Evaluation of the applicability and usefulness of Myocardial Performance Index in predicting the development of heart failure in comparison with other cardiac indices

Abstract

Back ground: The myocardial performance (MPI) is a combined index of systolic and diastolic dysfunction and has been shown to be a predictor of cardiovascular outcome in heart diseases.
 Aim : Evaluate the role of MPI in assessment of heart failure in comparison with other echocardiographic parameters. Methods : By M-mode echocardiography, measurement of ejection fraction (EF) and stroke volume (SV) had been done, then measurement of left ventricular mass (LVM ) by measurement of left ventricular internal dimension in diastole (LVIDd) and systole (LVIDs), posterior wall thickness in diastole (PWTd), and interventricular septal thickness in diastole (IVSd). Left ventricular mass (LVM) was calculated from the measurements of the left ventricle (LV) using the equation: LVM (g) = 0.81 [1.04 (interventricular septal thickness + posterior wall thickness + LV end-diastolic internal dimension)3 – (LV end-diastolic internal dimension)3] + 0.6. Left ventricular mass index calculated by dividing LVM on body surface area. Measurement of MPI by the apical five-chamber view with Doppler study . the sum of the isovolumic relaxation time (IVRT) and isovolumic contraction time (IVCT) divided by the left ventricular ejection time (LVET) obtained from the left ventricular inflow and outflow. Results: The percentage of abnormal MPI in this study is about 82% (normal value is 0.39±0.05) in comparison to EF and SV which are 39% and 54.2% respectively. MPI showed weak but negative correlation with EF and SV ( r = -0.163, -0.044) respectively, and positive correlation with LVM and LVMI (r = 0.416 , 0.413) respectively. EF showed negative correlation with LVET, IVCT and IVRT( r = -0.03 , -0.028 , -0.25 ) respectively . Conclusion : Use of MPI for assessing cardiac performance has a potential clinical advantage over the use of other classical echocardiographic indices