Atrial Septal Defect (ASD) & Patent Foramen Ovale (PFO) Closures

ASD and PFO Congenital Defects

Atrial septal defect (ASD) and patent foramen ovale (PFO) are congenital defects that leave a hole in the wall (septum) between the two upper chambers (atria) of the heart. People who have these heart defects are at increased risk for arrhythmias, stroke and heart failure. Although people are born with these defects, in many cases they are unaware they have an ASD or PFO; some may learn they have a defect when they experience problems as adults.

An ASD is a hole in the septum that allows blood to flow from one atrium to the other, usually from the left side to the right, causing an overload on the right side. While most small ASDs close on their own during childhood, larger defects are less likely to close on their own.

A PFO occurs when the foramen ovale does not seal after birth. The foramen ovale is a natural shunt (channel) that allows blood to enter the left atrium from the right atrium. In most people, the foramen ovale closes within a year of birth. In about 25 percent of people, the hole stays partially open, leaving a tiny passage between the atria (PFO). Many people learn they have a PFO following an ischemic stroke (a stroke caused by a blocked artery). Closing a PFO may reduce the risk of recurrent stroke. Patients with migraine more frequently have a PFO and the relationship between these two states is under investigation.

Echocardiography and transesophageal echocardiography (TEE) are used to diagnose ASD and PFO defects.

ASD and PFO Closure 

Medical College of Wisconsin physicians are skilled in evaluating and repairing these defects. If repair is required two approaches may be considered:

Minimally Invasive Surgery

In an operating room, the wall (septum) between the two upper chambers of the heart (atria) is closed with sutures or covered with a patch. In most cases, cardiac surgeons at Froedtert & the Medical College of Wisconsin are able to repair PFOs and ASDs through a small incision in the chest, without the need to open the entire chest.

Minimally Invasive Catheter Procedure

In the Cardiac Catheterization Laboratory, a minimally invasive procedure is performed to close an ASD or PFO. Froedtert & Medical College of Wisconsin were the first in Milwaukee to perform ASD and PFO closure without open surgery.

A catheter (a long, thin tube) is inserted into a large vein and advanced into the heart using imaging to guide the movement of the catheter. A special closure device is placed on a cable, inserted through the catheter and moved to site of the hole in the heart. Once in the correct position, the closure device is released to cover the hole. The device remains in the heart to stop the abnormal flow of blood between the two chambers of the heart. The catheter is removed. Over time, the tissue of the heart grows over the device.

Compared to open surgery, the catheter procedure results in fewer complications, less time in the hospital, less pain and a quicker return to activities. Patients may be offered both types of treatment options. A PFO can almost always be closed using a catheter and a closing device. Some ASDs, however, cannot be closed via a catheter and require open surgery.


For heart & vascular services:

  • 414-805-3666
Request AppointmentView Treatment Team


Heart & Vascular Center, Froedtert Hospital 9200 W. Wisconsin Ave.
Milwaukee, WI 53226

Learn more about heart & vascular services at:

All Heart & Vascular Locations