Heart disease and influenza

People with heart disease are more likely to have a heart attack immediately after a bout of the flu. With the flu season just around the corner, it’s time to book your influenza vaccination.

Woman in bed with flu

Influenza, or the flu, is a virus that infects the respiratory system (the lungs and other organs that allow us to breathe).

It is an ‘airborne’ virus. When someone with the flu coughs, sneezes or talks, droplets containing the virus are passed into the air and these droplets are then inhaled by other people nearby.

Alternatively these droplets can land on nearby surfaces, where the virus can live for several hours. So you can also catch the flu by touching an infected surface and then touching your eyes, nose or mouth.

Unfortunately, if you have heart disease, you’re at greater risk of catching the flu and you’re more likely to suffer complications from having it.

How does influenza affect people with heart disease?

The influenza virus puts added stress on the body, which can increase your blood pressure, raise your heart rate and increase your risk of a heart attack or stroke. A recent study found people with heart disease were six times more likely to have a heart attack in the week following a bout of the flu.

Flu can make the symptoms of your heart condition worse and be a trigger for atrial fibrillation episodes.

People with heart disease are also more likely to develop flu complications such as pneumonia or respiratory failure.

What are flu symptoms?

Influenza illness can include any or all of these symptoms:

  • fever
  • muscle aches
  • headache
  • lack of energy
  • cough
  • sore throat
  • a runny nose.

The fever and body aches can last three to five days and the cough and lack of energy may last for two weeks or more.

What is the difference between a cold and the flu?

The flu and a cold are commonly confused, but they’re two quite different conditions. A common cold only affects the nose, throat and upper chest.

The flu affects the whole body and lasts a week or more. Often the flu can result in hospitalisation, particularly if you’re elderly or have an ongoing medical condition, such as heart disease.

What is the best way to protect against flu?

The single best thing you can do to reduce your risk of getting the flu is to get an influenza vaccination (flu jab).

Other measures include:

  • Regular and effective handwashing (wash hands and wrists with soap and water for 20 seconds).
  • Avoiding close contact with people who are sick.
  • Maintaining your general health by taking any prescribed medications, eating and sleeping well and doing regular exercise. These actions help to keep your immune system strong.

What is the influenza vaccination and how does it work?

The influenza vaccination is a treatment that is given to stop you getting the flu.

The vaccine contains strains of the flu virus that have been “inactivated” (destroyed), so they are no longer live and are unable cause disease. When the vaccination is given, your body detects the strains of the flu virus and responds by making antibodies that can destroy them.

If you come into contact with the virus after your flu shot, your immune system will recognise the virus and the antibodies will destroy it before you get sick.

The flu shot is given as an injection into the upper arm.

Can I get a free flu jab?

In New Zealand, the flu jab is free for anyone who is 65 or older.

It is also free for people under 65 who have certain medical conditions. This includes anyone living with:

  • ischaemic heart disease (coronary artery disease)
  • congestive heart failure
  • rheumatic heart disease
  • congenital heart disease
  • cerebrovascular disease.

For a full list of conditions that are covered see the fightflu website or talk to your GP practice.

Where do I get a flu jab?

If you’re eligible for a free vaccination make an appointment with your local GP practice nurse.

If you’re not eligible for a free flu shot but would still like to get one, you can pay to get it at one of the following

When should I get vaccinated?

It’s best to get vaccinated as soon as the vaccination is available.

The 2019 flu vaccination programme in New Zealand is scheduled to begin on 1 April (subject to availability). This means you should be able to make an appointment with your GP practice for a jab any time from 1 April onwards.

How long will it take for the vaccination to work?

It takes up to two weeks for the vaccination to work. So if you come into contact with the virus before then, you won’t be protected against it.

Will the flu vaccine effect my heart medication?

No. The flu vaccination will not interact with your heart medication.

Is the flu jab 100% effective?

Unfortunately, the flu shot doesn’t guarantee you won’t get the flu, but it does significantly reduce your chances.

Can the vaccine give you the flu?

No. You can’t get the flu from the vaccine because it doesn’t contain any live viruses. Sometimes people may experience mild reactions such as muscle pains and headaches after the vaccination, but this isn’t the flu.

Can you get a reaction from the flu vaccination?

Most people don’t suffer any unpleasant or dangerous reactions to the flu jab.

The most common reaction is pain and redness where the needle went in. Sometimes the vaccination also causes side effects such as headaches, muscle aches and/or fever.

On very rare occasions people can suffer a severe allergic reactions. Studies have estimated the risk at less than two in a million. That means if the entire population of New Zealand received a flu vaccination, only six people would suffer a severe allergic reaction. In comparison, around 500 New Zealanders die every year from the flu.

You will be asked to wait for about 20 minutes at the clinic after your vaccination, to make sure you don’t have a severe allergic reaction.

Is there anyone who shouldn’t have a flu vaccination?

Children under six months of age are too young to be vaccinated.

You should also avoid getting vaccinated if you’ve got a fever of 38 degrees centigrade or above at the time of your jab. Talk to your GP or healthcare provider about rescheduling your appointment.

It is also important to talk to your health professional beforehand if you:

  • have previously had Guillain-Barre syndrome.
  • had an allergic reaction to a previous vaccination.

How often do I need to get vaccinated?

You need to get your flu vaccination yearly, at the start of every flu season.

The vaccine is developed each year to protect you against the most common influenza strains.

What should I do if I get the flu?

If you have heart disease and you get the flu, seek medical help early. Either call your GP or Healthline 0800 611 116 to see if you need treatment.

Seek urgent medical advice if you have:

  • a high fever that doesn’t come down
  • chills or severe shaking
  • difficulty breathing or chest pain
  • a purple or bluish colour round your lips, skin, fingers or toes
  • seizures of convulsions.

It’s important to talk to your pharmacist before taking any over the counter flu medications, as some of these can raise your blood pressure and interact with your heart medication.

Support for people living with heart diseaseWhat's my risk of heart attack or stroke?