Treatment of Atrial Septal Defects and Patent Foramen Ovale
The atrial septum is a stretch of cardiac tissue that separates the two upper chambers of the heart, the atria from each other. A hole in this septum can lead to the mixing of blood between the two sides of the heart. An atrial septal defect (ASD) arises from abnormalities in the development of the septum. There are three types classified based on the location of the hole and the mechanism of formation. A patent foramen ovale (PFO) is the persistence of a naturally occurring connection between the two atria that is necessary for the heart to function well prior to birth.
- Sinus venosus ASD: this occurs higher up in the septum
- Ostium primum ASD: This occurs lower in the septum. This type occurs frequently in individuals with Down’s syndrome
- Ostium Secundum ASD: This is the most common type and occurs in the middle of the septum.
Both ASD and PFO increase the risk of movement of blood clots from the body to the brain leading to stroke.
Management of ASD/PFO Medical therapy:
- Medications to treat respiratory infections (which are frequent with septal defects) should be administered.
- Drugs to control heart rate and rhythm in the event of atrial fibrillation, which is a frequent complication of ASD/PFO causing abnormal heartbeat and palpitations
- Control of blood pressure and heart failure
Operative Repair:
Indications:
- Severe ASD with a large shunting of blood from the left to the right atrium, who have not developed complications
- Patients who have had symptoms related to the movement of clots across the defect, like stroke or TIA (transient ischemic attack or mini-stroke)
- In patients undergoing repair for other cardiac defects
Small ASD/PFO with minimal shunts do not require repair.
Patients who have developed pulmonary hypertension, a complication of ASD with elevated pressures in the blood vessels in the lungs, are not candidates for repair as there is limited benefit.
Surgical Repair of the Defect
This is open-heart surgery with the closure of the ASD done using pericardial tissue or a patch. This is the treatment of choice in ASD, provided there are no contraindications to surgery.
Procedure
The patient is placed under general anesthesia. The heart is accessed through cutting open the chest. The heart is stopped and placed on a heart-lung machine. The defect in the atrial septum is located and the patch or pericardial tissue is used to close it.
Complications
- Complications related to general anesthesia
- Bleeding
- Abnormal heart rhythms
- Rupture of the patch requiring reoperation
Post Procedure
The patient recovers slowly from the surgery and is kept inpatient for several days. The individual is generally placed on blood thinners for a specific duration to prevent the formation of blood clots.
Percutaneous Transcatheter Device Closure
This is an alternative to surgery which is being performed more frequently over the last few years. This is minimally invasive and can be performed rapidly with quicker recovery
This is recommended in PFO and in ASD of the secundum type. The other types of ASD are generally not easily repaired through this method.
Procedure
The patient is generally under sedation for the procedure. The catheter containing a patch is inserted through an artery to reach the heart. The patch is released at the defect to close it. A dye is used to visualize the blood vessels and heparin, a blood thinner is injected to prevent clots. An echocardiogram can be used during the procedure to assist with the placement of the closure device. The procedure lasts for about an hour.
Complications
- Malpositioning of the device which may require surgery
- Abnormal heart rhythm
- Blood clots
- Erosion of the closure device leading to perforation
- Sudden Cardiac Death, which can occur rarely with multiple procedures being done as a result of abnormal heart rhythms
Post Procedure
The patient recovers completely within a couple of days. He or she receives blood thinners to prevent clots for a specified period of time.
Follow up:
All individuals who have undergone repair of the ASD/PFO through surgery or percutaneous device closure should be evaluated periodically by a Cardiologist with an echocardiogram to look at the status of the repair.
