Myocardial Deformation Pattern Differs between Ischemic and Non-ischemic Dilated Cardiomyopathy: The Diagnostic Value of Longitudinal Strains.

Both ischemic cardiomyopathy (ICM) and non-ischemic cardiomyopathy (NICM) are characterized by left ventricular (LV) dysfunction and dilation. Differentiation between ICM and NICM using non-invasive image modalities is a clinical challenge. This study compared the myocardial deformation patterns of ICM and NICM using 2-D speckle tracking echocardiography (2-D STE) and sought to find parameters valuable in the diagnosis and management of dilated cardiomyopathy. The study population comprised 84 consecutive patients with LV end-diastolic dimension >55 mm and ejection fraction (EF) <45 %. Of these patients, 41 were diagnosed with ICM and 43 with NICM by coronary angiography. 2-D STE was performed in all patients. The LV dimension did not differ between ICM and NICM. Compared with patients with ICM, patients with NICM had lower EF (29.0% vs. 33.0%, p = 0.024), lower global longitudinal strain (-5.4 ± 2.6% vs. -7.0 ± 2.5%, p = 0.006) and lower global radial strain (7.5 ± 4.5% vs. 10.7 ± 4.7%, p = 0.019). In contrast, global longitudinal strains did not differ significantly. However, NICM patients had higher apical and lower basal longitudinal strains compared with those with ICM. The ratio of basal to sum of mid- and apical longitudinal strains could predict NICM with a sensitivity of 63.4% and specificity of 88.4% by receiver operating characteristic curve analysis (cutoff value: 0.47, area under the curve: 0.792). Moreover, the concomitant presence of non-significant coronary artery stenosis (>50% and <70%) had no significant influence on global longitudinal strain in NICM. In conclusion, LV dilation and systolic dysfunction, relative apical sparing and a basal worsening pattern of LV longitudinal strain by 2-D STE were observed in patients with NICM but not ICM. The ratio of basal to sum of mid- and apical longitudinal strains could help differentiate NICM from ICM.