Heart Failure
Heart Failure
Definition
Heart failure is a broad term—often used interchangeably with congestive heart failure (CHF)—to describe the heart's inability to consistently pump enough blood to the body's organs and tissues. Heart failure occurs either from a structural or a functional abnormality. Since blood carries oxygen and vital nutrients to cells throughout the body, a decrease in blood supply interferes with the ability of organs and other tissues to function properly.
Description
According to the American College of Cardiology, approximately 4.8 million Americans live with CHF. Patients ages 65 and older are hospitalized for complications from CHF more often than for any other medical condition, accounting for about 875,000 hospital admissions each year. Anywhere between 400,000 and 700,000 cases of CHF are discovered annually, bringing the cost of treating patients in the United States between $10 billion and $30 billion. CHF is either a direct or contributing cause of death for as many as 250,000 people per year. As the population ages, the incidence of heart failure increases.
The term congestive heart failure describes its course of action. When the heart fails for some reason to deliver adequate blood supply to the body's tissues, edema (swelling, or fluid buildup) develops. Where the edema occurs in the body depends on the part of the heart that is failing in some way. For example, when the left ventricle (lower left chamber of the heart) is damaged, blood fails to get out to other parts of the body as quickly as it returns from the lungs. When blood cannot get back to the heart, it backs up inside blood vessels in the lungs. Some of the fluid in the blood is then forced into the breathing space of the lungs, causing pulmonary edema. Pulmonary edema causes varying degrees of breathing difficulty. The degree of severity depends on the amount of excess fluid in the lungs and can be life-threatening in severe cases. Abnormalities in heart structure or rhythms can also cause left-ventricular CHF. Patients often complain of feeling very tired, due to the lack of circulating oxygen and nutrients caused by an inadequate blood supply.
When the right side of the heart fails, the right ventricle (lower right chamber of the heart) cannot pump blood to the lungs as quickly as blood returns from areas throughout the body, via the veins. The blood then engorges the right side of the heart and veins. Fluid begins to back up in the veins and pushes out into the tissues, causing edema, most often in the feet, ankles, and lower legs. Abnormalities of the heart valves and lung disorders often cause right-ventricular CHF.
The failing heart keeps pumping, but not as efficiently as it should. Sometimes the heart tries to compensate for its lack of pumping ability by becoming hypertrophic (larger). When this happens, the heart chamber grows larger and the muscle in the wall of the heart thickens, sometimes helping to improve the pumping ability of the heart. Another way in which the damaged heart tries to compensate for declining pumping ability is by stepping up the frequency of heartbeats to improve blood output and circulation. Eventually the kidneys join the fight to compensate for the failing heart; they hold on to more salt and water in order to increase blood volume. But this extra fluid can also cause edema. This can further complicate the situation and make treatment even more difficult. As the condition worsens over time, these compensatory measures are not enough to keep the heart pumping enough blood to meet the body's demand.
For most people, heart failure is a chronic disease with no real cure. However, depending on the individual circumstances, heart transplantation is considered in some cases when all other treatment options fail. While there is no cure, heart failure can often be managed and treated effectively using medications, proper diet, modified exercise, and other lifestyle changes as needed.
Causes and symptoms
The most common causes of heart failure are:
- coronary artery disease (CAD)
- heart attack (which may be "silent")
- cardiomyopathy
- high blood pressure (HBP, or hypertension )
- heart valve disease
- infection of the heart valves or heart muscle
- congenital structural abnormality
- alcohol and drug abuse
CAD is the most common cause of heart failure. The arteries that supply the heart muscle with blood begin to narrow over time. Eventually they may become completely blocked. When the blood cannot reach a specific area of the heart, a heart attack occurs. Some heart attacks are so slight that they go unrecognized, while others prove lethal. The heart muscle is damaged when the blood supply is greatly reduced or blocked entirely. If the damage markedly impairs the heart's pumping ability, heart failure follows.
Cardiomyopathy is a general term describing disease of the heart-muscle tissue. It can be caused by CAD, an inherited abnormality, severe alcoholism or drug abuse, or a viral infection. When the cause of the condition cannot be identified, it is termed idiopathic cardiomyopathy. Some types of cancer treatments have been associated with the development of cardiomyopathy. Cardiomyopathy brought on by anthracycline or other cardiotoxic agents is termed toxic cardiomyopathy. Regardless of the cause of the condition, the heart muscle weakens and eventually fails.
Sustained and uncontrolled high blood pressure is another common cause of heart failure. The persistent high pressure exerted on arterial walls makes them thicker and less pliable, and resistant to normal blood flow. As a result, the heart compensates by pumping harder, in an attempt to regain normal blood flow. Eventually the heart cannot keep up with the increased demand and heart failure results.
Defective heart valves, congenital heart diseases, severe alcohol and drug abuse, cardiotoxic cancer treatments, and specific viruses can cause the heart to fail.
