Regional cardiac tamponade resulting in hypoxia from acute right to left inter-atrial shunting.

Loculated pericardial effusion, as a cause of acute hypoxia, is an unusual finding. Here, we describe the case of a patient who underwent percutaneous coronary intervention, complicated by a localized pericardial hematoma compressing the right atrium, resulting in right to left shunting of blood through a patent foramen ovale and subsequent hypoxia. Evacuation of the hematoma was eventually performed via a pericardial window with resolution of hypoxia.