Heart Failure
Signs and Symptoms
Heart failure develops when the heart doesn't function properly. The names "heart failure" and "congestive heart failure (CHF)" doesn't mean that the heart has actually "failed" or stopped but mean one or more chambers of the heart "fail" to keep up with the volume of blood flowing through them. Heart failure can be brought on by a variety of underlying diseases and health problems. Read The Causes of Heart Failure for more information.
Heart failure may involve the left side, the right side or both sides of the heart. Each side has two chambers — an atrium (upper chamber) and a ventricle (lower chamber). Heart failure occurs when any one of these four chambers is no longer able to keep up with the volume of blood flowing through it.
Two types of heart dysfunction can lead to heart failure, including:
Systolic Heart Failure — This is the most common cause of heart failure and occurs when the heart is weak and enlarged. The muscle of the left ventricle loses some of its ability to contract or shorten. In turn, it may not have the muscle power to pump the amount of oxygenated and nutrient-filled blood the body needs.
Diastolic Failure — The muscle becomes stiff and loses some of its ability to relax. As a result, the affected chamber has trouble filling with blood during the rest period that occurs between each heartbeat. Often the walls of the heart thicken, and the size of the left chamber may be normal or reduced.
The left side of the heart is crucial for normal heart function and is usually where heart failure begins. The left atrium receives oxygen-rich blood from the lungs and pumps it into the left ventricle, the heart's largest and strongest pump, which is responsible for supplying blood to the body.
After it has circulated through the body, blood returns to the right atrium and then travels to the right ventricle, which pumps it into the lungs to be replenished with oxygen. When the right side loses pumping power, blood can back up in the veins attempting to return blood to the heart.
Right heart failure may occur alone but is usually a result of left-sided failure. When the left ventricle fails, fluid backs up in the lungs. In turn, pressure from excess fluid can damage the heart's right side as it works to pump blood into the lungs.
Heart failure usually is a chronic, or long-term, condition that gradually gets worse. By the time most people notice and see a doctor about their symptoms, the heart has been "failing," little by little, for a long time.
This is a good reason to have regular health checkups. During a routine physical examination, your doctor may detect signs of heart failure long before you experience symptoms. Heart failure rarely occurs suddenly except after a major heart attack, severe heart valve problem or period of seriously high blood pressure.
Symptoms
People who experience any of the symptoms associated with heart failure, even if they are mild, should consult a doctor as soon as possible. Once a person is diagnosed, it's important to keep track of symptoms and report any sudden changes.
Typical signs of heart failure include:
Breathlessness or Shortness of Breath (Dyspnea) — When the heart begins to fail, blood backs up in the veins attempting to carry oxygenated blood from the lungs to the heart. As fluid pools in the lungs, it interferes with normal breathing. In turn, you may experience breathlessness during exercise or other activities. As the condition worsens, shortness of breath may occur when at rest or asleep. These periods of breathlessness may leave you feeling exhausted and anxious.
Fatigue — As heart failure becomes more severe, the heart is unable to pump the amount of blood required to meet all of the body's needs. To compensate, blood is diverted away from less-crucial areas, including the arms and legs, to supply the heart and brain. As a result, people with heart failure often feel weak (especially in their arms and legs), tired and have difficulty performing ordinary activities such as walking, climbing stairs or carrying groceries.
Chronic Cough or Wheezing — The fluid buildup in the lungs may result in a persistent cough or wheezing, that may produce phlegm (a thick, mucous-like substance) that may be tinged with blood.
Rapid or Irregular Heartbeat — The heart may speed up to compensate for its failing ability to adequately pump blood throughout the body. Patients may feel a fluttering in the heart (palpitations) or a heartbeat that seems irregular or out of rhythm. This often is described as a pounding or racing sensation in the chest.
Lack of Appetite or Nausea — When the liver and digestive system become congested they fail to receive a normal supply of blood. This can make you feel nauseous or full, even if you haven't eaten.
Mental Confusion or Impaired Thinking — Abnormal levels of certain substances, such as sodium, in the blood and reduced blood flow to the brain can cause memory loss or disorientation, which you may or may not be aware of.
Fluid Buildup and Swelling — Because blood flow to the kidneys is restricted, the kidneys produce hormones that lead to salt and water retention. This causes swelling, also called edema, that occurs most often in the feet, ankles and legs.
Rapid Weight Gain — The fluid build-up throughout the body, may cause you to gain weight quickly.
These symptoms occur as the heart loses strength and the ability to pumped blood throughout the body. In turn, blood can back up and cause "congestion" in other body tissues, which is why heart failure sometimes is called "congestive." In addition, excess fluid may pool in the failing portion of the heart and the lungs.
At the same time, the heart as well as other parts of the body attempt to adapt and make up for the deteriorating pumping ability. For example:
Heart Grows Larger — The muscle mass of the heart grows in an attempt to increase its pumping power, which works for a while. The heart chambers also enlarge and stretch so they can hold a larger volume of blood. As the heart expands, the cells controlling its contractions also grow.