The patient with heart failure can experience any number of the following symptoms:
- swollen, prominent veins in the neck area
- shortness of breath (causing crackling noises in the lungs)
- frequent coughing, especially when lying down
- swollen feet, ankles, and legs (edema)
- abdominal swelling (caused by ascites, an accumulation of peritoneal fluid) and pain (caused by organ engorgement)
- fatigue
- dizziness or fainting
- increased exercise intolerance
- sudden death
The person with left-sided heart failure may experience shortness of breath and increased episodes of coughing caused by fluid buildup in the lungs. Pulmonary edema often causes a patient to cough up bubbly, blood-tinged phlegm. In right-sided heart failure, fluid builds up in the veins and tissues, causing swelling of the lower extremities and the abdomen. When body tissues fail to get the oxygen and nutrients they require, they begin to lose their efficiency, causing increased dizziness and fatigue.
Diagnosis
Physicians base their diagnosis of heart failure on the results of the following evaluations:
- symptoms
- medical history
- physical examination
- blood work
- chest x ray
- electrocardiogram (ECG; also called EKG)
- metabolic exercise testing (stress test with gasexchange measurement)
- cardiac catheterization
A person's symptoms can provide important clues to the presence of heart failure. Patients who come to see a doctor, whether at the office or in an emergency room, will be examined by a physician, and in some cases also by a physician's assistant, a nurse, nurse practitioner, or nurse clinician. A patient who complains of shortness of breath while performing activities of daily living (ADL) and/or episodes of shortness of breath that wakes him or her from sleep is exhibiting classic symptoms of heart failure.
The health care professional who first examines the patient will also write down the patient's medical history. Often, something in the patient's medical history, such as a history of rheumatic fever or sustained hypertension, can help support the diagnosis of heart failure.
The physician will complete a thorough physical examination. He or she will listen to the heart and the lungs using a stethoscope, looking and listening for signs of heart failure. Irregular heart sounds (gallops), rapid heartbeats, and murmurs of the heart valves may be heard. A crackling sound in the lungs tells the physician that fluid is present in the lungs. Quick or shallow breathing may be present, along with a rapid pulse.
The physician will palpate (press down firmly with the fingertips of both hands) the patient's abdomen to feel if the liver is enlarged. He or she will also check the skin and nail beds on fingers and toes, looking for a bluish tint and a feeling of coolness to the skin. The bluish tint and coolness reflect a lack of oxygen in those regions.
At least one, but preferably two different views of the patient's chest will be taken in the upright position, by a licensed radiologic technologist, to determine whether there is fluid in the lungs and/or the heart is enlarged. Some heart-valve or other structural abnormalities can also be identified on plain chest films. A radiologist (a physician who specializes in radiology) reads the x ray and gives the report to the patient's doctor. If the patient is in distress, the radiologist may call the ordering physician with a "wet" (immediate) reading; otherwise, the chest films will be read and dictated, and the patient's doctor will receive a transcribed report the next day.
Routine blood work can sometimes give insight into both the cause of the heart failure and the extent of damage to the heart. For example, an abnormally low level of sodium can indicate advanced heart failure with a poor prognosis. Conversely, a high creatinine (used to assess kidney function) level can reflect kidney malfunction that either is contributing to the heart failure or is caused by the failing heart. Medical assistants, phlebotomists, medical technicians, and nurses are all trained to draw blood from veins. The blood samples are evaluated in the laboratory by laboratory technicians, medical technologists, pathologists, and/or other trained and licensed medical-laboratory professionals.
An electrocardiogram gives information about heart rhythm and size. It can demonstrate an enlarged heart chamber and whether or not damage to the heart muscle is caused by narrowing or blocked arteries.
Besides a chest x ray, the physician may order an echocardiogram or an ultrasound of the heart to help reach a diagnosis. Echocardiography uses sound waves to make images of the heart. These images can show whether the heart wall or chambers are enlarged, or if there are any abnormalities of the heart valves. An echocardiogram can also be used to find out how much blood the heart is pumping. It helps determine the amount of blood the ventricle pumps each time the heart beats (called the ejection fraction). A healthy heart pumps at least one half the amount of blood in the left ventricle with each heartbeat. A test called a radionucleide ventriculography is sometimes ordered to measure the ejection fraction. It uses very low doses of an injected radioactive substance and is imaged as it travels through the heart.
Cardiac catheterization involves threading a small tube (catheter) into either the arm or groin area and up into the heart. The test is used to measure pressure in the heart and the amount of blood pumped by the heart. It can detect abnormalities of the coronary arteries, heart valves, heart muscle, and other blood vessels. Cardiac catheterization is not always necessary in diagnosing heart failure, but when used in concert with echocardiography and other tests, it can help to pinpoint the cause of the condition.
