E-point septal separation, or EPSS, is a simple M-mode echocardiographic measurement that estimates left ventricular systolic function. It measures the minimum distance between the anterior leaflet of the mitral valve at its maximum opening, called the E-point, and the interventricular septum. In a normally functioning heart, the mitral valve opens widely and comes close to the septum, resulting in an EPSS of less than 7 millimeters. An increased EPSS suggests that the left ventricle is dilated and not contracting well, which correlates with a reduced ejection fraction. EPSS is particularly useful in point-of-care and emergency settings as a rapid assessment of cardiac function.
Sonography Term