Atrial septal defect
Atrial septal defect (ASD) is a hole in the membrane or wall that divides the upper
chambers of the heart, the atria. Consequently, an increased amount of blood flows
through the right heart chambers and the pulmonary artery leading to the lungs.
This added stream of fully oxygenated
pink blood recirculating through the lung vessels is a wasted effort as
no further oxygen can be picked up. ASD occurs in 1 in every 1500 births and represents 6%
to 10% of all congenital heart defects. ASD occurs more frequently in girls and women, by
a ratio of 2:1 . The most
common type of ASD is the ostium secundum atrial septal defect, which is often
located in the center of the septum.
Symptoms of ASD
The symptoms depend on the size of the hole, the number of holes and the
extent of other abnormalities.
Smaller defects may cause very few if any symptoms during childhood. Larger defects may cause exercise
intolerance.
The diagnosis of
ASD
Most
individuals with a significant ASD are diagnosed in utero or in early childhood
with the use of ultrasonography or listening to the heart sounds using a
stethoscope during physical examination.
Treatment for
ASD
Closure of uncomplicated small or moderate sized ostium secundum ASDs can
often be accomplished non-surgically by closure devices delivered by a cardiac
catheter (a tube inserted into the heart).
Closure of the large defect and surgical repair of associated
abnormalities is recommended and will result in excellent and usually permanent
repair with long life expectancy.
Pros and Cons of using a closure device to
treat ASD
Pros:
- Avoids having to undergo surgery in majority of cases
- Has a high success rate of accomplishing closure in ASD
Cons:
- Long term effects of hardware implanted in atria not
fully known
- Possible injury to or interference with heart valves
- Possibility of the device dislodging and drifting
through the heart or even into the aorta
- Failure of device implantation can require emergency
surgery