Sorry, but it's extremely rare for a young (30-something) to drop dead of a heart attack without some serious underlying issues. I should know--I lost my sister at age 31, and there were serious underlying issues in her case.
There was a fine fine young man in my family tree that dropped dead at 30 years and 5 days old. Unlike his older brothers, he never did drugs, drink or eat the wrong foods. He took excellent care of himself and was a good Christian young man. He, his wife and 2 small daughters were in the grocery store just before Christmas 12 years ago when he dropped dead of a "heart attack".
I said "heart attack" but because it was so unexpected the family had an autopsy done. It was found that his mother carried a gene for some type of heart problem. She had had 2 brothers drop dead at an early age under similiar circumstances. All the children got test but were free of the gene. It was doulbly sad because it could have been treated with medication if it had been known he was carrying the gene. His 2 daughters were spared the gene.
About 5 years ago his widow remarried and her and her new husband had a son. Their son is the spitting image of her departed husband at that age. It's unbelieveable how much he looks and acts like the departed husband.