The heart is simply a pump. It pumps the appropriate amount of blood (and therefore oxygen) throughout the body to meet the bodies demand. Congestive Heart Failure (CHF) is a term that refers to the inability of the heart to maintain appropriate output of blood to the various organs and tissues in the body. Blood therefore “backs up” and results in congestion. The lack of adequate oxygen delivery is detrimental to organ function. In the lungs, excessive “fluid buildup” blocks oxygen exchange and leads to shortness of breath. This may occur initially with certain positions (laying flat) and activity. As CHF progresses, however, the shortness of breath may be present continuously. Congestion of the stomach and legs may result in swelling of the feet and ankles as well as fullness in the stomach causing poor appetite and nausea. Lack of blood delivery to the brain may cause altered memory, confusion, or sluggish thinking. The prognosis of CHF is related to the severity of the individual’s symptoms as well as the function of the heart. Untreated, CHF leads to deteriorating quality of life and early death.
The causes of CHF are numerous and related to any disorder that leads to a mismatch of “supply and demand”. The primary causes are myocardial infarction (heart attacks), diastolic dysfunction, and valvular heart disease. Other causes include thyroid abnormalities, pregnancy, nutritional deficiencies, connective tissue disorders, alcohol, hypertension, and congenital heart abnormalities.
Heart function is gauged by the ejection fraction or the percentage of blood ejected from the heart chamber with each heartbeat. In a normal heart, the ejection is 60%. When a heart attack occurs, the heart muscle is damaged and weakened. Systolic heart failure results and the ejection fraction is reduced. The degree of injury to the heart may result in an ejection fraction that is slightly (40-60%), moderately (30-40%) or severely (≤30%) diminished. The individual’s outlook is directly proportional to the ejection fraction. Therefore, reducing heart attack size and damage is of paramount importance.
The term diastolic heart failure refers to a stiffening or inflexibility of the heart muscle that occurs with age and conditions such as hypertension. As the heart becomes stiffer, it will not allow as much blood to fill the chambers resulting in congestion. The ejection fraction is normal, but the heart is unable to fill with enough blood to meet the body’s demands.
Valvular heart disease may cause the heart to become overloaded with excessive blood from leaky valves (regurgitation) or excessive pressure from stiff valves (stenosis). Over time, the heart will lose its ability to compensate and will wear out leading to CHF.
Medical treatment in the modern era consists of fluid pills (diuretics), ACE inhibitors or ARB blockers, Beta-blockers and other selected drugs. Diuretics relieve congestion by acting directly on the kidneys to excrete more urine. ACE inhibitors and ARB blockers reduce “overload” of the heart muscle as well as reduce blood pressure. Beta-blockers slow the heart rate and, in combination with the above medicines, enable the heart to “remodel” itself. Remodeling is a process where the heart changes its shape to better pump blood. This allows more efficient blood flow and improved ejection fraction. Other medications are also administered to improve hormonal balances beneficial to the heart and to keep magnesium and potassium levels within an appropriate range. The ultimate goal is to reduce demands on the heart and improve its output.
Surgical treatment consists of a more aggressive approach to treatable conditions that are causing ongoing damage to the heart. “Off pump” bypass surgery as well as other improvements has enabled extremely ill individuals to undergo surgery. In addition, newer techniques for valve correction, particularly mitral valve repair, have led to a significant improvement in outcomes in patients with lower ejection fractions. Specialized pacemakers and defibrillators have improved the quality of life by better timing the heart muscle contractions between the four chambers and reducing sudden death.
Lifestyle changes involve reduction of salt in the diet and meticulous attention to fluid intake. These changes can often eliminate the need for increased doses of diuretics and other medications. As a general rule, patients are advised not to add salt to the food they eat and limit total intake of all fluids to 64 ounces per day. Should a fluctuation of weight greater than “2 pounds in 2 days” occur, adjustments in diuretics are probably needed. Daily exercise and a healthy diet to achieve an ideal body weight will also improve quality of life.
The future holds great promise for patients with congestive heart failure. Further refinements in the combinations of known medications as well as newer medications on the horizon are a cause for optimism. Gene therapy with the use of stem cells may one day lead to the regeneration of heart muscle in a damaged heart. In time, such therapies may eliminate the need for many of the medications, devices, and surgeries discussed above.
A Brief Overview
1. Do you have shortness of breath and swelling?
If so, you may have congestive heart failure (CHF). This is a term which describes symptoms attributed to a failing heart. The majority of CHF is caused by a weakened, failing heart muscle, often due to heart attacks. However, with increasing age, it may be caused by a stiffened or inflexible heart muscle (diastolic dysfunction).
2. Why is this important to you?
Individuals with CHF have a significantly higher mortality than the general population. This is directly related to the degree of symptoms.
3. How can my doctor identify if I have CHF?
Identification is simple, painless, and noninvasive. It begins with a detailed physical examination, followed by ECG, lab work, and echocardiography. Echocardiography uses ultrasound to view the heart and its structures. It is very useful in both identifying the cause and assessing treatment in CHF. Following initial evaluation, further testing is individualized depending on the patient’s history.
4. What are the treatment options for CHF?
Treatment focuses on improving the overall function of the heart. Lifestyle modification stresses fluid and salt restriction. Numerous medications are used including fluid pills, ACE inhibitors, beta-blockers, digoxin, and others. Options may also include pacemakers/defibrillators, heart surgery, and newer techniques.