الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
ASDs account for 5–10% of all congenital heart defects. These
defects should be closed when diagnosed during childhood or adulthood
because they lead to right atrial and ventricular volume load, arrhythmias,
and paradoxical embolism.
The atrial septal defect is the second most common congenital
heart defect in adults (behind bicuspid aortic valve) with an incidence of
3.78/1000 live births which counts for 5.9% of the diagnosed congenital
heart diseases in children.
In addition, ASDs are the most common congenital defect in adults
and are more common among women than men. Within the broad
category of ASDs, there are several types of defects. Atrial septal defects
are classified by where they occur and their size.
A secundum ASD is a hole in the middle of the atrial septum,
which lets blood flow from the left chamber to the right chamber, or from
the right chamber to the left chamber, depending on pressures in the atria.
More complicated and rare types of ASDs involve different parts of the
septum and also involve abnormal blood return from the lungs (sinus venosus)
or heart valve abnormalities (primum ASDs) or coronary sinus defect.
ASD can cause volume overload of the right side of the heart with the
potential for subsequent development of right heart failure, elevated
pulmonary vascular resistance or atrial arrhythmias or Stroke and
Pulmonary hypertension.
An assessment for an ASD includes different modalities of
investigations such as ECG, Chest X-ray, TTE, TEE, ICE, MRI, Heart
catheterization…etc.
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Closure of these defects is recommended to decrease the risk of
complications. Evidence of right heart enlargement by echocardiographic
imaging has gained acceptance as an indication for defect closure as it has
been shown to accurately estimate the degree of shunt. The presence of
significant ASD with right atrial (RA) and right ventricular (RV) volume
overload is an indication for closure of the defect as two thirds of
secundum ASDs may enlarge with time.
The natural history of secundum ASDs affects the need for and
timing of closure either surgically or in the catheterization laboratory.
65% of defects increase in diameter at a mean rate of 0.8 mm/year.
ASDs < 3 mm in diameter invariably close by 18 months of age
and are generally regarded as patent foramen ovale. Spontaneous closure
has been reported to occur in anywhere between 14: 66% of ASDs.
Factors such as smaller size of defect and earlier age at diagnosis
led to early spontaneous closure with increased likelihood of spontaneous
closure in those diagnosed before two years of age and the greatest
predictor of spontaneous closure is initial ASD size at diagnosis.
Closure eliminates the left to right shunting, volume overload of
the right-sided circulation, and the risk of pulmonary hypertension and
arrhythmias.
The clinical findings are usually absent until the second or third
decade of life, but the most ideal timing for closure is during early
childhood, or at time of diagnosis of an ASD detected later in life.
Closure can be done either Trans-catheter non-surgical or surgical
The first non-surgical closure of an ASD in the catheterization laboratory
was performed in 1974.Since this initial procedure, multiple devices have
been introduced and tested in the world.