Ventricular septal defect

Question 1

What is ventricular septal defect?

Answer 1

Ventricular septal defect is a birth defect where there is a hole in the ventricular septum of the heart.

Ventricular septal defect = the most common cause of congenital heart disease.

=> they spontaneously close ~50% of cases

Question 2

What is ventricular septal defect associated with?

Answer 2

1. Congenital VSD assoc. with chromosomal disorders:

=> Down’s syndrome (trisomy 21)
=> Edward’s syndrome
=> Patau syndrome
=> Cri-du-chat syndrome

2. Congenital infections
3. Acquired causes i.e. post-myocardial infarction

Question 3

Ventricular septal defect may be detected in utero during the 20 week scan.

What are the post-natal presentation of ventricular septal defect?

Answer 3

1. Failure to thrive
2. Features of heart failure in large VSD
   => hepatomegaly
   => tachypnoea (noticed during breastfeeding)
   => tachycardia
   => pallor
3. Classic pan-systolic murmur (louder in smaller defects)
   * may be poor weight gain as energy is diverted to breathing instead of growing

Question 4

How is ventricular septal defect diagnosed?

Answer 4

1. ECHO - allows visualisation of defect and characterisation of its severity
2. Chest x-ray + ECG also useful

Question 5

How is ventricular septal defect managed?

Answer 5

Majority self-resolve so infants may be managed conservatively with increased caloric intake and observation with follow up.

For moderate-large VSD causing signs & symptoms of heart failure, infants managed on diuretics i.e. captopril and nutritional support.

Corrective surgery in severe cases around 3-5 months

Question 6

What are the complications of ventricular septal defect?

Answer 6

1. Aortic regurgitation
   => due to poorly supported right coronary cusp resulting in cusp prolapse
2. Infective endocarditis
3. Eisenmenger’s complex
   => due to prolonged pulmonary hypertension from the left-to-right shunt

=> results in right ventricular hypertrophy & increased right ventricular pressure

=> this eventually exceeds left ventricular pressure resulting in reversal of blood flow

=> this in turn results in cyanosis and clubbing

=> Eisenmenger’s complex is an indication for heart-lung transplant

4. Right heart failure
5. Pulmonary hypertension
   => pregnancy is contraindicated in women with pulmonary hypertension as it carries a 30-50% risk of mortality