Heart Attack

(Myocardial Infarction)

Each year, according to the National Institutes of Health, almost a million Americans suffer a heart attack or myocardial infarction. For nearly a third of them, the attack is fatal. But many of those deaths could have been prevented - if only the victim had received help in time. That's why it's so essential for all of us to know the warning signs of a heart attack.

Warning signs of a heart attack

For all too many people, the American Heart Association (AHA) says, a heart attack is the first time they learn they have heart disease. (Read about "Coronary Heart Disease") The warning signs that you're having a heart attack can vary, but here are some common ones:

• Uncomfortable chest pain, pressure or a squeezing sensation in the chest that lasts for more than a few minutes
• Pain that radiates to the shoulders, neck, jaw or arms
• Chest pain accompanied by dizziness, sweating, nausea or shortness of breath (Read about "Sweating")

Not all of these symptoms will be present in all cases. The American Academy of Family Physicians says symptoms may come and go; some people having a heart attack may experience no observable symptoms.

In addition, the U.S. Food and Drug Administration (FDA) says that women are more likely to have so-called silent or unrecognized heart attacks. (Read about "Heart Disease and Women") That's because women often have different signs of a heart attack than men. Women are more likely to have nausea and pain high in the abdomen. They also may experience a burning in the chest that they dismiss as indigestion or heartburn. (Read about "Indigestion" "Heartburn") In women as well as men, the symptoms may subside and then come back. But it's still essential to get immediate medical help if you suspect a heart attack. AHA says clot-dissolving drugs and surgery are most effective when used in the early stages of a heart attack. But studies show that many heart attack victims wait several hours - even up to ten hours or more - before seeking help.

Why a heart attack happens

A heart attack results when blood supply to the heart is cut off or reduced. (Read about "The Heart & Cardiovascular System") This limits the supply of oxygen to the heart, resulting in potential damage to the heart muscle. The heart's blood supply can be cut off as a result of atherosclerosis (Read about "Arteriosclerosis & Atherosclerosis"), in which fatty deposits build up on the lining of the artery walls until a blockage occurs. (Read about "Heart Risks") Although heart attacks can strike without warning, an attack may also be preceded by periodic spells of chest pain called angina. (Read about "Angina") While the symptoms of angina may seem to mimic those of a heart attack, the National Heart, Lung, and Blood Institute (NHLBI) says angina is more often triggered by physical exertion, whereas a heart attack can occur at any time, even during rest. Although angina is not the same as a heart attack, it does indicate the presence of coronary artery disease and should not be ignored.

Get help fast

A heart attack is a medical emergency. Time is essential. If not treated, a heart attack can result in cardiac arrest and death. (Read about "Cardiac Arrest") If someone is experiencing symptoms that might indicate a heart attack, call 911 or your local emergency number and let medical personnel know when the symptoms started and how severe they are. According to AHA, it can be better to let an ambulance come to you. Ambulance personnel can start emergency treatment as soon as they arrive. However, if you suspect you're having a heart attack and ambulance service isn't available, you can have someone drive you (someone suspecting they're having a heart attack should not drive themselves) to the nearest emergency room. (Read about "Emergency Room")

After calling 911, AHA recommends taking aspirin as soon as possible, unless there's a reason not to (for example if you're allergic to aspirin or have some other condition that means you shouldn't take aspirin). According to AHA, research shows that taking aspirin when symptoms start significantly improves the chances of surviving a heart attack. (Read about "Aspirin & Heart") Remember though, that taking aspirin isn't advised during a stroke, because if the stroke is caused by a rupture instead of a blood clot, aspirin will make things worse. (Read about "Stroke")

The key is to remember that a heart attack does the most damage in the first two hours. The faster someone gets help, the better their chances of survival.

Treatment options

One of the most important reasons not to delay going to the hospital is the fact that special procedures can limit the damage done to the heart, if they are started soon enough. For example, defibrillators can help restore normal heart rhythm. In addition, what's called reperfusion therapy can take place that will increase the flow of blood to the heart.

