Thanks for posting your query.
Did your friend has chest pain/ squeezing sensation in chest at the time of admission?
Did your friend has any other associated symptoms?
Did your friend has involvement of any other organ at the time of admission?
What was the age of your friend?
After reading your query, vomiting
appears to be primary symptoms and heart attack
appeared after continuous bloody vomit.
Recurrent and persistent vomiting may compromise blood circulation and may decrease blood supply to heart and may cause heart attack changes in ECG.
In heart attack, vomiting may occur but blood vomit is less common.
Dr. Mayank Bhargava