"Stopping the heart is accomplished by shutting off its blood supply (a process called ). I discovered blood '... We initially realized the return of regular blood to a heart that has been without blood supply, will create severe damage. We then discovered how to prevent this injury by using a blood cardioplegic solution that contains selected chemical ingredients (including key amino acids...)that safely protects the heart... [E]ffectiveness... depended upon their arriving at specific locations... But many of our patients had narrowed arteries... This barrier was overcome by delivering it in a "backward direction" via the heart’s main vein... further enhanced by administering it at different temperatures during the beginning and end of the operation."