Category: Guide to Preventing and Treating Heart Disease

Essential Information You and Your Family Need to Know about Having a Healthy Heart

  • Medications to Treat Blood Clots

    Blood clots often play a prominent role in cardiovascular disease. In a healthy person, specialized blood cells called platelets have the capacity to form a clot in response to injury, as a way to limit loss of blood. How- ever, in a person with cardiovascular disease, a blood clot that forms abnormally in an artery leading to the heart can cause a heart attack (myocardial infarction), and one that travels to an artery leading to the brain can cause a stroke .
    In a person with coronary artery disease, the plaque that builds up in the coronary arteries can be destabilized by factors such as high blood pressure, high blood sugar, or the toxic ingredients in tobacco. A type of plaque called soft plaque (see page 154) can rupture, and the platelets respond as they would to an injury, by forming a clot over the damaged area. A blood clot in an already clogged artery can block the blood ?ow completely, causing a heart attack.

    Thrombolytic Agents

    Thrombolytic agents (“clot busters”) dissolve clots in the arteries, restoring blood ?ow to heart tissue. Their use has substantially reduced disability and death from heart attacks and strokes. These drugs (including streptokinase, urokinase, and tissue plasminogen activator, or tPA, used for strokes) can be given as soon as you have been diagnosed as having a heart attack or stroke, either because of your symptoms or in response to the results of an electrocardiogram. If you get to a hos- pital immediately and the thrombolytics go to work within 4 to 6 hours of the onset of your symptoms, you are very likely to have only minimal damage to your heart function. If too much time passes before the thrombolytics are given, the damage is already done and restoring blood ?ow will not revive the tissue.
    Emergency department personnel administer thrombolytic agents intravenously. The most serious drawback of these drugs is that they do not distinguish an abnormal blood clot from a useful one. You cannot receive them if you have a condition that might cause a bleeding prob- lem, such as a stomach ulcer, a recent injury or surgical procedure, or a recent stroke.

    Antiplatelets

    Antiplatelet drugs interfere with platelet function and the formation of blood clots. Platelets are the elements within the blood that stick together and form clots. Some drugs (such as aspirin) are used to prevent clot formation in people at high risk of heart attack. Some types are given if you are having uncontrolled chest pain (unstable angina) or during or immediately after a heart attack to reduce recur- rence. Antiplatelets are also given after an angioplasty, insertion of a stent, or bypass surgery to prevent clots from forming inside the vessel.
    Clotting is a chemically complex process, and different antiplatelet agents disrupt speci?c stages of clot formation. They are used alone or in combination to treat different types of heart attacks or under various circumstances.
    Aspirin is the most familiar antiplatelet drug. Because it is inexpensive, effective, and easy to take by mouth, it is often the first treatment given at the onset of heart attack symptoms, even before you get help from emergency medical services .

    Taking aspirin right after a heart attack may improve survival rates by as much as 20 percent. At the hospital, other antiplatelets (such as clopidogrel or glycoprotein inhibitors) may also be given, either orally or intra- venously. Doctors are learning more all the time about how to use these drugs to bene?t more patients.
    Because all antiplatelet drugs interfere with normal blood clotting, the main risk of taking them is bleed- ing. The bleeding is usually very minor, such as skin bruising or nosebleed. In people who are being treated in a hospital for heart attacks, the most common sites of bleeding are where catheters have been inserted— for example, in the groin where an access catheter is inserted for angioplasty. This type of bleeding is usu- ally easily controlled by applying pressure to the site. Rarely, bleeding occurs from another source such as a stomach ulcer.

    Anticoagulants

    Anticoagulants are used to prevent the forming or growth of a blood clot by interfering with the clotting process. But they do not dissolve an existing blood clot, as a thrombolytic agent does. Although they are commonly called blood thinners, they do not really thin your blood; they just reduce the blood’s ability to clot. These agents, such as war- farin, are stronger than the antiplatelet medications. Therefore, your doctor’s of?ce will need to do careful and frequent monitoring—in the form of a blood test—of the clotting factor in your bloodstream. This is vital to prevent bleeding complications and to ensure adequate clot- ting effect.
    If you have had a heart attack, you are at greater risk of developing a blood clot near the site of a clot that was dissolved by a thrombolytic agent. If severe damage occurred in your left ventricle, a clot could also form there, where it can cause serious complications, and your doctor may prescribe warfarin. Also, if you are in bed for a long time after a heart attack, blood clots can develop in your legs. Anticoagulants help prevent all these possibilities.
    Heparin, which is administered intravenously in the hospital, is a powerful and well-established anticoagulant for heart attack patients. If you undergo a procedure such as angioplasty, heparin will be adminis- tered to prevent clots from developing at the site of the procedure. The dosage must be carefully adjusted and its use must be monitored closely. A new type of heparin, called low-molecular-weight heparin, has been developed that is injected and does not require as much monitoring. Any form of heparin can cause unintended bleeding as a side effect. After an angioplasty, stronger clot-preventing medications such as clopidogrel may be prescribed.

    Aspirin for Heart Disease

    For some people, taking aspirin regularly is a means of preventing the recurrence of certain types of heart symptoms or events. Your doctor may recommend aspirin if you have had a heart attack, a transient ischemic attack , or an ischemic stroke , or if you have had trouble with recurring angina (chest pain; ). Some studies even suggest that aspirin may help prevent a ?rst occurrence of some of these events. Aspirin helps ensure adequate blood ?ow and may reduce the likelihood of clot formation. Aspirin works by slowing down the work of platelets in your bloodstream; when platelets are less sticky, clots are less likely to form. Aspirin may also help protect against the in?ammation of arteries that occurs with atherosclerosis and may help prevent heart attacks in people with diabetes.
    Taking aspirin regularly is different from taking it occasionally for something like a headache, and it poses some risks. You should not start taking aspirin for your heart without talking to your doctor ?rst. In evaluating whether aspirin ther- apy is right for you, your doctor will consider your medical and family history; other drugs you may take, including vitamin or herbal supple- ments; allergies; the likelihood of certain side effects such as stomach bleeding; the relative risk versus bene?t; and what dose is right. If you have some medical conditions such as bleeding disorders, asthma, ulcers, or kidney disease, aspirin may not be a safe choice.
    If your doctor recommends aspirin, it’s important to take it exactly as he or she directs so that you get the desired bene?t, and the chance of side effects is minimized. The instructions on the aspirin bottle are intended for general use, not for heart patients, so do not follow them. But read the label on the product you buy to be sure that it contains aspirin in the correct amount recommended by your doctor. Check the drug facts label for “active ingredients: aspirin” or “acetylsalicylic acid.” If you experience any adverse effects after you start taking aspirin—such as stomach pains, indigestion, cramps, or black tarry stools (a sign of internal bleeding)—tell your doctor immediately.

    WARNING!

    Aspirin during a Heart Attack or a Stroke

    If you are having warning signs of a heart attack (such as chest pain), the most important thing to do is to call 911 or the emergency number for your area. Do not take an aspirin to see if it will relieve the pain before calling 911. Although aspirin will not treat a heart attack by itself, many experts recom- mend chewing one adult aspirin if you think you may be having a heart attack. Of course, if you are allergic to aspirin or have a condition that prevents you from taking aspirin, then wait until you get advice from a doctor. The 911 emergency operator may ask you about allergies and then recommend that you take an aspirin, or the emergency medical technicians may give you one in addition to other treatments. A single adult aspirin may reduce the chance of dying from a heart attack by about 20 percent, making it one of the most cost-effective life-saving measures in medicine.
    If you or a family member is having a stroke, do not take or administer an aspirin, because not all strokes are caused by blood clots. The emergency department is best qualified to make a judgment about whether aspirin might be effective for the particular type of stroke.

