ABSTRACT
Objective To investigate the onset of left ventricular remodeling (LVRM) after acute myocardium infarction (AMI) and its changes within 6 hours in dogs on echocardiography. Methods AMI was induced in 14 dogs by ligating the left anterior descending arteries. Eight myocardium infarcted models were successful and were sacrified for pathological study. The indices of LVRM: wall infarction thickness (WIT), the wall motion score index (WMSI), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV) and left ventricular ejection fraction (LVEF) were evaluated before and 1 h, 2 h, 3 h, 4 h, 5 h and 6 h after operation. Results Compared with the pre-operation, WIT and LVEF were decreased (P<0.01), LVESV and WMSI were increased (P<0.01), and LVEDV was increased (P<0.05 or P<0.01) at every time point after operation. WIT had no significant difference at 1 h, 2 h, 3 h, 4 h, 5h and 6h after operation (P＞0.05). LVEDV, LVESV were higher (P<0.05) and LVEF was lower (P<0.05 or P<0.01) at 4 h, 5 h, and 6 h than at 1 h, and 2 h after operation. WMSI was higher at 3 h, 4 h, 5 h, and 6 h than at 1h (P<0.05). Conclusions In our experiment, LVRM occurred at 1 h after AMI in dogs. Thus echocardiography may evaluate early LVRM.