Determination of left ventricular function by emergency physician echocardiography of hypotensive patients

Abstract

Objective: To determine whether emergency physicians (EPs) with goal-directed training can use echocardiography to accurately assess left ventricular function (LVF) in hypotensive emergency department (ED) patients. Methods: Prospective, observational study at an urban teaching ED with >100, 000 visits/year. Four EP investigators with prior ultrasound experience underwent focused echocardiography training. A convenience sample of 51 adult patients with symptomatic hypotension was enrolled. Exclusion criteria were a history of trauma, chest compressions, or electrocardiogram diagnostic of acute myocardial infarction. A five-view transthoracic echocardiogram was recorded by an EP investigator who estimated ejection fraction (EF) and categorized LVF as normal, depressed, or severely depressed. A blinded cardiologist reviewed all 51 studies for EF, categorization of function, and quality of the study. Twenty randomly selected studies were reviewed by a second cardiologist to determine interobserver variability. Results: Comparison of EP vs. primary cardiologist estimate of EF yielded a Pearson's correlation coefficient R = 0.86. This compared favorably with interobserver correlation between cardiologists (R = 0.84). In categorization of LVF, the weighted agreement between EPs and the primary cardiologist was 84%, with a weighted kappa of 0.61 (p < 0.001). Echocardiographic quality was rated by the primary cardiologist as good in 33%, moderate in 43%, and poor in 22%. The EF was significantly lower in patients with a cardiac cause of hypotension vs. other patients (25 ± 10% vs. 48 ± 17%, p < 0.001). Conclusions: Emergency physicians with focused training in echocardiography can accurately determine LVF in hypotensive patients.