CORRELATIONS BETWEEN RESTING REGIONAL WALL-MOTION AND REGIONAL MYOCARDIAL BLOOD-FLOW (AT REST AND DURING EXERCISE) IN INFARCT-RELATED MYOCARDIUM - A STUDY WITH [N-13] AMMONIA POSITRON EMISSION TOMOGRAPHY

We evaluated quantitatively the correlations between resting wall moti on and regional myocardial blood flow (RMBF; at rest and during exerci se) in infarct-related myocardium. The study was performed in 28 subje cts: 21 patients who had previously suffered myocardial infarction of the anteroseptal wall, and 7 normal individuals. Positron emission tom ography (PET) with [N-13]ammonia was performed at rest and during low- grade exercise (bicycle ergometer fixed at 25 W for 6.5 min), and RMBF was measured quantitatively from the radioactivity in myocardial tiss ue and arterial blood. Resting regional wall motion was calculated usi ng the centerline method on left ventriculographic finding, Resting re gional wall motion was correlated with RMBF both at rest and during ex ercise in the infarct areas (anterior walls: y=-2.74+4.25 X 10(-2)x, r =0.43, at rest; and y=-2.48+3.04 X 10(-2)x, r=0.48, during exercise, p <0.05; septal walls: y=-3.61+5.64 X 10(-2)x, r=0.62, at rest; and y=-3 .46+4.31 X 10(-2)x, r=0.62, during exercise, p<0.01). In each infarct- related wall, the coefficient (the slope) during exercise was smaller than that at rest (3.04 vs 4.25 and 4.31 vs 5.64 in each), and the inf arct areas with preserved wall motion showed higher RMBF during exerci se than those with reduced wall motion. Our results may show that wall motion depends on viable but ischemic myocardium in infarct-related w alls.