E: peak velocity of the early diastolic filling wave, A: peak velocity of the late diastolic filling wave, E’: peak early diastolic … Rotation and twisting are known to increase with advancing age,18),19) and this can be explained by the subendocardial dysfunction that is believed to occur with age. In other words, aged people are more or less suffered from Inhibitors,research,lifescience,medical diastolic heart failure.

Despite of muscular disease, twisting is relatively preserved in hypertrophic cardiomyopathy.20) This seems to be due to reduced subendocardial function resulting from dysfunction of the subendocardial microcirculation. If interstitial fibrosis advances so that there is dysfunction across the full thickness of the myocardium in hypertrophic Inhibitors,research,lifescience,medical cardiomyopathy, then rotation will, of course, be reduced. In some cardiac diseases such as sarcoidosis, muscular dystrophy and myocarditis, subepicardial dysfunction can

occur earlier then subendocardial dysfunction. It would be interesting to investigate if there is hypo-rotation with preserved ejection fraction in the early stage of such diseases. Orientation of myocardial fibers The subendocardial fibers Inhibitors,research,lifescience,medical run at an angle of approximately 60° to the long-axis, and the subepicardial fibers run at an angle of approximately 60° in the opposite direction. If the cardiac chambers become rounded as a Aurora Kinase inhibitor result of heart failure, the angle becomes greater, resulting that the myocardial fibers run in a more transverse fashion. Rotation and twist are known to be reduced when this occurs. Fig. 8 shows Inhibitors,research,lifescience,medical the relationship between left ventricular shape and twist angle.21) Here, the sphericity index is defined as the ratio of the long-axis diameter and the

short-axis diameter in diastole. The smaller the sphericity index (i.e., the more spherical the left ventricle becomes), the less the twisting. A parabolic relationship exists between left ventricular shape and twisting, so that twisting is also reduced if the left ventricle becomes overly elliptical. Left ventricular shape Inhibitors,research,lifescience,medical is closely associated with the orientation of fibers. When you see the globular left ventricle, its twist would be small. Because the globular left ventricle Astemizole often accompanies with systolic dysfunction, the reduced twisting may be also due to myocardial dysfunction. Fig. 8 Relationship between left ventricular shape and torsion. Left ventricular shape is expressed by the sphericity index that is the ratio of the long-axis diameter and the short-axis diameter in end-diastole (left). A parabolic relationship is found between … Tanaka et al.22) found rotation and twist decreased in patients with congenital pericardial defect without changes in regional myocardial strains, and they concluded the pericardium played an important role in twist. In fact, this decrease in rotation and twist could probably be explained by left ventricular shape in addition to the role of pericardium. In animal studies, Chang et al.