IR is a marker of abnormal regional wall motion and ischemic myocardium.