Each year, approximately 1.2 million Americans suffer a heart attack. More than 400,000 of these patients will die before reaching a hospital. For those who do get to a hospital, advances in treatments have helped lower the number of deaths from heart attack. Today, those who recover from a heart attack are more likely to return to their past state of health than ever before. When a heart attack occurs, a fast and accurate medical response is crucial. Each minute that the heart is deprived of oxygen increases the chances of damaging or destroying part of the heart muscle.
What Causes a Heart Attack?
A heart attack is also called myocardial infarction (MI). Heart attacks are caused by partial or complete blockage of a coronary artery. A blocked coronary artery prevents oxygen-rich blood and nutrients from reaching a section of heart muscle, and damage begins to occur. Damaged heart muscle renders the heart incapable of doing its job: supplying blood to the entire body. Getting immediate medical treatment may reduce the amount of damage, but after a section of heart muscle dies, it is irreparable, and the heart’s ability to function properly is changed forever.
Heart attacks may be caused by:
• A buildup of plaque in the coronary arteries, which decreases or stops blood flow to the working heart muscle.
• A blood clot that blocks a coronary artery that is already narrowed by plaque. The blood clot may travel from another part of the body, and it decreases or stops blood flow to the working heart muscle.
• A blood clot that forms when “vulnerable” plaque on the inside of a coronary artery cracks and bleeds. Vulnerable plaque has a thin covering over it, and when it ruptures, the blood clot that forms decreases or stops blood flow to the working heart muscle.
• A coronary artery spasm, in which a coronary artery constricts or narrows. The constriction temporarily decreases or stops blood flow to the working heart muscle. Its cause is unknown, and it can happen in diseased or healthy arteries.
A heart attack is a true medical emergency. The patient should be taken immediately to the closest emergency medical facility, preferably by ambulance. The longer the patient delays, the more permanent damage is done to the heart muscle. In addition, irregular heart rhythms can occur during a heart attack, which can cause death within seconds to minutes if the patient is not on a heart monitor with the necessary medications and equipment, especially a defibrillator.
A heart attack is described as a sudden, powerful, crushing, or squeezing chest pain, or a very heavy weight on the chest. The pain may radiate to the arm, jaw, shoulder, back, or neck. Other symptoms include unexplained shortness of breath, lightheadedness, dizziness, fainting, sweating, or sick stomach. Every patient does not have the classic symptoms. For some, a heart attack feels like a burning sensation (like indigestion or heartburn), and the pain may be localized to a small area of the chest. Some patients do not feel anything at all.
Heart attack symptoms in women may be different from those experienced by men. Women are more likely to experience atypical heart attacks. They tend to feel a burning sensation in their upper abdomen and may experience more of the “other” heart attack symptoms, including shortness of breath, nausea or vomiting, lightheadedness, back or jaw pain, and sweating. Because they may not feel the sudden, intense “movie heart attack,” many women ignore these symptoms.
The crushing-type heart attacks get the most attention, but in general, most heart attacks start slowly with mild pain and discomfort. Often people aren’t sure what is happening and wait too long to seek help. Individuals must be encouraged to see a doctor right away if they experience unusual chest pain that lasts five minutes or longer. In the case of a heart attack, saving heart muscle is a race against time.
Heart Attack Warning Signs
Symptoms of a heart attack include:
• Pressure, fullness, tightness, or pain in the chest, lasting 5 minutes or longer.
• Constant indigestion-like discomfort.
• Chest pain that moves to the shoulders, arms, neck, jaw, or back.
• Lightheadedness, dizziness, fainting, sweating, or a sick stomach.
• Unexplained shortness of breath.
• Unexplained anxiety, weakness, or tiredness.
• Palpitations, a cold sweat, or pale skin.
Anyone who has any of these signs for 5 minutes or longer should see a doctor immediately, and an ambulance should be called (dial 911) to transport the patient to the nearest emergency department.
When a heart attack occurs, quick diagnosis and intervention are essential. In addition to recording symptoms, taking a brief medical history, and checking vital signs, emergency department staff will usually perform the following tests:
• An electrocardiogram (ECG) to determine which coronary artery is blocked and to monitor heart rhythm.
• A blood test to determine the level of enzymes that the damaged heart muscle cells have produced in the bloodstream.
• A chest x-ray to determine if the heart is enlarged or if the lungs are filled with fluid.
After the patient is stabilized, tests may be ordered to determine the extent of the damage:
• A nuclear (thallium) stress test.
• An echocardiogram.
• A percutaneous transcatheter coronary intervention (angiogram).
Heart Attack Outcomes
The outcome of a heart attack depends on several factors:
• Where the coronary artery blockage is located on the heart. Left side blockages are usually more dangerous.
• Whether or not normal heart rhythm is disturbed. If the blockage causes an arrhythmia, further complications exist, including the possibility of sudden death.
