Heart failure due to cardiopmyopathy means the heart muscle has lost its power to do the work it needs to do; it still functions, but not as effectively as it should. In this episode of Second Opinion, you'll learn about the causes and treatment of heart failure and how today's technology, including artificial hearts and heart transplants, is saving lives.
The heart is essentially a muscle, about the size of a fist, whose main job is to pump blood to all parts of the body, bringing needed nutrients and oxygen and delivering waste products for removal by other organs. The heart has four chambers. The upper two are the atria (the right and the left atrium) and the lower two are the right and left ventricles. These chambers contract in a regular sequence, or rhythm (the heartbeat); the contractions enable the heart to pump blood to all parts of the body. The rhythm of the contractions is controlled by the heart's "pacemaker," a group of cells in the right atrium (called the sinoatrial node, SA node, or sinus node) that generate electrical impulses. This is the "normal" rhythm, usually at a rate of 60 to 100 beats a minute. These impulses travel across the heart's chambers, making them contract.
There are several kinds of cardiomyopathy - and at least two ways to classify them. Sometimes doctors are unable to discover a specific cause for an individual's cardiomyopathy. In this case, the condition is known as primary cardiomyopathy. Secondary cardiomyopathy does have specific causes. Ischemic cardiomyopathy is caused by a chronic lack of oxygen to the heart muscle because of coronary artery disease. Non-ischemic cardiomyopathy is not caused by coronary artery disease, but by some other cause, and is often connected to diseases of other organs. Both kinds of cardiomyopathy can be chronic (long-standing) or acute (sudden and unexpected). For more information about the causes of cardiomyopathy, see Heart Failure Key Point #1.
Another classification system involves describing the condition of the heart itself.
- Dilated (or congestive) cardiomyopathy is the most common type. The heart muscle stretches (dilates), becomes thinner and weaker, and doesn't pump normally. This often leads to congestive heart failure.
- Congestive heart failure means the weakened heart action is causing excess body fluids to back up into the lungs and elsewhere because the heart cannot effectively move blood forward.
- Dilated cardiomyopathy can also lead to abnormal heart rhythms called arrhythmias or dysrhythmias. For more information about arrhythmias, watch the "Heart Rhythm Disorder" episode of Second Opinion.
- Hypertrophic cardiomyopathy means the heart muscle (especially, the left ventricle) thickens (or "hypertrophies"). In one form of this disease, the thickening obstructs the flow of blood into and out of the heart, referred to as hypertrophic obstructive cardiomyopathy; more than half the time, this condition is hereditary.
- Restrictive cardiomyopathy is another type. The heart muscle becomes hard, stiff, or rigid, which makes it more difficult for the ventricles to be filled with blood between heartbeats.
The symptoms of cardiomyopathy can vary, depending on the type, but in general they include:
- Swollen feet, ankles and/or hands; distended veins
- Shortness of breath, especially with and following physical exertion or when lying down
- Chest pain (technical name: angina pectoris) caused by an inadequate blood supply to the heart muscle
- Irregular heartbeat (technical name: arrhythmia)
Cardiomyopathy or heart failure means the heart muscle has lost its power to do the work it needs to do; it still functions, but not as effectively as it should. Cardiomyopathy can be treated with medicine and mechanical devices.
Although many cases of cardiomyopathy are congenital (the person was born with the condition), it is still wise to live in a "heart-healthy" way. That means:
- Get physical exercise
- Stop smoking
- Stop drinking alcohol heavily
- Keep your blood pressure under control
- Keep your cholesterol under control
- Eat a heart-healthy diet
The first heart transplant happened in South Africa in December of 1967, when Dr. Christiaan Barnard transplanted the heart of a 23-year-old woman killed in a motor vehicle accident into the chest of a middle-aged man. He lived for eighteen days, until the powerful drugs used to suppress rejection weakened him and he died of pneumonia. But Dr. Barnard's next heart-transplant patient lived for 18 months and became a symbol of hope for victims of heart disease. Today, the procedure is an established treatment for advanced heart disease.
About 4,000 people are currently on the waiting list for a heart in the U.S. About one third of them - more than 1,300 people - will die waiting. Becoming an organ donor may someday save a life.
It takes only a few hours to learn CPR, and when you do, you may save a life. Your local chapter of the Red Cross or American Heart Association offers CPR courses.
Ask Your Doctor
Provided by Nora Goldschlager, M.D.
Director, Coronary Care Unit, San Franciso General Hospital
Professor of Medicine, University of California, San Francisco
This list of questions is a good starting point for discussion with your doctor; however, it is not a comprehensive list.
- What exactly is heart failure?
- How do I know I have it? What are the symptoms?
- Are there different forms of heart failure?
- How does hypertension cause heart failure?
- Can I have heart failure and not have symptoms?
- What are the treatments for heart failure? Are there medicines? What kind, how many? What are the side effects?
- Can heart failure come from too fast a heartbeat?
- Can heart failure come from too high a blood pressure?
- Do pacemakers help in heart failure? How? What kind?
- If I join an exercise program, will it help my heart failure?
- Can heart failure run in families?
- Who needs a heart transplant? What are the results?
Key Point 1
Heart failure means that the heart muscle has lost its power to do the work it needs to do. The heart still functions, but not as effectively as it should.
Causes of heart failure include coronary heart disease, congenital heart disease, viruses, severe infection, muscular dystrophies, drugs, and chemicals naturally found in your body during and after pregnancy (it is uncommon, but it happens).
It is important to understand that for many, if not most, cases of cardiomyopathy, a specific cause may never be found. This form of the condition is called primary or idiopathic cardiomyopathy.
