If doctors in hospital can start treatment with clot dissolving drugs quickly, the heart muscle may be rescued or the damage minimised. If you have some, take one aspirin tablet as this greatly helps minimise the damage to heart muscle from the blocked artery. Rapid treatment with aspirin and clot dissolving drugs saves lives. Firstly, stop smoking . Secondly, stop others smoking.
Smoking is the major avoidable cause of heart disease.
It contributes to furring up of your arteries and reduces the oxygen carrying capacity of blood. Exercise will make you feel better and increase the stamina and blood supply of the heart. Obviously if you have pre-existing heart disease discuss this with your doctor. If you are not sure of your exercise limits and for healthy but unfit people, start gently, perhaps with brisk walking and build up your tolerance to exercise. If exercise brings on chest pain, see your doctor.