García MIM, et al. - Researchers measured the influence of various cardiovascular factors on left ventricular ejection fraction (LVEF). They also tested a new LVEF calculation taking these factors into account. They analyzed 10 pigs, sequentially changing afterload, preload and contractility as per the experimental protocol. Prior to and following each intervention, they obtained left ventricular (LV) pressure–volume (PV) loops and peripheral arterial pressure. They calculated LVEF as stroke volume (SV)/end-diastolic volume (EDV). Findings revealed that contractility and afterload changes mainly influenced LVEF. In addition, there was a strong association of LVEF changes with ventriculo-arterial coupling and LV mechanical efficiency. A better evaluation of LV contractility was offered by an adjustment to LVEF that takes into account the influence of afterload.