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.

Right ventricular ejection fraction with cardiac magnetic resonance using a wall motion score.

BACKGROUND: The volumetric method in cardiac magnetic resonance (CMR), the reference standard for right ventricular ejection fraction (RVEF), requires expertise because of the complex right ventricular geometry and anatomical landmarks. AIM: The aim of our retrospective study was to describe a new method to evaluate RVEF based on wall motion score index (WMSI) in CMR. METHODS: Visual assessment of wall motion was performed using an eight-segment model (normokinesia=1, hypokinesia=2, akinesia=3). Correlation between WMSI (WMS/8) and the reference volumetric RVEF was analysed. A regression equation was derived to convert the WMSI into RVEF. The accuracy of CMR WMSI-derived RVEF compared with CMR volumetric RVEF was evaluated using Bland-Altman analysis. RESULTS: In the 112 patients using the volumetric method, the mean RVEF was 48±14%. Fifty-nine patients had normal RV kinetics (WMSI=1), which corresponded to a volumetric RVEF of 56% (standard deviation 7%; range 43-76%). CMR WMSI showed a strong correlation with CMR volumetric RVEF (Spearman's Rho=-0.69). A regression equation was created: RVEF=80-22×WMSI. Overall, the WMSI-derived RVEF resulted in good agreement with the CMR volumetric RVEF (mean bias-3%, standard deviation±7.5%). In addition, using a WMSI cut-off of≥1.5 was highly accurate (92%) to predict a reference RVEF of˂45%, an important prognostic indicator in CMR. CONCLUSIONS: Our results suggest that using the WMS in CMR (eight-segment) to estimate RVEF is accurate, and correlates well with the volumetric method. A WMSI≥1.5 is optimal to categorize patients in the higher-risk subset of CMR RVEF˂45%.

Assessment of LVEF using a new 16-segment wall motion score in echocardiography.

BACKGROUND: Simpson biplane method and 3D by transthoracic echocardiography (TTE), radionuclide angiography (RNA) and cardiac magnetic resonance imaging (CMR) are the most accepted techniques for left ventricular ejection fraction (LVEF) assessment. Wall motion score index (WMSI) by TTE is an accepted complement. However, the conversion from WMSI to LVEF is obtained through a regression equation, which may limit its use. In this retrospective study, we aimed to validate a new method to derive LVEF from the wall motion score in 95 patients. METHODS: The new score consisted of attributing a segmental EF to each LV segment based on the wall motion score and averaging all 16 segmental EF into a global LVEF. This segmental EF score was calculated on TTE in 95 patients, and RNA was used as the reference LVEF method. LVEF using the new segmental EF 15-40-65 score on TTE was compared to the reference methods using linear regression and Bland-Altman analyses. RESULTS: The median LVEF was 45% (interquartile range 32-53%; range from 15 to 65%). Our new segmental EF 15-40-65 score derived on TTE correlated strongly with RNA-LVEF (r = 0.97). Overall, the new score resulted in good agreement of LVEF compared to RNA (mean bias 0.61%). The standard deviations (s.d.s) of the distributions of inter-method difference for the comparison of the new score with RNA were 6.2%, indicating good precision. CONCLUSION: LVEF assessment using segmental EF derived from the wall motion score applied to each of the 16 LV segments has excellent correlation and agreement with a reference method.

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.

Assessment of left ventricular ejection fraction using the wall motion score index in cardiac magnetic resonance imaging.

BACKGROUND: Left ventricular ejection fraction (LVEF) is an important indicator of left ventricular function and of the severity and prognosis of ischaemic heart disease. Assessment of regional function using the wall motion score index (WMSI) is an alternative means of evaluating left ventricular function. AIM: We attempted to evaluate LVEF by a method using the WMSI with cardiac magnetic resonance imaging (MRI). METHODS: One hundred and twenty-two patients referred for evaluation of heart disease had rest WMSI evaluation by cardiac MRI. The WMSI was evaluated using the 16-segment model and score proposed by the American Society of Echocardiography. In our first group of 80 patients, a correlation between WMSI and cardiac MRI LVEF was established and a regression equation was derived. This regression equation was then used in 42 consecutive patients to compare WMSI LVEF with the gold standard MRI LVEF. RESULTS: In the first 80 patients, MRI LVEF and WMSI correlated very well (r=0.93). Similarly, in the second group of 42 patients, WMSI LVEF derived from the regression equation correlated very well with MRI LVEF (r=0.94). CONCLUSION: An objective evaluation of LVEF can be easily made using the WMSI with cardiac MRI, which correlates very well with standard MRI planimetric methods.

