Right Ventricular Dilatation on Bedside Echocardiography Performed by Emergency Physicians Aids in the Diagnosis of Pulmonary Embolism

Study objective: The objective of this study was to determine the diagnostic performance of right ventricular dilatation identified by emergency physicians on bedside echocardiography in patients with a suspected or confirmed pulmonary embolism. The secondary objective included an exploratory analysis of the predictive value of a subgroup of findings associated with advanced right ventricular dysfunction (right ventricular hypokinesis, paradoxical septal motion, McConnell's sign). Methods: This was a prospective observational study using a convenience sample of patients with suspected (moderate to high pretest probability) or confirmed pulmonary embolism. Participants had bedside echocardiography evaluating for right ventricular dilatation (defined as right ventricular to left ventricular ratio greater than 1:1) and right ventricular dysfunction (right ventricular hypokinesis, paradoxical septal motion, or McConnell's sign). The patient's medical records were reviewed for the final reading on all imaging, disposition, hospital length of stay, 30-day inhospital mortality, and discharge diagnosis. Results: Thirty of 146 patients had a pulmonary embolism. Right ventricular dilatation on echocardiography had a sensitivity of 50% (95% confidence interval [Cl] 32% to 68%), a specificity of 98% (95% Cl 95% to 100%), a positive predictive value of 88% (95% Cl 66% to 100%), and a negative predictive value of 88% (95% Cl 83% to 94%). Positive and negative likelihood ratios were determined to be 29(95% Cl 6.1% to 64%) and 0.51(95% Cl 0.4% to 0.7%), respectively. Ten of 11 patients with right ventricular hypokinesis had a pulmonary embolism. All 6 patients with McConnell's sign and all 8 patients with paradoxical septal motion had a diagnosis of pulmonary embolism. There was a 96% observed agreement between coinvestigators and principal investigator interpretation of images obtained and recorded. Conclusion: Right ventricular dilatation and right ventricular dysfunction identified on emergency physician performed echocardiography were found to be highly specific for pulmonary embolism but had poor sensitivity. Bedside echocardiography is a useful tool that can be incorporated into the algorithm of patients with a moderate to high pretest probability of pulmonary embolism.