ASD / PFO closures

What is an ASD?

ASD stands for Atrial Septal Defect, often referred to colloquially as 'a hole in the heart'. An Atrial Septal Defect is the medical term given to a hole in the wall of the heart (the 'septum') that separates the two upper chambers (the 'atria'). In most cases it is a congenital condition where the septum does not form properly.

What problems can be caused by an ASD?

Many people with an ASD are unaware that they have one, especially if the hole itself is small. The presence of a larger ASD (more than 2cm in diameter) can cause heart arrhythmia such as atrial fibrillation or atrial flutter when older - half of all people with a larger ASD will develop these conditions after the age of 40. Other conditions linked to a larger ASD include enlargement of the right side of the heart, stroke and pulmonary hypertension.

What is a PFO?

PFO stands for 'Patent Foramen Ovale', which is another type of hole in the heart which occurs when a hole between the two upper chambers - which is normal and necessary when a baby is growing in the womb (blood flows through the heart differently in an unborn baby) - does not close up after birth. One in four people have a PFO and most are unaffected by it and have no symptoms at all. Many only find out when they are undergoing an unrelated medical test. Some PFO's can cause strokes by allowing a blood clot to pass between the heart chambers and make its way to the brain.

How are ASD's and PFO's diagnosed?

As ASD's and PFO's often have no symptoms, they are often detected during unrelated medical examinations - for example a heart murmur picked up by a stethoscope exam, although sometimes migraines are a symptom of ASD's and PFO's. Diagnosis is confirmed either by echocardiography or angiography.

NOTE: in babies and very young children there are also generally no symptoms, but a large ASD or PFO may cause listlessness, disinterest in food or no gain in weight.

How are ASD's and PFO's closed?

The general procedures used for closing both ASD's and PFO's are non-surgical, that is using minimally invasive techniques. Like angiography and TAVR procedures, a catheter (thin tube) is inserted into a blood vessel normally in the groin and moved up to the heart itself, where a closure device is affixed to the hole (using two small 'anchors') to close it. Shortly after the device has been fitted tissue forms over where the hole was in a natural process called 'endothelialisation'.

What happens during the procedure?

The procedure is very similar to other non-invasive heart procedures. You will remain awake during the procedure with only mild sedation used. The procedure generally takes no longer than two hours and does not normally require an overnight hospital stay.

How long is the recovery period?

Depending on the nature of the ASD or PFO, you may be required to take blood thinning medication for a year, or in some cases on an ongoing basis. There are generally some restrictions on physical activity for at least a month, and recommendations against sitting or standing in one position for a long time. It is also important to either avoid dental procedures for a 6 month period or - if they are essential - take a course of antibiotics prior to the procedure/s.