Heart failure

Also known as congestive heart failure

Heart failure occurs when the heart is unable to keep enough blood moving around the body. It does not mean the heart is about to stop, but it does mean that there is a problem with the heart’s pumping action.

Heart failure can affect the right side of the heart only, or it can affect both sides of the heart. It develops over time as the heart's pumping action grows weaker. This can lead to symptoms of breathlessness, ankle swelling and fatigue. 

(Congestive means parts of the body collect too much fluid due to the poor circulation of blood.)

Key points

  1. There are many things that you, your family and your health team can do to help you feel better and stay well for as long as possible.
  2. Taking your medications (or pills) correctly is one of the best things you can do to stay well and feel better.
  3. Learn to identify your early warning symptoms so you can take action and stay out of hospital. Talk to your doctor or nurse about an action plan for you.
  4. Increased shortness of breath, ankle swelling and needing more pillows at night are possible early warning signs.

How the heart works

The heart has four chambers with muscular walls. The upper chamber on each side is called the atrium (left and right atrium). The lower chambers are the ventricles (left and right ventricle).

Blood that is low in oxygen returns from the body and is collected in the right atrium. The blood passes into the larger, more muscular right ventricle which pumps it on to the lungs to pick up oxygen. Oxygen-rich blood from the lungs returns to the left atrium and passes into the left ventricle. The left ventricle does the most work, pumping oxygen-rich blood to the entire body.

Every minute your heart pumps four to six litres of blood around your entire body. When you are active, this amount increases dramatically.

If your heart is damaged, it may no longer be able to meet all of your body’s demands. If your body asks more than your heart can deliver, you are said to have heart failure.

What causes heart failure?

Heart attack (also called a coronary or myocardial infarction) is the most common cause of heart failure. A heart attack occurs when diseased arteries leading to the heart become blocked. This can cause scarring of the heart muscle and reduce the effect of the heart's pumping action.

NB: Myo means muscle, cardial refers to the heart, and infarction means death of tissue due to lack of blood supply.

High blood pressure: Long-term high blood pressure can also damage heart muscle.

Cardiomyopathy is a disease of the heart muscle itself. It commonly refers to an abnormally large, baggy heart that cannot pump well enough. It can be caused by:

  • some viral infections
  • regularly consuming four or more alcoholic drinks per day or binge drinking - this is thought to be enough to damage the heart (if you stop altogether, there is a 50% chance the heart will recover, often completely).

For some people, even after extensive testing, a likely cause for cardiomyopathy cannot be found.

Other causes: Heart valve defects and congenital heart defects can also cause heart failure, as can excess thyroid hormone levels. Heart failure may be triggered or made worse by anaemia, infection, irregular heart beat and some drugs.

Risks for heart failure

  • having had any sort of heart problem before
  • raised blood pressure
  • raised cholesterol level
  • smoking
  • diabetes
  • lack of physical activity
  • older age
  • gender - men at greater risk than women
  • family history of heart disease.


Symptoms vary, but can include one or more of the following:

  • Less physical reserve – climbing stairs or walking may leave you tired, weak and short of breath
  • Tiredness or fatigue
  • Shortness of breath with exercise or when lying flat
  • Swelling (also called oedema) of feet, legs and abdomen
  • Rapid weight gain – due to fluid build up
  • Dry, hacking cough (worse when lying down)
  • Loss of appetite or nausea
  • Rapid pulse rate
  • Confusion – this can be the only sign in the elderly

Shortness of breath when lying down flat is caused by a build-up of fluid in the lungs (called pulmonary oedema), which makes it harder for the lungs to transfer oxygen to the blood.


Tests often used to help diagnosis heart failure include one or more of the following:

  • blood test for electrolytes, renal function, full blood count, thyroid function
  • blood test for brain natriuretic peptide (BNP) test – If BNP is normal (< 30 pmol/L), a diagnosis of heart failure is unlikely.
  • ECG electrocardiogram to check the heart rhythm, axis and for signs of strain
  • Echocardiography (ECHO for short) - is like an ultrasound of the heart and shows how each part of the heart is functioning at rest and sometimes it is done after exercise (stress ECHO). The technician will look at each of the ventricles, valves and heart walls.