Chest x rays, echocardiography, cardiac catheterization, and radionucleide ventriculography are all performed by radiologic technologists and radiologists who are specifically trained in these specialty areas. The chest x ray and echocardiogram can be performed using a portable bedside unit if the patient is too ill to travel to the x-ray department.
Metabolic exercise testing provides a noninvasive method for getting a lot of information about the patient in heart failure. It not only gives the physician a good idea of the functional capacity of the heart, but also demonstrates the patient's maximal oxygen consumption during peak exercise. The test offers insight into any functional disability that the patient is experiencing, so that the physician can discuss individualized plans for rehabilitation in light of any physical limitations. This test if often performed by a cardiologist with a nurse, physical therapist, medical assistant, or technician present to assist.
Treatment
Heart failure is most often treated with different medications and lifestyle changes. In some cases, surgery is performed to correct abnormalities of the heart or heart valves. Heart transplantation is a last resort, considered only in certain cases.
Dietary changes designed to help the patient reach and maintain a proper weight and to reduce salt intake to reduce fluid buildup may be required (reducing salt intake helps decrease swelling in the lower extremities and abdomen). An individualized exercise program may be recommended, but only after a full evaluation by the physician. The physician works with cardiac-rehabilitation nurses, physical therapists, and the patient to determine what each patient can tolerate safely. The patient performs the exercise regimen in the cardiac-rehabilitation department for a number of weeks under the careful supervision of staff. The patients are hooked up to monitors, their vital signs taken at intervals throughout their program, to ensure their safety. Once exercise tolerance is established, the patient is encouraged to follow the program consistently and is cautioned not to change it in any way once he or she returns home, in order to avoid complications. The patient is also reminded to report any unusual symptoms to his or her physician. Depending on the patient's specific limitations and exercise needs, walking, bicycling, swimming, or even low-impact aerobic exercises may be recommended. Homebound patients will work with home health care nurses, therapists, and aides in much the same way to help manage their symptoms. Most medium- to larger-size hospitals in the United States have good cardiac-rehabilitation programs.
Other lifestyle changes that may reduce the severity of symptoms associated with heart failure include quitting smoking or other tobacco use, eliminating or reducing alcohol consumption, and not using certain drugs.
One or more of the following types of medications may be prescribed for heart failure:
- diuretics
- digitalis
- vasodilators
- beta blockers
- angiotensin-converting enzyme inhibitors (ACE inhibitors)
- angiotensin-receptor blockers (ARBs)
- calcium-channel blockers
Diuretic medication helps eliminate excess salt and water from the kidneys by making patients urinate more often. This increased flushing action helps reduce the swelling caused by fluid buildup in the tissues. It is important to monitor patients for electrolyte imbalance when they used diuretics regularly. Digitalis gives the heart muscle stronger pumping ability. Vasodilators, ACE inhibitors, ARBs, and calcium-channel blockers all help to lower blood pressure via different methods, expanding the blood vessels so that blood can move more freely through them. This expansion makes it easier for the heart to pump blood through the vessels.
Surgery is used to correct certain heart conditions that cause heart failure. Congenital heart defects and abnormal heart valves may be repaired with surgery. Narrowing or completely blocked coronary arteries can be effectively treated with angioplasty or coronary-artery bypass surgery.
In patients with severe heart failure, the heart muscle itself may become so damaged that available treatments cannot help. Patients in this condition are said to be in end-stage heart failure. The only available treatment option for patients in end-stage heart failure and for which all other treatments are no longer working is heart transplantation. However, the patient's age and a number of other health-related issues are taken into account in the decision-making process.
Support staff, including pharmacists, dieticians, physicians' assistants, nurses, technicians, physical therapists, respiratory therapists, and nurses' aides can play an important role in the effective management of the patient with heart failure. In communicating responsibly with one another and with the patient and his or her caregivers, many complications can be avoided and quality of life improved.
Prognosis
Most patients in mild or moderate heart failure can be successfully managed with a combination of dietary and exercise programs and the right medications. Many patients are able to participate in normal daily activities and lead relatively active lives. However, the patient's success with any treatment program depends a great deal on effective communication among members of the health care team and the patient's compliance with treatment recommendations.
Patients in severe heart failure may eventually have to consider heart transplantation. About 50% of patients diagnosed with CHF live for at least five years with the condition. Women who have heart failure often live longer than men with the same condition. However, survival statistics continue to improve some with newer and more advanced treatments.
Health care team roles
Each professional in the health care team plays an important role in helping to diagnose and treat a patient in any stage of heart failure. From the person who writes down the patient's medical history to the pharmacist who explains the patient's medications, attention to detail, effective communication, and a positive attitude are key to the patient's ability to realize good outcomes.
