Apport de l'échocardiographie Doppler dans le diagnostic et la prise en charge des tamponnades

Cardiac tamponade refers to the circulatory compromise secondary to a compressive pericardial effusion. Tamponade is a vital emergency that requires rapid diagnosis and prompt treatment. Echocardiography Doppler is a portable, non invasive imaging modality, which is ideally suited in this setting to rapidly confirm the clinical suspicion of tamponade and help guiding therapeutic management. Tamponade is typically the result of a circumferential pericardial effusion secondary to a medical disease that impairs venous return and right heart filling. Transthoracic echocardiography (TTE) allows the identification of a compressive pericardial effusion using two-dimensional imaging, with primarily collapsed right cardiac cavities. Increased respiratory variations of Doppler velocities of mitral and tricuspid blood flows reflect the hemodynamic compromise secondary to the compressive pericardial effusion, but are only present in spontaneously breathing patients. After cardiac surgery or severe blunt chest trauma, circulatory failure may be secondary to a localized tamponade associated with a loculated hemopericardium or a compressive mediastinal hematoma. In this clinical setting, transesophageal echocardiography (TEE) is required because TTE has a poor sensitivity. TEE is usually well tolerated since those patients are mechanically ventilated. It allows the accurate identification of both the mediastinal hematoma and collapsed cardiac cavity. Importantly, localised tamponade may result in the elective compression of left cardiac cavities. In all cases, echocardiography helps guiding therapy, whether it relies on a pericardocentesis or surgery. Echocardiography Doppler constitutes a valuable help for the identification and therapeutic management of patients with circulatory failure associated with cardiac tamponade.