  • Medications for Angina or Heart Attack

    If you experience angina, medications are certain to be a part of your treatment. Because angina is an indication that your heart needs more oxygen (usually because of a blocked coronary artery), treatment includes drugs that either reduce your heart’s oxygen requirements or increase blood ?ow to your heart so that it gets more oxygen. The goal of treatment with medications is to prevent or ease the discomfort of this symptom.
    If you have a heart attack, you may be given medications (throm- bolytic agents) at the hospital to dissolve blood clots that may have formed in an artery already clogged with plaque. This step limits the extent of damage to heart muscle and may save tissue before it is beyond repair.

    Nitroglycerin

    If you have angina, your doctor is likely to prescribe nitroglycerin, which is a vasodilator, meaning that it expands blood vessels to increase blood supply. Used properly, it relieves angina in as little as 2 minutes by reduc- ing the return of (depleted) blood to the heart and thereby easing its workload, and by relaxing the coronary arteries to allow more oxygen- rich blood to reach your heart. It’s important to remember that angina alone does not mean that you are having a heart
    attack or that heart muscle is being damaged it is a temporary decrease in blood to the heart because of restricted supply and increased demand. Nitroglycerin provides a “quick ?x” that allows you to be more active and free of pain.
    Nitroglycerin is inexpensive and not at all habit-forming. You can take it several times a day without harm. It works best if you take it at the very earliest sensation of discomfort. Better yet, doctors advise people with stable angina to learn to recognize the conditions (exertion, excitement, or deep emotion) that are likely to lead to the pain and take nitroglycerin preventively. Many people experience angina in predictable circum- stances, such as walking outdoors on a cold, windy, or humid day; carrying parcels or heavy items and hurrying; getting exercise after a heavy meal; working under deadline pressure; speaking in public; engaging in sexual activity; or feeling angry, worried, or tense. Being able to “head off ” angina or keep an episode short is an excellent way to take control of your heart condition.

    If your doctor prescribes nitroglycerin, ask for directions about how to take it (see box) and talk to him or her about any concerns you have about using it. If you feel uncertain about it, ask to take a nitroglycerin tablet in your doctor’s presence. You will probably feel a slight tingling sensation under your tongue, your face may ?ush, or you may have a sensation of fullness in your head as the medication works in your blood vessels, but more troublesome side effects (light-headedness or headache) are rare. Once you are accustomed to taking nitroglycerin freely, you can derive the full bene?t of the relief it provides.

    Beta-blockers

    Beta-blockers (or beta-adrenergic blocking agents) are a group of drugs that reduce the heart’s workload and decrease its need for oxygen. They are commonly prescribed for angina, high blood pressure (see page 62), irregular heartbeat, cardiomyopathy (disease of the heart muscle), and heart failure. (They are also used to treat non-heart-related conditions such as migraine headaches and glaucoma.)
    A beta-blocker works by interfering with the body’s natural response to stress. When your body is responding to stress, it releases hormones called catecholamines (norepinephrine and epinephrine) that stimulate an increase in heart rate, heart muscle contraction, and blood pressure. A beta-blocker diminishes the effects of the catecholamines, thereby modifying the heart’s response to stress. Numerous beta-blockers are available that act selectively on different aspects of the action of catecholamines.
    If your doctor prescribes beta-blockers for angina, the effects of the drug will enable your heart to work longer during exercise or other stress before the angina occurs. You will need to take the beta-blockers daily, in addition to other drugs such as nitroglycerin. Even if you have no symptoms, doctors will often prescribe beta-blockers, since studies have shown they can reduce the risk of a second heart attack.
    If you experience a heart attack, your body will produce high levels of catecholamines that cause your heart to work harder. Doctors may give you a beta-blocker to ease your heart’s activity and limit the injury done to heart tissue. After the heart attack, beta-blockers can help pre- vent another one from occurring. You may take the drugs inde?nitely to reduce your risk of another heart attack.
    Although beta-blockers are a well-established remedy for heart con- ditions, some people who take them experience muscle fatigue after exercise, light-headedness, or fainting. If you have a lung condition such as asthma, beta-blockers can cause a spasm of the bronchial muscles and thus interfere with passage of air into the lungs, resulting in shortness of breath or wheezing. Some people with diabetes may have light- headedness if the drug interferes with their recognition of when their blood sugar levels are too low. If you experience any side effects from beta-blockers, notify your doctor immediately. A different beta-blocker or an adjustment in the dosage may resolve the problem. However, do not stop taking the drug suddenly, and try not to miss any doses because that could worsen any cardiac symptoms. If you are taking other medi- cines or herbal remedies, be sure to tell your doctor to avoid a harmful drug interaction.
    The following are some commonly prescribed beta-blockers, listed by their generic names: acebutolol, atenolol, betaxolol, bisoprolol, carvedilol, metoprolol, nadolol, pindolol, propranolol, sotalol, and timolol.

    Calcium Channel Blockers

    A group of drugs called calcium channel blockers, or calcium antagonists, relax the arteries and increase the supply of blood to the heart, while reducing its workload by decreasing blood pressure, heart rate, and muscular contraction. Chemically, calcium channel blockers work by preventing an essential step in the process of muscle contraction the movement of calcium into muscle cells in the heart and blood vessels. As a result, the heart and blood vessels relax. Calcium channel blockers may be prescribed for high blood pressure  or angina and may also be used to prevent migraine headaches. Calcium channel blockers are also very effective for the treatment of coronary spasm and the variant angina it causes.
    There are many calcium channel blockers, including both short-acting and longer-acting types. Calcium channel blockers are often used in com- bination with beta-blockers. Possible side effects vary with different types of the drug, but some people experience headache; tenderness, swelling, or bleeding of the gums; drowsiness; constipation; or a slow pulse rate (less than 50 beats per minute). Talk to your doctor immediately about any side effects, but do not stop taking the medication abruptly.
    The following are some frequently prescribed calcium channel blockers, listed by their generic names: amlodipine, bipridil, diltiazem, felodipine, isradipine, nicardipine, nifedipine, nisoldipine, and verapamil.

    ACE Inhibitors

    ACE (angiotensin-converting enzyme) inhibitors are a group of drugs widely prescribed to treat high blood pressure and are now also given to many people after a heart attack to improve heart function. After a heart attack, some heart muscle is damaged and weakened, and it may con- tinue to weaken over time. By lessening the workload of the heart and arteries, ACE inhibitors slow down this weakening.
    As antihypertensives (drugs that lower blood pressure), ACE inhibitors reduce the workload on the heart caused by hypertension, and help prevent damage to the blood vessels of the heart, brain, and kidneys. Controlling high blood pressure reduces the likelihood of stroke, heart failure, kidney failure, and heart attack.
    ACE inhibitors appear to work by blocking an enzyme (protein) in the body that helps produce angiotensin, a substance that makes the blood vessels contract. By inhibiting this process, the drugs relax blood vessels, the vessels expand, blood pressure goes down, and the workload for the heart decreases.
    If your doctor prescribes ACE inhibitors after a heart attack, you will probably take the drugs for the rest of your life. These drugs also control blood pressure and preserve kidney function in people with diabetes.

    ACE inhibitors tend to increase the level of potassium in your blood, so it is particularly important that you remind your doctor if you are taking potassium, salt substitutes (which often contain potassium), or low-salt milk (which can increase potassium levels). Talk to your doctor about any other medications you are taking, and check with him or her before using any over-the-counter medications or supplements.
    Some people taking ACE inhibitors experience side effects including dizziness, light-headedness, or fainting; skin rash; fever; or joint pain. If you experience any of these effects or others, check with your doctor as soon as possible. A high potassium level often has no symptoms or very nonspeci?c symptoms such as nausea, weakness, malaise (feeling list- less), palpitations, irregular heartbeat, or a slow or weak pulse. Tell your doctor if you experience these symptoms. However, high potassium levels usually cause few symptoms until they are dangerously high, so your doctor may periodically monitor the potassium level in your bloodstream.
    The following are commonly prescribed ACE inhibitors, listed by their generic names: benazepril, captopril, enalapril, enalaprilat, fosino- pril, lisinopril, perindopril, quinopril, ramipril, and trandolapril.
    Angiotensin-2 receptor blockers (ARBs) may be prescribed. ARBs differ from ACE inhibitors in that ARBs inhibit the effect of angio- tensin, rather than blocking it in the ?rst place .

