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. Although it is often used interchangeably with the term "heart failure" (or "HF"), CHF refers to a stage of heart failure where fluid builds up in different areas of the body, causing swelling (or "edema"). The term "heart failure" does not mean that the heart stops beating completely, but that the heart is not working as efficiently.

CHF is one of the most common causes of hospitalization for people over 55 years of age. Approximately 750,000 Canadians are living with congestive heart failure.

People of African descent are considerably more at risk than those of European descent and also have a higher risk of death.

There are 2 basic types of congestive heart failure:

• Heart failure with reduced ejection fraction (HFrEF), previously known as systolic dysfunction, occurs when the heart muscles are too weak, and can't pump enough blood to supply all the body's needs.
• Heart failure with preserved ejection fraction (HFpEF), previously known as diastolic dysfunction, occurs when the heart muscles are too stiff and cannot relax to accept all the blood being sent to it.

People with HFpEF can often develop HFrEF as their condition worsens.

CHF is usually the result of other health problems and conditions that can lead to damage and weakening of the heart:

• coronary artery disease, a condition that causes narrowing of the arteries that supply the heart with blood
• heart valve disease, which may have been caused by abnormalities that have been present since birth or have developed over time
• persistent high blood pressure forces the heart to pump against higher pressure
• heart attack damages the heart muscle – people who have had heart attacks are at 5 times the average risk of developing HF
• diabetes
• arrhythmias (abnormal heart rhythms) can cause the heart to pump inefficiently, especially if the heartbeat is too fast
• infections of the heart muscle: for example, a virus can affect the heart muscle or rheumatic disease may 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
• use of illicit drugs, such as cocaine
• excessive, long-term alcohol use

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.

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
• pale skin and cold hands or feet
• frequent urination at night

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.

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 1.5 g or less each day. 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) reduce the ability of blood vessels to constrict, allowing blood to flow more easily and making the heart contract more efficiently.
• angiotensin receptor blockers (ARBs; e.g., candesartan, valsartan) may be useful in place of ACE inhibitors when they cannot be used.
• neprilysin inhibitors (e.g., sacubitril) help the body to retain natriuretic peptides, which are natural enzymes that help expel sodium and water from the body, through urine. It is normally used together with an angiotensin receptor blocker like valsartan.
• certain beta-blockers (e.g., bisoprolol, carvedilol, metoprolol) have been proven to help improve heart function
• mineralocorticoid receptor antagonists (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, nitroglycerin patches) causes the smooth muscles of the arteries to widen, which reduces the amount of force the heart requires to circulate blood. These medications tend to have a very potent effect in lowering the blood pressure, and are generally used as a last resort for treating heart failure, or for select patient populations (e.g., people of African descent).
• Sodium-glucose cotransporter inhibitors (or SGLT2is) have been shown to reduce the risk of hospitalization and death due to heart failure. These include medications such as empagliflozin and dapagliflozin. It is thought that these medications help by reducing fluid build-up in the body.

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
• exercise
• control blood sugar levels (especially if you have diabetes)
• maintain good blood cholesterol levels
• quit smoking
• reduce alcohol consumption

Ask your doctor or pharmacist about getting an annual influenza vaccine and a one-time pneumococcal vaccine. Influenza and pneumonia may put a person with heart failure at risk of a sudden worsening of their condition.