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Atrial septal defect (ASD) is a congenital defect between the two upper heart chambers (the atria). This defect allows mixing of oxygenated and deoxygenated blood, eventually causing right heart enlargement and high pressure in the lungs (pulmonary hypertension).
Moderate- to large-sized Atrial Septal Defect (ASD) causing right heart dilatation and raised pressure in the lungs should be closed. Closure can be performed either via percutaneous method using devices (through the femoral vein) or through open-heart surgery.
Small Atrial Septal Defect (ASD) with no chamber enlargement, raised lung pressure or other complications needs only to be followed up at the clinic.
Many babies born with atrial septal defects do not exhibit signs and symptoms. In adults, signs or symptoms usually begin by age 30, depending on the size of the defect and the flow across. However, in some cases, the signs and symptoms may not occur until years later.
Signs and symptoms of atrial septal defects (ASD) may include:
Doctors know that heart defects present at birth (congenital) arise from errors early in the heart's development, but there's often no clear cause. Genetics and environmental factors may play a role.
If your doctor suspects you have a heart defect, your doctor may request one or more of the following tests:
The defect can be closed percutaneously by inserting a device through the blood vessels in the groin (percutaneous transcatheter approach) or via surgical repair. The choice of treatment depends on the size of the defect and the presence of pulmonary hypertension. After the defect is closed, the patient will need regular follow up with a cardiologist.
This procedure is performed by inserting a device through the blood vessels in the groin (percutaneous transcatheter approach) which will close the ASD.
This minimally invasive procedure typically takes 1 to 2 hours, with a success rate of approximately 95%. However, it carries certain risks, including:
Other potential risks include allergic reactions to dye or anaesthesia, bleeding or bruising at the groin site, injury to blood vessels or nerves in the groin, perforation of the oesophagus from the TEE probe, headache or migraine, infection or allergic reaction to the nickel component of the device.
Some complications, if they occur, may require further treatment such as surgery or prolonged hospitalisation. In the case of device dislodgement, surgery may be needed to remove the device and close the defect simultaneously.
Not all ASDs are suitable for device closure. Factors that may make a defect unsuitable include:
Detailed imaging, including transthoracic and transoesophageal echocardiograms, is necessary to determine if a defect is suitable for device closure.
In most cases, this procedure is performed under general anaesthetic (GA) which is given by a qualified anaesthetist. Once anaesthetised, an imaging probe (TEE) will be passed into your gullet (oesophagus) for accurate sizing of the ASD and to assist during deployment of the device. You will lie on an X-ray table and an X-ray camera will move over your chest during the procedure. A plastic catheter (a long tube) will be inserted via a vein in the groin and navigated until it reaches the heart.
Sometimes (depending on individual case), the catheter is positioned at different chambers of your heart to measure the pressure and oxygen content prior to device closure. In certain circumstances, balloon sizing of the ASD may be required. Once your doctor is satisfied with all the measurements, the appropriate size device is connected onto a cable, put into a special delivery tube, advanced through your ASD and carefully deployed. Your doctor will study the device's position and stability before releasing the device. The catheter and imaging probe are removed and the procedure is completed.
For defects unsuitable for device closure, surgical repair is performed. This is often recommended for very large defects or those close to critical heart structures.
Patients with small defects rarely experience complications. However, moderate to large defects may lead to:
Medications may be required to manage these issues.
Some of these complications, if they do occur, are of a serious nature and may require further treatment including surgery and prolonged hospitalisation. In the event of device dislodgement, you may require surgery for removal of the device and closure of the hole at the same time.
Activity restrictions are unnecessary unless there are associated problems that you and your cardiologist have discussed. However, after ASD device closure, patients will be advised to refrain from strenuous activity and heavy lifting for at least six months.