Heart Pumps Faster — In an attempt to circulate more blood throughout the body, the heart speeds up.
Blood Vessels Narrow — As less blood flows through the arteries and veins, blood pressure can drop to dangerously low levels. To compensate, the blood vessels become narrower, which keeps blood pressure higher, even as the heart loses power.
Blood Flow Is Diverted — When the blood supply is no longer able to meet all of the body's needs, it is diverted away from less-crucial areas, such as the arms and legs, and given to the organs that are most important for survival, including the heart and brain. In turn, physical activity becomes more difficult as heart failure progresses.
Although the body's ability to compensate for the failing heart initially is beneficial, in the long run these adaptations contribute to the most serious cases of heart failure. For example:
An enlarged heart eventually doesn't function as well as a normal heart, and the extra muscle mass adds stress to the entire cardiovascular system.
The organ systems from which blood has been diverted may eventually deteriorate because of an inadequate supply of oxygen.
Narrowing of the blood vessels limits the blood supply and can contribute to conditions such as stroke, heart disease and clogged or blocked blood vessels in the legs and other parts of the body.
Pumping blood too fast for too long can damage the heart muscle and interfere with its normal electrical signals, which can result in a dangerous heart rhythm disorder.
Eventually, the heart and body are unable to keep up with the added stress. If patients wait until they experience obvious symptoms of heart failure before seeing a doctor, the condition already may be life-threatening. If you experience any of these symptoms, consult your doctor as soon as possible.
Diagnosis
If you think that you are suffering from heart failure, your doctor will begin by taking a complete medical history, asking you about your symptoms and performing a physical examination. Blood tests probably will be ordered to assess kidney and liver function, sodium and potassium levels, blood count and other measurements.
In addition, your doctor may order the following tests:
Chest X-ray — This allows your doctor to check the size of your heart and to see if there is excess fluid in the heart or lungs.
Electrocardiogram (ECG or EKG) — A simple, painless test that records the electrical activity of the heart through electrodes placed on the skin of the chest. The machine that does this test, which often is performed in the doctor's office, prints out a graph showing how the heart is beating and records electrical activity.
If these tests suggest heart failure, the next step will be an imaging study to evaluate the structure and function of the heart and measure the heart's ejection fraction (EJ) — the proportion of blood that is pushed out by the ventricle with each contraction or heartbeat. A normal heart pumps out one-half to two-thirds of the blood in the left ventricle with each heartbeat. An EJ below 40 percent indicates a weakened heart.
Based on the patient's medical history and symptoms, the doctor will order one or more of the following tests to measure the EJ and diagnose whether the problem is due to systolic or diastolic failure.
Echocardiography — A safe, painless test that uses sound waves (ultrasound) to examine the heart's structure and motion. The patient lies still as a technician moves a device called a transducer over the chest. The transducer gives off silent sound waves that bounce off the heart. The sound waves create moving images of the chambers and valves of the heart that are viewed on a video monitor. This test provides information about the heart's pumping ability, blood-flow activity, valve function, size and pressure.
Radionuclide Venticulography — This test also is called Multiple-Gated Acquisition Scanning (MUGA) and involves injecting a small amount of radioactive dye into a vein. Isotopes in the dye attach to red blood cells that are traced by a special camera as they pass through the heart and are circulated throughout the body. In turn, this test measures the heart's pumping ability. The dye is only mildly radioactive and is safely excreted in your urine.
Sometimes, the images created by the nuclear medicine camera are synchronized with an electrocardiogram (ECG) that simultaneously measures the electrical activity of the heart. A nuclear medicine scan may be given twice -- once when the patient is at rest and again when he or she is exercising.
Treadmill Exercise Test with peak VO2 — This test measures how much oxygen the heart can provide to your muscles while you exercise.
Electrophysiology (EP) Study — In an EP study, local anesthetics are used to numb areas in the groin or near the neck, and small flexible tubes called catheters are inserted through the blood vessels into the heart to record its electrical signals. During the procedure, the doctor studies the speed and flow of electrical signals through the heart, which allows him or her to identify rhythm problems and pinpoint abnormal areas.
The doctor uses information gathered from these tests to determine the type and severity of heart failure, the short-term outlook and the best course of treatment.
After the diagnosis is confirmed, the doctor usually will classify, or rank, the heart failure based on the severity of symptoms. The most commonly used classification system is called the New York Heart Association Functional Classification. Patients are placed in one of four categories, depending on the extent their condition affects the performance of normal physical activities. The four categories are:
Class I — Patients in this category feel no symptoms and can perform ordinary physical activities without any limitations. They represent about 35 percent of patients with heart failure.
Class II — Another 35 percent of patients with heart failure are in this category. They have mild symptoms, such as occasional swelling, and may be somewhat limited in their ability to exercise or do other strenuous activities. They don't feel symptoms when at rest.
Class III — These patients are limited in their ability to exercise or participate in mildly strenuous activities, and are comfortable only at rest. About 25 percent of heart failure patients are in this class.