  • Outcomes of a Heart Attack

    Lack of blood ?ow to the heart (myocardial ischemia) usually causes symptoms such as angina, a sensation of pressure in the chest; shortness of breath; or light-headedness. Ischemia may lead to a heart attack (myocardial infarction), as some part of the heart is deprived of blood for a period long enough for the heart muscle tissue to die. It is impor- tant to recognize these symptoms and seek medical help urgently, espe- cially if you have any risk factors for coronary artery disease. Prompt medical help, in which the blocked arteries can be opened quickly with medications or a procedure such as angioplasty (which compresses the plaque on the artery walls), can minimize damage to heart tissue.
    Insuf?cient blood supply can also cause cardiac arrest—when the heart stops abruptly. Cardiac arrest most often occurs when a person’s heart rhythms are disturbed. The electrical impulses that control heart rhythms become either too fast (tachycardia), chaotic (?brillation), or in rarer cases, extremely slow (bradycardia). A person in cardiac arrest is in extreme danger. To reverse cardiac arrest, the person’s circulation should be maintained by cardiopulmonary resuscitation (CPR), and the heartbeat must be restored with an electrical shock (defibrillation). Brain death begins in just 4 to 6 minutes after a person’s heart stops.
    In some people the main effects of a heart attack are seen in the pericardium, the layer of protective tissue around the heart (see “Pericardi- tis,” ).
    The worst possible outcome of a heart attack is sudden cardiac death. Any form of heart disease can cause sudden death. But in most victims (about 90 percent) two or more major arteries are blocked by plaque, and the heart also shows scars from previous attacks. Sudden cardiac death can occur without a warning sign.

    Ischemic Cardiomyopathy

    Cardiomyopathy is a term for disease of the heart muscle  that results from a condition that impairs the muscle tone of the heart and reduces its ability to pump blood. One form of the disease, called

    ischemic cardiomyopathy, starts as a result of damage from blockage in a coronary artery supplying a portion of the muscular walls of the heart. This damage leads to the inef?cient pumping that is characteris- tic of cardiomyopathy. Frequently, cardiomyopathy is diagnosed by an echocardiogram (see page 132). The echocardiogram measures the ejection fraction, which is the amount of blood pumped with each heartbeat. In people with cardiomyopathy, this number is low, meaning that not enough blood is being pumped. Often the heart will dilate (widen) to compensate, so people with cardiomyopathy often have an enlarged heart.
    Treatment for ischemic cardiomyopathy focuses on restoring the heart’s pumping ability with medications and opening the blocked arter- ies to improve blood supply to the heart. Other types of cardiomyopathy include a viral cardiomyopathy, in which the heart is damaged by a virus, and toxic cardiomyopathy, in which the heart is damaged by some out- side agent—for example, alcohol. If the heart has been severely and irreparably damaged by the disease, doctors may recommend a heart transplant .

    Pericarditis

    Pericarditis is an inflammation of the pericardium, the membrane surrounding your heart. The pericardium actually has two layers, one of which is attached to the heart’s muscular walls and the other which lines the cavity of the chest in which the heart is located. Fluid between the two layers enables the heart to move as it beats, yet stay in position. When pericarditis inflames the membrane, the amount of fluid increases and the heart’s movement (particularly its ability to ?ll with blood) can become restricted. About 10 percent of people who have had a heart attack develop pericarditis, as a result of the death of tissue. Peri- carditis occurs more often in men than in women. Infection, often due to a virus, is a common cause of pericarditis, especially in young adults. In many cases the causes of pericarditis may be unknown. Other causes of pericarditis include cancer or radiation therapy for cancer, injury to the chest, prior chest surgery, autoimmune disease, kidney failure, or use of medications that suppress the immune system.
    The most common symptom of pericarditis is a sharp, stabbing pain in the center or the left side of the chest, and it sometimes radiates to the neck or shoulder. It can easily be mistaken for a symptom of a heart attack. Your doctor can begin to diagnose pericarditis by listening to your description of the pain and how it began. He or she can also listen with a stethoscope for characteristic rubbing sounds in your chest, which sometimes can be heard when the in?amed layers of the pericardium rub against each other as the heart beats. A chest X-ray may show an accumulation of ?uid around your heart, which can be con?rmed by an echocardiogram . An electrocardiogram can show changes that indicate pericarditis. Occasionally, periocardiocentesis—a pro- cedure in which a sample of ?uid is withdrawn and analyzed—is needed to help determine the cause of the pericarditis.
    Pericarditis is usually treated with pain relievers and anti-in?ammatory medications such as aspirin or ibuprofen. When the condition is the result of a heart attack, pericardi- tis usually responds well to treatment and you are likely to recover in 1 to 3 weeks.
    However, if the condition causes an accumulation of ?uid around your heart that is seriously restricting your heart’s ?lling ability (a rare but life-threatening disorder called cardiac tamponade), your doctor may perform pericardiocentesis (either with a needle or as minor sur- gery) to remove the excess ?uid. Examination of the extracted ?uid can help determine the cause of the cardiac tamponade. Repeated accumu- lations of ?uid may require surgery.
    Complications of pericarditis are rare, but the infection can cause arrhythmias or even a heart block (when the electrical impulses triggering heart rhythm fail to perform).
    Constrictive pericarditis can also develop, in which the in?ammation causes the pericardium to thicken and develop scar tissue (adhesions) between the pericardium and the heart. The pericardium becomes in?exible, and heart failure can result. In such cases, surgical removal of part or all of the pericardium is the only remedy.
    There are other complications after a heart attack, depending on where the damage is located in the heart and how severe it is. The heartbeat may slow markedly, requiring a pacemaker. Arrhythmias or heart failure may also occur.

    Considering Your Options

    If testing shows that you have blockages in your coronary arteries, if you have angina, or if you have a heart attack, your physician may recom- mend treating your condition with lifestyle changes, medications, or procedures such as angioplasty or bypass surgery. In making a treat- ment recommendation, he or she will consider the overall pumping strength and electrical sta- bility of your heart, as shown by testing, and also the severity of your symptoms. Deciding which treatment or combination of treatments is best for you is complex, but you and your doctor may discuss these strategies:
    • Lifestyle changes. Lifestyle changes such as eating a healthy diet, getting regular exercise, and quitting smoking are proven to be beneficial in reducing the risk of heart attack, improving angina, or slowing the progression of disease after a heart attack. These factors are essential to support any other treatments you may receive. Your doctor will provide you with information and support, but only you can follow through.
    • Medications. Medications such as beta- blockers, calcium channel blockers, ACE inhibitors, or statins (cholesterol-lowering drugs) can improve your heart’s function and treat contributing factors such as high blood pressure and high cholesterol. They may relieve symptoms such as angina and may play an important role in controlling inflammation and preventing the plaque ruptures that lead to some heart attacks. They also may be prescribed after surgery to support your heart during recovery.
    • Angioplasty. If one or more of your arter- ies is substantially blocked, angioplasty  will clear the blockage and restore blood flow. If you are having a heart attack, angioplasty at the time of the heart attack may help minimize heart damage. It is a considerably less invasive, less risky, and less expensive procedure than bypass. But some arteries are not suitable for angio- plasty because they are too small. Other blockages are too dense or too large to pen- etrate with angioplasty. During angioplasty, a stent may be placed in an artery in an attempt to keep it from closing up .
    • Bypass. Bypass grafting is the best approach for some people with severe angina or extensive blockages. Your doctor may recommend bypass surgery if your left main coronary artery, which supplies the left ventricle (the major pumping chamber), is significantly blocked, because any problem with angio- plasty could cause serious damage to the heart muscle; if you have several major coronary arteries blocked; or if you have had previous angioplasty procedures. Bypass also may be necessary if you have another condition such as heart failure or diabetes.

