What is the treatment for massive hemopericardium and cardiac tamponade?

Relieve the pressure off the heart by removing the excess fluid or blood.

This is performed either by pericardiocentesis, which is the procedure where a large needle is inserted into the pericardium and the blood/fluid is removed. If the cause is an injury to the heart itself, this may be enough of a temporizing measure (but definitely not curative) to allow the patient to have the time to make it to the operating room with a cardiac surgeon who can repair the injury. If the patient loses vital signs in the Emergency room and is not stable enough to go to the operating room (OR), an emergency thoracotomy may need to be performed. The left chest is opened emergently and the pericardium is entered primarily in an effort to find the damage to the heart and repair it temporarily to allow the patient to go to the OR for primary repair and closure.

Unfortunately, hemopericardium and tamponade caused by primary cardiac rupture/injury is not something most will survive, and emergency thoracotomy has a survival rate of less than 5 percent (probably on the order of 1 to 2 percent survival). It really is a last-ditch effort to save someone's life, but in most cases is not successful, despite a physician's best efforts.