ABSTRACT
Differentiation between ischemic and non ischemic cause for left ventricular dysfunction has important therapeutic implication in patients with chronic heart failure. Tissue Doppler imaging [TDI] has provided an objective means to quantify global and regional left ventricular [LV] function with improved accuracy and high reproducibility. The present study aimed to use tissue Doppler imaging of the left ventricle for differentiation between ischemic and dilated cardiomyopathy. A total of 40 subjects were included in this study, 15 patients with ischemic cardiomyapathy [1CM], 15 patients with dilated cardiomyapathy [DCM] and 10 healthy subjects as a control group. All studied subjects underwent 12 lead electrocardiogram transthoracic echocardiographic examination and TDI. The following regional parameters were measured in the four basal LV myocardial segments [lateral, septal, anterior and inferior walls]: myocardial systolic [Sm], early diastolic [Em] and late diastolic [Am] velocities, with calculation of dispersion index of each TDI velocity. Both Sm and Em were significantly lower in patients group than in control group [P<0.05]. The mean dispersion index of Sm in control group was [8%+4%], in ICM group [28%+8.1%] and [14%+7.1%] in DCM group, the Sm dispersion index was higher in patients than in the control group and in 1CM group compared to DCM group [P=0.01]. The mean dispersion index of Em in control group was [14%+9%], in ICM group [31%+11.6%] and [19%+4.4%] in DCM group, the Em dispersion index was higher in ICM group in comparison to control group or DCM groups [P=0.001]. The mean dispersion index of Am in control group was [5%+3%]. in ICM group [28%+11.8%] and [19%+9.6%] in DCM group, the Am dispersion index was higher in both patients groups in comparison to control group [P=0.0001]. Receiver operating characteristic [ROC] analysis showed that Sm dispersion index cut off value of [14%] detected patients with ICM with a sensitivity [73%] and a specificity of [90%] while Em dispersion index cut off value of [22%] could detect ICM patients with a sensitivity [80%] and a specificity [90%]. Both systolic [Sm] and Early diastolic velocity [Em] and dispersion of myocardial velocities[Sm, Em and Am] measured by TDI can help for differentiation between ischemic and dilated cardiomyopathy