Congestive heart failure (CHF) occurs when the heart muscle, whether from weakness or stiffening, does not pump with sufficient force to circulate the blood properly. As a result, blood backs up in other parts of the body, such as the liver, abdomen, lower legs and lungs, because the heart is unable to keep pace with the body's circulatory needs. While CHF can occur on either side of the body, it usually begins on the left, where the left ventricle, the primary pumping chamber of the heart, is located.
Types of Congestive Heart Failure
There are four types of congestive heart failure: left-sided, right-sided, systolic and diastolic. Left-sided heart failure results in fluid backup in the lungs, whereas right-sided heart failure causes fluid backup in the abdomen, or legs and feet.
In systolic heart failure, there is a pumping problem: the left ventricle cannot contract strongly enough. Diastolic heart failure indicates that there is a filling problem because the left ventricle cannot fully relax.
CHF can be either chronic or acute.
Causes of Congestive Heart Failure
An unhealthy lifestyle can contribute to congestive heart failure, but congenital defects, coronary artery disease, diabetes or hypertension are also underlying causes.
Coronary Artery Disease
The most common cause of CHF is coronary artery disease, in which there is a buildup of fatty deposits in the arteries that supply blood to the heart muscle. This accumulation of plaque is known as atherosclerosis.
If, as a result of plaque buildup, the arteries rupture, a blood clot forms, blocking blood flow to an area of the heart. This may result in permanent damage that weakens the heart muscle.
When a patient has hypertension (high blood pressure), the heart is working harder than necessary to circulate the blood, causing the heart muscle to thicken. Over time, the heart muscle weakens to the point that it no longer pumps blood efficiently.
Faulty Heart Valves
Blood flow is directed by the heart valves. If a valve is damaged, the blood backs up, causing the heart to work harder than it usually does. Heart-valve damage may be the result of a congenital defect, a heart infection, or coronary artery disease.
Cardiomyopathy (damage to the heart muscle) can result from infection (such as myocarditis), alcohol or drug abuse, chemotherapy, or a disease process. In some cases, cardiomyopathy is caused by genetic factors.
Congenital Heart Defects
Infants may be born with a defective heart in which, because of anatomical abnormalities, the valves or chambers do not work properly, resulting in CHF.
Other causes of CHF include heart arrhythmia, infections and diseases, allergic reactions, certain medications, and blood clots in the lungs.
Symptoms of Congestive Heart Failure
There are a number of symptoms of congestive heart failure, including the following:
- Ascites (abdominal swelling)
- Edema (swelling) in the legs, ankles and feet
- Fatigue and weakness
- Reduced ability to exercise
- Increased need to urinate during the night
- Persistent coughing or wheezing
- Production of pink-tinged phlegm
- Rapid or irregular heartbeat
- Shortness of breath, especially upon exertion
When CHF is caused by a heart attack, patients also experience chest pain.
Diagnosis of Congestive Heart Failure
In order to diagnose CHF, in addition to a comprehensive medical examination, the following tests may be administered:
- Blood tests
- Chest X-rays
- Electrocardiogram (EKG or ECG)
- Stress test
- CT or MRI scan
- Coronary angiogram
In some cases, a myocardial biopsy is performed.
Treatment of Congestive Heart Failure
CHF must be treated; if not, it can lead to kidney failure and death. Medication and surgery are both treatment options.
Medications used to treat CHF include the following:
- Beta blockers
- Digoxin (digitalis)
- Aldosterone antagonists
Angiotension-converting enzyme inhibitors (ACD) or angiotension II receptor blockers are also used to treat CHF.
Surgical treatments are undertaken when medications do not resolve the problem. Several types of surgeries, including the following, can be performed to treat CHF:
- Coronary bypass
- Heart-valve repair or replacement
- Implantation of cardioverter-defibrillators (ICDs)
- Cardiac resynchronization therapy (CRT)
- Implantation of ventricular assistive device (VAD)
In the most severe cases of CHF, implanting a total artificial heart (TAH) or having a heart transplant may be necessary.