Pathology: Abnormal connectionbetween the left and right atrium
There are two maintypes of ASD:
Ostiumsecundum (80%): defect in centre of atrial septum (foramen ovale)
Ostiumprimum (10%): defect in lower atrial septum (involving AV valve)
Aetiology: Congenital, morecommon in female. Down syndrome is associated with ostium
primum
Symptoms: Usuallyasymptomatic until adult hood
Heart failure (poor feeding, failure tothrive, tachypnoea, sweating, vomiting) or
palpations and recurrent chest infections
Signs: Softsystolic murmur, upper left sternal edge, fixed splitting of 2ndheart sound,
left parasternal heave, clubbing
Investigations: ECG: Ostium primum– Left axis deviation
Ostiumsecundum - right axis deviation, right bundle branch block
Chest X-Ray:Cardiomegaly and increased pulmonary vasculature
Echo: Assessesheart structure and confirms defect
Treatment: ConservativeManagement: Small defects with minima, shunting can be
monitored
Surgical: Closure at 4-5 years of age
Complications: Ifsurgical correction is not undertaken, heart failure or arrhythmias may occur
Eisenmenger Syndrome (reversal of left to right shuntresulting in cyanosis)
Prognosis: 90% close achievedby insertion of an occlusion device in the catheter laboratory
Prognosisis good once defects corrected however development of Eisenmenger Syndrome is alife threatening complication.
