A heart attack, or myocardial infarction, occurs when a coronary arterybecomes completely blocked due to a blood clot or arterial plaque. Part of the heart muscle dies due to oxygen deprivation, and this gives rise to the crushing chest pain characteristic of a heart attack.

While chest pain is the most common symptom of a heart attack, victims might suffer from other symptoms

Physical symptoms include :

• Shortness of breath
• Palpitations (irregular heart beats)
• Quickened heartbeat
• Weak spells or dizziness
• Nausea
• Sweating
• Unusual tiredness, sometimes for days

Caregivers and family members of cardiac patients should be alert to a sudden and complete loss of responsiveness, as well as a cessation of signs of circulation, both of which may also be warning signs of a heart attack.

Immediate treatment for heart attack victims is critical because their chances of survival rapidly diminish with every passing minute. When the heart stops beating, brain damage sets in after 3 minutes, and death is virtually certain if no resuscitation is given to the victim within the first 10 minutes.