Final answer:
The most effective treatment for cardiac tamponade is pericardiocentesis, which involves the removal of excess fluid from the pericardial cavity.
Step-by-step explanation:
The most effective treatment for cardiac tamponade is pericardiocentesis. Cardiac tamponade is a condition in which excess fluid, often blood, accumulates within the pericardial cavity, putting pressure on the heart and preventing it from fully relaxing. Pericardiocentesis involves the insertion of drainage tubes into the pericardial cavity to remove the excess fluid, relieving the pressure on the heart.