How do you get a heart on its own to start beating again after it has stopped?

Question: How do you get a heart on its own to start beating again after it has stopped?
- Keywords:
  beating,
  heart
Asked by alex.a to Noel on 9 Mar 2015.
- Noel Carter answered on 9 Mar 2015:
  
  We created an artificial circulatory system with a dialysis machine to act as the kidney and a pump to help the heart and we add sugar for energy and blood to transport oxygen. We warm the heart up slowly and pump fluid round then we give it a small electrical shock to get it started again .

Question: How do you get a heart on its own to start beating again after it has stopped?