Atrial Septal Defect: (ASD) this
congenital defect, an opening between the left and right atria allows shunting
of blood between the chambers. The left atrial pressure normally
is slightly higher than right atrial pressure, blood shunts from left to
right. The pressure difference forces large amounts of blood through
the defect and leads to right heart volume overload, therefore, affecting
the right atrium, right ventricle, and pulmonary arteries. Eventually,
the right atrium enlarges, and the right ventricle dilates to accommodate
the increased blood volume.
ASD is usually a benign defect during infancy and childhood, delayed
development of symptoms and complications makes it one of the most common
congenital heart defects diagnosed in adults. Asymptomatic patients
have an excellent chance of recovery; the outlook is less hopeful for individuals
with cyanosis caused by large, untreated defects.
Cause: Unknown
Symptoms:
May often be asymptomatic, especially if the patient are young preschooler.
He may only complain of feeling tired after extreme exertion. If
large amounts of shunting occur, his growth may become retarded.
Upon auscultation at the second or third left intercostal space may
reveal a superfical early to midsytolic murmur. The doctor may hear
a fixed, widely split S2 and a systolic click or late systolic murmur at
the apex. In patients with large shunts, auscultation at the lower
left sternal border may reveal a low pitched diastolic murmur that becomes
more pronounced on inspiration.
Older Patients with ASD may develop pronounced fatigability clubbing,
and cyanosis. Dyspnea on exertion may severely limit the patient’s activity,
especially after age 40. Syncope (faint, temporary loss of consciousness)
or hemoptysis (spitting up blood) may occur in adults with severe pulmonary
vascular disease.
Treatment:
ASD seldom produces complications in infants and toddlers, the
doctor may delay surgery until the patient reaches preschool or early school
age. For large defect: the patient may require immediate surgical
closure with sutures or a patch graft.