Heart Attack or Myocardial Infraction
What is a Heart Attack?
A heart attack (myocardial infraction) is the death of heart muscle due to the loss of blood supply. Usually, the loss of blood supply is caused by a complete blockage of a coronary artery (an artery that supplies blood to the heart muscle) by a blood clot.
What are the features of a Heart Attack?
Pain: is the cardinal symptom of a heart attack. The pain is often described as a tightness or heaviness in the chest. It is often severe enough to be the worst pain that can be experienced. The usual location of the pain is in the center of the chest but it frequently radiates to the left arm or the jaw.
Some heart attacks though can pass unrecognized; these painless attacks are called as ‘silent infracts’ and are particularly common in diabetics.
Anxiety: Fear of impending death.
Brightlessness,
Nausea and vomiting,
Sweating, pallor and a fast pulse.
Sudden death: Loss of blood supply disturbs the orderly transmission of electrical impulses in the heart and as a result the heart stops to effectively pump blood. Permanent brain damage and death can occur unless oxygenated blood flow is restored within five minutes. Approximately 40% of people suffering a heart attack die before reaching to the hospital.
What causes a Heart Attack?
A heart attack is almost always caused by the formation of a blood clot on a cholesterol plaque located on the inner wall of an artery to the heart (coronary artery). It is believed that the process of formation of these plaques starts in the late teens. Over a period of time the accumulation of cholesterol plaque causes thickening of the artery walls and narrowing of the arteries; a process called atherosclerosis.
Many factors have been found to influence this plaque formation. It can be accelerated by smoking, high blood pressure, elevated cholesterol and diabetes. Whereas, factors like exercise, low fat diet, avoiding stress seem to help in retarding this process.
Ultimately, the arteries narrow to an extent where they are unable to supply enough blood to the heart muscle during periods of increased demand like during exercise or excitement. This results in a condition called ischemia which leads to chest pain called as angina.
Occasionally, however, for unknown reasons, the surface of the cholesterol plaque can become sticky, causing blood clotting. When a blood clot forms on top of this plaque, the artery becomes completely blocked, causing death of the heart muscle (heart attack).
How is Heart Attack Diagnosed?
The initial diagnosis of a heart attack is made by a combination of clinical symptoms and characteristic electrocardiogram (ECG) changes. An EKG is a recording of the electrical activity of the heart. However, confirmation of a heart attack can only be made hours later through detection of elevated creatinine phosphokinase (CPK) in the blood. CPK is a muscle protein enzyme, which is released into the blood circulation by dying heart muscles when their surrounding membranes dissolve.
What is the early Management of a patient of a Heart Attack?
Most of the patients of heart attack are managed in a dedicated heart care unit. Following are the elements in the management:
· Bed rest
· Oral Aspirin
· High flow oxygen
· Intravenous analgesia with morphine
· Monitoring the E.C.G.
Reperfusion: The immediate goal of treatment is to quickly open blocked arteries and restore blood flow to the heart muscles; a process called “reperfusion” Early reperfusion minimizes the extent of the heart muscle damage and preserves the pumping function of the heart. Many drugs are available to dissolve the clots and restore blood supply. Drugs like tissue plasminogen-activator (t-PA) and streptokinase given intravenously can open 80% of the blocked arteries within 90 minutes.
How can I prevent a second heart attack?
The best chances of preventing a second heart attack come from a combination of medications and change of diet and lifestyle.
Drugs: Aspirin and beta blockers (drugs like Tenormin), have been shown to reduce chances of a second heart attack and improve future survival.
Diet: Reducing weight and dietary fat.
