The role of echocardiography in suspected and established PE

Acute obstruction of more than 30% of the pulmonary arterial bed often results in abnormal right ventricular (RV) transthoracic Doppler echocardiography (TTE), usually defined as RV dysfunction, dilatation, or hypokinesis. The presence of such changes strongly increases the clinical probability of pulmonary embolism (PE) (specificity, 81 to 94%; PPV, 71 to 86%) and indicates a worse prognosis, especially if a patent foramen ovale is found at contrast TTE. Normal RV echocardiography indicates a good prognosis. Integrating TTE with venous ultrasound and transesophageal imaging increases the possibility of immediate definitive justification for specific therapy. This strategy permits direct visualization of thrombi either in proximal veins, pulmonary arteries, or right heart chambers. Mobile thrombi require immediate thrombolysis or urgent embolectomy. Whether any echo-based criteria might identify normotensive patients with PE who should receive thrombolytic therapy remains a subject for an overdue large prospective trial.