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Heart attack is a medical condition in which blood flow to a part of the heart is totally stopped or severely reduced. In heart attack, a particle of fatty deposit in a clogged coronary artery enlarges, swells, and ruptures, forming a blood clot.

The blood clot partially or totally blocks the artery, and severely restricts or completely shuts down the blood supply to the affected area of the heart. When blood flow remains stopped for a few minutes, the cells in the affected part of the heart muscle (myocardium) die. This condition is called heart attack or myocardial infarction (MI). Infarction means death of tissue. Heart attack is an emergency condition to be treated in the hospital.

GENERAL SYMPTOMS OF HEART ATTACK
A person may present certain symptoms in a heart attack, such as:

• Chest discomfort that lasts for a few minutes or that goes away and comes back.

• Intense chest pain that lasts for more than 10 to 15 minutes and is not relieved by resting or by putting 2 to 3 nitroglycerin pills under the tongue every several minutes.

• The chest pain may accompany other symptoms such as:

• Excessive sweating, especially cold sweats.

• Shortness of breath.

• Light-headedness.

• Dizziness, nausea, and vomiting.

• Pain spreading to the shoulders, neck, and arm.

• Upset stomach.

• Back pain or flu-like symptoms, especially in women.

• Pain in one or both arms, usually the left arm.

• A feeling that life is about to end.

CLINICAL SYMPTOMS OF HEART ATTACK
Physical examination of a patient in a hospital, immediately after a heart attack, will show any of the following symptoms:

• Heartbeat may be too fast or too slow.

• Blood pressure may be high or low, but generally, it is lower than normal.

• EKG often detects areas of damage to the heart, inadequate blood supply to the heart muscle, and irregular heartbeats.

• Blood test shows elevated levels of certain enzymes and proteins such as CK-MB, troponin, myoglobin, and LDH, which are usually raised in the blood when a heart attack has injured the heart muscle or some part of the muscle has died. Another blood test known as ACB (Albumin Cobalt Binding) can detect raised blood levels of free cobalt, a sign of heart attack.

EMERGENCY TREATMENT OF HEART ATTACK
As soon as you are admitted in the emergency room of a hospital with symptoms of heart attack, EKGs, X-rays, and blood tests are taken to quickly assess your condition. If your heartbeats are irregular, an electrical device called defibrillator is applied to you immediately to restore regular heartbeats. To treat you for a heart attack, the following measures may be taken in the emergency room of a hospital in which you:

• Receive oxygen.

• Chew an uncoated aspirin (160 to 325 milligrams) to prevent blood clotting and reduce the risk of death from heart attack. If chewing is not possible, an aspirin suppository (325 mg) is given. However, if you had a reaction with aspirin in the past, you will get other medications such as clopidogrel, ticlopidine, or dypyridamole, which are also helpful.

• Receive nitroglycerin pills (0.3 to 0.4 mg) under the tongue or nitroglycerin patches on the skin to dilate blood vessels for increased blood flow. (Nitroglycerin, will not be given if your blood pressure is too low).

• Receive intravenously a clot-dissolving drug called rt-PA.This drug dissolves the clot, an action that restores blood flow and saves the heart muscle from damage. To be effective, rt-PA must be given within six hours of the beginning of the heart attack symptoms and before the heart attack has caused any permanent damage to the heart muscle.

• Receive blood thinners (anticoagulants) intravenously to dissolve an existing blood clot and prevent a new clot from forming in the coronary artery. Heparin is a popularly used blood thinner. A new class of blood thinner called glycoprotein IIb/IIIa inhibitor has also been introduced. This blood thinner has been found very effective, relatively safe, and its use has resulted in reduction of death rates.

• Receive beta-blocker drugs to slow down your heart rate so that your heart work less hard and tissue damage, if any, is limited.

• Receive a drug of the ACE inhibitor class that has been shown to reduce death rates from heart attacks.

• May undergo heart surgery such as balloon angioplasty or the bypass surgery on an emergency basis. ( When the symptoms of heart attack are not relieved even after more than 12 hours of treatment from the time the symptoms started, your doctor may refer you for balloon angioplasty or the bypass surgery for restoring blood flow to your heart).

RISK FACTORS FOR HEART ATTACK
Below listed factors may increase the risk for heart attack:

• Age. Men older than 45 years, and women older than 50 (menopause age) are at high risk. However, even younger men and women can also have heart attacks.

• Family history of heart disease.

• A previous heart attack.

• Surgery such as bypass operation, stenting, or balloon angioplasty.

• Diabetes.

• High blood pressure.

• Blood cholesterol disorder.

• Lack of physical activity.

• Excess weight, especially abdominal obesity.

• Depression.

• Exposure to traffic. A study published in the New England Journal of Medicine in 2004 reported that people at risk can have a heart attack within 1 hour after their exposure to traffic in urban areas while traveling in cars, buses, and while riding on bicycles or motorcycles.

• Air pollution. A study, appearing in the medical journal Lancet in 2002, showed that a ban on burning coal in Ireland resulted in a 10 percent fall in deaths from heart disease.

