Endomyocardial Radial Strain Imaging and Left Ventricular Relaxation Abnormalities in Patients With Hypertrophic Cardiomyopathy or Hypertensive Left Ventricular Hypertrophy

Background: Asymmetrical septal hypertrophy and impaired left ventricular (LV) diastolic function are common echocardiographic features of hypertrophic cardiomyopathy (HCM). However, it is difficult to differentiate nonobstructive HCM from hypertensive LV hypertrophy (H-LVH). Methods and Results: Standard echocardiography and tissue Doppler imaging were performed in 14 patients with HCM, 16 patients with H-LVH, and 21 control subjects. Endomyocardial radial strain, systolic strain rate (SR), and the early diastolic SR at the posterior and septal segments of the LV short axis were calculated. Endomyocardial peak strain (E) and the absolute value of peak early diastolic SR at the posterior segment were significantly smaller in patients with HCM than in those with H-LVH. whereas the thickness of the LV posterior wall did not differ between these 2 groups. Multivariate analysis of discrimination, including the ratio of interventricular septal thickness and posterior wall thickness (IVST/PWT), E, and SR parameters, between HCM and H-LVH patients revealed that E at the LV posterior segment was the highest discriminant parameter (discriminant coefficient: -14.6, P=0.012). The E: at the posterior segment significantly correlated with early diastolic mitral annular velocity. Conclusions: Endomyocardial radial strain imaging may prove informative for discriminating between HCM and H-LVH. (Circ J 2009; 73: 2294-2299)