• Whether or not the heart has developed “collateral” circulation during the disease process. Some hearts respond to the gradual blocking of an artery by widening other vessels that supply blood to the same part of the heart. If this is the case, less damage is caused by the major blockage.
• When medical help was sought. In most cases, getting medical attention within an hour of the start of an attack reduces the amount of heart muscle lost.
The immediate goals of heart attack treatment are to open the blocked artery, return blood flow to the heart muscle, restore a normal heartbeat, and allow the heart time to recover.
The development of thrombolytic agents or "clot busters" has dramatically increased survival rates for heart attack patients. These medicines can dissolve a clot within minutes, but they must be given as soon as possible after a heart attack.
Patients who are cared for at a facility with a cardiac catheterization laboratory “cath lab” may not be given thrombolytic medication. Instead, they are immediately taken to the cath lab for complete diagnostic and treatment procedures, including angiography, balloon angioplasty, and stenting. Patients who do not respond to these interventions may need further emergency care, such as coronary artery bypass surgery.
Heart attack patients may receive aspirin or other blood-thinning medicines (anticoagulants) to stop clots from forming or growing. Oxygen may be given to increase the level of blood oxygen still flowing through the heart. Pain medication may be used, along with medicines that slow heart rate, open and relax the blood vessels, and reduce the workload of the heart.
Rest is important immediately after a heart attack. Within a few days, patients should be up and moving around, taking short walks, and getting pre-approved, limited exercise. Studies have shown that the heart benefits from exercise, even after a heart attack.
Studies have led to better therapies and more information about the heart after a heart attack. Most patients stay in the hospital for a week or less.
Patients need rest after returning home. Returning to normal activities, including work, may take anywhere from 2 weeks to 3 months. “Normal” varies for each individual and depends on their level of activity before the heart attack, the severity of the attack, and their body's response to it. Recovery occurs more quickly if stress is reduced, temperature extremes are avoided, and conditions that place an added load on the heart are controlled.
Exercise is also important. Patients should start slowly and increase their level of physical activity as advised by their doctor. Many hospitals and clinics offer incredibly beneficial cardiac rehabilitation programs that include exercise groups, stress reduction, and educational information about diet, sexual activity, additional treatment, and other issues. Cardiac rehabilitation programs also give patients the opportunity to talk with their peers to share concerns, problems, recovery strategies, and success stories.
Most heart attack survivors must scrutinize their lifestyle and make decisions that will positively affect their future health. Those who smoke need to quit. Other areas of change include diet and exercise. Stress reduction can reduce blood pressure. Some patients may need to look at their jobs and responsibilities or revise their approach to career and work. A return to old habits can lead to another, perhaps deadly, heart attack.
A person who survives a heart attack remains at risk for future heart problems. At the very least, the patient still has the narrowed artery that led to the heart attack. Bypass surgery, percutaneous coronary interventions, or medicines may be needed to reduce the risk of another heart attack. Whatever the course of action after a heart attack, future health greatly depends on following the advice of health care professionals, making positive lifestyle changes, and taking medicines as directed.
A comprehensive rehabilitation plan includes:
• Blood pressure management.
• Lipid management, especially cholesterol.
• Blood sugar management, especially for patients with diabetes.
• Tobacco cessation.
• A personalized daily exercise prescription.
• A personalized diet prescription that includes "good" fats, foods containing antioxidants, and fresh (unprocessed) foods but that avoids salt, "bad" fats, and cholesterol.
• A stress management plan to reduce blood pressure and the heart’s workload.
Most heart attack survivors experience strong feelings about what has happened, including denial, anger, fear, anxiety, and depression. Patients should talk about these feelings with their doctor. Depression may last up to 6 months. Common signs of depression include sleep problems, loss of appetite, fatigue, loss of interest in previously important things, and low self-esteem. Some patients need professional help and/or medication for depression. The negative feelings after a heart attack will pass as recovery progresses and normal activities slowly return.
A positive attitude toward recovery and treatment is one of the most useful tools for patients. Physical recovery begins in the hospital, but emotional and mental recovery is also part of the process. Patients should talk to their doctor about what has happened, why it has happened, and the various treatment options. Understanding and accepting the condition are the first steps toward a good mental outlook. Supportive friends and family are crucial. Family, friends, and coworkers are affected by the heart attack. They have concerns about the future and questions about the condition. Lifestyle changes and a new diet may cause stress within a family.
Texas Heart Institute www.texasheartinstitute.com/HIC/Topics/Cond/HeartAttack.cfm
Mayo Clinic www.mayoclinic.org/heart-attack/index.html
American Herat Association www.americanheart.org/presenter.jhtml?identifier=1200005
Medline Plus www.nlm.nih.gov/medlineplus/heartattack.html