Abnormal fast heart rhythms arising from the upper chambers of the heart. In people with a Fontan, it is often a rhythm called atrial flutter.

They happen particularly in people who have had an atrio-pulmonary Fontan operation (the original version of the Fontan). There are two main reasons why they develop: firstly because the right atrium becomes progressively more enlarged, and secondly because there are scars in the atrium after the previous surgery. These things combined make abnormal fast rhythms more likely to occur.

It is a problem because it often makes the heart rate too fast and also makes the heart pump less efficiently. Blood clots may form in the atrium too. Rhythms like atrial flutter can make people with a Fontan get very sick and this can happen quickly. Sometimes it can even be life-threatening.

When it happens we can usually restore normal heart rhythm either with medications or with a DC cardioversion (an electric shock). It’s important that you get to hospital quickly so that the treatment can be given promptly if required.

Usually not, although some people find that abnormal fast heart rhythms are triggered by things like alcohol, caffeine, stress or tiredness.

If you have abnormal rhythms then we may recommend medication to reduce the chance of it happening again. Sometimes a heart catheter procedure or even further surgery may be recommended too.

In order to reduce the risk of blood clots developing we will often recommend that you take a “blood thinning” medicine to reduce blood clotting. Aspirin, warfarin and dabigatran are the most common ones that we use in New Zealand.

The liver can be affected in various ways, from liver fibrosis, through to cirrhosis, and in a small number of people the development of hepatocellular carcinoma (liver cancer)

It happens because the blood pressure in the main veins of the body is much higher than normal after the Fontan operation. This means that there is back-pressure onto the liver which can gradually cause liver damage leading to these complications.

The liver is a very important organ and if it is impaired this can have various major effects. The most important complication is liver cancer, which is often fatal if not picked up early.

If we do see problems developing with the liver, such as cirrhosis, then we will watch even more carefully for the development of liver cancer.

Sometimes there are things that we can do to improve blood flow through the Fontan and these may take a bit of pressure off the liver.

If liver cancer is detected we will work with the cancer specialists to plan the best treatment. This will often involve surgery to remove the tumour and may also involve chemotherapy for some people.

The most important thing you can do is to make sure you get the tests that your medical team recommend for monitoring your liver, so that any problems can be picked up early. We will usually recommend regular blood tests and liver ultrasounds, and sometime other tests such as an MRI.

Excessive alcohol can cause extra damage to your liver, so you should be careful with your alcohol intake.

This is a term that is used to refer to several different ways in which the Fontan circulation can start to work less well. This can include weakness of the pumping function of the heart, fluid accumulation or protein losing enteropathy (loss of protein through the gut).

There are many different things that can contribute to Fontan failure and it is often down to a combination of problems. Sometimes the pumping function of the heart becomes weaker or the heart valves can become leaky over time. The resistance of the blood vessels in the lungs can get higher with time and this can make it harder for blood to get through the Fontan and the lungs. Abnormal fast or slow heart rhythms can also be a factor. Protein losing enteropathy can be both a cause and an effect of Fontan failure.

People with Fontan failure will usually feel less well, with reduced exercise tolerance, reduced appetite, breathlessness or swelling from fluid accumulation. Sometimes these things can be accompanied by impaired liver or kidney function and an increased risk of blood clots developing.

We will usually do various tests to look for the specific causes. This may include an echo and MRI scan, blood tests and a heart catheter. If there are problems that have a specific treatment then this may be recommended, for example steroid medicines for protein losing enteropathy, surgery for leaky heart valves or heart catheter procedures to open up  narrowed blood vessels.

In some cases there may not be a specific treatment that we can offer, and some people may eventually need to be considered for heart transplantation.

Make sure that you keep up with your regular cardiology follow-up and that you attend for the tests that you need. These help to monitor your heart health and the general health of your Fontan circulation. This helps to pick up any problems before they become too advanced.

There is increasing evidence that keeping active is beneficial for the Fontan circulation, so try to do regular exercise, at least 3 or 4 days a week. General health considerations like avoiding becoming overweight and not smoking are particularly important for people with a Fontan circulation.