Background: The interventricular septum in hypertrophic cardiomyopathy (HC) has a unique shape, which is characterized by the convex curvature toward the left ventricle (LV). The aim of this study was to examine the relationship between curvature of the LV wall and regional myocardial strain.
Methods and results: Fifty-six patients with HC (mean age, 55±12 years) and 20 age- and sex-matched control subjects (mean age, 56±8 years) were enrolled. The curvature index (1/radius) was measured by drawing along the endocardial surface from the apical 4-chamber and short axis views. Peak systolic strain was calculated in the septal and lateral walls using 2-D speckle tracking echocardiography. The septal curvature index and septal longitudinal strain were significantly lower in the HC group than in the control group. A multivariate model using the HC patient data showed that the septal curvature index and septal thickness were the independent determinants of septal longitudinal strain (septal curvature index: β=-0.421, P<0.001; septal thickness: β=0.401, P=0.002). In addition, global longitudinal strain and E/e' were worse in the lower septal curvature index group compared with the higher group.
Conclusions: Septal longitudinal strain is associated with the degree of septal curvature. This indicates a possible link between LV wall configuration and regional myocardial function.