A High-Echoic Layer Surrounding the Heart Suggesting Cardiac Tamponade by Clotting.

A 16-year-old boy experienced a sudden loss of consciousness. On arrival, he was in cardiac arrest. An ultrasound study revealed a high-echoic layer surrounding the heart. He received a diagnosis of clotting cardiac tamponade. Urgent thoracotomy with pericardiotomy was performed, but he failed to obtain return of spontaneous circulation. Physicians should focus on not only low-echoic but also high-echoic areas to accurately diagnose clotting, which can result in a critical condition if not managed properly.