  • Recognizing Symptoms of a Heart Attack

    Clearly, knowing the signs of a heart attack and responding quickly are important. If people live long enough to reach the hospital, their chances of dying are dramatically reduced. Treatment to open clogged arteries is most effective within the ?rst 60 to 90 min- utes after symptoms (such as chest pain) occur. If the blood ?ow is completely shut off, permanent damage to heart muscle occurs in about 20 minutes. So every minute counts, both to save your life (or someone else’s) and to improve the quality of life after the attack.
    Calling 911 or the emergency services (?re depart- ment or ambulance) in your area should be your ?rst step, before doing anything else. Paramedics can begin treatment immediately, even before you reach the hos- pital. If your heart actually stops beating, paramedics have the knowledge and equipment to begin advanced life support and to restore a heartbeat. Also, a heart attack victim who arrives by ambulance gets faster treatment at the hospital, because emergency medical technicians begin treatment as soon as the ambulance arrives.
    Take an aspirin if you have one on hand. Chew it; don’t swallow it. If you’re unsure whether you person- ally should take aspirin, wait until the paramedics arrive. If you’re alone, unlock your door, then sit down or lie down while you wait for the ambulance.

    What to Do If Symptoms Occur

    Many people delay going to a hospital, sometimes for as long as 2 hours after they ?rst notice symptoms. Some people are just hoping the symptoms will disappear, some don’t want to feel embarrassed by a false alarm, some think that a “real” heart attack would be dramatic and unmistakable, and some don’t realize the enor- mous advantage of immediate treatment. Although these feelings are understandable, doctors urge you to seek help at the ?rst signs of a heart attack, so that effective treatment begins as soon as possible.
    It’s easier to respond quickly to symptoms—either your own or some- one else’s—if you have thought through the steps you will take before an emergency arises. First, of course, you have to learn the warning signs. Talk to your doctor about your personal risk of a future heart attack and how you should respond—for example, whether you should take aspirin or use nitroglycerin. If you are at risk, talk with your family, friends, and coworkers about the warning signs and the best response. Find out who, if anyone, knows cardiopulmonary resusci- tation (CPR) and alert him or her to the possible need for it. If 911 serv- ices are not available, keep the numbers for your area’s emergency medical services (?re department and ambulance) next to the telephone. Find out which hospitals nearby have 24-hour emergency cardiac care.
    When you arrive at the emergency room, a doctor or other staff may ask you questions about your symptoms. If you are able to respond, the information you give them will help guide your treatment. Questions may include:

    • When did you ?rst notice symptoms?
    • What were you doing at the time?
    • Were the symptoms most intense right away, or did they build up gradually?
    • Did you notice any symptoms other than the ?rst or most intense ones?
    • On a scale of 1 to 10, how would you rate the discomfort you felt?
    • What medicines have you taken today?
    • What medicines do you usually take?

    Chest Pain

    Most people would probably name chest pain as the symptom they associate most closely with heart attack. But very often the symptom that a person experiences from a blockage in the coronary arteries is not a sharp or stabbing pain. People who have experienced a heart attack often go to great lengths to say that the sensation they had was not exactly pain, but rather an uncomfortable feeling of squeezing or pressure (angina pectoris; ).
    The somewhat confusing fact is that chest pain may be caused by a heart condition other than heart attack, and it can also result from problems having nothing to do with the heart, such as gallbladder dis- ease, a muscular disorder, or a digestive problem. The most important distinguishing feature of pain caused by coronary artery disease is prob- ably a link to some sort of stress, either physical or emotional—an indication that the heart’s increased need for oxygen is not being met. Chest pain at rest deserves immediate medical attention, especially in a person with risk factors for heart attack. The ?rst episode of chest pain in a per- son’s life may be the sign of an impending heart attack, so don’t delay seeking medical help.
    For reasons that are not at all clear, women with heart disease are more likely to experience symptoms other than chest pain—such as shortness of breath, indigestion, or fatigue—making diagnosis more complex. People with diabetes also may not experience typical chest pain. Some people may have jaw pain or arm pain that for them is the equivalent of chest pain—a sign of a heart attack. If you have experi- enced symptoms of heart attack before, the important point is to learn to recognize them when they occur so that you can respond without hesitation.
    A form of chest pain related to heart disease may also be caused by in?ammation of the outer surface of the heart, the pericardium. Like in?ammation anywhere in the body, an in?amed pericardium swells and causes pressure on nerve endings that may result in pain when you breathe in, when you move in certain ways such as leaning forward, or when you lie down. Even though not all chest pain indicates a heart attack, you should still get medical help if you experience any kind of a chest pain that lasts for as long as 5 minutes. It is de?nitely better to be safe than sorry.

    Angina Pectoris

    Angina, or angina pectoris, is the term that describes the typical chest discomfort or pain that signals an inadequate ?ow of blood to the heart, most often the result of a blockage in the coronary arteries. Many people who have experienced angina struggle to characterize it, but they often describe it as a constricting pressure or fullness; a squeez- ing, crushing, or burning sensation; or a dull pain in the center of the chest. It may radiate out to the arms, shoulder, back, neck, or jaw. But it may also be con?ned to a small area of the chest, and it can last several minutes. Alternatively, it goes away and returns over a period of minutes. However, pain that lasts less than 30 seconds or more than 30 minutes is usually not anginal pain.
    Angina usually occurs when the heart demands more blood for a variety of reasons: physical exertion, such as walking uphill or having sexual intercourse; mental or emo- tional stress, including fright or anxiety; cold temperatures; or even eating a meal that trig- gers digestive activity. When pain brought on by exercise is relieved by rest, angina is suspected by your doctor. Many people have “stable angina”—that is, they have episodes of angina that occur in a fairly predictable pattern. This is the reason behind stress testing as a way to reproduce a person’s chest pain symptoms during exercise: to help diagnose coronary artery disease. Usually, a person with stable angina can relieve the symptom with rest or nitroglycerin, or both.
    Unstable angina is a form of chest discomfort that occurs for the ?rst time in that person or occurs when the person is at rest. It can be more severe and prolonged than stable angina. The blockage in the arteries that brings on unstable angina may be atherosclerosis, a blood clot, in?ammation, or infection. The experience of unstable angina is an emergency situation. If you have new, unpredictable, or increasingly severe chest discomfort, go to a hospital emergency department imme- diately for evaluation.
    A variant form of angina, sometimes called Prinzmetal’s angina, dif- fers from other types because it is not related to physical or emotional stress. It usually occurs when the person is at rest or asleep, often between midnight and 8 o’clock in the morning. Variant angina is a symptom of coronary artery spasm, which may occur in an open artery or in an artery already blocked by atherosclerosis. The spasm occurs close to the blockage and obstructs blood ?ow to the heart muscle.
    Angina can occur more rarely as a symptom of other heart condi- tions such as valve disease, cardiomyopathy (disease of the heart muscle; , or extreme high blood pressure. Angina may be treated with nitroglycerin or other medication .

    Shortness of Breath

    Shortness of breath is another common symptom of a heart attack that can be dif?cult to differentiate and describe. Dif?culty breathing can take the form of feeling unusually breathless with exertion; experienc- ing rapid or shallow breathing; or feeling short of breath at rest. Some people report that they feel conscious of the need to draw breath.
    Of course, it is normal to feel short of breath for a while after stren- uous exercise. Anxiety can cause hyperventilation, a form of rapid or shallow breathing. An overweight person may breathe more heavily just from the exertion of carrying extra weight, or someone who is out of shape may feel short of breath with even limited exercise. You are the best judge of when your shortness of breath feels abnormal.
    If you feel short of breath at what for you is a moderate level of exer- cise, or if you become short of breath while at rest, or if your breathless- ness occurs with chest pain, don’t hesitate to get medical help.

