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Heart Disease

Heart Failure

Introduction
Signs and Symptoms
Treatment

Introduction

Heart failure is a collection of symptoms and signs produced by a complex circulatory and neurohormonal response (a neurohormone is a hormone produced by a specialized neuron into the blood stream) to cardiac dysfunction. Nearly five million people in the United States suffer from heart failure. This number is expected to reach six million by the year 2005 and 37 million by 2037. Around 550,000 new cases of heart failure are diagnosed each year. Over 200,000 people die from heart failure each year. About 50% die within five years of diagnosis, and 40% to 50% die from sudden cardiac death. There are more deaths from heart failure than from all forms of cancer combined.

Heart failure is the only cardiovascular disease that is increasing in incidence and prevalence.

Contributing factors to the rise in the heart failure are:

  1. aging population
  2. improved therapies and survival rates for high blood pressure and coronary heart disease

Some sobering statistics:

  1. 20% of heart attack victims will develop heart failure within six years of their heart attack.
  2. 75% of heart failure patients had high blood pressure before their diagnosis.
  3. Heart failure is the most frequent cause of hospitalization for persons older than 65 years of age and contributes to 3.5 million hospitalizations annually.
  4. Annual expenditures are over 20 billion dollars in the United States alone.

There are many risk factors for heart failure. They include:

  1. coronary artery disease or history of heart attack
  2. high blood pressure
  3. heart valve disease
  4. left ventricular dysfunction without any of the usual symptoms
  5. alcoholism
  6. diabetes
  7. congenital heart defects
  8. obesity
  9. age
  10. smoking
  11. anemia
  12. left ventricular hypertrophy (thickening of the muscle of the left ventricle)
  13. previous history of drugs damaging to the heart, such as some chemotherapeutic agents

Signs and Symptoms

The sequence of heart failure begins when an injury occurs causing myocardial (heart muscle) damage. This leads to a fall in left ventricular function or ejection fraction (the pumping ability of the heart). This decrease in ejection fraction activates numerous hormone systems within the body, which all then speed up to try to improve the performance of the left ventricle. In the short run, left ventricular performance is improved, but in the long run, these hormone systems cause worsening heart muscle damage, blood vessel constriction, and fluid build up in the lungs and/or legs and abdomen. The fluid build up is what causes the heart failure symptoms, that is shortness of breath, fatigue and fluid retention. The worsening heart muscle damage over time leads to hospitalization continued worsening of symptoms, and death.

Heart failure can be diagnosed by a number of tests. A chest X-ray may show an enlarged heart or fluid in the lungs. An echocardiogram may be performed which is a sound wave test of the heart. It involves placing a transducer on the chest wall, which can give an image of the heart. This test allows for a diagnosis of reduced left ventricular function, heart valve disease, clots in the heart, or congenital heart disease. Cardiac catheterization might be used which allows the placement of catheters into the heart via the femoral artery. These catheters are passed into the coronary arteries and dye is injected for diagnostic purposes. Cardiac catheterization allows the doctor to measure pressures inside the heart and allows treatment by angioplasty or stenting.

Recently the American Heart Association and the American College of Cardiology have developed a new approach to the classification of heart failure. Previously, only those patients with symptomatic heart failure or severe end stage heart failure have been diagnosed and treated for heart failure. The new classification scale now recognizes that there are a number of conditions that are pre-heart failure conditions, which should also be treated to prevent the development of heart failure. These conditions include such diseases as high blood pressure, coronary artery disease, diabetes mellitus or family history of cardiomyopathy. The goal is to prevent heart failure from entering the symptomatic stage when sickness and death from the disease dramatically increase.

The signs and symptoms of heart failure include the following:

  1. exertional dyspnea, or shortness of breath with exertion
  2. fatigue and weakness
  3. sleeping on more than one pillow at night in order to breathe more comfortably
  4. waking up in the middle of the night short of breath and needing to sit up to catch one's breath
  5. swelling in the legs or abdomen
  6. fluid in the lungs
  7. cough, which is usually worse at night
  8. abdominal problems such as nausea, vomiting, right upper quadrant pain or fluid in the abdomen
  9. anorexia or weight loss due to lack of appetite

Why do heart failure symptoms worsen over time? First of all, there is the unavoidable progression of the disease. Sadly, this is a disease that is felt to become worse and progress over time. Treatment may slow down the progression of the disease or improve the disease process slightly, but rarely cures the disease. Secondly, heart failure symptoms worsen over time because of poor adoption of chronic management guidelines by practitioners who treat patients with heart failure. Another problem is the increasing frequency of chronic heart failure due to the aging population and better treatment of coronary artery disease and heart attacks. Finally, non-compliance with diet and drugs on the part of the patient also allows heart failure symptoms to worsen over time.

Treatment

The treatment of heart failure patients depends on the severity of the symptoms. At each heart failure visit, the patient's weight, blood pressure, pulse and heart failure symptoms are assessed. Additionally, the determination of the patient's functional classification between classes I and IV is determined. The New York Heart Association Functional Classification Scale includes classes I through IV. The patient with class I heart failure has no symptoms (shortness of breath or fatigue). The patient with class II symptoms has shortness of breath and fatigue with exertional activity only. The patient with class III symptoms develops shortness of breath and fatigue with minimal activity. And finally, class IV patients suffer shortness of breath and fatigue at rest. Compliance with medications and diet is determined by discussing the patient's fluid and sodium intake. Education is given regarding how the patient and family can improve their compliance.

