Heart is only one in a human body. As such heart donation is rare and one canot give his heart when he is alive. However, a patient who is brain dead can donate a heart. At the same time who is in ventilator can follow same procedure. For doing transplant formality, one need to put his name in national list. In America, 4000 people are waiting for such type of list. When the Donner heart is received may take 6-8 hours for transplant.
There is a factor for matching like surgery, blood type, size of body etc. Normally a surgery takes place and heart patient may require few days to stand on feet. He can release from hospital within 2 weeks. Heart transplant can save a life and there are 85% survival rate. Moreover medication can also reduce the risk of complication after a heart is transplanted.
95% of Americans are in favor of being a donor but the registration rate is only 58%.