Cardiology - Atrial Septal Defect

Question 1

Definition

Answer 1

Defect in the septum between the 2 atria causing a left to right shunt due to the higher pressure in the left atria

Question 2

Risk factors

Answer 2

Maternal rubella infection during pregnancy
Maternal alcohol or drug use during pregnancy
Maternal use of certain medications during pregnancy : statins, isotretinoin

Question 3

Types of ASD

Answer 3

• Ostium secondum = septum secondum fails to fully close, leaving a hole in the wall.
• Patent foramen ovale = foramen ovale fails to close (not strictly classified as ASD).
• Ostium primum = septum primum fails to fully close, leaving a hole in the wall. This tends to lead to atrioventricular valve defects making it an atrioventricular septal defect.

Question 4

Symptoms

Answer 4

SIGNS
- Mid-systolic, crescendo-decrescendo murmur loudest at the upper left sternal border
- Wide fixed split S2 sound which doesn’t change with insp/exp
- Tachypnoea
SYMPTOMS
- SOB
- Difficulty feeding
- Poor weight gain
- Lower respiratory tract infections

Question 5

Investigations

Answer 5

ECG
Echo

Question 6

Treatment

Answer 6

• If small can be managed conservatively and will close within 12 months of birth
• Surgical closure, usually if ASD > 1cm
  = transvenous catheter closure (via the femoral vein
  = open heart surgery
• Anticoagulants e.g. aspirin, warfarin, NOACs used to reduce risk of clots and stroke in adults

Question 7

Complications

Answer 7

Stroke from DVT
Atrial fibrillation or atrial flutter
Pulmonary HTN
Eisenmengers syndrome