PFO/ASD Closure and Valvuloplasty
These are actually three different procedures that have similarities. A PFO and an ASD both involve the atrial septum. This is a flap of tissue between the left and right atria. The atria (atrium for singular) are the heart's receiving chambers. The right atrium receives venous (oxygen depleted) blood from the body. The left atrium receives arterial (oxygen rich) blood from the lungs. Each atrium fills the corresponding ventricle. The ventricles are the heart’s pumping chambers. The right ventricle pumps venous blood to the lungs to become full of oxygen and the left ventricle pumps blood out to the body so the oxygen can be used. For the blood to pass from the atria to the ventricles and then to the main arteries (aorta and pulmonary artery) the blood passes through cardiac valves. These open to allow the blood to flow from one chamber to the other and then close to allow refilling.
A PFO stands for patent foramen ovale which is when the flap which is between the left and right atria does not fuse closed after birth. This can allow blood to flow from the right to the left atrium in some circumstances.
An ASD stands for atrial septal defect which is the medical for one of the conditions commonly called “a hole in the heart”. It is a malformation of this flap (atrial septum) between the two atria. This allows flow from the right to the left atrium at all times.
This right to left blood flow is not good for the heart. If an ASD is big enough it will be detected as a baby. The baby will be a “blue” baby which basically means that the baby is not getting enough oxygen (in the blood) to the body. The reason for not enough oxygen in the blood is the ASD. It allows venous (oxygen depleted) blood to flow from right atrium to left atrium, and from there to the left ventricle and out to the body, without going through the lungs where it gets oxygenated.
If the ASD is small it may not be detected until you are older.
ASD’s and PFO’s can be closed surgically. Until a few years ago this was the only option. Now these defects can be closed using a wire mesh device that can be inserted thought the femoral vein via a catheter.
The preparation and access of the femoral vein is the same as for an angiogram. The device is passed up the femoral vein to the IVC (inferior vena cava—the main vein from your lower body to the heart) and then into the right atrium and across the defect to the left atrium. The device is then deployed so there is some mesh on both sides of the atrial septum effectively closing the defect.
A valvuloplasty is a procedure to open a stenosed cardiac valve. There are four valves in the heart. These are the structures between chambers that open to let the blood flow from one chamber to the next. Valves that have problems can either not open properly or not close properly. When a valve does not close properly it allows some of the blood that just went from one chamber to the next to leak back. This means that the heart has to work harder to get the same amount of blood out to the body. Valves that don’t close properly need to be fixed surgically—either by replacing the valve with a mechanical, pig or human valve or repairing the leaky valve.
When a valve does not open properly the heart has to push a lot harder to get the same amount of blood through a smaller opening in the same timeframe. Sometimes a stenosed valve (one that doesn’t open properly) is suitable for a valvuloplasty. This procedure stretches the restricted leaflets of the valve with a balloon and allows more blood flow through the valve.
The two valves that tend to be suitable for valvuloplasty are the mitral and aortic valves. These are the valves on the left side (high pressure) side of the heart. The mitral valve is between the left atrium and left ventricle. The aortic valve is between the left ventricle and the aorta.