Transthoracic Echocardiography for Diagnosing Pulmonary Embolism: A Systematic Review and Meta-Analysis

Objective: Pulmonary embolism (PE) is a common diagnosis with significant mortality if not appropriately treated. The use of transthoracic echocardiography in patients with PE is common; however, its diagnostic capabilities in this use are unclear. With the increased use of ultrasonography in medical settings, it is important to understand the strengths and limitations of echocardiography for the diagnosis of PE.

Methods: We conducted a systematic review of PubMed, CINAHL, and EMBASE through 2016 for articles assessing the diagnostic accuracy of transthoracic echocardiography for PE. Two authors independently abstracted relevant data from the studies. We assessed quality using the QUADAS-2 tool for diagnostic studies.

Results: Undefined "right heart strain" was the most common sign used, and it had a sensitivity of 53% (95% CI, 45%-61%) and a specificity of 83% (95% CI, 74%-90%). Eleven other distinct signs were identified: ventricle size ratio, abnormal septal motion, tricuspid regurgitation, 60/60 sign, McConnell's sign, right heart thrombus, right ventricle hypokinesis, pulmonary hypertension, right ventricular end-diastolic diameter, tricuspid annular plane systolic excursion, and right ventricular systolic pressure.

Conclusions: Studies show a consistently high specificity and low sensitivity for echocardiography in the diagnosis of PE, making it potentially adequate as a rule-in test at the bedside in critical care settings such as the emergency department and intensive care unit for patients with a suspicion of PE, especially those unable to get other confirmatory studies. Future research may continue to clarify the role of bedside echocardiography in conjunction with other tests and imaging in the overall management of PE.