A 51-year-old woman presented to the emergency department (ED) with severe shock, unresponsiveness, and motor restlessness. She had been found unconscious in an open field with horses. Primary survey revealed a self-maintained airway and spontaneous breathing without external blood loss. Glasgow Coma Scale score was 7. Complete physical examination revealed parasternal bruising resembling a horseshoe print (Figure 1). Initial systolic blood pressure was between 70 and 90 mm Hg, with a pulse rate of 130 beats/min, with no improvement despite volume replacement with 0.9% normal saline solution. After intubation, a markedly elevated jugular venous pressure was observed and sinus tachycardia persisted. A pulsus paradoxus was not observed. Chest radiograph showed an enlarged cardiac silhouette (Figure 2). Abdominal ultrasonography result was normal. Bedside cardiac ultrasonography was not available in the ED.Figure 2Chest radiograph showing enlarged cardiac silhouette.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Cardiac tamponade caused by a blunt thoracic trauma. Initial diagnosis of traumatic cardiac tamponade is difficult, especially in blunt chest injury. Clinical suspicion increases when sinus tachycardia, elevated jugular venous pressure, or pulsus paradoxus is present and irresponsive to volume replacement.1Spodick D.H. Acute cardiac tamponade.N Engl J Med. 2003; 349: 684-690Crossref PubMed Scopus (530) Google Scholar Blood in the pericardial sac causes pressure on the cardiac ventricles and reduces diastolic compliance, and then causes a decrease in systemic and venous return, and eventually death from cardiogenic shock, ie, cardiac tamponade.1Spodick D.H. Acute cardiac tamponade.N Engl J Med. 2003; 349: 684-690Crossref PubMed Scopus (530) Google Scholar, 2Von Wachenfelt H, Nilsson C, Ventorp M. Measurement of kick loads from horses on stable fittings and building elements. 2013. Available at: http://pub.epsilon.slu.se/10949/7/wachenfelt_etal_131220.pdf. Accessed April 2, 2015.Google Scholar, 3Fitzgerald M. Spencer J. Johnson F. et al.Definitive management of acute cardiac tamponade secondary to blunt trauma.Emerg Med Australas. 2005; 17: 494-499Crossref PubMed Scopus (47) Google Scholar Our patient immediately underwent needle pericardiocentesis at the ED (Figure 3), where 150 mL of blood was drained, resulting in hemodynamic stability. After the pericardiocentesis, right-sided cardiac failure developed, which was successfully treated with diuretics. The patient fully recovered and was discharged home after 9 days.