Left ventricular ejection fraction using a simplified wall motion score based on mid-parasternal short axis and apical four-chamber views for non-cardiologists.

BACKGROUND: There is a need for a convenient, yet reliable method to assess left ventricular ejection fraction (LVEF) with point-of-care ultrasound study (POCUS). We aim to validate a novel and simplified wall motion score LVEF based on the analysis of a simplified combination of echocardiographic views. METHODS: In this retrospective study, transthoracic echocardiograms of randomly selected patients were analysed by the standard 16-segments wall motion score index (WMSI) to derive the reference semi-quantitative LVEF. To develop our semi-quantitative simplified-views method, a limited combination of imaging views and only 4 segments per view were tested: (1) A combination of the three parasternal short-axis views (PSAX BASE, MID-, APEX); (2) A combination of the three apical views (apical 2-chamber, 3-chamber and 4-chamber) and (3) A more limited combination of PSAX-MID and apical 4-chamber is called the MID-4CH. Global LVEF is obtained by averaging segmental EF based on contractility (normal = 60%, hypokinesia = 40%, and akinesia = 10%). Accuracy of the novel semi-quantitative simplified-views WMS method compared to the reference WMSI was evaluated using Bland-Altman analysis and correlation was assessed in both emergency physicians and cardiologists. RESULTS: In the 46 patients using the 16 segments WMSI method, the mean LVEF was 34 ± 10%. Among the three combinations of the two or three imaging views analysed, the MID-4CH had the best correlation with the reference method (r2 = 0.90) with very good agreement (mean LVEF bias = - 0.2%) and precision (± 3.3%). CONCLUSIONS: Cardiac POCUS by emergency physicians and other non-cardiologists is a decisive therapeutic and prognostic tool. A simplified semi-quantitative WMS method to assess LVEF using the easiest technically achievable combination of mid-parasternal and apical four-chamber views provides a good approximative estimate for both non-cardiologist emergency physicians and cardiologists.

Left ventricular ejection fraction assessment by non-cardiologists from transverse views using a simplified wall motion score index.

For the non-cardiologist emergency physician and intensivist, performing an accurate estimation of left ventricular ejection fraction (LVEF) is essential for the management of critically ill patients, such as patients presenting with shock, severe respiratory distress or chest pain. Our objective was to develop a semi-quantitative method to improve visual LVEF evaluation. A group of 12 sets of transthoracic echocardiograms with LVEF in the range of 18-64% were interpreted by 17 experienced observers (PRO) and 103 untrained observers or novices (NOV), without previous training in echocardiography. They were asked to assess LVEF by two different methods: i) visual estimation (VIS) by analysing the three classical left ventricle (LV) short-axis views (basal, midventricular and apical short-axis LV section) and ii) semi-quantitative evaluation (base, mid and apex (BMA)) of the same three short-axis views. The results for each of these two methods for both groups (PRO and NOV) were compared with LVEF obtained by radionuclide angiography. The semi-quantitative method (BMA) improved estimation of LVEF by PRO for moderate LV dysfunction (LVEF 30-49%) and normal LVEF. The visual estimate was better for lower LVEF (<30%). In the NOV group, the semi-quantitative method was better than than the visual one in the normal group and in half of the subjects in the moderate LV dysfunction (LVEF 30-49%) group. The visual estimate was better for the lower LVEF (ejection fraction <30%) group. In conclusion, semi-quantitative evaluation of LVEF gives an overall better assessment than VIS for PRO and untrained observers.