Cardiac-rehabilitation nurses—registered nurses who see the patient either in the hospital or at the doctor's office—will be responsible for assessing the patient's condition from the time the patient first presents with symptoms and complaints, and throughout return visits. All nurses take vital signs and monitor the patient's compliance with medications, diet, and exercise regimens. Nurses are expected to document their findings thoroughly in progress notes and to communicate any problems with the physician or other appropriate health care professional. Nurses explain and teach patients about their disease and different aspects of their treatment programs, and serve as the pipeline between the patient and the physician. They are also the patient's advocate. Nurses spend more time with patients than the other members of the health care team do, so they get a better opportunity to gain insight into the patient's total health picture.
Radiologic technologists are responsible for performing certain diagnostic procedures, either directly or by assisting a radiologist or cardiologist. Prior to the exam, the technician is responsible for explaining any procedure to the patient and for getting a consent form signed whenever contrast material will be injected into the body. The technician needs to ask whether the patient has any known allergies and communicate those findings to the radiologist before any contrast material is injected.
Respiratory therapists and physical therapists are required to explain any procedures or therapy they administer to patients. Dieticians explain different diet plans with patients and family caregivers to help patients get used to buying and preparing foods in ways that reduce both salt and caloric intake.
Patient education
Each member of the health care team is responsible for explaining the connection between his or her specific discipline and the patient's condition. For example, if breathing treatments are ordered by a physician to help keep a patient from getting pneumonia, the therapist needs to explain the procedure and the reason for the procedure to the patient. When a patient gets a chest x ray, the radiologic technologist should tell the patient that he or she will need to take in a deep breath and hold it in, so that the lungs fully expand and the radiologist can determine whether the lungs are clear and get an accurate measurement of heart size.
Nursing staffers teach patients about the signs and symptoms of heart failure, treatment interventions, and expected outcomes. They are required to teach the patient about his or her specific heart failure and why certain interventions are necessary. For example, if a patient tells the nurse that he or she gets very short of breath walking from one end of the house to the other, the nurse can suggest that the patient choose a point in between to sit down for a few moments to rest. Nurses look for physical signs and symptoms of heart failure, chart assessments and vital signs, and review treatments with patients, keeping an eye out for compliance issues and whether treatment appears effective.
Patients who undergo cardiac catheterization are asked a number of questions before the procedure takes place, and then are asked to sign a consent form. Contrast material will be injected into the patient through a small catheter that may require a small incision in the groin or elbow area. The radiologist or technologist explains what physical sensations to expect while the contrast media is being injected, as well as any allergic-reaction potential, including symptoms and side effects.
Patients who undergo metabolic exercise testing will be monitored carefully throughout the procedure and asked to let the doctor know immediately if they feel any chest pain or dizziness during the procedure.
Prevention
Heart failure is usually caused by the effects of some type of heart disease. The best way to try to prevent heart failure is to eat a healthy diet and get regular exercise, but many causes of heart failure cannot be prevented. People with risk factors for coronary disease (such as high blood pressure and high cholesterol levels) should work closely with their physician to reduce their likelihood of heart attack and heart failure.
Heart failure can sometimes be avoided by identifying and treating any conditions that might lead to heart disease. These include HBP, alcoholism or drug abuse, obesity, and CAD. Regular blood-pressure checks and seeking immediate medical care for symptoms of CAD, such as chest pain, will help to get these conditions diagnosed and treated early, before they progress and damage the heart muscle.
Finally, diagnosing and treating heart failure before the heart becomes severely damaged can improve the prognosis. With proper treatment, many patients may continue to lead active lives for a number of years.
KEY TERMS
Angioplasty— A technique used for treating blocked coronary arteries by inserting a catheter with a tiny balloon at the tip into the artery and then inflating it.
Angiotensin-converting enzyme (ACE) inhibitor— A drug that relaxes blood-vessel walls and lowers blood pressure.
Arrhythmia— Abnormal heartbeat.
Atherosclerosis— Buildup of a fatty substance called a plaque inside blood vessels.
Calcium-channel blocker— A drug that relaxes blood vessels and lowers blood pressure.
Cardiac catheterization— A diagnostic test for evaluating heart disease; a catheter is inserted into an artery and passed into the heart.
Cardiomyopathy— Disease of the heart muscle.
Catheter— A thin, hollow tube.
Congenital heart defects— Abnormal formation of structures of the heart or of its major blood vessels, present at birth.
Congestive heart failure— A condition in which the heart cannot pump enough blood to supply the body's tissues with sufficient oxygen and nutrients; backup of blood in vessels and the lungs causes buildup of fluid (congestion) in the tissues.
Coronary arteries— Arteries that supply blood to the heart muscle.
Coronary artery bypass— A surgical procedure to reroute blood around a blocked coronary artery.
Coronary artery disease— Narrowing or blockage of coronary arteries by atherosclerosis.