These work best if taken regularly. If they cause you problems or side effects, talk to your doctor before stopping. Sometimes some fine-tuning is needed to find the right dose and combination for you. Many of the pills you will need to take to strengthen your heart have to start with a small dose and be built up gradually.

Standard heart failure medications:

  • Diuretics - or water pills, allow the kidneys to remove excess fluid and salt from the body by increasing the amount of urine produced.
  • ACE (angiotensin-converting enzyme) inhibitors – ACE inhibitors relax the blood vessels, making it easier for the heart to pump blood to all the body’s tissues. This should also allow you to do more without becoming quite so breathless or tired.
  • Angiotensin-II receptor antagonists - These are an alternative for patients who have difficulty tolerating ACE inhibitors.
  • Digoxin - helps your heart beat strongly and regularly.
  • Beta-blockers – assist with the heart's pumping action.
  • Spironolactone (aldosterone antagonist) - has a diuretic effect and may help in severe heart failure.

Other medications:

  • Calcium channel blockers - are sometimes used to slow down the heart rate if it cannot be controlled by beta-blockers and digoxin.
  • Warfarin - helps to stop blood clots from forming.

Cardiac rehabilitation

You may be advised to attend a cardiac rehabilitation group at your local hospital. These are an excellent place to learn more about ways to strengthen your heart again and support to get more active. (read more - cardiac rehabilitation, Heart Foundation NZ)


Coronary bypass surgery may be helpful for those who have coronary artery disease as a cause of their heart failure. Other treatments, such as pacemakers and implantable cardioverter defibrillators (ICDs) are being used to help manage heart failure in some people.

Self care

Managing heart failure well needs the input of your GP, who knows about your heart failure and other health issues that affect it. A heart specialist may also be involved in your care. There are also some things you can do yourself to monitor and help improve your symptoms, such as:

Weigh yourself each day

Your doctor may recommend you do this. If you put on more than 2kg over a few days, your body is retaining fluid, not fat. Your doctor will help you work out your target weight - this is your weight with no extra fluid, and is the weight at which your body and heart will work the best. Weigh yourself every morning (after you have been to the toilet, before you eat or drink anything for the day, and before you get dressed). Use digital scales, and use these on a firm surface, eg, lino or tiles.

Avoid salt (sodium) - Try not to have salt in or on your food. Salt can make you retain fluid, which can lead to breathlessness and swollen ankles.

Healthy eating - choosing healthier foods, wholegrain, smaller portions, healthy fats and less processed foods. Read more in the healthy eating section

Limit fluids Avoid excess fluid intake, but you need not overly restrict your fluids unless your doctor advises it. Drink about the same amount each day.

Stop smoking: Smoking will make you even more breathless and will continue to damage your heart and dramatically increase your chances of a heart attack. Quit smoking section

Limit alcohol People with weak hearts do not cope as well with alcohol even in moderate amounts. It is best to drink only a little alcohol, and avoid binge drinking.

Rest and get a good night’s sleep  It is important not to overdo things and not to become too exhausted.

Limit stress Try to avoid stressful situations and use relaxation techniques such as taking six deep breaths if you are becoming stressed.

Remain active Slowly increase activity, as tolerated. Try walking gently around the house or down the road.

Lose weight if you are overweight takes strain off your heart.

Vaccination against influenza is recommended and against pneumococcal disease may be recommended.

Learn more

Your guide to heart failure British Heart Foundation (has tips and advice about medications, treatment, self-management and dealing with everyday challenges)
Heart Failure Matters  useful website from the European Society of Cardiology
Heart failure – Explained Watch, Learn, Live: Interactive Cardiovascular Library – American Heart Association
Heart Failure NIH Senior Health 
Information on heart failure Heart Foundation NZ

Credits: Heart Foundation of New Zealand and updated by Health Navigator NZ July 2016.