Mechanical Evaluation of Human Heart Wall Motion Using Magnetic Resonance Tagging Technique

The cardiac contractility in human heart was investigated by analyzing deformation of the left ventricular wall 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 circumferential strain at a short-axis section was employed as an index for an evaluation of the cardiac contractility. The obtained results showed that the circumferential 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 circumferential strains of the patients with a HHD were similar to those of the normal humans in whole regions. This study may suggest that the circumferential strain could be an effective index for the quantitative evaluation of the cardiac contractility