Analysis of Human Left Ventricular Torsional Motion Using Magnetic Resonance Tagging Technique.

Abstract

In this research work, we investigated the torsional motion of the left ventricle about the long axis, which has been assumed to be one of the components of the normal systolic motion. The myocardial wall motions were analyzed for four normal volunteers and a patient with hypertrophic cardiomyopathy (HCM), by using the magnetic resonance tagging technique. It was recognized from the results for the normal volunteers that there was the counterclockwise rotation of the apical side plane with respect to the basal side plane during the ejection period when looked toward the base from the apex, and that the torsional motion in the septal wall was minimum. It was confirmed that this torsional motion did not appear in the diseased part of the patient with HCM. This study may suggest that the torsional motion of the left ventricle is an important component of the normal myocardial wall motion, and that the quantification of the torsional motion is useful for the evaluation of the cardiac contractility.