According to NHLBI and the American Medical Association, there are several treatment options that can be used to improve blood flow:

• Drugs - Clot-busting or thrombolytic agents can be injected to dissolve clots and reopen arteries. NHLBI says that clot-dissolving drugs need to be injected within a few hours of the onset of the heart attack. Keep in mind, however, that there are dangers from clot-dissolving drugs including stroke and internal bleeding in the brain (Read about "The Brain"), so the type of drug used and the decision to use them depends on the situation and the patient.
• Coronary angioplasty or balloon angioplasty - In this procedure, a fine tube, or catheter, is threaded through an artery into the narrowed heart vessel. The catheter has a tiny balloon or other device at its tip, that is used to open or stretch the artery. This is done to improve blood flow, after which the tube is removed. (Read about "Angioplasty")
• Stents - Stents are often inserted during angioplasty to help keep the artery open. A stent may also be used without angioplasty. Basically, a stent is a wire mesh tube that's inserted into an artery to help keep it from closing up again. Even with a stent, however, an artery can reclose, requiring either another angioplasty or a bypass. NHLBI says this is especially common for people with diabetes or unstable angina. (Read about "Diabetes" "Angina") The new re-narrowing is called in-stent restenosis. AHA says the use of stents, coated with drugs to help keep the vessel from closing, can help to reduce this risk. Brachytherapy can also be used, according to FDA. It is a procedure in which radioactive material is placed into the body. After initial opening of the in-stent restenosis blockage with a balloon catheter (PTCA), a brachytherapy device is temporarily placed at the site of the in-stent restenosis. FDA says the radiation treatment prevents an exaggerated healing response at the lesion site and a recurrence of a significant blockage.
• Bypass surgery - In this procedure, a piece of vein is taken from the leg, or a piece of an artery is taken from the chest or wrist, and then attached to the heart artery above and below the narrowed area, thus creating a "bypass" around the blockage. In many cases, besides fixing the artery that is blocked, the surgeon will fix additional arteries on the heart that are starting to look blocked. The number of arteries repaired becomes the name of the procedure. For example, if the surgeon repairs three of the arteries, it is called a triple bypass. If four arteries are repaired, it's a quadruple bypass. NHLBI says bypass can be the preferred procedure for some patients and is also appropriate when angioplasty hasn't been successful, or when the blockage can't be reached by angioplasty. Sometimes, more than one bypass operation is needed. A bypass also can close again. This happens in more than 10 percent of bypass surgeries, usually after 10 or more years. (Read about "Coronary Bypass Surgery")

The success of all these treatments depends on how quickly they start after a heart attack begins.

Following or in conjunction with treatments, a patient will also go through a period of cardiac rehabilitation, involving exercise and lifestyle changes. The success of rehab is dependent on the extent of the damage, and on a patient's ability to make changes and follow through with the advice of their doctor. (Read about "Cardiac Rehabilitation")

In addition to physical rehabilitation (Read about "Rehabilitation"), your physician may also recommend continued treatment with medication. Recent guidelines from the AHA and the American College of Cardiology say continued treatment with drugs, including ACE inhibitors and beta-blockers, has been shown to reduce the risk of death in patients who have survived a heart attack. The groups also stress the importance of smoking cessation and recommend avoiding secondhand smoke as well. (Read about "Quit Smoking") Eating foods high in omega-3 fatty acids and the use of newer antiplatelet agents for patients unable to take aspirin to reduce the risk of blood clots are also among the groups' recommendations.

Other ways to reduce the risk of further heart problems include taking all medicines that have been prescribed by your doctor if you have high blood pressure or high cholesterol. (Read about "Hypertension: High Blood Pressure" "Cholesterol") In addition, if you have diabetes (Read about "Diabetes"), it is very important that you follow all recommendations of your doctor in order to maintain your blood sugar within the normal range.

Related Information:

    Cardiovascular Tests

    Peripheral Arterial Disease

    The Heart and Its Valves

    Cardiomyopathy

    Homocysteine

    Vascular System

    Thrombophilia

    Deep Vein Thrombosis

    Glossary of Heart Terms