PROSPECTS OF RECOVERY FROM HEART ATTACK
Studies show that when a patient gets required medical treatment within 1 hour of the beginning of symptoms of a heart attack, the prospects of survival are brighter. About 50 percent of people die of heart attack because they do not get medical treatment within 1 hour of the appearance of heart attack symptoms. By providing quick medical help, these deaths can be prevented.

Recent studies suggest that strict control of blood sugar in the period immediately after a heart attack increases the survival rate of people with diabetes. A large number of studies have shown that each 20 mg/dL increase in blood sugar over 100 mg/dL increased the risk of death in patients under intensive care in hospitals. However, patients whose blood sugar was brought down to less than 110 mg/dL through intensive insulin therapy experienced the highest survival rates.

Recovery after a heart attack, however, depends on the extent and location of the damage caused to the heart. A heart attack that damages 10 percent of the heart muscle in a critical area can cause instant death; whereas people with heart damage up to 30 to 40 percent in a less critical area of the heart muscle survive easily. Most people who survive a heart attack beyond several days usually recover fully within 2 to 3 months.

 Copyright© 2010 hotresearch.com

Several tests are available for detecting and managing coronary heart disease, popularly known as heart disease. Some of these tests are used on a routine basis; others are specialized or high-tech tests performed in a hospital:

Physical Examination
The doctor can diagnose heart disease by doing a physical examination, which includes listening to your heartbeats through a stethoscope. In the presence of heart disease, the heart is likely to produce abnormal sounds due to blockages in the coronary arteries.

Measuring Blood Pressure
Purpose: Measurement of blood pressure.
Check how often: The doctor will check your blood pressure on every visit.
Desirable goal: Less than 120/80 mmHg (as recommended by the National High Blood Pressure Education Program).  

Lipid Profile
Type of test: Blood test.
Purpose: Measures cholesterol and other fats in the blood.
Test how often: Once a year
Desirable goals:

C-Reactive Protein Test
C-Reactive protein (CRP), a substance found in the blood, is a sign of inflammation in the body. Current research strongly suggests that inflammation of the coronary arteries, and the resulting raised CRP levels in the blood, are a serious risk factor for heart disease. A laboratory test, namely, hs-CRP test is available that measures CRP in the blood. This test, which is increasingly becoming popular, helps the doctor assess your risk for heart disease.

PLAC Test
The PLAC test is a blood test that measures an enzyme called Lp-PLA2. Raised levels of this enzyme in the blood may indicate inflammation of the coronary arteries associated with heart disease. People who have elevated levels of Lp-PLA2, along with raised LDL cholesterol levels, are at significantly increased risk of having heart disease. This risk is 2 to 3 times higher in these people compared to people with lower values on the PLAC test. This test, when used with other methods of risk assessment, provides additional information about the risks to your heart health.

Electrocardiogram
An electrocardiogram (EKG) traces the electrical impulses produced by the heart on a moving paper strip. The EKG can indicate various heart abnormalities if present, including a previous heart attack and insufficient supply of oxygen and blood to the heart at present.

Heart X-rays
The doctor may order heart X-rays to see its outline. The X-ray can show if the heart is regular in size or of an usual shape. A larger than normal shape of the heart may indicate an abnormality, which needs further investigation.

Plaque Imaging
Piling up of calcium deposits in the coronary arteries is a sign of hardening of the arteries and an increased risk for heart disease. A simple screening tool, known as electron-beam tomography (EBT), is now used that can detect calcium deposits in the coronary arteries long before the symptoms of heart disease actually appear. Such a detection can be a strong motivating factor for people to make necessary lifestyle changes to prevent the actual occurrence of heart disease. The EBT is a noninvasive imaging tool that takes more detailed X-ray pictures than a CT scan; it is currently the most sensitive noninvasive method of detecting coronary artery disease.

Holter Monitoring
AHolter monitor is a small monitor with small rubber pads called electrodes. You wear the monitor on your shoulder with electrodes attached to your body for 24 to 48 hours in a holter monitoring test. The monitor makes a continuous recording of electrical changes in your heart. This record helps the doctor detect heart disease, if present.

Exercise Stress Test
Exercise stress test, also known as exercise tolerance test, aims to see how the heart performs during increased physical activity. Exercise stress test is a combination of exercise, EKG, and blood pressure monitoring. In stress testing, you exercise on a treadmill. After every 2 to 3 minutes, the difficulty level of the treadmill is increased, making you exercise harder. The EKG continuously monitors how well your heart responds to exercise, and blood pressure is taken several times. When the coronary arteries supplying blood to the heart have blockages, blood flow to the heart is obstructed, and the doctor notices abnormal changes in EKG patterns and blood pressure levels. In such a case, you may feel chest pain or unusual shortness of breath (signs that may indicate presence of coronary heart disease). If for some reason such as leg pain or severe weakness you are unable to exercise, the doctor may give you a chemical stress test instead. In a chemical stress test, a drug such as dipyridamole, adenosine, or dobutamine is injected, which has an exercise-like effect on the body.

