A man had heart attack symptoms on a flight. A cardiologist and a pocket-sized tool on board may have helped save his life

Oklahoma cardiologist Dr. TJ Trad was fast asleep on his flight from Uganda last month when a member of his team woke him up to say someone needed a doctor.

​ Oklahoma cardiologist Dr. TJ Trad was fast asleep on his flight from Uganda last month when a member of his team woke him up to say someone needed a doctor. Read More Breaking News, Latest News and Videos | CNN