    Light-headedness and Other Symptoms

    Some people feel light-headed—like they might pass out—as a symp- tom of a heart attack. (This sensation is different from dizziness, which makes you feel as if you or your surroundings are whirling.) Light- headedness can also signal other heart conditions, such as heart rhythm problems or problems unrelated to your heart.
    Women are more likely than men to have atypical or more vague symptoms of heart attack such as light-headedness, nausea or queezi- ness, or fatigue, rather than chest pain. Researchers have only relatively recently recognized this gender difference, and the reasons for it are not yet clear. Genes, hormones, or lifestyle differences may be at work. Both women and their doctors need to be aware of the nature of a

    woman’s symptoms and respond quickly to the possibility of heart attack. It is vital to keep in mind that heart disease is the leading cause of death for women, just as it is for men.

    Silent Ischemia

    A person can have an episode of ischemia (lack of blood to the heart) without angina or other symptoms, a phenomenon called silent ischemia. If the ischemia is severe or lasts too long, it may cause a heart attack with all the attendant dangers of heart damage or cardiac arrest, even if there is no chest pain. For many people the ?rst sign of heart dis- ease may be a cardiac arrest. Cardiologists estimate that 3 to 4 million Americans have silent ischemia every year. The resulting damage to the heart muscle is a leading cause of heart failure (when the heart’s pump- ing action is inadequate). Most people who have episodes of angina or chest pain are likely to have episodes of silent ischemia, too. Although there is no way to know when silent ischemia occurs, an exercise stress test (see page 125) indicates how the blood ?ow in your coronary arter- ies is affected by exercise, and Holter monitoring (see page 124) records an episode of silent ischemia if it occurs while you wear the monitor.
    Treatment for silent ischemia is aimed at improving the ?ow of blood to your heart and reducing your heart’s need for oxygen—just like the treatment for any other symptoms of coronary artery disease. Your doctor will recommend lifestyle changes, medications, or perhaps ulti- mately surgical procedures such as angioplasty to reach these goals.

    Coronary Artery Spasm

    Chest pain may result from a spasm of the artery. Some people’s coro- nary arteries have a tendency to go into spasm periodically (doctors are not sure why). The spasm, called a vasospasm, temporarily constricts the passageway and blocks blood ?ow to the heart. A spasm usually occurs in a coronary artery that is already blocked by atherosclerosis, but it can occur in an otherwise healthy vessel.
    The spasm is temporary, but it can cause a heart attack, irregular heart rhythm (arrhythmia), or even sudden cardiac death. The major symptom of coronary artery spasm is a variant form of angina that is particularly painful and often occurs at the same time each day. To treat coronary artery spasm, your doctor may prescribe a medication called a calcium channel blocker , which relaxes the smooth muscle in the artery walls and eases the discomfort of angina. In some cases, a nitrate may be prescribed also.

    Heartburn or Heart Attack?

    It’s not always easy to distinguish between the chest discomfort of a heart attack and the burning sensation of heartburn (acid reflux). About one out of ten people who go to an emergency department complain- ing of chest pains has heartburn. Either symptom occurs in the general area of the chest, may have a burning quality, and may occur after a big meal. The location of the pain may be a clue: heart attack pain is likely to radiate from the chest into the shoulder, arm, or neck, especially on the left side, while heartburn usually stays more centered and travels into the neck or throat. But don’t take any chances. Remember that most of the damage done by a heart attack occurs in the first hour or so. Get to an emergency department quickly if you have any doubt about the nature of your discomfort.

    What Is a STEMI?

    You may hear or read about the danger of a STEMI—an ST elevation myocar- dial infarction. This technical term describes a severe heart attack in which an artery is completely blocked. An ST elevation is a characteristic rise in a partic- ular segment of the waves seen in an ECG reading for a person who is having symptoms of a heart attack. Cardiologists identify certain parts of the wave by the letters of the alphabet from Q through T. Injured heart muscle does not conduct electrical impulses normally. The characteristic wave patterns on an ECG show how the electrical impulses are being affected by the injury, and what part of the heart appears to be affected. Also, problems with the heart’s rhythm can be detected. An ST elevation when you have chest pain is a strong indication of a heart attack. Also, a non-Q-wave heart attack may be indicated by a drop in the pulse rate; this type of attack is called minor but may indicate that a major heart attack is imminent.
    What does your doctor want you to know about STEMI? A STEMI is likely to be preceded by chest pain, shortness of breath, or feelings of weakness, nausea, or light-headedness. If you have these symptoms for 5 minutes or more, call 911 or your local emergency number immediately. The sooner you get help, the more likely you are to survive and to return to an active lifestyle. Every minute counts.

    Calling for Emergency Help

    If you or someone you know might be hav- ing a heart attack, call 911 or the emer- gency services number for your area. More than 90 percent of the United States now has 911 service, but in some communities the emergency number is that of the fire department, police department, or town hall. Keep the number handy at home for all family members. If you call for emer- gency services from a cell phone, be sure to mention the location you’re calling from because the location can’t be traced quickly, as it can from a landline. Also, if you use cable or broadband service for Internet-generated calls, find out whether your service will give you access to a 911 service or to some other administrative service office that does not handle emer- gency calls.

    Warning Signs of Heart Attack

    Heart attacks may start with relatively mild symptoms. Call 911 or the emergency medical services in your area if you experience any of these symptoms for as much as 5 minutes:
    • Chest discomfort. An uncomfortable feeling—such as pressure, squeezing, or a sensation of fullness—in the center of the chest that lasts for a few minutes or that goes away and then comes back. The feel- ing may not be truly painful.
    • Discomfort in other parts of the upper body. The uncomfortable feeling or pain may spread to one or both arms, the back, the neck, the jaw, or maybe the stomach.

    • Shortness of breath. Difficulty breath- ing often occurs with or just before chest discomfort. It may be the only sign of a heart attack.
    • Light-headedness, cold sweats, nau- sea, or indigestion. Some people, par- ticularly women, experience these symptoms, and some report having a sense of impending doom.
    If you have heart attack symptoms and for some reason cannot call 911 (or the emergency number for your area), have someone else drive you to the nearest hospital immediately. Never drive yourself unless you have absolutely no other choice.

  • The Role of Inflammation

    Scientists now know that in?ammation is a major component of the process of atherosclerosis. Just as in?ammation of bones and joints can, over time, lead to arthritis, an in?ammatory process inside blood vessels can lead to coronary artery disease or stroke.
    Research has not yet pinpointed what causes the low-grade in?am- matory process that may contribute to or even cause atherosclerosis in some people. In the future, a speci?c bacterial or viral infection may be identified, and treatment for coronary artery disease may include antimicrobial or antiviral agents, just as treatment for stomach ulcers now involves antibiotics for the bacteria that is known to be the cause.
    In many people who have heart attacks, in?ammation has caused the artery wall itself to absorb fat particles to form a type of plaque some- times called “soft” or “vulnerable” plaque. This plaque, buried in the wall of the artery, is not the same as the plaque that builds up in the channel of an artery. Soft plaque is composed of fat-?lled cells con- tained in a thin shell. If the shell containing the soft plaque breaks open, the plaque spills into the bloodstream, and a blood clot forms at the site of the rupture—the body’s usual response to injury. This blood clot— rather than the plaque—may be the blockage that shuts off the blood supply. The in?amed and swollen artery may be less elastic as well. This process, starting with a type of in?ammation and leading to a blood clot, may explain heart attacks in some people who do not have the tra- ditional risk factors for coronary artery disease, such as high cholesterol.
    A marker of the in?ammatory (or immune) response is the presence of a substance called C-reactive protein (CRP) in the blood. Everyone’s body makes CRP, but in different amounts, depending in part on genetic factors and in part on lifestyle. The same factors that tend to contribute to increased risk of heart attack—smoking, overweight, high blood pressure, lack of exercise—contribute to high levels of CRP. A person’s CRP levels can be elevated early in the development of plaque in the arteries, and at the time of a rupture. When a heart attack occurs, CRP levels rise dramatically. As a result, measuring CRP levels in a person’s blood is a good predictor of the development of coronary artery dis- ease and the risk of future heart attacks, as well as a good indicator in an emergency department that a heart attack has occurred.
    Nowadays, CRP is measured through a relatively simple test that can be done in a doctor’s of?ce. An elevated CRP level may be as reliable a predictor of heart attack risk in some people as a high level of LDL ( low-density lipoprotein, the harmful choles- terol; see page 132). Research suggests that in some people, high levels of CRP are a signi?cant risk fac- tor for heart disease, independent of high choles- terol. It may be a better predictor in women than in men. Other factors may raise the CRP level in the blood, however. At present, there is no speci?c treat- ment for high CRP levels, except for treating any underlying conditions.