Diuretic— A type of drug that helps the kidneys eliminate excess salt and water.
Edema— Swelling caused by fluid buildup in tissues.
Ejection fraction— A measure of the portion of blood that is pumped out of a filled ventricle.
Heart valves— Valves that regulate blood flow into and out of the heart chambers.
Hypertension— High blood pressure.
Hypertrophic— Enlarged.
Idiopathic cardiomyopathy— Cardiomyopathy without a known cause.
Pulmonary edema— Buildup of fluid in the tissue of the lungs.
Vasodilator— Any drug that relaxes blood-vessel walls.
Ventricles— The two lower chambers of the heart.
Resources
BOOKS
Anderson, K. N., L. E. Anderson, and W. D. Glanze, editors. Mosby's Medical, Nursing, & Allied Health Dictionary, 5th edition. St. Louis: Mosby-Year Book, 1998.
Beers, M. H., and R. Berkow. The Merck Manual. Whitehouse Station: Merck Research Laboratories, Division of Merck & Co., 2005.
Fuster, V., R. W. Alexander, and R. A. O'Rourke, eds. Hurst's the Heart, 10th edition. New York: McGraw-Hill, Medical Publishing Division, 2001.
Levy, D., ed. 50 Years of Discovery, Medical Milestones from the National Heart, Lung, and Blood Institute's Framingham Heart Study. Center for Bio-Medical Communications, Inc., 1999.
PERIODICALS
Connolly, K. "New Directions in Heart Failure Management." Nurse Practitioner 25, no. 7 (July 2000): 23, 27-8, 31-4.
Naccerelli, G. V., "Biventricular Pacing in Congestive Heart Failure: A Post-ACC Meeting Perspective." 50th Annual Scientific Session of the American College of Cardiology Day 3 (March 20, 2001). 〈http://www.medscape.com/Medscape/CNO/2001/ACC/ Story.cfm?story_id=2128〉.
Singh, B. N. "Heart Failure and Atrial Fibrillation: Impact of New Research Finding on Treatment." 50th Annual Scientific Session of the American College of Cardiology. Day 3 (March 20, 2001). 〈http://www.medscape.com/ Medscape/CNO/2001/ACC/Story.cfm?story_id=2129〉.
ORGANIZATIONS
"Congestive Heart Failure." 〈http://www.americanheart.org/Heart_and_Stroke_A_Z_Guide/congest.html〉.
Heart Failure
Heart Failure
Definition
Heart failure is a condition in which the heart has lost the ability to pump enough blood to the body's tissues. With too little blood being delivered, the organs and other tissues do not receive enough oxygen and nutrients to function properly.
Description
According to the American Heart Association, about 4.9 million Americans are living with congestive heart failure. Of these, 2.5 million are males and 2.4 million are females. Ten of every 1,000 people over age 65 have this condition. There are about 400,000 new cases each year.
Heart failure happens when a disease affects the heart's ability to deliver enough blood to the body's tissues. Often, a person with heart failure may have a buildup of fluid in the tissues, called edema. Heart failure with this kind of fluid buildup is called congestive heart failure. Where edema occurs in the body depends on the part of the heart that is affected by heart failure. Heart failure caused by abnormality of the lower left chamber of the heart (left ventricle) means that the left ventricle cannot pump blood out to the body as fast as it returns from the lungs. Because blood cannot get back to the heart, it begins to back up in the blood vessels of the lungs. Some of the fluid in the blood is forced into the breathing space of the lungs, causing pulmonary edema. A person with pulmonary edema has shortness of breath, which may be acute, severe and life threatening. A person with congestive heart failure feels tired because not enough blood circulates to supply the body's tissues with the oxygen and nutrients they need. Abnormalities of the heart structure and rhythm also can be responsible for left ventricular congestive heart failure.
In right-sided heart failure, the lower right chamber of the heart (right ventricle) cannot pump blood to the lungs as fast as it returns from the body through the veins. Blood then engorges the right side of the heart and the veins. Fluid backed up in the veins is forced out into the tissues, causing swelling (edema), usually in the feet and legs. Congestive heart failure of the right ventricle often is caused by abnormalities of the heart valves and lung disorders.
When the heart cannot pump enough blood, it tries to make up for this by becoming larger. By becoming enlarged (hypertrophic) the ventricle can contract more strongly and pump more blood. When this happens, the heart chamber becomes larger and the muscle in the heart wall becomes thicker. The heart also compensates by pumping more often to improve blood output and circulation. The kidneys try to compensate for a failing heart by retaining more salt and water to increase the volume of blood. This extra fluid also can cause edema. Eventually, as the condition worsens over time these measures are not enough to keep the heart pumping enough blood needed by the body. Kidneys often weaken under these circumstances, further aggravating the situation and making therapy more difficult.
