A novel quantitative indicator of the left ventricular contraction based on volume changes of the left ventricular myocardial segments

Abstract: Ejection fraction (EF) is commonly measured by echocardiography, by dividing the volume ejected by the heart (stroke volume) by the volume of the filled heart (end-diastolic volume). Utilizing volume changes of left myocardial segments per a cardiac cycle, physical laws and mathematical equations specific echocardiographic data, this paper serves to generalize EF by a novel parameter over the time that it can make available, more detailed, valuable and practical information to fully describe the left ventricular (LV) contractility function.Patients who underwent clinically-directed standard transthoracic echocardiography using 2D conventional echocardiography machines armed to measuring strain components, were asked to estimate displacements and longitudinal, radial and circumferential strains for each LV echocardiographic segments per a cardiac cycle. Volume fractional changes of the LV echocardiographic segments are expanded based on their strain components over the time. Ejected blood volume fraction induced by a left myocardial sample, is computed within a cardiac cycle. Total fraction of the ejected blood volume in the left ventricular cavity was obtained by integrating over the times and LV myocardial segments. EF is an especial value of this total fraction at the end systolic time. The common measurement of EF is only based on LV cavity volumes at the end diastolic and systolic phases. These findings lead to determine detailed aspects of the left ventricular contraction. This generalized parameter has important implications to give the real value of EF in the sever Mitral valve regurgitations.