Cardiac tamponade is a cardiovascular emergency that can potentially be fatal if left untreated. It consists of a rapidly developing pericardial effusion, accumulating so fast that it doesn¿t allow the heart to distend properly during diastole, essentially ¿compressing¿ the heart. This results in a markedly diminished left ventricle diastolic volume, and therefore stroke volume and cardiac output are also compromised. The end results are signs and symptoms of low cardiac output and systemic congestion. The most common cause is secondary to large pericardial effusions due to malignancies, iatrogenic (peri-procedure) and post-cardiac surgery. The diagnosis is made clinically, supported by hypotension, tachycardia, muffled heart sounds, jugular venous distention, and the presence of pulses paradoxus. Echocardiography should confirm the diagnosis, not make it. It is important to keep in mind that several echocardiographic parameters should be assessed before reaching a conclusion and one single echocardiographic abnormality by itself is not definitive. Other diagnostic tools include chest radiograph, electrocardiogram, and computed tomography, but echocardiogram remains the most useful paraclinical assessment. Treatment of cardiac tamponade generally involves drainage either by pericardiocentesis or surgical drainage (these procedures are covered in another chapter). The timing of the intervention depends on the hemodynamic stability of the patient and the etiology of the effusion.
