Abstracts of Poster Discussions and Posters; Presented at the Society of Cardiovascular Anesthesiologists; 20th Annual Meeting; Seattle, Washington; April 25-29, 1998
Introduction: E point-septal separation (EPSS) was first described on M-mode echocardiography and defined as the minimal distance between the E point of the anterior mitral valve leaflet and the septum.  EPSS measurement is simple and reproducible and is frequently used as a qualitative and dynamic estimator of left ventricular function on 2D echocardiography. While EPSS is reliably measured on 2D echo using the parasternal long-axis view, the most comparable view, if any, on multiplane transesophageal echocardiography (TEE) has not been demonstrated.
Methods: Patients having coronary artery bypass grafting (CABG) with a TEE in situ and without aortic insufficiency, mitral valve stenosis, or basal septal akinesis were included in the study. No efforts were made to control for anesthetic technique, filling volumes, heart rate, or rhythm in order to evaluate the independence of EPSS of these variables. EPSS was measured on 2D echo as the minimal distance between the anterior leaflet of the mitral valve and the septal endocardium over several cardiac cycles. EPSS was measured at 0[degree sign] and 120[degree sign] as the aortic outflow tract was viewed. Measurements were randomly made both before and after cardiopulmonary bypass. Concomitant was EPSS measurements, the TEE probe was advanced into the stomach and LVEF was estimated in the short-axis papillary muscle view by an experienced echocardiographer blinded to EPSS measurements.
Results: Figure 1 demonstrates the data, regression line and coefficient for the comparison of EPSS 0[degree sign] to estimated LVEF. The comparison of EPSS 0[degree sign] to EPSS 120[degree sign] displayed a high correlation (R2 0.76). When the EPSS 120[degree sign] was >or=to 10 mm the LVEF was abnormal (<or=to 50%) 100% (9/9) of the time.
Discussion: EPSS is dependent on mitral valve excursion (limited in mitral valve stenosis or aortic insufficiency), transmitral blood flow, and ventricular contraction while independent of ventricular volume, rhythm, and wall motion abnormalities. [1,2] In our study, we demonstrated that EPSS by TEE is a reliable qualitative estimate of normal versus abnormal LVEF. Furthermore, regression analysis demonstrated EPSS to be a relatively good quantitative indicator of LVEF. Finally, our study showed an EPSS >or=to 10 mm at 120[degree sign] to have 100% specificity for an abnormal EF, consistent with previous transthoracic echocardiography studies. 
1. Massie B, Schiller NB, Ratshin RA, Parmley WW: Mitral-septal separation: new echocardiographic index of ventricular function. Am J Cardiol 1977; 39:1008-16
2. Lehmann KG, Johnson AD, Goldberger AL: Mitral valve E point-septal separation as an index of left ventricular function with valvular heart disease. Chest 1983; 83:102-8