    Signs of Cardiac Arrest
    A person in cardiac arrest:
    • Loses consciousness
    • Stops breathing
    • Lacks a pulse
    Respond immediately:
    • Call 911 or the emergency number for your area.
    • If you are trained in CPR, use it to help keep the person alive until emergency help arrives to perform defibrillation.
    • Look for automated external defibrillator (AED) equipment to use on the person. See also the box on page 155 on using an AED.

  • Atherosclerosis

    Most coronary artery disease leading to heart attack results from the process of atherosclerosis, the stiffening and narrowing of arteries. Early changes are seen in people as young as their twenties. A healthy artery is highly elastic, responding readily to changes in the amount or pressure of the blood ?owing through it. As you age, the walls of your arteries tend to become somewhat thicker and stiffer, causing some resistance to the pumping action of the heart. This loss of ?exibility in the arteries, which tends to accelerate as you get older, is the cause of higher blood pressure in older people and con- tributes to several forms of heart disease.
    Apart from or in addition to these effects of aging, atherosclerosis is a disease process affecting the interior walls of the major arteries, including the coronary arteries that supply the heart. The inner walls of the arteries become in?amed and irregular and begin to accumulate fatty materials, cholesterol, and other debris that together form plaque. The plaque gradually builds up until it sig- nificantly narrows the channel through which blood is ?owing. This unhealthy process of athero- sclerosis is not fully understood, although a high- fat diet, high levels of cholesterol, smoking, and other known risk factors (see pages 19–22), along with genetic background, are major contributing causes. As plaque builds up, it can form accumulations (called athero- mas or plaques) that ultimately shut off the blood ?ow. A blood clot traveling through the bloodstream can lodge on an accumulation of plaque and block the already narrowed channel altogether.
    When a coronary artery is temporarily blocked, it can deprive some portion of the heart of oxygen and nutrients, resulting in a condition called myocardial ischemia. Prolonged ischemia can damage or destroy tissue anywhere in the heart, leading to an infarction (or death of tis- sue), depending on what part of the heart the affected artery supplies. Extensive damage to the left ventricle, the main pumping chamber of the heart, will affect a person’s long-term health and activity level.

  • Heart Attack

    A heart attack occurs when a blockage in the coronary arteries those that supply the heart itself—shuts off the ?ow of oxygen- rich blood to heart muscle tissue. Without oxygen and nutrients, the heart muscle will begin to die. Prompt medical attention can restore blood ?ow and limit the extent of damage, but dead tissue cannot be restored. The lack of blood supply, called ischemia, can weaken your heart or stop it altogether. If there is a prolonged decrease in blood sup- ply, tissue dies, so this is an urgent matter. The severity of the heart attack depends on how much tissue is damaged and where in your heart the damage occurs.
    Several different mechanisms can cause a heart attack:
    • Atherosclerosis, in which the walls of the arteries thicken and accumulate fatty deposits called plaque, can narrow or block one or more arteries supplying a section of heart muscle.
    • A blood clot can form within the artery and stick to the walls of the narrowed coronary artery, already thickened with plaque, and stop the blood ?ow.
    • A blood clot also can form in the coronary artery itself, as a result of atherosclerotic plaque that cracks open, emptying its choles- terol and other components into the bloodstream.

    • A coronary artery can temporarily spasm, narrowing the artery and restricting or stopping blood flow. These spasms most commonly occur in a blocked artery but may occur in a normal one.
    The most common mechanism begins when a fracture develops within atherosclerotic plaque, exposing the inside of the plaque. This causes platelets to stick to the site of the rupture, triggering a cascade of events resulting in the formation of a blood clot that blocks the artery. This explains why aspirin, which helps reduce stickiness of platelets, is effective in reducing the risk of heart attack.
    Every year in the United States, about 1.2 million people have heart attacks, and more than 40 percent of those people die before they reach a hospital. As scary as these numbers may sound, they are substantially lower than the ?gures of 25 years ago. Today, many Americans are doing a better job of reducing their own risk of heart attack. Doctors have made major advances in treatment, so that a person who gets medical help quickly is much more likely to survive a heart attack. A heart attack survivor has a much better chance of getting fully rehabilitated than ever before. The survival rates for men after a heart attack have improved in recent years, but this has not yet occurred for women. See also chapter 16, Women and Heart Disease.

  • Cardiac Catheterization

    Cardiac catheterization is a technique doctors use to perform many tests and procedures on the heart and blood vessels. Catheterization is an invasive procedure in which a catheter (a long, thin tube) is inserted into your body. For cardiac catheterization, a small puncture is made, usually in your groin, to access directly the underlying vein or artery. The catheter is guided through a blood vessel into your heart. A num- ber of tests and some treatments can be accomplished by injecting sub- stances (such as dyes) or guiding instruments into the catheter.
    Typically, cardiac catheterization is the method by which iodine- based dye is introduced for a coronary angiogram (imaging of the inside of your blood vessels, such as your coronary arter- ies; ); a ventriculogram (imaging of the interior of your ventricles, done for some types of heart valve diseases or diseases of the heart muscle); or electrophysiology studies (an assessment of your heart’s electrical activity). Specialized types of angiograms can be done via catheterization to get information about your peripheral blood ves- sels and the arteries in your lungs (pulmonary angiography). Cardiac catheterization can also be done to study congenital heart defects and to assess the pressures of the blood within the heart.
    Less invasive and less expensive tests (such as echocardiography or nuclear scanning) can provide a great deal of information, but only cardiac catheterization can detect some types of problems such as blockage in the artery. Cardiac catheteriza- tion may be done after other tests, in order to con?rm or build on those results. Doctors can also do a biopsy (obtaining a sample of tissue) of heart muscle via a cardiac catheter, to detect in?ammation or to check for tissue rejection after a heart transplant .

    Elective Cardiac Catheterization

    If you are having cardiac catheterization done for a diagnostic test such as an angiogram or other nonurgent reason, you will probably go to a hospital, but often it is an outpatient procedure. Cardiac catheterization is a relatively common procedure, but because it is invasive it does carry some risk. Your doctor may still recommend it because he or she thinks that the bene?t from the information the test can provide is greater than the risk. Talk to your doctor beforehand and ask any ques- tions that concern you. Some people experience problems such as bruis- ing, temporary numbness, or bleeding at the site of the catheter insertion, but these reactions are infrequent. Some people have allergic reactions to the iodine-based dye that is used as a contrast medium .
    More serious complications such as inducing a heart attack, stroke, or an arrhythmia are even rarer and usually occur only in people who are already seriously ill. Remember that you will be carefully monitored and sterile procedures will be followed throughout the test.