Class IV — The most severe form of heart failure occurs in about 5 percent of patients. They are severely limited in their ability to perform any activity, having symptoms even while at rest.
Treatment
Although heart failure is a serious condition that progressively gets worse over time, certain cases can be reversed with treatment. Even when the heart muscle is impaired, there are a number of treatments that can relieve symptoms and stop or slow the gradual worsening of the condition.
The goals of heart therapy are to:
Treatment options depends on the type, cause, symptoms and severity of the heart failure. Usually, more than one therapy is used. These options include:
Treating the Underlying Causes
A number of conditions can contribute to heart failure. Treatment of these other factors may range from surgery or angioplasty to open clogged blood vessels in patients with coronary artery disease to medications prescribed to control high blood pressure, diabetes, anemia or thyroid disease. In addition, it's particularly important to treat abnormal heart rhythms called arrhythmias in patients with heart failure.
These modifications often improve or control some of the factors contributing to heart failure. For example, people with heart failure will see an improvement if they:
A number of medications are prescribed for heart failure, and most patients will take more than one drug. Medications may be prescribed to:
Types of medication include:
Angiotensive converting enzyme (ACE) inhibitors, which dilate, or widen, the arteries, improving blood flow and making it so that the heart doesn't have to pump as hard. ACE-Inhibitors counteract the action of certain compounds formed by the body to regulate heart failure but which can contribute to disease progression.
Beta-blockers lower blood pressure and decrease and block the effect of harmful hormones that can cause disease progression.
Diuretics or water pills help the kidneys produce more urine and rid the body of excess fluid, which can stress the heart.
Spironoachone is a form of diuretic that preserves potassium and has been shown to reduce hospitalization and prolong life when used to treat advanced heart failure.
Potassium and magnesium supplements are often prescribed with diuretics to replace these minerals, which are excreted in urine.
Digoxin makes the heart beat stronger and slower, and regulates the rhythm of its contractions.
Anti-arrhythmic drugs treat abnormal heart rhythms.
Surgical options to treat underlying causes of heart failure include:
Coronary artery bypass graft (CABG or "cabbage") or angioplasty to prevent and treat heart failure caused by blocked arteries. During bypass surgery, blood vessels taken from another part of the body -- usually the leg -- are used to link the open parts of a blocked artery around the blockage.
In angioplasty, a thin flexible tube called a catheter is inserted through a small incision in the groin or neck into a blood vessel. In one procedure, a balloon is introduced through the catheter into the center of a blocked blood vessel. When the balloon is inflated, the blockage material is compressed back against the walls of the artery. A small metal device, called a stent, may be inserted through the catheter to serve as a permanent barrier to keep the plaque compressed. In another type of procedure, instruments are introduced through the catheter to remove the plaque.
Implantation of pacemakers and other devices such as artificial heart valves
Repairing congenital heart defects
Surgical treatments for heart failure itself include:
Heart Transplantation -- Although a heart transplant may be the best option for patients with the most severe types of heart failure, this treatment is available to only a small number of people due to a shortage of donor hearts. Recent advances may make artificial heart transplantation an option in the future.
Left Ventricular Assist Devices (LVAD) — These may be implanted in the chest to increase heart pumping action. Until recently, LVADs required that the patient be hooked up to a large, hospital-based console while awaiting a transplant. Miniaturized battery-powered LVAD units, however, are allowing many patients to leave the hospital. The devices may be used as a primary treatment or as a bridge to heart transplant in adults.
Heart Reconstruction — The electrical signals that cause the heart to contract move in a spiral pattern. Ideally the heart is an elliptical shape, like a football, for this makes it easier to receive the electrical signals that trigger heartbeats. In heart failure, the heart often enlarges and become spherical, more like a basketball, which no longer "fits" the electrical pattern and makes the heart less efficient. A number of promising surgical procedures are being investigated to address this problem by reconstructing parts of the heart to normalize its shape. These heart reconstruction procedures include:
Valve repair and revascularization, which may reduce heart size and improve cardiac function.
Dynamic cardiomyoplasty, in which one end of a muscle from the patient's back is detached and wrapped around the ventricles of the heart. After a few weeks, the relocated muscles are conditioned with electrical stimulation to behave and beat as if they were heart muscles. The procedure may improve pumping ability, thereby limiting heart enlargement and reducing stress.
The Batista procedure, also called "partial left ventriculectomy," removes a section of the wall of the left ventricle. The edges of the ventricle are repositioned and sewed together and the mitral valve and valve parts are repaired or replaced. This procedure has been largely abandoned due to poor results.
The Dor procedures, also called "endoventricular circular patch plasty" or EVCPP, are used when a widening (aneurysm) forms in the ventricle following a heart attack. In the surgery, a looped stitch is created to shrink the area of dead, scarred tissue where the aneurysm formed. Sometimes, a patch made of Dacron or tissue is used to cover other areas of defective muscle. The goal of the surgery is to return the ventricle to a more normal size and shape.
The Acorn procedure involves slipping a mesh-like "sock" around the heart and stitching it in place to reduce or prevent any further heart enlargement.
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