Abstract 2352: Echocardiographic Characterization of Myocardial Mechanics By Velocity Vector Imaging in Murine Post-MI Remodeling and the Effect of Anti-Angiotensin Therapy
Purpose: To assess left ventricular (LV) remodeling using Velocity Vector Imaging (VVI) in post-myocardial infarction (MI) murine model treated with anti-angiotensin therapy.
Methods: Five mice were sham-operated controls (no MI) and 18 mice underwent LCA ligation without reperfusion. Of the 18 post-MI mice, 5 animals were untreated (no Rx), 5 were treated with captopril (C) (60mg/kg/day) or losartan (L) (20mg/kg/day), and 4 with combination (C + L) (C: 30mg/kg/day; L: 10mg/kg/day). Echocardiography was performed 4 weeks post-MI to measure LV end-diastolic dimension (LVd) and EF. LV apical twist velocity (ARV) and magnitude (ARA) was measured using VVI.
Results: There was no significant difference in LVd in the untreated post-MI vs. the treated groups. But LVEF improved significantly in all treated groups. ARV and ARA also improved in all treated groups: velocity (C: 200%; L: 33%; and C+L: 367%), magnitude (C: 254%; L: 71%; and C+L: 362%). Apical CS also showed similar improvement (C: 50%; L: 25%; and C+L: 75%). Thus, C+L treated group showed the best improvement in apical mechanics (p<0.05 for ARV and ARA, C+L vs. C or L) for a comparable increase in LVEF.
Conclusion: Echocardiographic characterization of myocardial mechanics is a novel and better method to delineate post-MI reverse LV remodeling with anti-angiotensin therapy.