Chronic heart failure

• What is Chronic Heart Failure
• Statistics on Chronic Heart Failure
• Risk Factors for Chronic Heart Failure
• Progression of Chronic Heart Failure
• Symptoms of Chronic Heart Failure
• Clinical Examination of Chronic Heart Failure
• How is Chronic Heart Failure Diagnosed?
• Prognosis of Chronic Heart Failure
• How is Chronic Heart Failure Treated?
• Chronic Heart Failure References

What is Chronic Heart Failure

Heart failure is a term used to describe the state when the heart is no longer able to maintain its function – that is, to maintain an adequate cardiac output (to pump blood adequately) or to be able to do so only because it is under so much strain that it is causing itself damage. In other words, the heart is weakened and the pumping action is impaired casusing heart failure. The heart does not completely fail or stop functioning (as in a cardiac arrest, a situation in which the heart actually stops beating), but instead functions less effectively. Heart failure can come on quickly because of some major event like a heart attack, or more slowly. In these slow cases, the heart often adapts to working harder and compensates quite well for a while, but eventually cannot cope and people start to have symptoms. For health concerns on heart conditions consult your doctor.

Statistics on Chronic Heart Failure

Chronic heart failure tends to affect elderly people. It occurs in about 1% of people aged 50-59, but becomes more common in the age group 80-89 where its occurrence rate is over 50%, so it certainly is not uncommon. Lifetime risk for developing heart failure is 1 in 5 among both men and women. In Australia, nearly one in every one hundred admissions to hospital is because of chronic heart failure, and it also accounts for 2% of all deaths. It is estimated that in the United States, almost five million people have heart failure and over 600,000 develop new heart failure each year.

Risk Factors for Chronic Heart Failure

Common Causes of Chronic Heart Failure

• Ischaemic Heart Disease where the heart is not getting enough oxygen.
• Previous heart attack
• Essential hypertension (high blood pressure): makes it harder for the heart to get blood and makes coronary artery disease worse.
• Diabetes: doubles the risk of developing chronic heart failure in men and increases risk five times for women

Less Common Causes of Chronic Heart Failure

• Dilated Cardiomyopathy: a condition where the heart just gets bigger and wider, without a known cause.
• Valvular Heart Disease: especially aortic stenosis, where blood has trouble getting past one of the major valves in the heart.

Uncommon Causes of Chronic Heart Failure

• Valvular Heart Disease: especially mitral and aortic regurgitation (also called ‘leaky valves’, where blood can flow back through them).
• Alcoholic Cardiomyopathy: too much alcohol can cause the heart to get bigger, making it pump less efficiently.
• Inflammation of the heart muscle, or myocarditis: usually viral in origin
• Chronic arrhythmias
• HIV-related cardiomyopathy
• Some drugs, especially the really dangerous ones, can cause heart damage
• Restrictive cardiomyopathy: the heart is stopped beating effectively by something stopping it, which can be of unknown cause, or can be secondary to infiltrative diseases such as amyloidosis

Lifestyle Factors affecting Chronic Heart Failure

• Smoking
• Obesity
• Excess alcohol consumption
• High salt intake
• High fat, low nutrient diet

Progression of Chronic Heart Failure

Some patients who have heart failure are not even aware of the problem until it progresses to a more serious form, called congestive heart failure. The term “congestive” refers to a fluid build-up that happens when the heart gets behind in its work. Because the heart is not efficient in pumping blood out, there is less blood leaving the heart and thus the blood that returns to the heart gets backed up. This results in an increase in pressure causing seepage into surrounding tissue. Very often it is at this stage that patients start noticing symptoms and seeking help.

Symptoms of Chronic Heart Failure

Common symptoms of chronic heart failure include:

• Shortness of breath on exercise: while this can start out only happening with exercise, eventually it can get so bad that there is breathlessness on just walking, or even when at rest
• Shortness of breath on lying down (orthopnoea): frequently people say that they are requiring more pillows to ‘prop themselves up’ at night, otherwise they get short of breath
• Attacks of breathlessness at night that wake you up. This has the medical name of Paroxysmal Nocturnal Dyspnoea.
• A dry, irritating cough is common
• Fatigue and weakness are common
• Dizzy spells
• Heart Palpitations where you can feel your heart beating in your chest
• Loss of appetite, indigestion
• Nausea and vomiting
• If Chronic Heart Failure gets very bad, fluid can build up, leading to swollen feet and ankles

Clinical Examination of Chronic Heart Failure

If a patient presents with symptoms that could mean chronic heart failure, then they will want to examine lots of different systems of the body. Firstly, lots can be learnt just from general inspection of how comfortable a person is by their rate of breathing and their heart rate. This is especially important on lying down, as in chronic heart failure shortness of breath is usually made much worse when laying flat. Next, they may want to examine the patient’s neck veins, as they can give information about how the right side of the heart is functioning, and can show whether any blood is being pushed back into them due to faulty heart valves. After this, the doctor will want to examine the patient’s chest where sometimes the beat of the heart can be seen through the chest wall. This can give an idea as to how big the heart is and where it sits in the chest. They will then want to listen to the heart which can give information about blood flow and also about the valves. The doctor will then want to listen to the lungs. This is because in chronic heart failure, fluid can ‘build up’ behind the left heart and start pooling in the lungs in a condition called pulmonary oedema. This fluid creates tiny crackles called crepitations that can be heard with a stethoscope. Examination will then move to other areas like the liver, which can become enlarged and tender in chronic heart failure. This is because of the pressure building up on this side of the heart and blood not being able to leave the liver as well as it should. The doctor will also want to check for free fluid called ‘oedema’ in areas that it is likely to drain to such as your ankles and back. This oedema fluid builds up because the blood is not being pumped efficiently through the heart. This causes a lot of pressure in the veins that bring blood back towards the heart, pushing fluid out of the blood vessels and into the tissues.

