Answer
Nearly all gunshot wounds penetrating the heart are fatal. Large caliber and high velocity penetrating trauma to the heart cause too much damage to allow a quick repair. An occasional victim, shot from a great distance or with a small caliber weapon will survive.
The heart shielded by the skin, muscles and bone of the chest, is surrounded by pericardium, a tough, slick sack that protects, lubricates and holds the heart in position. A puncture of the pericardium is not fatal and the bullet can usually be found in the pericardial fluid or partially embedded in the heart muscle (myocardium). Any amount of bleeding from a perforation of the heart muscle or great vessels rapidly fills the pericardium with blood and compresses the heart itself, preventing it from filling (pericardial tampanade). This causes and abrupt loss of blood pressure, unconsciousness and death. The treatment in this case if you still have a live patient is to open the chest and percardium and plug the hole, usually with a finger until you can get to the operating room. A suture repair of the hole is required to stop the impressive bleeding. Following surgery drains are placed, large plastic tubes, and applied to suction and the chest is closed. The patient will spend a variable amount of time in the intensive care unit depending on the location and severity of the injury to the heart. The patient may have other injuries or might have brain damage because of loss of blood pressure. Hope this helps.
