INFLUENCE OF INFARCT SIZE AND LOCATION, P ATENCY OF THE INFARCTION AND NON-INFARCTION VESSELS ON LEFT-VENTRICULAR REMODELING AFTER MYOCARDIAL-INFARCTION - ESTIMATION WITH CINE MAGNETIC-RESONANCE-IMAGING DURINGTHE FIRST 6 MONTHS

Background: Aim of the study was to evaluate the influence of infarct size and location and patency of the infarction and non-infarction ves sels on left ventricular morphology and function in the first 6 months after myocardial infarction. Methods: 61 patients (17 female, 44 male , 36-83 years) were examined with Cine Magnetic Resonance Imaging (CMR I) 1 and 26 weeks, and with coronary angiography 4 weeks after infarct ion. 32 patients had anterior, 29 patients posterior myocardial infarc tion. 15 patients had small infarcts (< 20 gm), 19 intermediate sized (20-40 gm) and 27 patients large infarcts (> 40 gm). CMRI was done in the short axis of the left ventricle. Left ventricular enddiastolic an d endsystolic volume indices (LVEDVI, LVESVI), ejection fraction (LVEF ), muscle mass (VM) and motility (VMOT) of the vital myocardium, mass (IM) and area (TA) of the infarction zone, and volume-mass-ratio (VMR) of the left ventricle were determined on each examination. Results: A fter 6 months large infarctions had 25% more LVEDVI, 41% more LVESVI, 20% less LVEF, 11% more VM, 13% less VMOT, 13% more IM, 47% more IA, a nd a 17% increased VMR compared to small infarcts. Anterior infarction s showed 11% more LVEDVI 19% more LVESVI, 7% less LVEF, 4% more VM, th e same VMOT, 5% more IM, 21% more IA, and 6% more VMR than posterior i nfarctions. If the infarction vessel was not perfused, after 6 months LVEDVI was 12% more, LVESVI 19 % more, LVEF 7 % smaller, VM 4% less, V MOT the same, IM 5% more, IA 17% more, and VMR 7 % more increased than in the group with open infarction artery. When both non-infarction ve ssels were stenosed, LVEDVI rose 24% more, LVESVI 49% more, LVEF fell 25% more, VM rose 12% more, VMOT fell 26% more, and VMR rose 12% more than in patients with indisturbed perfusion of the vital myocardium. C onclusion: Perfusions of the vital myocardium and infarct size seem to be the most important factors for post infarction remodeling of the l eft ventricle. Infarct location and patency of the infarction vessel a re of less influence.