During each visit the heart failure patient makes to a heart failure center, many things are assessed. First, evaluation of fluid status is done by examining the patient for fluid overload. An evaluation for cardiac output (amount of blood pumped by the heart in a minute) is done by examining skin temperature or listening to the heart for extra sounds. The patient is encouraged to assist their health care providers in managing their treatment by keeping a daily log including weight, blood pressure and pulse, fluid and salt intake. It is important that the patient be consistent every day and avoid binges of fluid or salt. Compliance is very important.

The key to the treatment of heart failure is to block the hormones that have led to the worsening symptoms of heart failure. These hormones come from the sympathetic nervous system and the renin angiotensin system (this system controls sodium balance, fluid volume and blood pressure by renal secretion). Angiotensin converting enzyme inhibitors (ACE inhibitors) were the first class of drugs found to improve survival in heart failure patients. These drugs work by blocking the hormone angiotensin II. These drugs have been shown to both improve heart failure symptoms and prolong life. They work by improving the ejection fraction, lowering blood pressure, and improving cardiac output. There are many different brands of ACE inhibitors, including enalapril, captropril, lisinopril, ramopril.

Angiotensin receptor blockers may be substituted or added to ACE inhibitors. If a patient is unable to tolerate an ACE inhibitor, then an angiotensin receptor blocker is an appropriate substitute. These drugs have also been shown to prolong life and improve heart failure symptoms. Examples of angiotensin receptor blockers are losartan, valsartan, irbesartan, and candesartan.

Diuretics are medications that help the body eliminate extra fluid that has built up because of the hormones. These drugs improve heart failure symptoms but there has been no evidence that they prolong life. They should only be used if an ACE inhibitor or angiotensin blocker is used. Side effects include lowering of potassium levels, lowering of magnesium levels, dehydration and muscle cramps. Some common diuretics are furosemide (Lasix), torsemide (Demadex), metolazone (Zaroxolyn), and hydrochlorothiazide (HCTZ).

Digoxin (Lanoxin) is a medication that can improve the contraction of the heart. It is a drug that has been around for centuries and is made from the foxglove plant. It has been shown to improve heart failure symptoms and hospitalizations. It neither prolongs life nor shortens it. It may be useful in patients with high resting heart rates and is particularly helpful in patients with atrial fibrillation.

Beta blockers block the hormones epinephrine and norepinephrine. These drugs have been shown to prolong life and decrease hospitalization. They can also prevent progression of heart failure and may also increase ejection fraction. Some examples of beta blockers are carvedilol (Coreg), Metoprolol (Lopressor, or Toprol XL).

Spironolactone (Aldactone) is a drug that blocks the hormone aldosterone. Aldosterone is a hormone that increases fluid levels in the body. It has been shown that spironolactone prolongs the life of a patient with class III or IV heart failure.

Inotropes are intravenous drugs that are used to treat hospitalized patients with decompensated or severe heart failure. They are given either in a continuous intravenous infusion or by intermittent infusion. They have been shown to improve cardiac output but unfortunately have been shown to increase the risk of death. These drugs include dobutamine, milrinone, and dopamine.

Nesiritide or Natrecor is a newer intravenous agent that is actually a synthetic version of a good hormone that the body makes in heart failure called brain natriuretic peptide. This is actually a beneficial hormone that dilates blood vessels and improves symptoms in volume-overloaded patients. It is safer than the inotropes previously mentioned, but it is also only available intravenously.

Devices are often used in patients with heart failure to prolong life. In particular, sudden cardiac death is increasing in prevalence in the United States largely because of the rise of heart failure. Sudden cardiac death is caused by an abrupt arrhythmia or fast irregular heart rhythm that results in lack of blood flow to the brain and can result in death. This condition can be treated with an implantable cardiac defibrillator that will deliver a shock to the heart when it recognizes such a rhythm and shock the heart back into normal rhythm. Another device that has been recently used to treat heart failure is called a biventricular pacemaker. This is a device that is used in patients that have a bundle branch block. Using this type of device, which has three leads (one to the right atrium, one to the right ventricle, and one through the coronary sinus to the left ventricle), restores synchrony to the right and left sides of the heart and improves cardiac output, ejection fraction and reduces the amount of mitral valve regurgitation. These devices have been shown to improve quality of life, exercise tolerance and mortality.

Another type of device that has been used in heart failure is called a left ventricular assist device. An example is the HeartMate® left ventricular assist system. This is a surgically implanted device that can be used to pump blood for the heart that has failed. It can be used to bridge a patient who is failing all other therapies to a heart transplant and is now also indicated for destination (permanent support) therapy in patients who are not transplant candidates. The future of this technology rests in developing newer models that are fully implantable and smaller so that this technology can be extended to children and small adults. Currently the system available has a driveline that exits from the right lower quadrant and goes to a battery pack that powers the device.

Also in investigation is the AbioCor implantable replacement heart, also known as the total artificial heart. This system has been used in select centers to replace a heart that is badly damaged, both left and right sides.

Cardiac transplantation is used in patients with severe end stage heart failure, often those requiring continuous IV medications. These patients must not have other diseases such as emphysema, cancer, or other diseases that would shorten their life. Unfortunately, this is limited by donor availability.

The information in this article is based on " HEART FAILURE 2003 AND BEYOND: How UC is Making a Difference," presented October 21, 2003 at the University of Cincinnati Mini Medical College, and was adapted for use on NetWellness with permission, 2004.

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Last Reviewed: Jan 01, 2004

University of Cincinnati Lynne Wagoner, MD
Associate Professor
Division of Cardiovascular Diseases
Department of Internal Medicine
College of Medicine
University of Cincinnati
Lynne Wagoner, MD