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.