A 30 year old man with history of blunt trauma to the chest presents with dialated neck veins, BP 80/50mmHg and pulse rate of 100/ min. What is the most likely diagnosis?

Cardiac tamponade may result from bleeding into the pericardial space after cardiac operations, trauma, and treatment of patients with acute pericarditis with anticoagulants. The accumulation of fluid in the pericardial space in a quantity sufficient to cause serious obstruction to the inflow of blood to the ventricles results in cardiac tamponade, giving rise to decrease in stroke volume and decreased cardiac output. Beck's triad are hypotension, soft or absent hea sounds, and jugular venous distention with a prominent x descent but an absent y descent. Paradoxical Pulse is an impoant clue to the presence of cardiac tamponade, consists of a >10mmHg inspiratory decline in systolic aerial pressure. Diagnosis by echocardiography. Pericardiocentesis carried out once manifestations of tamponade appear. Ref: Advance Assessment and Treatment of Trauma By Michael D. Pante, Page 146 ; Harrison's Internal Medicine, 18th Edition, Pages 1972-74, 2179-2181