Myofibril shortening and the oblique fiber orientation of the left ventricular myocardium results in a twisting motion of the left ventricle. Advances in cardiac magnetic resonance imaging (MRI) have made it possible to label the myocardium noninvasively and track this motion (twist) through the cardiac cycle, but little data exist on its complete systolic time course. The purpose of this study...

The principal function of the left atrium is to modulate left ventricular (LV) filling and cardiovascular performance through reservoir, conduit, and booster pump functions; the latter is often (mistakenly) regarded synonymously with atrial function, and in contrast to the reservoir and conduit phases, has been studied extensively. Typically, the importance of atrial contraction has been estima...

BACKGROUND Fibro-elastic deficiency (FED) and diffuse myxomatous degeneration (DMD) are phenotypes of degenerative mitral valve disease defined morphologically. Whether physiological differences in annular and valvular dynamics exist between these phenotypes remains unknown. METHODS AND RESULTS We performed triple quantitation of cardiac remodeling and of mitral regurgitation severity and of ...

Cross-sectional echocardiographic measurements of normalized septal curvature (NSC), systolic anterior motion of the center of the left ventricular cavity (CAM), and the M mode ratio of left ventricular posterior wall epicardial motion (PEM) to posterior wall thickening (PWT) were made in eight normal subjects, 16 patients with right ventricular volume overload (RVVO) and five with pressure ove...

Only limited data are available from which normal ranges of mitral annular (MA) and tricuspid annular (TA) dimensions have been established. Normative data are important to assist the echocardiographer in defining the mechanism of atrioventricular valve regurgitation and to inform surgical planning. This study was conceived to establish normal MA and TA dimensions. Consecutive healthy subjects ...

We explore M. Gromov's counterexamples to systolic inequalities. Does the manifold S 2 × S 2 admit metrics of arbitrarily small volume such that every noncontractible surface inside it has at least unit area? This question is still open, but the answer is affirmative for its analogue in the case of S '~ × S n, n > 3. Our point of departure is M. Gromov's metric on S 1 x S 3, and more general ex...

The view that1 tlhe heart remains relatively constant in volume in diastole as in systole, has been maintained by one of us on the basis of an analysis of tjhe cardiopneumogram (1). Thus cardiac volume changes produce pressure changes within the lungs which, when transmitt,ed through the respiratory t,ree and corrected for tlhe elastic give of the chest walls, seem to be produced by a cardiac v...

OBJECTIVE To complement the ISO 5840 standards concerning the duration of left ventricular systole and diastole as a function of changes in heart rates according to in vivo studies from the physiologic literature review. METHODS The systolic and diastolic durations from three in vivo studies were compared with the durations of systole proposed by the ISO 5840:2010 and ISO 5840-2:2015 for hydr...

29 Although the distribution of average fetal pulmonary trunk (PT) blood flow favors the ductus 30 arteriosus (DA) over the lungs, the phasic aspects of this distribution during systole and 31 diastole are not well understood. Accordingly, flow profile and wave intensity (WI) analyses 32 were performed at baseline and during brief flow increases accompanying an extrasystole 33 (ES) in ten anest...