He didn't want to get upset in case he had a heart attack.
What is he upset about?
His investments did poorly.
When life serves us disappointments he should be mindful over his health especially since he is prone to heart attacks. If he endured too much stress, the worst might happen.
I'm sure he's fine. I've already helped him get past a heart attack, he will be fine.
It might be good to take him to get a new EKG to be sure. Have you tried talking with him about his investment choices? It might be good to let him have a professional take control to get some moderate growth.