Fig. 1
Relationship between ventriculo-arterial coupling, left ventricular mechanical efficiency and left ventricular ejection fraction. Left: linear regression analysis between ventriculo-arterial coupling (VAC), calculated as the ratio between effective arterial elastance (Ea) and left ventricular end-systolic elastance (Ees), and left ventricular ejection fraction (LVEF). Right: linear regression analysis between left ventricular mechanical efficiency, calculated as the ratio between stroke work (SW) and the left ventricular pressure–volume area (PVA), and left ventricular ejection fraction. Colors inside circles represent different experimental interventions: red, afterload; green: preload; blue: contractility