Accuracy of emergency physician assessment of left ventricular ejection fraction and central venous pressure using echocardiography

Abstract

Objectives: Emergency department (ED) bedside echocardiography may offer useful information on cardiac function and volume status. The authors evaluated the accuracy of emergency physician (EP) performance of echocardiography in the assessment of left ventricular ejection fraction (LVEF) and central venous pressure (CVP).

Methods: The authors conducted a cross-sectional observational study at an urban teaching ED, involving a convenience sample of patients presenting to the ED between September 2000 and February 2001. Level III-credentialed EP sonographers who had undergone a three-hour training session in limited echocardiography, focusing on LVEF and CVP measurement, performed echocardiograms. Vital signs and indication for echocardiography were documented on a study data sheet. LVEF was rated as poor (<30%), moderate (30%-55%), or normal (>55%) and an absolute percentage. Central venous pressure categories included low (<5 cm), moderate (5-10 cm), and high (>10 cm). Formal echocardiograms were obtained within a four-hour window on all patients and interpreted by a staff cardiologist. Correlation analysis was performed using the kappa correlation coefficient for LVEF and CVP categories and a Pearson correlation coefficient for LVEF measurement.

Results: A total of 115 patients were assessed for LVEF, and 94 patients had complete information for CVP. Indications for echocardiography included chest pain (45.1%), congestive heart failure (38.1%), dyspnea (5.7%), and endocarditis (10.6%). Results showed a LVEF correlation of r(2) = 0.712 with 86.1% overall agreement. Subgroup analysis revealed the highest agreement (92.3%) between EP and formal echocardiograms within the normal LVEF category, followed by 70.4% agreement in the poor LVEF category and 47.8% in the moderate LVEF category. Central venous pressure measurements resulted in 70.2% overall raw agreement between EP and formal echocardiograms. Subgroup analysis revealed the highest agreement (83.3%) within the high CVP category followed by 66.6% in the moderate and 20% in the low categories.

Conclusions: Experienced EP sonographers with a small amount of focused additional training in limited bedside echocardiography can assess LVEF accurately in the ED.