Secondary cardiomyopathy does have a specific cause. Ischemic cardiomyopathy is caused by a chronic lack of oxygen to the heart muscle because of coronary artery disease.
Non-ischemic cardiomyopathy is not caused by coronary artery disease, but by other causes. Those causes include:
- Congenital heart disease, that is, heart problems that have been inherited
- Viral infections
- Bacterial infections
- Muscular dystrophies
- Dystrophy is a general term for the progressive degeneration or abnormal development of tissues or organs
- Drug abuse, especially of cocaine, amphetamines, and antidepressants
- Certain chemicals found in the body during and after pregnancy
- Alcohol abuse
- Chronic untreated high blood pressure (hypertension)
- Problems with metabolism, such as thyroid disease or diabetes
- Uncontrolled diabetes increases the risk of developing coronary artery disease and hypertension, both of which can lead to cardiomyopathy
- Problems with heart valves
- Chronic rapid heart rate
- Inadequate nutrition, especially of essential vitamins and minerals
- Morbid obesity
- Genetic disorders
Cardiomyopathy can be diagnosed through a variety of tests, including:
- Echocardiogram: sound waves are bounced off the heart to produce still and moving images of it (similar to ultrasound imaging used with pregnant women to produce images of fetuses)
- Cardiac catheterization: in this more invasive test, the doctor inserts a small tube (catheter) through a blood vessel, running it into the heart, to remove a tiny sample for examination in the laboratory (biopsy) or to inject dye into the heart chambers to measure cardiac function, measure pressures produced by the heart muscle, examine blood flow through the heart, and examine the coronary arteries.
You can find detailed information about these and other diagnostic techniques on the American Heart Association's website.
Key Point 2
Heart failure is treatable through drugs or mechanical intervention.
A number of medicines are now available that can effectively help people with heart failure. Of course the specific ones prescribed depend on the type and severity of the condition, but among the most frequently used are:
- Anticoagulant drugs to prevent blood clots
- Aspirin (also useful in preventing blood clots)
- Beta blockers , that is, drugs that slow down the heart rate and decreases the heart's workload
- Vasodilators , that is, drugs that open ("dilate") the arteries, lowering blood pressure and therefore the heart's workload.
- ACE inhibitors ACEIs, one of the newest and most frequently prescribed class of vasodilators, stop the production of a substance that contricts the blood vessels
- ARB's angiotensin receptor blockers which also reduce constriction of blood vessels in a manner similar to ACEI's
- Calcium-channel blockers are another class of drugs that dilate blood vessels, but only in some forms of heart failure
- Antiarrhythmic drugs that regulate the heartbeat
- Diuretics, that is, drugs that help eliminate excess fluid, and therefore aid the heart in working more efficiently; they also reduce the swelling and shortness of breath that often accompany cardiomyopathy
- Digitalis, a drug that strengthens the heartbeat
There are also a number of mechanical devices that can be implanted within a person to correct heart failure. They include:
- Pacemaker : small (smaller than a matchbook) device surgically placed under the skin that sends electrical signals to the heart to restore its regular rhythm
- Usually used to correct heart rhythms that are too slow
- Biventricular pacemakers, with wires to both the upper (atria) and lower (ventricle) chambers of the heart synchronize the heart beats.
- Ventricular assist device (VAD or LVAD for left ventricular assist device): a mechanical pump implanted in the chest cavity to help the heart circulate blood. It is a transitional step or bridge to transpant.
- Battery operated; microchip controlled (responds to individual's needs)
- Weighs about five pounds
- Usually considered a temporary implant, that is, a transitional step until a heart transplant can be done, but approved by the FDA as destination therapy, meaning a transplant is not expected or intended.
Soon, an artificial heart may become available for general use. Also known as a Total Artificial Heart (TAH), this self-contained device would completely replace a natural heart. Presently, the TAH is still in the experimental stage, but at least one company is now running clinical trials of their TAH using human subjects.
Key Point 3
Heart transplants work. However, there are not nearly enough donors of hearts or other organs. You can help save lives by being an organ donor.
Many of us can still remember when heart transplants sounded like something from science-fiction and the first actual transplants seemed like true medical miracles. They are still miracles and they are not exactly "everyday" operations. But in fact, in hospitals across the country heart transplants are done every day and they are normally quite successful. The most serious problem facing people who need the operation is not the procedure itself, but the difficulty in finding a heart to transplant.
The United Network for Organ Sharing (UNOS) is the organization that manages the fair allocation of the limited number of donor hearts (and other organs). It maintains a centralized computer network that links all organ procurement organizations and transplant centers. UNOS member organizations, transplant candidates, recipients and donor family members work together to develop policies that give every transplant candidate an opportunity to receive the organ they need.
When the decision is made for a patient to be a candidate for a heart transplant, the person's name is entered into both the national and regional UNOS data banks. Patients are grouped into categories according to the severity of their heart condition. Doctors submit ongoing reports to UNOS and alert them to any change in a person's condition, which can change their position on the priority list.
Aside from the patient's condition, other criteria used to choose a recipient include blood type, size match between patient and donor, how long the patient has been waiting, and the patient's location (because a donor heart cannot safely be outside of the body for more than four hours).
Learn how to get on the national heart transplant waiting list
500,000 people will die this year with heart failure. In the U.S. alone, there are more than 4,000 people currently on the waiting list for a heart for intractable heart failure. About one third of them - more than 1,300 people - will die waiting.
Conduct an off-site search for Heart Failure information from MedlinePlus. These up-to-date search results are based on search terms specific to Second Opinion Key Points.