Purpose of the operation
The main purpose is to relieve the symptoms of a type of irregular heart beat called atrial fibrillation (AF). The usual symptoms are palpitations (a feeling of the heart thumping in the chest), breathlessness, tiredness and generally feeling awful when AF is present. Some patients have AF all the time and others only get it occasionally, when it may last up to a few hours or even days.
The other purpose of the operation is to reduce the medications taken for AF and the problems associated with them. Most patients who have AF take a variety of drugs to control the heart rhythm and a drug called warfarin to thin the blood. This is because AF can cause blood clots to form in the heart and these may travel with blood and cause problems anywhere in the body, with the possibiliy of a stroke. All drugs have side-effects; warfarin can increase the risk of bruising or bleeding. Taking warfarin can also be a nuisance because it requires regular blood tests to ensure that the dose is right.
Effect on patients
This is a big operation. It is not terribly painful, but there is pain afterwards. Usually the chest, back, neck and shoulders can hurt, but this is easily treated with standard painkillers. The operation also makes patients feel tired and lacking in energy for the first few weeks.
Usually, breathlessness and tiredness improve soon after the operation and continue to do so for some time. The risk of heart failure and death is also smaller once the patient has recovered from the operation.
It is important to know that the maze procedure does not have a 100% success rate. Usually anything between 60-95% of patients are cured of AF. There are two ways of creating the maze. In the first, the tissue is cut and sewn together. In the second, a source of energy is applied to the tissue to create the electrical block. The latter is relatively quick but may be less effective in some patients than the “cut-and-sew” maze. The best results (95%) are in patients who have AF only some of the time, have not had it for too long and have nothing else wrong with their heart (like a valve problem or a large heart). The lowest success rates (60%) are in patients who have AF all the time, have had it for years or decades and have valve problems and enlarged hearts.
A new type of non-surgical treatment, called AcQMap, may also be suitable for patients with persistant AF. This is a procedure being innovated at Royal Papworth Hospital.
What happens during the operation?
The operation is done under general anaesthetic. The anaesthetist puts in tubes and drips to closely monitor the patient and to give appropriate anaesthetic. The chest is cut over the breastbone. A heart-lung machine is used to keep the blood circulating while the heart is stopped for surgery. The surgeon then uses either a scalpel and stitch or an energy source to make several cuts in the tissue of the atria (the collecting chambers of the heart) so that the area that is cut can no longer conduct electricity. By doing this, the abnormal electric channels are blocked and this allows the normal electric function of the heart to take over. Once the maze is completed, the heart is restarted, the heart-lung machine is stopped and the wound is closed.
What to expect afterwards
You stay overnight in the hospital's critical care unit and about four to eight days recovering on the ward. Most tubes are removed in the first two days. You can have food and drink the day after the operation, but your appetite may be poor at first. You may sit in a chair on the first day, walk to the toilet on the second and walk about the ward from the third or fourth day. Once you can climb a flight of stairs, it is nearly time to go home. Many patients will still be in AF when they go home. This is because heart operations themselves can cause AF because the heart is irritable for a while afterwards, so many patients go home still taking the AF medication, including warfarin. This is usually dealt with at follow-up later.
You are encouraged to be active and to go for walks after leaving hospital. The general rule is that most things are allowed if you feel up to them, apart from activities which may delay the healing of the breastbone (heavy lifting or other activities which stress the upper arms are banned for three months after the operation). By six weeks, most patients feel almost normal.
When you come back to the follow-up clinic, the effects of the operation will have worn off. If you are still in AF, you will be asked to come back to the hospital for a “cardioversion”. This is an electric shock given under general anaesthetic, and should bring back the normal heart rhythm. Usually, you only need to be in hospital for one day to have the cardioversion. If successful, the feelings of palpitations, breathlessness and tiredness will be better and you may be able to cut some of your medications.