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Atrial septal defects are holes between the atriums, the top chambers of the heart. We are all born with a hole between the atriums, but this should normally close sometime during the first few months of life. In some people this normal closure process does not take place, and the result is an atrial septal defect (ASD). This type of defect is call a “secundum ASD” and is the most common type of ASD.
In most people these defects don’t tend to cause problems during childhood, and it is quite common for them to be picked up for the first time during adult life. There are two ways to close secundum ASD’s, firstly with surgery and secondly with a heart catheter procedure. This section discusses the potential problems that can caused by an ASD in adult life and why we would recommend closing these defects.
The boxes below describe three of the most important problems that we see in adults with an
Atrial Septal Defect
For further information about Atrial Septal Defects click on the links at the bottom of the page
Right Ventricular Enlargement
The right ventricle is the right sided pumping chamber of the heart. In people with an ASD, the right ventricle is usually enlarged.
Because blood usually passes across the ASD from left to right, the right side of the heart has to deal with more blood than usual. This results in enlargement of the right ventricle and also the right sided collecting chamber, the right atrium.
Over many years the muscle of the right ventricle can get tired as a result of the extra work that it has to do because of the ASD.
When we see enlargement of the right atrium and right ventricle, we usually regard this as an indication that the ASD requires closing. In most cases the preferred way of doing this is with a heart catheter procedure, although some people will require an operation to close the ASD.
Click here to find out more about ASD closure using a heart catheter.
The ASD will have been present since birth, so there isn’t anything you can do to change it. Talk carefully with your medical team to work out if it should be closed, and what the best technique is for you.
Atrial Flutter
It’s an abnormal fast heart rhythm arising from the atriums (the top chambers) of the heart.
It arises because of the enlargement of the right atrium that is commonly seen in people with an ASD. We know that right atrial enlargement will often eventually lead to the development of abnormal heart rhythms like atrial flutter and also atrial fibrillation, especially once people reach middle age.
It can be a dangerous heart rhythm because it can make your heart go too fast. This doesn’t always cause problems immediately, but if your heart stays fast for too long it will make your heart muscle get weak. Also it makes you more likely to develop blood clots in the atriums of the heart which can potentially break off and go to your brain, causing strokes.
To get you back into a normal heart rhythm we either use medications or cardioversion, which is an electrical shock to get your heart back into rhythm (you have a quick general anaesthetic for this). Click here to find out more about cardioversion.
To stop the atrial flutter happening again, first up we will often use heart rhythm medicines. Sometimes we will do a specialized heart catheter procedure to try to stop the abnormal rhythm from occurring. This is called a catheter ablation procedure. Click here to find out more about catheter ablation.
Not usually, although some people will notice that abnormal heart rhythms are made worse by things like excessive alcohol or caffeine.
If you notice a change in your heart rhythm it’s important that you get checked out straight away. If you do go into atrial flutter we will usually want to try to get you back into a normal heart rhythm as soon as possible.
Pulmonary Hypertension
Pulmonary hypertension means high blood pressure in the lung blood vessels.
In people with an ASD there is extra blood going through the lungs as a result of the blood crossing the ASD from the left side of the heart to the right. In a minority of people with an ASD this results in the blood pressure gradually rising in the lungs. The exact reasons for this remain unclear in most people.
Pulmonary hypertension can be a dangerous complication because the right ventricle has to work harder to pump at higher pressure. This puts extra strain on the heart muscle of the right ventricle, and the right ventricle can get gradually weaker as a result.
There are medicines that we can use to improve pulmonary hypertension, but at this stage there is no cure. Sometimes closing the ASD can help, but in some people with major pulmonary hypertension this can make things worse. This decision has to be weighed up very carefully in people who have developed pulmonary hypertension.
In most cases, probably not. It seems that some people have a tendency to develop pulmonary hypertension, but others do not, and we don’t fully understand the reasons for this.
There are some things that can make you more likely to develop pulmonary hypertension, like smoking and obesity, so if you have an ASD you should avoid smoking and watch your weight carefully.