Measurement of postsystolic shortening to assess viability and predict recovery of left ventricular function after acute myocardial infarction.

OBJECTIVES: We sought to determine whether left ventricular (LV) postsystolic shortening in the region of acute myocardial infarction (MI) predicts functional recovery after primary angioplasty.
BACKGROUND: Previous studies in experimental animals have shown that postsystolic shortening during temporary coronary occlusion predicts functional recovery after reperfusion.
METHODS: Contrast ventriculography was performed on 35 patients with acute MI before and immediately after angioplasty, and one day, one month, three months and one year later. The centerline method was used to measure regional LV wall motion at end systole from all six ventriculograms as well as motion during isovolumic relaxation (motion(iso)) and postsystolic shortening from end systole until the end of contraction. The ventriculograms of 23 patients with normal anatomy were similarly analyzed.
RESULTS: Wall motion at end systole improved significantly from baseline to follow-up in the infarct region. Postsystolic shortening at baseline correlated most closely with the recovery of wall motion at three months in patients with anterior infarction (r = 0.69, n = 25, p = 0.0001) but also with recovery at one month and one year. The correlation was slightly less powerful for motion(iso). Functional recovery could not be predicted from assessment of motion(iso) and postsystolic shortening in patients with inferior infarction.
CONCLUSIONS: In patients with acute anterior MI, analysis of postsystolic shortening in the infarct region predicts the recovery of systolic LV function after reperfusion. Postsystolic shortening represents active contraction and indicates viable myocardium.