Heart Attack
A heart attack or acute myocardial infarction
is the damage and death of heart muscle due to blockage in blood
flow. Medically speaking, an infarct is dead
tissue caused by loss of blood supply, whereas myocardium
means to the heart muscle.
Note that a myocardial infarction is different from other acute
heart disease, such as a cardiac arrest caused by the failure
of the heart's electrical system.
Heart Attack / Myocardial Infarction Symptoms
The symptoms of a heart attack include:
- Angina or chest pain
A classic heart attack symptom is crushing pain or squeezing
sensation underneath the breast bone or in the left side of
the chest.
This pain is actually caused by lactic acid
and waste product in the heart muscle, which build up when the
muscle is deprived of oxygen.
Pain in the chest may precede a heart attack by a period of
weeks, months, or even years before an actual attack. It may
even develop after the attack.
- Chest pain that radiates to the arm, neck, throat, and jaw
- Shortness of breath
- Sweating and feeling of coldness or clamminess
- Nausea and light-headedness
- Feeling of indigestion and vomiting
- Fearful feeling or sense of impending doom
- Loss of consciousness or near-fainting
Diagnosis
Your doctor would look for the following tests to diagnose a
heart attack:
- Electrocardiogram or ECG
A heart attack would show a specific pattern in an ECG test.
- Blood test
A heart attack would result in elevated levels of heart muscle
enzymes, which are released when the heart muscle is damaged.
Causes of Heart Attack
Causes of a myocardial infarction include:
- Reduced blood flow due to atherosclerotic plaque in the arteries
that supply blood to the heart muscle (in a condition called
coronary artery
disease or atherosclerosis of the heart)
- Rupture of a plaque, which then lodges downstream to cause
a complete blockage of blood supply in the artery.
Treatment for Heart Attack or Myocardial Infarction
If you suspect that you are having a heart attack:
- Call for medical help immediately.
- Take nitroglycerine tablet or aspirin
If you have nitroglycerine tablet, place it under the tongue
immediately and repeat every 3 minutes. You can also chew a
regular aspirin to help thin the blood and prevent clotting.
If you suspect someone else is having a heart attack, call for
medical help immediately. If that person stops breathing or loses
consciousness, administer CPR or cardiopulmonary rescue.
Your doctor would administer the following medical treatments:
- Morphine to help with the pain
- Oxygen to help breathe
- Clot-dissolving drugs, such as t-PA or tissue
plasminogen activator
- Streptokinase derivatives to restore blood
flow
After the immediate treatment for heart attack, your doctor may
prescribe the following medications to reduce the risk of another
attack:
- Anti-coagulants, such as aspirin, dicumarol,
heparin, and warfarin, to help prevent blood clotting
- Beta blockers to reduce the heart's oxygen
consumption
- Digitalis to improve the heart's pumping
power
- ACE inhibitors or angiotensin converting
enzyme inhibitors, such as captopril and enalapril
to help prevent heart attack and help it recover
Depending on the severity of the heart attack and the condition
of the blocked artery, your doctor may perform the following medical
procedures:
- Balloon dilation or
coronary angioplasty
Here, a catheter or tube is threaded into the heart's
blood vessel and a baloon is inflated to dilate the artery at
the point of atherosclerotic plaque deposit. A wire stent is
sometimes then placed to keep the artery open.
- Coronary bypass grafting or a heart
bypass surgery
A surgeon grafts another blood vessel from the chest or leg
and "bypasses" the blocked artery.
Complications of a Heart Attack
In the first week after a heart attack episode, there is a risk
of the following medical complications:
- Weakness in the heart wall and the possibility of rupture
Although it is rare and occurs in only 1% of heart attacks,
rupture of the heart wall is immediately fatal.
- More heart attack
In the first two weeks, the risk of repeat heart attack is about
10%.
- Pericarditis
Inflammation of the pericardium or tissue covering the heart
occurs in about 20% of the patients.
Prognosis
About 20% of heart attack patients die before even reaching the
hospital. Early treatment is crucial in saving a heart attack
patient's life - it can reduce the death rate by half.