Congestive heart failure (CHF) occurs when the heart isn't able to pump blood normally. As a result, there is not enough blood flow to provide the body's organs with oxygen and nutrients. The term "heart failure" does not mean that the heart stops beating completely, but that the heart is not working as efficiently.
CHF affects over 6 million people in North America and is one of the most common causes of hospitalization for people over 65 years of age. Approximately half a million Canadians are living with congestive heart failure.
Men are slightly more at risk than women. People of African descent are considerably more at risk than those of European descent and also have a higher risk of death.
There are two basic problems in congestive heart failure:
- systolic dysfunction occurs when the heart can't pump enough blood to supply all the body's needs
- diastolic dysfunction occurs when the heart cannot accept all the blood being sent to it
Many people have both systolic and diastolic heart failure.
CHF is usually the result of other health problems:
- coronary artery disease, a condition that causes narrowing of the arteries that supply the heart with blood, can damage and weaken areas of the heart
- heart valve disease, which may have been caused by abnormalities that have been present since birth or have developed over time, can weaken the heart
- persistent high blood pressure forces the heart to pump against higher pressure, which causes it to weaken over time
- heart attack damages the heart muscle – people who have had heart attacks are at 5 times the average risk of developing CHF
- diabetes also increases CHF risk
- arrhythmias (abnormal heart rhythms) can cause the heart to pump inefficiently and to weaken over time, especially if the heartbeat is too fast
- heart valve damage may have been caused by rheumatic disease or infection
- infection of the heart muscle can seriously weaken the heart. For example, a virus can affect the heart muscle or rheumatic disease can damage the valves
- an enlarged wall between the heart chambers (a genetic condition) may prevent normal heart function
- certain kidney conditions that increase blood pressure and fluid buildup can increase the risk of CHF by placing more stress on the heart
- use of illicit drugs such as cocaine can significantly weaken the heart
- long-term use of excessive alcohol can weaken the heart
In addition, all the risk factors that normally increase the chances of heart disease, such as smoking, diabetes, and obesity, increase your risk of congestive heart failure.
Symptoms and Complications
The appearance of symptoms of CHF can be delayed for years. This is because the heart tries to compensate when it is not pumping efficiently. The heart compensates in three ways:
- dilating (enlarging) to form a bigger pump
- adding new muscle tissue to pump harder
- beating at a faster rate
As the heart compensates, several things happen that can result in symptoms. The heart cannot pump well enough to pump the blood through the body and back to the heart again. Blood then backs up into the legs and the lungs, causing fluid buildup. This causes visible swelling of the ankles and legs and shortness of breath.
The most common symptoms of CHF include:
- breathing difficulties during the night or when lying down
- coughing and wheezing
- fatigue and weakness
- shortness of breath
- swollen ankles
Other symptoms of CHF include:
- abdominal pain, bloating, or loss of appetite
- accumulation of fluid in the abdomen
- bluish skin around the mouth
- pale skin and cold hands or feet
- frequent urination at night
Making the Diagnosis
If you have the symptoms mentioned in the previous section, along with one of the conditions that puts you at risk, your doctor may suspect CHF. Your doctor will examine you to see if your legs are swollen or if your lungs are filled with fluid.
Your doctor may also order tests to check your heart. They may send you for blood and urine tests, an electrocardiogram (ECG), or a chest X-ray, which can show the excess fluid in the lungs. An echocardiogram (an ultrasound of the heart) will help diagnose heart failure. An echocardiogram can also tell the doctor how much of the blood in your heart is actually being pumped out to the rest of the body. The proportion of blood that gets pumped out is called the ejection fraction.
Treatment and Prevention
All treatment for CHF should be carried out under the supervision of a doctor. CHF usually is managed with lifestyle adjustments and medications. If you have CHF, you may have to make some of the following lifestyle adjustments:
- cut back on fluids – weighing yourself daily is often necessary to help adjust fluid intake and medications
- stay active, but avoid triggering CHF symptoms
- lower sodium intake. If possible, try for 2 g or less each day – lower (1.5 g) if you also have high blood pressure. Less sodium reduces fluid retention
- wear special elastic stockings to reduce swelling in the legs caused by fluid retention
- follow an appropriate weight-loss program (for those who need it)
Congestive heart failure can be treated with the following medications:
- ACE inhibitors (e.g., enalapril*, lisinopril) expand blood vessels, allowing blood to flow more easily and making the heart's work easier or more efficient
- angiotensin receptor blockers (ARBs; e.g., candesartan, valsartan) may be useful in place of ACE inhibitors when they cannot be used or sometimes in addition to ACE inhibitors.
- certain beta-blockers (e.g., bisoprolol, carvedilol, metoprolol) have been proven to help improve heart function
- aldosterone receptor blockers (e.g., eplerenone, spironolactone) work by blocking the effects of aldosterone, which can make CHF worse, and by helping the body eliminate excess salt and water. They may help to reduce the risk of death in certain people with heart failure who have had a heart attack.
- digoxin increases the force of the pumping action of the heart
- diuretics (e.g., furosemide, hydrochlorothiazide) help the body eliminate excess salt and water
- hydralazine and nitrates (e.g., isosorbide dinitrate, nitorglycerin patch) may be useful in place of ACE inhibitors or ARBs when they cannot be used, or sometimes in addition to other therapies when symptoms are still present
Your doctor may prescribe these medications, usually in combination, to manage your CHF. In some cases, surgery (e.g., surgery to insert a pacemaker) may be necessary to help improve heart function.
CHF can't always be prevented, but there are many things you can do to help. Try preventing CHF by practising good heart health. This will also guard against heart attack, stroke, and coronary artery disease. Tips to follow include:
- control high blood pressure
- eat a healthy diet
- control blood sugar levels (especially if you have diabetes)
- maintain good blood cholesterol levels
- quit smoking
- reduce alcohol consumption
*All medications have both common (generic) and brand names. The brand name is what a specific manufacturer calls the product (e.g., Tylenol®). The common name is the medical name for the medication (e.g., acetaminophen). A medication may have many brand names, but only one common name. This article lists medications by their common names. For information on a given medication, check our Drug Information database. For more information on brand names, speak with your doctor or pharmacist.