Predictive value of regional left ventricular circumferential shortening in jeopardized myocardium - A two-dimensional SPAMM cine-MRI study in a canine model

OBJECTIVE. TO determine whether myocardial circumferential shortening asses sed in the different myocardial layers by SPAMM cine-MRI may help to discri minate between various degrees of myocardial injury in reperfused myocardiu m. METHODS. Dogs underwent 90 minutes of coronary occlusion and 24 hours of re perfusion, Using a 1.5 T whole-body MR scanner, SPAMM cine-MRI images were acquired before and 24 hours after surgery on the short axis plan of the le ft ventricle and analyzed to evaluate the mean myocardial circumferential s hortening (%MCS) in the different layers, Based on the residual blood flow, animals were assigned to group I (residual flow <22.5%) or group II (resid ual flow > 22.5%), RESULTS. Dogs in group I developed larger infarctions (25.3% +/- 14.6 of th e area at risk, n = 5) compared with those in group II (5.81% +/- 1,1, n = 7, P < 0.05). In the jeopardized zone, the %MCS of the subendocardium decre ased more significantly in group I (-0.03% +/- 3.7 to 2.2% +/- 5.2) compare d with group II (14.7% +/- 1.5 to 18.4% +/- 1.4). CONCLUSIONS. SPAMM cine-MRI is a fast and noninvasive means of measuring %M CS. The MR measurement of this parameter in the subendocardial layer appear s quite accurate in describing the degree of damage in reperfused myocardiu m.