What Is a Heart Attack?
Heart attack (known as a
myocardial infarction) is the death of heart muscle from the sudden
blockage of a coronary artery (blood vessels that supply the heart muscle with blood and oxygen) by a blood clot. Blockage
of a coronary artery deprives the heart muscle of blood and oxygen, causing injury to the heart muscle. Injury to the heart muscle causes
chest pain and pressure. If blood flow is not restored within 20 to 40 minutes, irreversible death of the heart muscle will begin to occur.
Muscle continues to die for six to eight hours at which time the heart attack usually is "complete." The dead heart muscle is replaced
by scar tissue.
Causes of Heart Attack
Following is a list of causes or underlying conditions that could possibly cause Heart attack includes:
- Heart disease
- Coronary heart disease
- Atherosclerosis
- Coronary thrombosis(see Heart symptoms)
- Arrhythmias
- Electrolyte imbalance
- Shock
- Severe injury
- Hemorrhage
- Electrocution
- Anaphylactic shock
Symptoms of a heart attack are:1. Discomfort, pressure, heaviness, or pain in the chest, arm or below the breastbone
2. Discomfort radiating to the back, jaw, throat or arm
3. Fullness, indigestion or choking feeling (may feel like heartburn)
4. Sweating, nausea, vomiting or dizziness
5. Extreme weakness, anxiety or shortness of breath
6. Rapid or irregular heartbeats
7. During a heart attack, symptoms last 30 minutes or longer and are not relieved by rest or oral medications (medications taken by mouth).
Some people have a heart attack without having any symptoms (a "silent" myocardial infarction). A silent MI can occur in any person, though it is more common among
diabetics.
How Is a Heart Attack Diagnosed?
The diagnosis of the heart attack is based on the symptoms, ECG and the results of blood tests. The goal of treatment is to treat the patient quickly and limit heart muscle damage.
Tests taken
1.
ECG(also known as EKG or electrocardiogram) can tell how much damage has occurred to
the heart muscle and where it has occurred. In addition, the heart rate and rhythm can be monitored.
2.
Blood may be drawn to measure levels of cardiac enzymes that indicate heart muscle
damage. These enzymes are normally found inside the cells of the heart and are needed for their function. When the heart muscle cells are
injured, their contents (including the enzymes) are released into the bloodstream. By measuring the levels of these enzymes,
the size of the heart attack and approximately when the heart attack started can be determined.
3.
Echocardiography is an imaging test that can be used during and after a heart attack to learn how the heart is pumping and what areas are not pumping normally.
The "echo" can also tell if any structures of the heart (valves, septum, etc.) have been injured during the heart attack.
4.
Cardiac catheterization, also called cardiac cath, may be used during the first hours of a heart attack if medications are not relieving the
ischemia or symptoms. The cardiac cath can be used to directly visualize the blocked artery and help determine which procedure is needed to treat the blockage.
Treating a heart attack
If a heart attack is suspected, emergency medical treatment is vital - getting to a hospital quickly
and receiving specialist care greatly improves the chances of survival. If you suspect someone is having a heart attack, call the ambulance immediately.
If the person can swallow, give them a single aspirin tablet to chew, unless you know that they are allergic to it. This thins the blood and
can help to prevent the clot that is blocking the coronary artery from spreading.
Surgery
After a heart attack, one will usually be offered an exercise test. If this suggests that the coronary
arteries have narrowed, an angiogram will be carried out. This involves injecting a dye into the blood so that the coronary blood vessels show
up on an X-ray. If your arteries are narrowed, you can sometimes be treated with
angioplasty or coronary artery bypass grafting.
Angioplasty involves widening the artery by inflating a balloon in the narrowed coronary artery.
Coronary artery bypass grafting (CABG) is a type of open-heart surgery (the chest is
opened). It is sometimes carried out if angioplasty is unsuccessful. It involves rerouting the blood around the affected coronary artery,
using a replacement section of a blood vessel - the graft - which is usually taken from a leg vein. This helps people with dangerously narrow
coronary arteries, especially if the left side of the heart is not pumping well.
Prevention
The risk of a first and repeat heart attack can be reduced by making changes to ones lifestyle. Not
smoking, losing excess weight, taking regular exercise and sticking to a diet that is low in fat and high in fibre will all reduce the chance of having a heart attack.
Ask her your health related questions at pallavi[at]hungrybangalore[dot]com.
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