Nuclear (Thalium) Stress Test
This test is almost the same as the exercise stress test (noted above) except that a minute dose of a radioactive substance is injected into the vein to see how well the blood is flowing to the heart muscle (myocardial perfusion study). Some of the radioactive substances commonly used are thallium-201, sestamibi (Cardiolite), and tetrofosmin (Myoview).

The test is performed in two phases: during exercise (stress) and at rest. In the first phase, you exercise on a treadmill to your maximum fitness level. When blood stimulation is at its peak after exercise or chemical stress, a minute dose of a radioactive substance, thallium for example, is injected into a vein of your arm. At this moment, a special camera, known as the gamma camera, takes pictures of thallium circulating in your blood.

When a coronary artery has a blockage, the blood flow is also reduced to the clogged artery and the amount of injected thallium reaching the heart is not as much as it should be. In the second phase of this test, after you have taken rest for 1 to 2 hours, you will again receive an injection of the radio-active substance. Another set of pictures is taken that will reveal the position of blood flow at rest. The nuclear test gives a good idea of how your heart performs during exercise and at rest.

Images taken from the nuclear stress test provide information about the size of the heart’s chambers, how the heart is pumping blood, whether the heart has any damaged muscle, or the coronary artery has any narrowing or a blockage.

If the exercise stress test or the nuclear stress test indicates a blockage or blockages in the coronary arteries, and the blood flow to the heart is not normal, the doctor may order a more definitive and accurate test called a coronary angiogram (see below).   

Nuclear Stress Test
This is a stress test in which a small amount of a radioactive substance will be injected in your vein to see how well the blood is flowing to your heart muscle (myocardial perfusion study). Some of the radioactive substances commonly used are thallium-201, sestamibi (Cardiolite), and tetrofosmin (Myoview).

The test is performed in two phases: during exercise (stress) and at rest. In the first phase, you exercise on a stationary bicycle or a treadmill to your maximum fitness level. If for some reason such as leg pain or severe weakness you are unable to exercise, the doctor will give you a chemical stress test in which a drug such as dipyridamole, adenosine, or dobutamine is injected for stimulating blood flow to your heart. When blood stimulation is peaking after exercise or chemical stress, a minute dose of a radioactive substance, thallium for example, will be injected in your vein. A special camera, known as the gamma camera, will take pictures of thallium circulating in your blood. When a coronary artery has a blockage, the blood flow will also be reduced to the clogged artery and the amount of injected thallium reaching the heart will not be as it should; its flow will also be reduced. In the second phase of this test, after you have taken rest for 1 to 2  hours another set of pictures will be taken, which will reveal the position of blood flow at rest.

If the cardiac stress test or the nuclear stress test is positive, meaning that there is a blockage or blockages in the coronary arteries and the blood flow to the heart is not normal, the doctor may order a more definite and accurate test called the coronary angiogram.

Stress Echocardiography
Stress echocardiography is a combination of exercise stress test (noted above) and ultrasound scan.This is a completely noninvasive procedure that uses ultrasound waves to evaluate blood flow to the heart muscle before and after exercise.  To have a stress echocardiogram, first you will take the exercise stress test. After your heart rate reaches a certain level while exercising on the treadmill, the doctor will ask you to lie down on an examination table. Here ultrasound images are taken. This imaging technology is similar to ultrasound scans used to monitor the developing baby during pregnancy.

Electron- Beam Tomography (EBT)
The EBT is a noninvasive imaging tool for looking into the coronary arteries. This test helps detect calcium buildup in the arteries. Piling up of calcium deposits in the coronary arteries contributes to hardening of the arteries, a condition that increases the risk for heart disease in men, women, young, and old. EBT takes detailed pictures of calcium deposits present in the arteries. It is a simple tool that can detect progression of coronary artery calcium (CAC) long before the symptoms of heart disease actually appear. EBT scanning is generally recommended for screening the risk of heart disease in people who do not present its symptoms. However, this test can be included in a comprehensive diagnostic plan for detecting coronary heart disease.

Coronary Angiogram
A coronary angiogram is a special X-ray of the coronary arteries, the arteries that supply blood to the heart. It aims to detect if the coronary arteries are narrowed or fully blocked. The procedure of doing an angiogram is called angiography.

The most common method of performing this procedure is called cardiac catheterization, because it involves the use of a catheter, a thin flexible tube. The doctor inserts the thin catheter into a blood vessel in your leg (thigh) or arm, and advances it to the heart. A contrast material or dye is injected through the catheter to highlight the coronary arteries, because the coronary arteries do not show up on a plain X-ray. Pictures are taken of the contrast dye flowing through the arteries. When the arteries are clear, the dye flows smoothly, but if there are blockages or obstructions, the dye does not go through as it should, and the obstructions show up on the pictures. If a coronary blockage or obstruction is detected during the angiography, the surgeon may clear it through a catheter on the spot, a procedure called angioplasty.

Currently, the cardiac catherization is the most accurate imaging technique and regarded as the “gold” standard for detecting blockages in the coronary arteries.