Impact of Global and Segmental Hypertrophy on Two-Dimensional Strain Derived from Three-Dimensional Echocardiography in Hypertrophic Cardiomyopathy: Comparison with Healthy Subjects.

BACKGROUND: Patients with hypertrophic cardiomyopathy (HCM) present unusual myocardial mechanics. The aim of this study was to assess the impact of hypertrophy on global and regional two-dimensional (2D) strain derived from both tomographic images (2D/2D) and volumetric image acquisition (2D/three-dimensional [3D]) in patients with HCM compared with control subjects.

METHODS: Comprehensive resting 2D and 3D echocardiography was performed in 40 patients with HCM and in 53 control subjects, with comparable distributions of age, gender, and left ventricular (LV) ejection fraction. LV global and segmental measurements of all 2D/2D and 2D/3D peak strain components (global and segmental longitudinal strain, global and segmental circumferential strain, global and segmental radial strain, and global and segmental area strain) and 3D indexed LV end-diastolic myocardial mass were obtained from all patients. LV wall thickness was assessed in short-axis views and classified in four quartiles (<10.5, 10.5-13.0, 13.0-16.5, and >16.5 mm).

RESULTS: The reproducibility of 2D/3D strain was similar or greater and more consistent for all components compared with 2D/2D strain analysis. There was a significant correlation between 3D LV end-diastolic mass and all 2D/3D strain components (P < .05). Two-dimensional/3D global circumferential strain had the strongest association with 3D LV ejection fraction (r = 0.50, P = .001). For segmental deformation, patients with HCM had lower longitudinal deformation whatever the LV wall thickness, whereas circumferential function was increased in nonhypertrophied and poorly hypertrophied segments compared with control subjects.

CONCLUSIONS: Two-dimensional/3D strain is a reliable technique to assess myocardial deformation. Myocardial mass is related to 2D/3D strain components in patients with HCM. Circumferential deformation, compared with longitudinal deformation, seems to be the main component of the maintenance of systolic function in HCM.