Visual Estimation of Bedside Echocardiographic Ejection Fraction by Emergency Physicians

Abstract

IntroductionThe objective of this study was to determine whether bedside visual estimates of left ventricular systolic function (LVSF) by emergency physicians (EP) would agree with quantitative measurement of LVSF by the modified Simpson’s method (MSM), as recommended by the American Society of Echocardiography.MethodsAfter limited focused training, 2 trained EPs performed bedside echocardiography (BECH) procedures s between January and June 2012 to prospectively evaluate patients presenting to the emergency department (ED) with dyspnea. EPs categorized their visually estimated ejection fractions (VEF) as either low or normal. Formal echocardiography were ordered and performed by an experienced cardiologist using the MSM and accepted as the criterion standard. We compared BECH results for each EP using chi-squared testing and performed correlation analysis by Pearson correlation coefficient.ResultsOf the 146 enrolled patients with dyspnea, 13 were excluded and 133 were included in the study. Comparison of EPs vs. cardiologist’s estimate of ejection fraction yielded a Pearson’s correlation coefficient of 0.77 (R, p<0.0001) and 0.78 (R, p<0.0001). Calculated biserial correlations using point-biserial correlation and z-scores were 1 (rb, p<0.0001) for both EPs. The agreement between EPs and the cardiologist was 0.861 and 0.876, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and the positive and negative likelihood ratios for each physician were 98.7–98.7%, 86.2–87.9%, 0.902–0.914, 0.980–0.981, 7.153–8.175, 0.015–0.015, respectively.ConclusionEPs with a focused training in limited BECH can assess LVSF accurately in the ED by visual estimation.

Introduction of portable bedside echocardiography to acute general medicine

“…The accuracy of our echoes is comparable with that reported elsewhere . We have demonstrated that 85% of our studies were concordant or largely concordant with formal echocardiographic studies.…”

“…However many of our patients had abnormal physical signs that were confirmed or ruled out by PBU, thus speeding up the decision‐making process as to whether further investigations were required in or out of hospital . With regard to heart failure, left ventricular function cannot reliably be estimated from physical examination, but both systolic and diastolic dysfunction can be rapidly diagnosed by PBU . Therefore, in the breathless, volume‐overloaded patient, the acute team can confirm rapidly that heart failure is the mechanism before aggressive diuretic therapy is started.…”

“…7 With regard to heart failure, left ventricular function cannot reliably be estimated from physical examination, but both systolic and diastolic dysfunction can be rapidly diagnosed by PBU. 8,9 Therefore, in the breathless, volume-overloaded patient, the acute team can confirm rapidly that heart failure is the mechanism before aggressive diuretic therapy is started. Volume status can be difficult to assess in patients with severe respiratory disease and right ventricular failure.…”

Transthoracic echocardiography in the perioperative setting

“…Echocardiography most of the time relies on eyeballing for the estimation of ejection fraction. Eyeballing correlates well with quantitative techniques and allows us to categorize ejection fraction in subgroups [38,39]: more than 52%; normal, 41-52%; mildly abnormal, 30-40%; moderately abnormal and less than 30%; severely abnormal [40 & ]. Eyeballing of ejection fraction may be performed from the apical four-chamber and parasternal views.…”

Cardiac Ultrasonography in the critical care setting: a practical approach to asses cardiac function and preload for the “non-cardiologist”

“…Some articles state that focused training in the 'eyeballing technique' can result in acceptable accuracy in estimating LVEF [21].…”