MYOCARDICAL INFARCTION (Heart Attack)
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A heart attack, or myocardial infarction, occurs when the flow of blood to the heart muscle is blocked. If the blood and oxygen supply is cut off, muscle cells of the heart begin to suffer damage and start to die. Irreversible damage begins within 30 minutes of blockage. MI can be fatal, but treatment has improved dramatically over the years.
Symptoms
The following are the most common symptoms of a heart attack. However, each individual may experience symptoms differently. Symptoms may include:
- Chest pain: Severe pressure, fullness, squeezing, pain and/or discomfort in the center of the chest that lasts for more than a few minutes
- Pain or discomfort that spreads to the shoulders, neck, arms, or jaw
- Chest pain that is not relieved by rest or by taking nitroglycerin
- Profuse sweating
- Cold sweat
- Shortness of breath
- Nausea or vomiting
- Dizziness or fainting
Causes
It occurs due to blockage of coronary artery. The blockage is often a result of atherosclerosis—a buildup of plaque composed of fat deposits, cholesterol, and other substances in the arteries that feed the heart (coronary arteries). When a plaque ruptures, a blood clot quickly forms. The blood clot is the actual cause of the heart attack. Sometimes blockage may occur due to spasm of coronary artery.
Diagnosis
Diagnosis is based on
- Clinical symptoms
- Lab changes: Changes in enzyme level of myoglobin ,cardiac troponin T and I, Creatinine phosphokinase(MB), LDH
- ECG changes
- Additional tests: Angiogram, Exercise stress test, Echocardiography may be done after few hours or days of heart attack.
Risk Factors
- Age
- High BP
- Tobacco
- High blood cholesterol
- Diabetes
- Family history
- Lack of physical activity
- Obesity
Stress
Complications
- Heart failure
- Irregular rhythm of heart
- Rupture of myocardium
- Valve problems
Treatment
The goal of treatment for a heart attack is to relieve pain, preserve the heart muscle function, and prevent death.
- Aspirin
- Continuous monitoring of the heart and vital signs.
- Thrombolytic therapy: medication which dissolves the blood clot, thus, restoring blood flow.
- Nitroglycerin
- Oxygen therapy
- Pain medication
- Cardiac medications, such as beta-blockers, promote blood flow to the heart, improve the blood supply, and prevent arrhythmias, and decrease heart rate and blood pressure.
- Antithrombin/antiplatelet therapy is used to prevent further blood clotting.
- Antihyperlipidemics are medications used to lower lipids (fats) in the blood. Statins ( atorvastatin, simvastatin, pravastatin), Bile acid sequestrants (colesevelam, cholestyramine, and colestipol) and nicotinic acid (niacin) are some group of medications to lower cholesterol.
Additional procedures to restore coronary blood flow may be used. Those procedures include:
- Coronary angioplasty
- Coronary artery bypass surgery
