Assessment of ST-Elevation Myocardial Infarction-Related Diastolic Dysfunction with Compensatory Rise in Left Atrial Ejection Force

Background: It is well known that patients with ST-elevation myocardial infarction (STEMI) show both systolic and diastolic left ventricular dysfunction. The aim of this study was to assess postmyocardial infarction diastolic dysfunction using left atrial ejection force (LAEF) in patients treated with primary percutaneous coronary intervention (PCI). Methods and Results: We enrolled 58 patients presenting with STEMI who were treated with primary PCI and 23 healthy subjects as a control group. A detailed transthoracic echocardiogram, including mitral flow velocities, tissue Doppler mitral annular velocities, and left atrial (LA) phasic volumes, was performed in both groups. We also measured the level of B-type natriuretic peptide (BNP). LAEF was calculated using the formula: 0.5xPxMitral orifice areax(Peak A velocity)2. Correlations between variables were studied using Pearson and Spearman's rho test. In the test group, we found that the level of BNP in the plasma, E/E ratio, and the LA volume measurements were higher than that of the control group, and those differences were statistically significant. LAEF was increased in patients with myocardial infarction (MI); moderately correlated to BNP (r=0.383 and P=0.001) and E/E (r=0.473 and P=0.001), and strongly correlated to A-wave velocity (r=0.731 and P=0.001). LAEF was also negatively correlated to E/A ratio (r=0.419 and P=0.001) and LVEF (r=0.339 and P=0.003). Conclusion: Impaired diastolic function in STEMI affects LA and increased LAEF is one of its manifestations. LAEF may also have diagnostic importance in diastolic dysfunction, but these findings should be confirmed by further studies.