I take my heart outside with me, every time I go out. If you meant outside the chest cavity, I would estimate perhaps 3 minutes before brain death.
6 hours.
1 to 3
If your heart beats 60 times per minute (a good heart rate for an athlete) your heart will beat 180 times in three minutes.
10 minutes
25-30 minutes....
about 30 minutes per day
7000
Twelve minutes.
About as many times as its heart beats in two minutes divide by 2...
40,000,000
500 times
72 beats per minute