Ischemic cardiomyopathy; Cardiomyopathy - ischemic
Patients with this condition have weakened heart pumps, either due to previous heart attacks or due to current blockages of the coronary arteries. (There may be a build-up of cholesterol and other substances, called plaque, in the arteries that bring oxygen to heart muscle tissue).
The term “ischemic” means that an organ, in this case the heart muscle, has not received enough blood and oxygen. “Cardio” refers to the heart and “myopathy” means this is a muscle-related disease.
In summary, ischemic cardiomyopathy is a medical term that doctors use to describe patients who have congestive heart failure that is a result of coronary artery disease.
Causes, incidence, and risk factors
Ischemic cardiomyopathy results when the arteries that bring blood and oxygen to the heart, called coronary arteries, are blocked. Ischemic cardiomyopathy is a common cause of congestive heart failure. Patients with this diagnosis may at one time have had a heart attack, angina or unstable angina. A few patients may not have noticed any previous symptoms.
Ischemic cardiomyopathy is the most common type of cardiomyopathy in the US. It affects approximately 1 out of 100 people, most often middle-aged to elderly men. In the older age ranges, the gender difference becomes less pronounced.
Risks include having a personal or family history of heart attack, angina, unstable angina, atherosclerosis,or other coronary artery diseases. High blood pressure, smoking, diabetes, high fat diet, high blood cholesterol, obesity and (rarely) stress can all precipitate ischemic heart disorders.
- chest pain o experienced under the sternum o may radiate to the neck, jaw, back, shoulder, arm o may feel tight, pressure, crushing, squeezing o may or may not be relieved by rest or nitroglycerin
- sensation of feeling the heart beat (palpitations)
- irregular or rapid pulse
- shortness of breath, especially with activity
- shortness of breath that occurs after lying down for a while
- fatigue, weakness, faintness
- decreased alertness or concentration
- decreased urine output
- excessive urination at night
- overall swelling
- breathing difficulty when lying down
Signs and tests
The physical examination may be normal, or it may reveal signs of fluid buildup (leg swelling, enlarged liver, “crackles” in the lungs, extra heart sounds, or an elevated pressure in the neck vein). There may be other signs of heart failure.
The diagnosis of this condition is usually made only if a test shows a decreased ejection fraction (the pumping function of the heart). A normal ejection fraction is around 55-65%. Most patients with this disorder have ejection fractions much less than this. Tests used to measure ejection fraction include:
- Ventriculogram performed during a cardiac catheterization
- Gated SPECT
- MRI of chest
An ECG may show enlargement, previous heart attack, changes to the blood supply to the heart, arrhythmias, or other abnormalities.
A biopsy of the heart is rarely needed to rule out other disorders.
Lab tests that may be used to rule out other disorders and to assess the condition of the heart include:
- Coronary risk profile
- Blood chemistries
- Cardiac biochemical markers (CK-MB, troponin)
Treatment is focused on relieving the symptoms and treating the underlying cause of the condition. Hospitalization may be required when the symptoms are severe.
There have been many major studies in this area, because this condition is so common and serious. Several types of medications have been found to help patients live longer with this disorder. They are ACE-inhibitors (e.g., captopril, lisinopril, etc.), beta-blockers (e.g., metoprolol, carvedilol, etc.), and aldosterone. In addition to these, diuretics (“water pills”) and digoxin are frequently used.
Patients with this disorder usually will have a cardiac catheterization performed to see if they are candidates for bypass surgery or angioplasty (“balloon procedure”). The goal of these treatments is to improve blood flow to the damaged or weakened heart muscle.
A number of studies have shown that heart failure symptoms can be improved with a special type of pacemaker. It paces both the right and left sides of heart. This is referred to as biventricular pacing or cardiac resynchronization therapy. Ask your provider if you are a candidate for this.
A heart transplant may be recommended for patients who have failed all the standard treatments and still have very severe symptoms. Recently, implantable, artificial heart pumps have been developed. At this point, very, very few patients will be able to undergo either of these advanced treaments.
If you smoke or drink alcohol excessively, stop doing so, because these habits increase the workload of the heart.
This is a very serious disorder. Patients with this condition, in general, do not have a normal lifespan. For some, the prognosis is just as bad as for many forms of cancer. Thus, it is very important to discuss your particular situation with your doctor to ensure that you can improve it as much as possible.
- Arrhythmias, including lethal arrhythmias
- Cardiogenic shock
Calling your health care provider
Go to the emergency room or call 911 if you have symptoms that may be ischemic cardiomyopathy, or if chest pain is present and not relieved by rest or nitroglycerin.
The best way to prevent ischemic cardiomyopathy is to avoid getting heart disease. Stop smoking, eat a healthy diet, maintain a healthy weight, exercise as much as possible, avoid excessive drinking, and see your doctor to control blood pressure, cholesterol, and diabetes.
by Amalia K. Gagarina, M.S., R.D.