Two-dimensional echocardiography estimation of right ventricular ejection fraction by wall motion score index.

BACKGROUND: Radionuclide angiography (RNA) and echocardiography (biplane Simpson method) are the most accepted methods for right ventricular ejection fraction (RVEF) evaluation. The authors tried to determine a new method to measure RVEF based on wall motion score index (WMSI). OBJECTIVES: One hundred forty-one patients with RV dysfunction had transthoracic echocardiography (TTE) evaluation of the right ventricle. In a first group of 54 patients, a correlation between RVEF using the biplane Simpson method (four chamber and two chamber [4C+2C]) and RV-WMSI was established from a polar map using an eight-segment model to find a regression equation. With the second group of 51 subsequent patients, this equation (RVEF=73.07-20.7 x WMSI), comparing the RVEF-WMSI with the biplane Simpson RVEF (4C+2C), was validated. In a third group of 36 consecutive patients with abnormal RV contractility, the RVEF was calculated by RNA and this RVEF was correlated to the RV-WMSI. RESULTS: The first group of 54 patients had a correlation coefficient of 0.84 between WMSI and RVEF (biplane Simpson method). The results from the second group of 51 patients with RVEF derived from the estimated regression equation correlated well with the biplane Simpson RVEF (r=0.84). The correlation coefficient for these two groups taken together (105 patients), that is, between WMSI and RVEF (biplane Simpson method), was 0.92. The third group of 36 patients with RNA-EF displayed a correlation coefficient of 0.83 with RV-WMSI. CONCLUSION: This new semiquantitative method for estimating RVEF from RV-WMSI is easy to use in routine TTE and shows an excellent correlation with the biplane Simpson method and RNA.

A new tool for estimating left ventricular ejection fraction derived from wall motion score index.

BACKGROUND: Radionuclide angiography (RNA) and echocardiography (biplane Simpson method) are the most accepted techniques for left ventricular ejection fraction (LVEF) assessment. A new method to evaluate LVEF based on the regional wall motion assessment of the LV was attempted. OBJECTIVE: To develop a simple method for LVEF estimation using wall motion score index (WMSI) with transthoracic echocardiography (TTE). METHODS: Two hundred and forty-three patients with abnormal LV contractility had TTE and RNA performed less than three days apart. The WMSI was calculated in all patients using the 16-segment model as proposed by the American Society of Echocardiography. For the first 150 patients, a correlation between LV WMSI and RNA EF was established to create a regression equation. This regression equation (RNA LVEF=92.8-25.8xWMSI) was used on 93 consecutive patients to compare this equation with RNA EF. From the total cohort (243 patients), three subgroups were studied specifically: atrial fibrillation (AF) (n=50 patients), dyskinesia (DK) (n=40 patients) and aneurysm (AN) (n=42 patients). RESULTS: Correlation between RNA EF and WMSI in the first 150 patients was r=0.82. In the second group of 93 consecutive patients, WMSI EF derived from the estimated regression equation correlated well with RNA EF (r=0.86). Correlation remained high in the three subgroups: AF (r=0.87), DK (r=0.87) and AN (r=0.80). In the 111 patients without DK, AN or AF correlation between RNA and the studied method was even higher (r=0.91). In a random subgroup of 54 patients, RNA was compared with the biplane Simpson method (49 of 54 patients, r=0.82). In the same subgroup of 54 patients, the score was modified to allow for mild hypokinesia (score=1.5) and severe hypokinesia (score=2.5) (54 of 54 patients, r=0.83). CONCLUSION: LVEF assessment by this new simple mathematical model using the WMSI is feasible and easy to use during routine TTE. It has excellent correlation with other methods such as biplane Simpson and RNA.