Acute Coronary Syndrome

(Heart Attack, Unstable Angina)
Definition
Acute coronary syndrome is a term given to a group of symptoms associated with chest pain at rest or during mild exertion.
Acute coronary syndrome also refers to certain types of heart attack and unstable angina, a very serious condition that indicates a heart attack could soon occur.
Acute coronary syndrome is life-threatening and requires immediate medical treatment.

Coronary Artery

Causes
Acute coronary syndrome is caused by a narrowing of the arteries so the amount of blood that reaches the heart muscle is greatly reduced or completely blocked leading to muscle damage or death. This typically results from years of plaque build-up in an artery, which over time can:
• Narrow arteries to lessen blood flow to the heart muscle
• Completely block the arteries and flow of blood
• Cause blood clots to form in the arteries
Risk Factors
The following factors increase your chances of developing acute coronary syndrome. If you have any of these risk factors, tell your doctor:
• You are a man over 45 years old or a woman over 55 years old
• A family history of heart disease
• Being overweight or obese
• Smoking
• High cholesterol
• High blood pressure
• Diabetes
• Being sedentary
• Having angina, a previous heart attack, or other types of coronary artery disease
Symptoms
Acute coronary syndrome is very serious and requires immediate medical treatment. If you experience any of these symptoms, see your physician.
• Chest pain, pressure, tightness, burning or other discomfort. It may last a few minutes, go away and then come back. Unstable angina often occurs at rest, while sleeping, or with very little exertion, and typically lasts as long as 30 minutes.
• Pain or discomfort in one or both arms, shoulders, the back, the neck, jaw or stomach.
• Shortness of breath that accompanies chest pain or may occur just before it
• Feeling light-headed or dizzy
• Nausea and vomiting sometimes occur
• Sweating
Diagnosis
Your doctor will ask about your symptoms and medical history, and perform a physical exam. If you suspect acute coronary syndrome, call an ambulance. At the hospital, tests may include the following:
• Electrocardiogram (ECG or EKG) to measure the rate and regularity of your heartbeat. A 12-lead EKG is used in diagnosing a heart attack. Acute coronary syndrome is used to describe two types of heart attack:
o A Non-ST segment elevation myocardial infarction (NSTEMI), caused by partial or temporary blockage, does not cause changes on an electrocardiogram.
o A ST segment elevation myocardial infarction (STEMI) is caused by a prolonged period of blocked blood supply, and does cause changes on an electrocardiogram.
• Blood tests to measure different enzymes that are released when cells in the heart die. The specific tests include:
o Troponin test, considered the most accurate test to determine if a heart attack has occurred and how much damage was done to the heart.
o CK or CK-MB test to measure the amount of the different kinds of creatine kinase in the blood.
o Myoglobin test to check for the presence of myoglobin in the blood, which is released when the heart or other muscle is injured.
• Nuclear heart scan, which uses radioactive tracers to outline heart chambers and major blood vessels leading to and from the heart. It can show any damage to your heart muscle.
• Cardiac catheterization, in which a thin, flexible tube (catheter) is passed through an artery in the groin or arm to reach the coronary arteries. This can determine pressure and blood flow in the heart's chambers, collect blood samples from the heart, and examine the arteries of the heart by x-ray.
• Coronary angiography, a test usually performed along with cardiac catheterization. A dye that can be seen using x-ray is injected through the catheter into the coronary arteries. Your doctor can see the flow of blood through the heart and see where there are blockages.
• Echocardiogram is a test that uses sound waves to create a moving picture of your heart. Echocardiogram provides information about the size and shape of your heart and how well your heart chambers and valves are functioning. The test, used to diagnose angina, also can identify areas of poor blood flow to the heart, areas of heart muscle that are not contracting normally, and previous injury to the heart muscle caused by poor blood flow.
Treatment
If you are having a heart attack, doctors will work quickly to restore blood flow to the heart and closely monitor vital signs to detect and treat complications. To restore blood flow, the main treatments are:
• Aspirin is given to all patients suspected of acute coronary syndrome.
• Anti-ischemic drugs are used to help relieve chest pain.
• Thrombolytic (or “clot-busting”) drugs, used to dissolve blood clots blocking blood flow to the heart. When given soon after a heart attack begins, these drugs can limit or prevent permanent damage to the heart. To be most effective, they need to be given within one hour after the start of heart attack symptoms.
• Angioplasty, in which a stent is placed in the artery to keep it open.
• Coronary artery bypass surgery uses arteries or veins from other areas in your body to bypass your blocked coronary arteries.
Prevention
To help reduce your chances of getting acute coronary syndrome, take the same heart-healthy lifestyle steps to prevent other forms of coronary artery disease. These include:
• Eating a healthy, well-balanced diet, one that is low in saturated fats and rich in fruits, vegetables, and whole grains.
• Exercising regularly.
• Not smoking. If you smoke, quit.
• Managing diabetes, blood pressure, and cholesterol (with medications, if necessary)