José Luis Palma, the vice-president of the Spanish Heart Society, says more than 50 per cent of people who have a heart attack die in the first 48 hours, in addition to the two to four per cent who die in the coronary units of hospitals.
Altogether, about 70,000 people die of cardiac failure in Spain every year.
The difference between surviving or dying lies in something as simple as knowing what to do.
"If someone suffers a strong and intense pain in the chest and a feeling of immediate death, there is no time to lose," says the specialist.
"Ring the 112 emergency number and take an aspirin as quickly as possible."
In women, this pain often manifests itself as a severe stomach ache.
Sometimes there is no warning of an impending heart attack. There are no symptoms. It is often the luck of the draw.