Transthoracic echocardiography for suspected pulmonary embolism in the intensive care unit: unjustly underused or rightfully ignored?

Transthoracic echocardiography (TTE) is an established part of modern medical practice, and its use in documenting cardiac disorders has long been recognized. Since the introduction of 2-dimensional TTE, the right-sided heart chambers have become amenable to fairly accurate analysis, enabling the evaluation of morphologic and functional abnormalities associated with many cardiopulmonary diseases, including pulmonary embolism (PE). The availability of small, portable echocardiographic units combined with an increasing number of intensive care specialists trained in echocardiography makes TTE an attractive modality for the diagnosis of PE in the intensive care unit (ICU). In the ICU setting, prompt decision-making and appropriate triage of critically ill patients can facilitate early institution of therapy for PE while awaiting patient stabilization and further definitive testing. Although several prior reviews incorporate TTE in the overall approach and clinical decision algorithms pertaining to the diagnosis and treatment of pulmonary embolism, no dedicated review exists that focuses purely on TTE. We attempt to fill that gap by reviewing the available literature pertaining to use of TTE in the diagnosis of suspected PE, and by better defining the use of TTE in the ICU setting. Emphasis is placed on the use of TTE as a clinical triage tool for suspected PE.