Role of Echocardiography in Patients With Acute Pulmonary Thromboembolism

Abstract

Introduction Acute pulmonary thromboembolism (PTE) is a common problem. There are at least 600,000 estimated cases of newly diagnosed PTE and more than 50,000 related deaths in the United States each year. The overall 3-month mortality rate for all patients who present with PTE is reported to be about 15% and the reported mortality rate for those in shock is nearly 50%.3) This fatality rate for PTE exceeds the mortality rate for acute myocardial infarction. In spite of increasing knowledge about PTE and imaging technology, the antemortem diagnosis of fatal PTE has not changed appreciably over the last 40 years and remains fixed at approximately 30%. Acute coronary syndromes, acute aortic syndromes and acute PTE are the three major disease entities in patients presenting with chest pain in the emergency room. The problem is the similarity in clinical presentation between acute coronary syndromes and PTE. The most common symptoms in PTE include dyspnea in 80% and chest discomfort in 65% of patients. However, these symptoms are nonspecific in the differentiation of PTE and acute coronary syndromes. Also, features of PTE on physical examination are nondiscriminatory in the differentiation. Given the significant overlap of signs and symptoms between PTE and acute coronary syndromes, clinicians, especially cardiologists, should be familiar with this disease entity. PTE should be considered as one of the possible causes. Presently, accepted diagnostic modalities for the confirmation of PTE include ventilation/perfusion (V/Q) scanning, chest computed tomography (CT), and standard angiography. Although chest CT scanning has for the most part replaced lung scanning as the main diagnostic test for PTE, transthoracic echocardiography (TTE) is a noninvasive modality providing rapid results at the bedside. This modality is one of the most useful tests in aiding diagnosis and risk stratification in patients with PTE. In this review, we will discuss the role of echocardiography in patients with PTE.