A heart attack occurs when blood flow to part of the heart is blocked, often by a blood clot, causing damage to the affected muscle.
This is usually caused by atherosclerosis – hardening of the artery walls. The clot, often caused by rupturing or tearing of plaque in an artery is sometimes called a coronary thrombosis or a coronary occlusion.
If blood supply is cut off for a long time, muscle cells are irreversibly damaged and die, leading to disability or death depending on the extent of the damage to the muscle.
A heart attack, also known as myocardial infarction, can also occur when a coronary artery temporarily contracts or goes into spasm, decreasing or cutting the flow of blood to the heart.
An unexpected and abrupt heart attack occuring soon after the onset of symptoms can result in sudden death.
It accounts for about half of all coronary heart disease deaths and can be caused by nearly all types of heart disease.
Three main symptoms of a heart attack:
1. Pressure or pain in the centre of the chest, lasting more than a few minutes or going away and coming back
2. Pain spreading to the shoulders, neck or arms
3. Chest discomfort combined with light-headedness, fainting, sweating, nausea or shortness of breath
Other common warning signs of heart attack include unusual chest, stomach or abdominal pain, nausea or dizziness, shortness of breath or difficulty breathing, unexplained anxiety, weakness or fatigue, palpitations, cold sweat or paleness.
What to do if someone has a heart attack
Check the victim for a response
If no response, ask someone to call for an ambulance. If you are on your own, do this yourself; you may need to leave the victim
Check the victim is breathing normally
If breathing is normal, place them in the recovery position and await help
If not, open their airway using a head tilt and chin lift and begin 30 chest compressions
Open the airway again and give two rescue breaths (mouth to mouth)
Continue the chest compressions and rescue breaths in a ratio of 30:2
For detailed instructions, visit the Resuscitation Council website.
Anybody experiencing these symptoms should call an ambulance immediately, but should not try to drive themselves to hospital, as complications can begin to occur before they get there.
Most people do have time to get to hospital and be treated before collapsing, but they do need to act quickly.
Some people wait for hours or even days before seeking help – they are the ones that get into trouble.
After a heart attack
Diagnosis of a heart attack usually involves a clinical examination, an electrocardiogram, heart rhythm monitoring and blood tests.
Echocardiograms or angiograms will detect the extent of damage to the heart.
Immediately after a heart attack, clot-busting drugs will be used to restore blood flow. Aspirin, to aid blood flow, and beta-blockers, to ease the heart’s work rate, may also be used.
In the days or weeks after a heart attack, surgery – either angioplasty or coronary artery bypass surgery – may be performed.
http://news.bbc.co.uk/2/hi/health/medical_notes/g-i/764015.stm
