Left Ventricular Wall Motion and Thickening Abnormalities Affect both Systolic and Diastolic Function after Acute Myocardial Infarction

Objectives: The aim of this study is to assess the effect of left ventricular (LV) wall motion and thickening abnormalities in cardiac dysfunction after acute myocardial infarction (AMI).

Methods: Left anterior-descending branch of 12 healthy Ba-Ma miniature swines were balloon occluded for 90 minutes to create AMI model. All animals underwent gated myocardial perfusion imaging examination repeatedly within 4 weeks after AMI.

Results: At 24 hours following AMI, the ejection fraction (EF) was significantly lower than that of the basic state ((49.89 ± 10.902)% vs. (71.56 ± 12.043)%, P < 0.05), while the diastolic function parameter peak filling rate (PFR) was obviously lower 7 days later ((1.99 ± 1.216) vs. (2.87 ± 1.022), P < 0.05). The summed motion score (SMS) and thickening score (STS) increased significantly at 24 hours after AMI, however, STS reached a maximum at 7 days. In the simple linear regression model, both SMS and STS were highly negatively correlated with EF (r = -0.921 and r = -0.926, respectively, all P < 0.001); meanwhile, there were moderate negative correlations between PFR and both SMS and STS (r = -0.564 and r = -0.586, respectively, all P < 0.001).

Conclusions: LV systolic and diastolic dysfunction occurred in the early stage after AMI, and systolic dysfunction occurred much earlier than diastolic dysfunction. Left ventricular wall motion and thickening abnormalities after AMI were closely related to left ventricular dysfunction (both systolic and diastolic dysfunction ). Furthermore, a closer relationship can be observed in left ventricular systolic dysfunction. Key Words: Wall motion and thickening abnormality; Acute myocardial infarction; Cardiac dysfunction; Animal model; Gated myocardial perfusion imaging. Fund Project: Natural Science Foundation of China (81471690); Key Development Foundation of Jiangsu Province (BE2015635).