For most people, heart failure is a chronic disease with no cure. However, it can be managed and treated with medicines and changes in diet, exercise, and life-style habits. Heart transplantation is considered in some cases.
Causes and symptoms
The most common causes of heart failure are:
- coronary artery disease and heart attack (which may be "silent")
- cardiomyopathy
- high blood pressure (hypertension )
- heart valve disease
- congenital heart disease
- alcoholism and drug abuse
The most common cause of heart failure is coronary artery disease. In coronary artery disease, the arteries supplying blood to the heart become narrowed or blocked. When blood flow to an area of the heart is completely blocked, the person has a heart attack. Some heart attacks go unrecognized. The heart muscle suffers damage when its blood supply is reduced or blocked. If the damage affects the heart's ability to pump blood, heart failure develops.
Cardiomyopathy is a general term for disease of the heart muscle. Cardiomyopathy may be caused by coronary artery disease and various other heart problems. Sometimes the cause of cardiomyopathy cannot be found. In these cases the heart muscle disease is called idiopathic cardiomyopathy. Whatever the cause, cardiomyopathy can weaken the heart, leading to heart failure.
High blood pressure is another common cause of heart failure. High blood pressure makes the heart work harder to pump blood. After a while, the heart cannot keep up and the symptoms of heart failure develop.
Defects of the heart valves, congenital heart diseases, alcoholism, and drug abuse cause damage to the heart that can all lead to heart failure.
A person with heart failure may experience the following:
- shortness of breath
- frequent coughing, especially when lying down
- swollen feet, ankles, and legs
- abdominal swelling and pain
- fatigue
- dizziness or fainting
- sudden death
A person with left-sided heart failure may have shortness of breath and coughing caused by the fluid buildup in the lungs. Pulmonary edema may cause the person to cough up bubbly phlegm that contains blood. With right-sided heart failure, fluid build-up in the veins and body tissues causes swelling in the feet, legs, and abdomen. When body tissues, such as organs and muscles, do not receive enough oxygen and nutrients they cannot function as well, leading to tiredness and dizziness.
Diagnosis
Diagnosis of heart failure is based on:
- symptoms
- medical history
- physical examination
- chest x ray
- electrocardiogram (ECG; also called EKG)
- other imaging tests
- cardiac catheterization
A person's symptoms can provide important clues to the presence of heart failure. Shortness of breath while engaging in activities and episodes of shortness of breath that wake a person from sleep are classic symptoms of heart failure. During the physical examination, the physician listens to the heart and lungs with a stethoscope for telltale signs of heart failure. Irregular heart sounds, "gallops," a rapid heart rate, and murmurs of the heart valves may be heard. If there is fluid in the lungs a crackling sound may be heard. Rapid breathing or other changes in breathing may also be present. Patients with heart failure also may have a rapid pulse.
By pressing on the abdomen, the physician can feel if the liver is enlarged. The skin of the fingers and toes may have a bluish tint and feel cool if not enough oxygen is reaching them.
A chest x ray can show if there is fluid in the lungs and if the heart is enlarged. Abnormalities of heart valves and other structures also may be seen on chest x ray.
An electrocardiogram gives information on the heart rhythm and the size of the heart. It can show if the heart chamber is enlarged and if there is damage to the heart muscle from blocked arteries.
Besides chest x ray, other imaging tests may help make a diagnosis. Echocardiography uses sound waves to make images of the heart. These images can show if the heart wall or chambers are enlarged and if there are any abnormalities of the heart valves. An echocardiogram also can be used to find out how much blood the heart is pumping. It determines the amount of blood in the ventricle (ventricular volume) and the amount of blood the ventricle pumps each time it beats (called the ejection fraction). A healthy heart pumps at least one-half the amount of blood in the left ventricle with each heartbeat. Radionuclide ventriculography also measures the ejection fraction by imaging with very low doses of an injected radioactive substance as it travels through the heart.
A new test that measures the level of a particular hormone in the blood was introduced in 2003 and researchers said the test may be useful for testing for heart failure in physicians' offices because it could provide results in 15 minutes.
Cardiac catheterization involves using a small tube (catheter) that is inserted through a blood vessel into the heart. It is used to measure pressure in the heart and the amount of blood pumped by the heart. This test can help find abnormalities of the coronary arteries, heart valves, and heart muscle, and other blood vessels. Combined with echocardiography and other tests, cardiac catheterization can help find the cause of heart failure. It is not always necessary, however.
Treatment
Heart failure usually is treated with lifestyle changes and medicines. Sometimes surgery is needed to correct abnormalities of the heart or heart valves. Heart transplantation is a last resort to be considered in certain cases.
Dietary changes to maintain proper weight and reduce salt intake may be needed. Reducing salt intake helps to lessen swelling in the legs, feet, and abdomen. Appropriate exercise also may be recommended, but it is important that heart failure patients only begin an exercise program with the advice of their doctors. Walking, bicycling, swimming, or low-impact aerobic exercises may be recommended. There are good heart rehabilitation programs at most larger hospitals.
