Pericardial effusion and tamponade: evaluation, imaging modalities, and management.

Pericardial effusions may be present in a variety of clinical situations, often presenting challenging clinical diagnostic and therapeutic problems. Although several imaging modalities are available, ECHO has become the diagnostic method of choice due to its portability and wide availability. CT and MRI may also be employed and may be more accurate. A pericardial effusion under pressure may result in hemodynamic compromise and tamponade. Although there are several echocardiographic clues to tamponade (including diastolic chamber collapse, Doppler flow velocity paradoxus, and inferior vena cava phlethora), the diagnosis remains a clinical and hemodynamic one. The clinical signs include elevated jugular venous pressure, hypotension, tachycardia, and pulsus paradoxus. Hemodynamic measurements include equalization of diastolic pressures and decreased cardiac output Treatment of tamponade involves drainage of the effusion and prevention of reaccumulation. Needle pericardiocentesis via the subxiphoid approach is a reasonable initial treatment. However, this may need to be accompanied by catheter drainage or surgical pericardial window. A new catheter based technique--percutaneous balloon pericardiotomy-- appears useful in select patients with malignancy in order to avoid more invasive surgical procedures. Occasionally, in patients with recurrent effusions, instillation of sclerosing agents into the pericardial space or even total pericardiectomy may be necessary.