Analysis of regional left ventricular function in the post-infarct mouse by magnetic resonance imaging with retrospective gating

Our aim was to test, in a murine myocardial infarction (MMI) model, the feasibility of a new MRI protocol with no ECG/respiratory gating, and compare normal mice versus MMI, in terms of global and regional LV function. A control group (C, 10 mice) and a MMI group (18 mice) were studied. MRI with retrospective gating was performed. End-diastolic (EDV) and end-systolic (ESV) LV volumes with ejection fraction (EF) were computed. In addition, regional fractional area change (RFAC) was used as index of regional wall motion. In MMI, LV size (in muL) was larger compared to C (EDV: 92plusmn25 vs 36plusmn4, ESV: 66plusmn27 vs 10plusmn3), with a significant decrease in EF (31plusmn10 vs 72plusmn7%). RFAC in C showed heterogeneous values. In MMI, RFAC decreased from LV base to apex, with a min (26%) in the anterior segment, in agreement with the occluded LAD. MRI with retrospective gating is feasible in mice, and regional LV function analysis allows the localization of the induced infarction.