Enhanced external counterpulsation (EECP) is a noninvasive procedure in which a set of inflatable cuffs (much like blood pressure cuffs) mechanically compress the blood vessels in the patient's lower limbs to increase blood flow in the coronary arteries of the heart. The blood pressure cuffs are wrapped around the patient's calves, thighs, and buttocks. Computer technology, electrocardiography , and blood pressure monitors enable the accurate timing of gentle but firm inflation and deflation of the pressure cuffs with the patient's heartbeat and blood pressure.
EECP is performed to restore blood flow to the heart and to relieve chest pain (angina) and ischemia. The goals of the procedure are to relieve symptoms of coronary artery disease, enable the patient to resume a normal lifestyle, and lower the risk of a heart attack or other heart problems. EECP may encourage blood vessels to open small channels (called collaterals) to eventually bypass blocked vessels and improve blood flow to the heart.
The concept of counterpulsation is not new (it was first introduced in the late 1950s at Harvard), but the computerized technology currently available with EECP makes it a relatively new procedure, introduced less than 10 years ago. As of 2003 it is available in only about 200 centers across the United States.
EECP is used to treat patients with chronic stable angina, coronary artery disease, or high blood pressure. Most recently, the Food and Drug Administration (FDA) has approved EECP for the treatment of congestive heart failure. The treatment may be appropriate for patients who are not eligible for such non-surgical interventional procedures as balloon angioplasty , stent placement, rotoblation, atherectomy, or brachytherapy. It may also be used for patients who do not qualify for such surgical treatment as coronary artery bypass graft surgery .
EECP is not the first-line treatment for angina. Rather, it is reserved for patients who have not achieved good results from medication or interventional management of their symptoms.
EECP may benefit patients with such other medical conditions as erectile dysfunction, kidney disease, eye disease, diabetic neuropathy, and other circulatory disorders. More research is needed to evaluate the outcomes of EECP for these patients.
Many insurance providers and Medicare have approved EECP treatment for reimbursement.
EECP is not recommended for patients who have certain types of valve disease; uncontrolled arrhythmias (irregular heart rhythms); severe hypertension; uncontrolled congestive heart failure; significant blockages or blood clots in the leg arteries; or those who have had a recent cardiac catheterization , angioplasty, or bypass surgery.
While the patient lies on a bed, the leg cuffs are deflated and inflated with each heartbeat. A computer synchronizes the compression of the cuffs with the heartbeat. The electrocardiogram indicates when each heartbeat begins, triggering the cuffs to be mechanically deflated. As each heartbeat ends, the cuffs are mechanically inflated in sequential order, starting with the cuffs on the calves and working upward. The pressure produced by the inflation of the cuffs when the heart is at rest pushes the blood in the legs upward toward the heart. The deflating action that occurs just when the heart begins to beat reduces the work of the heart as it pumps blood to other parts of the body.
EECP treatments are performed on an outpatient basis and generally last one to two hours. Treatments must be repeated about five times a week for up to seven weeks to achieve improved circulation.
The patient is usually instructed to wear tight-fitting, seamless cycling pants or athletic tights to prevent chafing, one of the main adverse side effects.
Before the procedure, the patient's weight, blood pressure, pulse, and breathing rate are measured and recorded. The patient's legs are examined for areas of redness and signs of potential vascular problems.
The patient is asked to record his or her symptoms during the course of treatment to determine if and how symptoms improve over time. The patient should record the severity and duration of troublesome symptoms, the time the symptoms occurred, and any activities that may have triggered the symptoms. This patient record is reviewed before each treatment session.
PATIENT EDUCATION. The health care team will ensure that the patient understands the potential benefits and risks of the procedure. Informative and instructional handouts are usually provided to explain the procedure. Because the procedure requires multiple outpatient visits (generally 35 visits over a seven-week period), the patient must be able to meet the treatment schedule.
INFORMED CONSENT. Informed consent is an educational process between health care providers and patients. Before any procedure is performed, the patient is asked to sign a consent form. Before signing the form, the patient should understand the nature and purpose of the diagnostic procedure or treatment; the risks and benefits of the procedure; and alternatives, including the option of not proceeding with the test or treatment. During the discussion about the procedure, the health care providers are available to answer all of the pa tient's questions.
SMOKING CESSATION. Patients who will undergo any procedure to treat cardiovascular disease are encouraged to stop smoking and using any tobacco products before the procedure, and to make a commitment to be a nonsmoker after the procedure. There are several smoking cessation programs available in the community. The patient should ask a health care provider for more information if he or she needs help quitting smoking.
Patients report little or no discomfort during the procedure. Some people may feel tired after the first few treatments, but this loss of energy improves over time.
To manage heart disease, the patient needs to make several lifestyle changes before and after the procedure, including:
EECP is a relatively safe and effective treatment, and few adverse side effects have been reported. The main adverse side effect is chafing (skin irritation from the compression of the cuffs). To reduce or prevent this side effect, patients are instructed to wear tight-fitting cycling pants or athletic tights. Leg pain is another adverse side effect.
The benefits of EECP are comparable to the results of angioplasty and coronary artery bypass graft surgery: 80% of patients experience significant improvement after EECP treatment. The largest research study on EECP indicates that after receiving treatment, patients used less medication, had fewer angina attacks with less severe symptoms, and increased their capacity to exercise without experiencing symptoms. EECP improves the patient's sense of well-being and overall quality of life; and in some cases, prolongs the patient's life. Benefits five years after EECP treatment are comparable to surgical outcomes.
The effects of EECP treatment last from three to five years and sometimes longer.
EECP does not prevent coronary artery disease from recurring; therefore, lifestyle changes are strongly recommended and medications are prescribed to reduce the risk of recurrent disease.
Morbidity and mortality have not been reported with this procedure.
All patients with coronary artery disease can help improve their condition by making such lifestyle changes as quitting smoking, losing weight if they are overweight, eating healthful foods, reducing blood cholesterol, exercising regularly, and controlling diabetes and high blood pressure.
All patients with coronary artery disease should be prescribed medications to treat their condition. Such Antiplatelet medications as aspirin or clopidogrel (Plavix) are usually recommended. Other medications used to treat angina may include beta blockers, nitrates, and angiotensin-converting enzyme (ACE) inhibitors. Medications may also be prescribed to lower lipoprotein levels, since elevated lipoprotein levels have been associated with an increased risk of cardiovascular problems.
Treatment with vitamin E is not recommended because it does not lower the rate of cardiovascular events in people with coronary artery disease. Although such antioxidants as vitamin C, beta-carotene, and probucol show promising results, they are not recommended for routine use. Treatment with folic acid and vitamins B 6 and B 12 lowers homocysteine levels (reducing the risk for cardiovascular problems), but more studies are needed to determine if lowered homocysteine levels correlate with a reduced rate of cardiovascular problems in treated patients.
Such nonsurgical interventional procedures as balloon angioplasty, stent placement, rotoblation, atherectomy, or brachytherapy can be performed to open a blocked artery.
Coronary artery bypass graft surgery is a surgical procedure in which one or more blocked coronary arteries are bypassed by a blood vessel graft to restore normal blood flow to the heart. These grafts usually come from the patient's own arteries and veins located in the leg, arm, or chest.
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Angela M. Costello
EECP is performed by health care providers trained in the procedure. Interventional cardiologists, registered nurses, and other health care professionals may perform the procedure. Currently, EECP credentialing is being investigated by the International EECP Therapists Association (IETA). EECP is generally performed in an outpatient clinic or hospital.