Regional rotation of the left ventricle in healthy and cardiomyopathic subjects measured with radial myocardial tagging

Background Left ventricular rotational deformation, which arises from contraction of myofibers arranged in a helical structure, plays a crucial role in cardiac mechanics. Myocardial dysfunction in cardiomyopathies is usually associated with altered diastolic rotation [1-3]. However, regional myocardial abnormalities in various cardiomyopathies may result in regional alterations of both systolic and diastolic rotational motion. The regional variation of LV rotation in healthy subjects has been previously studied [4-7]. We hypothesize that LV regional rotation abnormalities may be a sensitive marker in heart diseases where myocardial structure is disordered. In this regard, we investigate the regional rotation pattern of the mid LV wall in both healthy subjects and patients with cardiomyopathies. In this study, LV regional rotation is assessed through dense radial tagging [8], which facilitates analysis of the rotational motion and provides detailed regional measurement by increasing the achievable circumferential resolution.