2. Atrial septal defect
▪ Atrial septal defect (ASD) is an abnormal opening
between right and left atria resulting left to right
shunting of blood. It accounts for 9% of all CHDs
3. Types
▪ There are three types of ASDs
1. Ostium secundum ASD: It is most common type of ASDs.
An abnormal opening in the middle of the atrial septum
presents due to abnormal development of the septum
secundum.
4. 2. Ostium primum ASD: It presents as an abnormal
opening at the bottom of the atrial septum due
to improper development of the septum primum.
There may be increased association with cleft
mitral valve and atrioventricular defects.
5.
6. Pathophysiology
there is flow of oxygenated blood from higher pressure
left atrium to lower pressure at right atrium across the
ASD resulting volume overload to right ventricles and
right ventricular dilation. Thus increased blood flow to
lungs leads to elevated pulmonary artery pressure.
7. Clinical manifestations
▪ Ostium secundum and sinus venous ASDs are usually
asymptomatic.The manifestations due to ostium primum ASD
depend upon the associated defects.
▪ Child may have recurrent chest infestions, dyspnea on exertion,
easy fatigability, bulging of the chest, poor weight gain, cardiac
enlargement and CCF [congestive cardiac failure]
8. Diagnostic evaluation
▪ Auscultation of heart sound is important
▪ In ostium secundumASD, soft systolic flow murmur heard best at the left upper sternal
border
▪ In ostium primum ASD, systolic murmur heard best at the lower left sternal border
because of mitral regurgitation.
▪ Chest X- ray shows right atrial and ventricular dilation and increased pulmonary marking
▪ ECG demonstrates right ventricular hypertrophy and right axis deviation.
▪ 2D echocardiogram with Doppler study and color flow mapping and cardiac
catheterization are useful approach for detection of problems and associated
complications
9. Management
▪ Surgical closure of defect is planned in early childhood to prevent further
complications
▪ CCF and arrhythmias should be managed medically.
▪ Antibiotic prophylaxis is necessary during dental procedures, if needed.
▪ Repair of the defect is done by suture closure of pericardial patch repair by open heart
surgery
▪ Result of surgical interventions are gratifying. Supportive nursing care is very
important
10. complications
▪ The complications of ASD may include
▪ infective endocarditis,
▪ pulmonary arterial hypertension,
▪ CCF
▪ growth retardation and
▪ post operative complications after surgical repair