    What to Expect

    Before having cardiac catheterization, talk to your doctor about any med- ications you are taking, because he or she may want you to stop taking them—especially blood thinners or anticoagulants—for several days before the procedure. It’s a good idea to make a written list of your med- ications, including dosages, and bring it with you to the procedure, so that any doctors and technicians present know exactly what you are taking.
    You will be told not to eat or drink anything after midnight before having cardiac catheterization. If you have diabetes, talk to your doctor beforehand about your food and insulin intake. If you are allergic to iodine dye, you will receive steroids the day before the test and another medication just before the test (see also the box on page 139.)
    On the day of the cardiac catheterization, you can expect that the preparations and the procedure together will take 2 to 3 hours, with several more hours spent in a recovery room. You will probably have blood tests, an ECG (see page 122), and a chest X-ray done ?rst. The procedure itself will be done in a catheterization laboratory, or cath lab. You will be attached to an ECG machine and will wear a blood pressure cuff. An IV will be inserted into your arm, and you will receive a mild sedative to relax you throughout the procedure.
    The doctor or nurse will prepare the area of your groin where the catheter will be inserted by cleansing it and shaving it if necessary. He or she will inject your groin area with a local anesthetic so that you will not have any pain, but you will be awake so that your doctor can tell you what is happening and what he or she will do next throughout the procedure. Then the doctor will puncture the skin to enter the artery or vein into which the catheter will be inserted, using a specialized needle, and he or she will thread the catheter into the blood vessel toward your heart. You should not feel any pain during this process.
    The doctor will thread the catheter through your artery and up into your heart. Then whatever test or procedure you are having will be per- formed via the catheter. The doctor may guide more than one catheter into different areas of your heart. A variety of instruments can be inserted to guide the tip of the catheter, draw blood samples, inject dye, take pressure readings in the chambers of the heart, and perform other

    testing procedures. Depending on what you are having done, you may feel sensations such as ?ushing, brief nausea, or your heart skipping a beat. These feelings are normal, so don’t worry if they occur. Ask your doctor beforehand what you might expect. If you feel any chest pain, tell your doctor right away.
    When the procedure is complete, the catheter and the IV will be removed. To stop any bleeding, the doctor or nurse will press very ?rmly on the insertion site, which may be uncomfortable, and then will put on a bandage.
    You will be moved to a recovery room, and pressure will be applied on the insertion site for another 15 minutes or so. In some people, stitches or a closure device like a plug are needed to close the artery. You should try to lie still and keep your leg straight for several hours. A nurse will continue to monitor your heart rate and blood pressure. You will be free to leave when the sedative has worn off and any bleeding is controlled.
    Someone else should drive you home. At home, plan on resting with your leg (or arm, if that was the insertion site) still for 6 to 8 hours. You should not strain or lift heavy objects for 48 to 72 hours, but you can probably resume normal activities after that. You may be told to take plenty of ?uids to ?ush out the dye. Most people can walk in about 6 hours or so.

    What the Results Mean

    Cardiac catheterization can be used both as a diagnostic tool and for treatment. The most common diagnostic use is to help show clearly the anatomy of your heart and in particular the blood vessels of your heart. Through imaging during cardiac catheterization, doctors can detect if there are blockages in your blood vessels and also the sizes and locations of the blockages. Treatment options include management with medica- tions and a healthy lifestyle, surgery, or treatment done during catheter- ization. For example, your doctor may perform balloon angioplasty (see page 176) as part of the cardiac catheterization if he or she sees plaque inside the arteries that needs to be compressed against the walls of the blood vessels to allow for improved circulation of blood. In addi- tion, the doctor might place a stent to improve blood ?ow through a blocked artery. If after catheterization it appears that your blood vessels will need surgical repair, the doctor will discuss with you the possibility of a cardiac artery bypass graft . The information from the pictures taken during the catheterization helps the surgeon in plan- ning the procedure. See also “Considering Your Options,”.

    Angiography

    Angiography is an X-ray examination in which a contrast dye outlines the heart or blood vessels. To perform an angiogram, your doctor will insert a cardiac catheter (see page 143), positioning the tip of the catheter either into your left ventricle or at the opening of each of the coronary arteries. Then an iodine-based contrast agent (dye) will be injected so your doctor can watch the blood ?ow through these struc- tures. Some people are allergic to the iodine-based dye (see the box on page 139 for information on what to do if you are allergic). When the dye is in your ventricle, you may feel warm.
    The angiogram shows how well the heart is pumping, its shape and internal parts, and whether there is any faulty valve action that causes leakage or backflow. If the dye is in your coronary arteries, the angiogram shows whether any narrowing or blockages are restricting or cutting off blood supply.

    The diagnostic catheterization and angiogram will probably take about 1 hour, but you should allow most or all of the day for the entire procedure. After the test, you will rest until the sedative has worn off. You can drink lots of liquids to help rid your body of the contrast agent.

    Electrophysiology Studies

    For some people with problems related to their heart’s electrical activ- ity, such as arrhythmias (irregular heartbeats), an ECG or other tests do not give enough information. Electrophysiology studies are tests that require cardiac catheterization to enable doctors to send controlled electrical impulses into the heart to determine where the problem is and how it might be corrected.
    To perform electrophysiology studies, the doctor inserts a cardiac catheter  and then passes a type of electrode into the chambers of your heart. This electrode catheter will relay impulses into your heart to make it beat at different speeds. Your doctor can follow the impulses and map your heart’s electrical conduction system and its reaction to the impulses. You might be given a medication through the catheter to cause an arrhythmia, or you might be given medications designed to stop the arrhythmia in order to see which ones work best in you.
    Tilt-table testing is another type of electrophysiology test. You will not feel pain, but you will feel your heart changing speeds, and this feel- ing might be uncomfortable or even alarming. In the course of the studies, the table you are lying on may be tilted to bring you into an upright position, because your heart rhythm or blood pressure might change when you are upright. Straps around your chest will hold you securely. This test is usually done on people who have unexplained light-headedness. Because the studies may involve both diagnosing your condition and testing some drugs, the procedure may be lengthy. Depending on what is being done, the studies may take 1 to 4 hours.
    After the studies are done, your recovery period will be similar to that for any cardiac catheterization . The risks involved in electrophysiology studies include the risks of any catheterization proce- dure. In addition, even though the electrical stimulation of your heart is very carefully controlled, there is some risk of severely abnormal heart rhythms occurring. The laboratory in which the studies are done is equipped with a de?brillator (a machine that stops abnormal heart rhythms with electric shock). If such an emergency occurs, you may lose consciousness and the doctors will use the de?brillator and resuscitate you if necessary. If you do remain conscious, you will be given a fast- acting anesthetic before the de?brillator is used.

    The Testing Process

    Very probably, your doctor will need to do several tests to gather enough information to diagnose your condition and decide on the right course of treatment. The series of tests your doctor recommends for you will not necessarily be the same as for someone else with a similar problem. The results of one test might yield information that requires more testing to fully understand your unique situation. You also might need to have the same test several times to determine how your heart is responding to any medications, surgical procedures, or other treat- ments. Your personal medical history is also a factor in determining which tests are appropriate.
    Don’t hesitate to ask your doctor why a speci?c test is required at this time and what information he or she hopes to derive. Ask the doc- tor directly about the pros and cons of any procedure, and discuss thoroughly how you feel about any risks versus bene?ts of having the procedure.
    You can also ask what different results might indicate about the next steps in your treatment. If you have any questions or concerns, you always have the option of seeking a second opinion. Remember that you are in charge of your own health and should make sure you have enough information to make an informed decision about any test or treatment.
    If you decide to get another opinion, either to con?rm a diagnosis or to get more information about your options, tell your doctor that you plan to do so. Your primary-care physician or local medical society can help you ?nd another quali?ed doctor. Never feel guilty about getting a second opinion or think this will hurt your doctor’s feelings.
    When you go to see a doctor for a second opinion, bring a complete set of your records and copies of any tests that have been done. If you get a different recommendation from a second doctor, it doesn’t neces- sarily mean that one is right and the other is wrong. There is room for legitimate differences of opinion, especially concerning a complicated problem or major treatment decisions.
    You are the most important decision maker. Your con?dence in the choices made and your priorities about how treatments for your heart condition affect your life are extremely important factors to consider. Your overall treatment will be most successful if you and your doctor or doctors are working together to make decisions that positively affect your life.

