4. Perspiration
It is common for profuse sweating to be one of the most common signs of a heart attack about to occur. This is due to a sudden rush of catecholamines right before the heart attack.
This hormone acts like dopamine and is what causes ‘cold sweats’ and clamminess. Again, this can be a symptom of other things but it should be considered a serious warning sign if it happens along with other symptoms on this list.