Other lifestyle changes that may reduce the symptoms of heart failure include stopping smoking or other tobacco use, eliminating or reducing alcohol consumption, and not using harmful drugs.
One or more of the following types of medicines may be prescribed for heart failure:
- diuretics
- digitalis
- vasodilators
- beta blockers
- angiotensin converting enzyme inhibitors (ACE inhibitors)
- angiotensin receptor blockers (ARBs)
- calcium channel blockers
Diuretics help eliminate excess salt and water from the kidneys by making patients urinate more often. This helps reduce the swelling caused by fluid buildup in the tissues. Digitalis helps the heart muscle to have stronger pumping action. Vasodilators, ACE inhibitors, ARBs, and calcium channel blockers lower blood pressure and expand the blood vessels so blood can move more easily through them. This action makes it easier for the heart to pump blood through the vessels. Cholesterol-lowering drugs called statins can help prevent death from heart failure. A 2003 study showed a 62% drop in mortality rate among patients with severe heart failure who took statin therapy.
In 2003, a new noninvasive procedure was being tested for patients with congestive heart failure. Called enhanced external counterpulsation (EECP), it consisted of inflating three sets of pneumatic cuffs attached to the patient's legs. The therapy had positive effects on the blood pressure and reduced frequency of episodes of angina (pain) in a clinical trial by as much as 70%.
Surgery is used to correct certain heart conditions that cause heart failure. Congenital heart defects and abnormal heart valves can be repaired with surgery. Blocked coronary arteries usually can be treated with angioplasty or coronary artery bypass surgery.
With severe heart failure, the heart muscle may become so damaged that available treatments do not help. Patients with this stage of heart failure are said to have end-stage heart failure. Heart transplant usually is considered for patients with end-stage heart failure when all other treatments have stopped working.
Prognosis
Most patients with mild or moderate heart failure can be successfully treated with dietary and exercise programs and the right medications. In fact, in 2003, the American Heart Association said that even those awaiting heart transplants could benefit from exercise. Many people are able to participate in normal daily activities and lead relatively active lives.
Patients with severe heart failure may eventually have to consider heart transplantation. Approximately 50% of patients diagnosed with congestive heart failure live for five years with the condition. Women with heart failure usually live longer than men with heart failure.
Prevention
Heart failure usually is caused by the effects of some type of heart disease. The best way to try to prevent heart failure is to eat a healthy diet and get regular exercise, but many causes of heart failure cannot be prevented. People with risk factors for coronary disease (such as high blood pressure and high cholesterol levels) should work closely with their physician to reduce likelihood of heart attack and heart failure.
KEY TERMS
Angioplasty— A technique for treating blocked coronary arteries by inserting a catheter with a tiny balloon at the tip into the artery and inflating it.
Angiotensin-converting enzyme (ACE) inhibitor— A drug that relaxes blood vessel walls and lowers blood pressure.
Arrhythmias— Abnormal heartbeat.
Atherosclerosis— Buildup of a fatty substance called a plaque inside blood vessels.
Calcium channel blocker— A drug that relaxes blood vessels and lowers blood pressure.
Cardiac catheterization— A diagnostic test for evaluating heart disease; a catheter is inserted into an artery and passed into the heart.
Cardiomyopathy— Disease of the heart muscle.
Catheter— A thin, hollow tube.
Congenital heart defects— Abnormal formation of structures of the heart or of its major blood vessels present at birth.
Congestive heart failure— A condition in which the heart cannot pump enough blood to supply the body's tissues with sufficient oxygen and nutrients; back up of blood in vessels and the lungs causes buildup of fluid (congestion) in the tissues.
Coronary arteries— Arteries that supply blood to the heart muscle.
Coronary artery bypass— Surgical procedure to reroute blood around a blocked coronary artery.
Coronary artery disease— Narrowing or blockage of coronary arteries by atherosclerosis.
Digitalis— A drug that helps the heart muscle to have stronger pumping action.
Diuretic— A type of drug that helps the kidneys eliminate excess salt and water.
Edema— Swelling caused by fluid buildup in tissues.
Ejection fraction— A measure of the portion of blood that is pumped out of a filled ventricle.
Heart valves— Valves that regulate blood flow into and out of the heart chambers.
Hypertension— High blood pressure.
Hypertrophic— Enlarged.
Idiopathic cardiomyopathy— Cardiomyopathy without a known cause.
Pulmonary edema— Buildup of fluid in the tissue of the lungs.
Vasodilator— Any drug that relaxes blood vessel walls.
Ventricles— The two lower chambers of the heart.
