Mechanical Evaluation of Cardiac Contractility in Left Ventricle with Disease Using Magnetic Resonance Tagging Technique.

Abstract

The cardiac contractility in human hearts was investigated by analyzing the deformations of the left ventricular myocardial walls during systole using a magnetic resonance tagging technique. Subjects were ten normal humans, eight patients with a hypertrophic cardiomyopathy (HCM) and seven patients with a hypertensive heart disease (HHD). The minimum principal strain, which describes the maximum contraction, was employed as an index for an evaluation of the cardiac contractility. The obtained results showed that the minimum principal strains in local regions of the patients with a HCM were significantly smaller compared with those in corresponding regions of the normal humans, while the minimum principal strains in whole regions of the patients with a HHD were similar to those in corresponding regions of the normal humans. This study suggests that to evaluate the cardiac contractility from a mechanical point of view is useful for a quantitative evaluation of heart diseases.