How is the heart stopped during open heart surgery?

How is the heart beat stopped during surgery when connected to the heart lung machine?

Submitted by Vasanth from Guntut on 03/17/2014

by Denton A. Cooley, MD

The surgeon infuses a chemical agent (cardioplegia) which stops the heart’s function. The solution contains potassium ion which has a quieting effect on the heart. To restart the heart, blood flow is resumed in the coronary arteries which removed the potassium. Other agents may be used for this purpose, but potassium seems most practical.