The treatment for pericardial tamponade is a heroic procedure called a pericardiocentesis, during which, a needle is placed through the pericardial sac and the fluid is drained. This relieves pressure on the outer walls of the heart, increases cardiac filling, and improves cardiac output. According to my favorite medical search engine, @OpenEvidence , surgery (pericardotomy or pericardial window) is indicated “for tamponade due to aortic dissection, trauma, ongoing bleeding, or when percutaneous

Anatomy of the Heart