How is Chronic Heart Failure Diagnosed?

There are lots of tests that a doctor can do in chronic heart failure. These tests can be used for diagnosing the condition as well as working out just how severe it is. First, the doctor may want to do some blood tests to check on kidney function, liver function, thyroid function and the amount of cells in the blood. There are also two hormones found in the chambers of the heart called ANP and BNP. These are released when the heart is stretched (as happens in chronic heart failure) and so these can also be tested for. Next, the doctor may want to work out just how much exercise and activity a patient is capable of. There are several tests for this:

• Six Minute Walk: A six minute walk test involves walking a circular track of 25m as many times as is possible in six minutes. If a person starts walking less and less each time then it is a sign the disease is getting worse.
• Exercise Testing: This involves getting on a bike or treadmill and working out how much exercise a person can do.

There are also some other types of specific tests that may be done if the doctor things they will be helpful:

• Electrocardiogram (ECG): This measures the electrical activity of the heart and can give lots of information about any abnormalities
• Chest x-ray: There are lots of changes in an x-ray that are caused by heart failure
• Echocardiography: This is like an ultrasound of your heart, and can give information about blood flows and the function of the valves
• Coronary Angiography: This involves placing some dye through a small tube into the heart vessels and seeing where the dye flows to, giving a good idea about blood flow to the heart
• Nuclear Cardiology: Nuclear scans such as Cardiac PET can give some useful information about blood flow to the heart
• Spirometry: This test checks how well the lungs are working and can help to exclude other causes of breathlessness, especially in smokers

Prognosis of Chronic Heart Failure

The outlook for heart failure depends to some extent on the underlying cause of the problem and on the presence or absence of an obvious problem causing the heart failure. If an obvious cause can be identified and removed, the outlook is better. Generally, chronic heart failure carries a poor prognosis. Approximately 50% of patients with severe heart failure due to left ventricular dysfunction will die within 2 years. It should be pointed out that this is only in extremely severe cases however, and most people will live for many years.

How is Chronic Heart Failure Treated?

There are several methods of treatment that aim to improve both the symptoms and lifespan of those suffering from chronic heart failure. Lifestyle Changes in Chronic Heart Failure

• Improved Diet and Weight Loss: This will improve both exercise tolerance and quality of life. Reduction in saturated fats is particularly important in those who have poor blood flow to the heart. Exercise is espcially important in someone with cardiac failure. Sometimes, the output of the heart can be so bad in chronic heart failure, that not much blood gets to the gastrointestinal system and this can lead to constipation, so high-fibre diets are usually recommended. Also, if a big meal is eaten then a lot of blood is needed in the intestines to take all the nutrients away which means that it is diverted from other parts of the body. This can lead to so little blood in the heart and brain that people can have angina and even faint. This can be avoided by having regular, small meals that require less blood to digest.
• Reduced Salt Intake: Salt intake of less than 2000mg/day is recommended as this will reduce the amount of fluid that the body keeps.
• Fluid Restriction: Despite an increased thirst, fluid intake should generally be less than 1500mL per day in moderate chronic heart failure and 1000mL in severe cases. This restriction is more relaxed if the weather is warm though.
• Smoking: All patients should be discouraged from smoking, especially those with heart problems as smoking has major effects on the blood vessels of the heart, clogging them up and making them unable to let enough blood through.
• Alcohol: Alcohol is discouraged as it stops the heart from pumping as efficiently as it should while also increasing both the fluid and energy intake. Due to this, alcohol intake should not exceed 1-2 standard drinks a day.
• Caffeine: Excessive caffeine can cause the heart to beat faster and more irregularly, as well as increasing the blood pressure so generally coffee and tea drinks should be kept to about one or two a day.

Medications for Chronic Heart Failure

• ACE Inhibitors: These are a type of blood-pressure lowering medication that are very good in the treatment of chronic heart failure. They decrease symptoms, as well as keeping people healthy enough to stay out of hospital much more than if they were not treated.
• Beta-Blockers: These medications slow the heart, forcing it to rest a little bit and actually increasing the effectiveness of pumping.
• Diuretics: These drugs act on the kidneys meaning that they do not absorb nearly as much fluid as they usually would, causing more fluid to be lost as urine. This means that less fluid is available to pool in the legs and on the lungs, relieving some of the symptoms of chronic heart failure.
• Digoxin: Digoxin (digitalis) is derived from a plant called the Foxglove and increases the strength of the heart’s beats.

Other Treatments for Chronic Heart Failure

• Pacemakers: Electronic implants that cause the heart to beat that are used to correct symptomatic slow heart rates.
• Surgery: There are numerous surgical options that can result in improved symptoms, but these are only ever options in very severe cases and should be thoroughly discussed with a specialist after referral from a GP.

Chronic Heart Failure References

1. Guidelines on the Contemporary Management of the Patient with Chronic Heart Failure in Australia. National Heart Foundation of Australia and The Cardiac Society of Australia and New Zealand. 2002.
2. Haslett C et al., editors. Davidson’s Principles and Practice of Medicine (19th edition). Edinburgh, Churchill Livingstone. 2002.
3. Kumar P, Clark M. Clinical Medicine (Sixth Edition). Philadelphia, Elsevier Saunders. 2005.
4. Lloyd-Jones DM, Larson MG, Leip EP, et al. Lifetime risk for developing congestive heart failure: the Framingham Heart Study. Circulation. 2002; 106: 3068-72.