  • Other Imaging Techniques

    Still more advanced technologies can be used to study your heart’s structure and function. These procedures include computed tomogra- phy (CT), magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), and positron emission tomography (PET). Such techniques are used to get more detailed information or to avoid more invasive procedures. These scanners are not available at all hospitals or diagnostic centers and are used only when needed to answer speci?c questions your physician may have.

    Computed Tomography

    CT scanning is an advanced X-ray technique that can take cross-sectional images of your heart. To have a CT scan done, you lie on a movable table that slides into the tubular CT scanner. Many images are taken from all sides of your body. A computer combines these images to construct a detailed cross section of a structure. Your doctor can assess images of your heart, lungs, or major blood vessels. CT scans are often used to see if calci?cation, a natural reaction to injury, has occurred in your blood vessels as a result of atherosclerosis (see page 152), or in your heart muscle as a result of a heart attack. As with other X-ray techniques, CT scanning passes some radiation through your body, but it is a minimal, safe amount that does not remain in your body after the test.

    In some cases, a contrast agent (iodine-based dye) is injected into your bloodstream to get a clearer image. If you are not being injected with the dye, you will be told not to eat for about 2 hours before the test. If you are being injected with the dye, you should not eat for about 4 hours beforehand. In some people, this contrast agent causes hot ?ushing and other allergic symptoms, but this reaction is rare .
    You will be asked to put on a hospital gown and lie down on the table. If a contrast medium is being used, an intravenous line will be placed into your arm. The table will be moved slowly into the scanner. The technician will start taking pictures, and you will be asked to lie still and hold your breath brie?y as each image is taken. After the test, you may resume your usual activities.

    Electron Beam Computed Tomography

    Electron beam computed tomography (EBCT or fast CT) is a faster form of CT scanning that takes images in about one-tenth of a second (compared to 1 to 10 seconds for a conventional
    CT scan). Because the heart is always in motion, a conventional CT sometimes creates a blurred image. EBCT is fast enough to avoid this prob- lem. EBCT enables your doctor to detect calci- ?cation in your arteries. EBCT is sometimes used for “whole body screening” for healthy people, but there is no evidence it is effective for that purpose.

    Spiral Computed Tomography

    Spiral computed tomography (or spiral or hel- ical CT) is another form of fast CT scanning. For a conventional CT, you rest on a table while the scanner is moved slightly for each picture; with spiral CT, you lie on a table that moves slowly through the scanner while it takes images nonstop. These scanners are particu- larly helpful in ?nding aneurysms (ballooning in the wall of a weakened artery) and blood clots in the lungs (pulmonary emboli).

    Magnetic Resonance Imaging

    MRI is another technology that uses magnetic ?elds and radio signals to form an image. Brie?y, the MRI scanner surrounds your body with a magnetic ?eld that reacts with magnetic elements in your body (such as hydrogen). The reaction causes radio signals from which a computer can construct an image. MRI scans produce images that are similar to those from a CT scan, but no radiation is used, and the MRI shows slightly different tissues. The test is painless, does not involve any injections, and does not pose any known risks. People who have pacemakers or other internal metallic devices cannot have an MRI, but people with arti?cial heart valves that are not magnetically active can have one safely. This test can be performed safely in the second half of pregnancy.
    You do not need to prepare in any way for an MRI. You will change into a hospital gown and lie on a table that will be placed in the scan- ner, which is a long, narrow tube. Some people with claustrophobia may find the scanner uncomfortable. However, many scanners are now made with open ends that eliminate this problem. If you are con- cerned about being inside the scanner, talk to your doctor before the test is done; a sedative may be administered to help you relax through the test.
    When you are inside the scanner, you may be asked to hold your breath brie?y while images are taken. You may hear loud noises inside the scanner. Sometimes you can listen to music through headphones while you are inside the scanner, but the technician’s instructions will also be transmitted via the headset. After the test, you can go about your usual activities.

    Magnetic Resonance Angiography

    MRA uses an MRI scanner to analyze the blood vessels leading to the brain, kidneys, and legs. This type of scan is done using different set- tings on the scanner, so the procedure is the same as for an MRI from your point of view. Usually, an MRA is done using gadolinium, a mag- netic contrast agent to which virtually no one is allergic. This contrast agent is given as an injection, usually in your arm, before the scanning is done.

    Positron Emission Tomography

    PET scanning uses information about the energy released by subatomic particles in your body to form an image. A radioactive substance is injected into your body that will travel to damaged or malfunctioning tissues. These tissues have increased or decreased metabolic activity. The PET scanner detects and measures the radioactive substance in these areas of your body, and a computer constructs images. A PET scan is highly accurate because it shows your heart tissue at work. The uses for this technology are still developing, but it has the poten- tial to show how your heart uses energy at a cellular level. Currently, PET scans are used mainly in research rather than in patient care or diagnosis of heart disease.
    You do not need to prepare for a PET scan in any way. You will be asked to remove your clothes from the waist up, and a technician will place a ring of detectors around your chest. You will lie down on a table that will be moved into the PET scanner. The scanner is shaped like a large funnel, and your body will be in the tube. The technician or doctor will take a picture of your heart before the radioactive sub- stance is injected. You need to keep your arms above your head during this part of the test, which takes about 15 to 30 minutes. Then the radioactive material will be injected, usually in your arm. You will have to wait about 45 minutes for the substance to move into your heart. Again, you will be asked to keep your arms over your head while the images are being taken. After the test, you may resume your usual activities.

    Multidetector CT Scans

    A type of CT scanner with more detectors than a conventional CT machine can be used to provide the same kind of infor- mation about the coronary arteries as an angiogram reveals (see page 146). Because having a CT scan is easier and less expensive than an angiogram, the multidetector CT scan might be used more frequently in the future. A recent application is CT angiography, in which dye is injected and images are made of the coronary arteries that may detect both calcified and noncalcified deposits. CT angiography is being used as a screen- ing tool in high-risk people and as a diag- nostic tool in some hospital emergency departments with specialized chest pain centers. Medical experts are working on standards to guide the use of the new multidetector scanners.

  • Multiunit Gated Blood Pool Scan (MUGA)

    A multiunit gated blood pool scan (MUGA) is an assessment of how your blood pools in your heart during rest or exercise, or both. The test shows how well the heart pumps blood and whether it has to compen- sate for blocked arteries. It also reliably measures your ejection fraction, which is the percentage of your blood pumped out of your ventricles with each heartbeat. The ejection fraction normally increases during exercise.

    What to Expect

    If you are having only a resting scan MUGA, no special preparation is necessary. You should check with your doctor whether you need to stop taking any heart medications for a day or two beforehand. If you are having an exercise MUGA, you should not eat or drink anything other than water the night before the test. Depending on the extent of the testing, you should allow 2 to 4 hours for its completion. For the test, you will usually be asked to change into a hospital gown, and a techni- cian will attach electrodes to your chest. The electrodes will be wired to a nuclear imaging computer. Then the technician will draw a small amount of your blood and mix it with the radioactive tracing material. About 10 minutes later, he or she will inject the prepared blood back into your arm. Then you will lie down on a table while the technician takes a number of images of your heart with the gamma camera. If you are having only a resting MUGA, the test is complete and you can go home.
    If you are having an exercise MUGA, you will move to a different table with pedals at the foot. While you lie on the table, you will pedal as if you were on a bicycle, and the technician will take images. You will pedal through a warm-up stage, and then the exercise will be gradually increased until you are tired. You will be carefully monitored through- out the test.
    After your MUGA, you may feel tired, but you can return to your usual activities. The harmless radioactive substance will leave your body in 2 or 3 days. This test should not be performed during pregnancy.

    What the Results Mean

    The full results of your test will be ready in a few days. In addition to the images produced, the computer also calculates the size and shape of your ventricles and measures the amount of blood in them. A low ejec- tion fraction may be due to blockages in your coronary arteries or a problem with a heart muscle.