Heart failure sometimes can be avoided by identifying and treating any conditions that might lead to heart disease. These include high blood pressure, alcoholism, and coronary artery disease. Regular blood pressure checks and obtaining immediate medical care for symptoms of coronary artery disease, such as chest pain, will help to get these conditions found and treated early, before they can damage the heart muscle.
A 2003 initiative called OPTIMIZE H-F was aimed at preventing severe heart failure and deaths among patients discharge from hospitals. The project created a registry or database of patients with heart failure that could be shared among hospitals. Finally, diagnosing and treating heart failure before the heart becomes severely damaged can improve the prognosis. With proper treatment, many patients may continue to lead active lives for a number of years.
Resources
PERIODICALS
"Even Heart Failure Patients Should Exercise." Clinician Reviews April 2003: 50-52.
Jancin, Bruce. "Noninvasive Procedure Eyed for Heart Failure: Enhanced External Counterpulsation." Family Practice News June 1, 2003: 12.
"New Care Initiative to Improve Outcomes for Heart Failure Patients." Heart Disease Weekly April 20, 2003: 45.
"Rapid Congestive Heart Failure Test a Useful Tool in Physician Offices." Heart Disease Weekly June 15, 2003: 19.
Zoler, Michael N. "Heart Failure Deaths Plunge with Statins." Internal Medicine News April 15, 2003: 35-41.
ORGANIZATIONS
American Heart Association. 7320 Greenville Ave. Dallas, TX 75231. (214) 373-6300. 〈http://www.americanheart.org〉.
National Heart, Lung and Blood Institute. PO Box 30105, Bethesda, MD 20824-0105. (301) 251-1222. 〈http://www.nhlbi.nih.gov〉.
Texas Heart Institute. Heart Information Service. PO Box 20345, Houston, TX 77225-0345. 〈http://www.tmc.edu/thi〉.
heart failure
The most common single cause in modern Western society, accounting for about half of the cases, is a heart attack. By killing one region, the attack leaves heart function compromised. Until the later decades of the twentieth century a very major cause was undiagnosed and untreated high blood pressure — the heart in this instance must work harder and harder to force blood into the arteries where the pressure is too high, and eventually ‘tires’. Although long-term high blood pressure is still a contributor to heart failure, modern drugs have helped to reduce its significance. A range of other causes include the various heart valve malfunctions, certain infections, congenital structural abnormalities, genetically-determined disorders, and drug abuse. There is clear evidence that the factors that increase the likelihood of heart attack also contribute to the severity of the ensuing heart failure. These factors include high blood cholesterol, atheromatous vascular disease, sedentary lifestyle, and smoking. In third-World countries, infections such as the insect-transmitted trypanosomal Chagas' disease are among the main causes of heart failure. Even amongst economically advanced nations there are wide differences in the incidence of heart failure between, say, Japan (very low) and Western Europe and the US (high); nation-specific combinations of dietary and genetic factors are thus the target of much research into underlying causes. There is widespread agreement that taking regular exercise not only strengthens the heart and improves its own circulation (particularly by improving collateral blood supplies) but also that exercise is a very useful part of any rehabilitation regime designed to prevent the development of heart failure after a heart attack.
Heart failure refers to a characteristic pattern of features caused by an abnormality of the heart. It is a complex clinical syndrome resulting from the entanglement of cause and effect, of symptoms and compensatory changes. Several body systems and organs are involved, especially the lungs, kidneys, and blood vessels, their associated hormonal systems, as well as the heart itself. It is increasingly clear that many and varied patterns of disturbance to each of these systems can result in convergence into the full repertoire of malfunctions which together are termed heart failure.
In normal circumstances, the ‘challenge’ to the heart posed by ‘demand’ for increased blood supply is most obvious during exercise, however mild. The physiological challenge is similar when the heart is unable, by virtue of disease, to meet even normal requirements. In either case, homeostatic mechanisms operate which promote the maintenance of two parameters of heart function: blood pressure and blood flow. An example of these compensatory processes is one promoting retention of water and salts by hormonal influences on the kidneys. This will increase blood volume and tend to keep up both blood pressure and cardiac output (the volume pumped). Unfortunately, in heart failure, the compensatory mechanisms prove clearly ineffective; they actually contribute to the symptoms observed (e.g. breathlessness and ankle swelling) and become important factors in the gradual worsening of the condition. The use of diuretic drugs (which stimulate kidney function and reverse fluid retention) is widespread in the treatment of heart failure. The heart itself generally responds to an abnormal workload by increased growth (hypertrophy), but the nature of the growth is abnormal in subtle ways, unlike the hypertrophy associated with general physical fitness which is positively beneficial. It is now known, for example, that a hypertrophied failing heart both contracts and relaxes more slowly, and is more prone to life-threatening electrical abnormalities.
David J. Miller, and Niall G. MacFarlane
See also heart; heart attack.