Role of echocardiography as a screening test in patients with suspected pulmonary embolism

ABSTRACT

BACKGROUND AND OBJECTIVES: Pulmonary embolism (PE) is a disease with high mortality if left untreated. But, confirmative diagnosis is difficult because many diagnostic modalities are nonspecific. Pulmonary angiography, which is considered as the gold standard diagnostic tool, is invasive, costly, time-consuming, and not always available in small centers. Echocardiography is a non-invasive and available in the emergency room without significant time delay. We investigated the role of echocardiography as a screening test in patients with suspected PE. MATERIALS AND METHODS: (A) Retrospective study We analyzed the recorded videotapes of transthoracic echocardiography in fifty patients with confirmed PE from Jan 1995 to Aug 1999. From the frequent echocardiographic findings of those patients, positive criteria were defined as followed ( 2 among 1-5 or only 6). (1) RV or pulmonary artery dilatation (RVEDA/LVEDA 0.6) (2) RV hypokinesis (3) paradoxical septal wall motion (4) pulmonary hypertension (5) TR (moderate degree or more) (6) Visible thrombus. Although the degree of TR was less than moderate, if the degree of pulmonary hypertension was more than moderate, we considered as PE. (B) Prospective study From Nov 1999 to June 2000, patients with suspected pulmonary embolism underwent a transthoracic echocardiography and perfusion-ventilation lung scan or chest CT. We assessed echocardiographic findings, sensitivity and specificity of the previously defined echocardiographic positive criteria for PE. RESULTS: (A) Retrospective study The sensitivity of echocardiography for PE was 74%. (B) Prospective study The number of enrolled patients was thirty-four. In twenty patients the diagnosis was PE. The sensitivity of echocardiography was 75% but the specificity was 14%. CONCLUSION: Echocardiography may be used as a good screening test in patients who are clinically suspicious of pulmonary embolism.