Ventricular septal defects

Question 1

How are VSDs classified?

Answer 1

By size:

• Small VSD (smaller than the aortic valve <3mm)
• Large VSD (bigger than aortic valve >3mm)

Question 2

What is a VSD?

Where?

Answer 2

Ventricular septal defect

• Defect anywhere in the ventricular septum: perimembranous (adjacent to the tricuspid) or muscular

Question 3

What are the symptoms and signs for a small VSD?

Answer 3

Symptoms:

• Asymptomatic

Physical signs:

• Loud pansystolic (regurg) murmer at LLSE (loud=small)
• Quiet pulmonary second sound

Question 4

What investigations should be done for a suspected small VSD?

What would be found?

Answer 4

Chest x-ray:

• Normal

ECG:

• Normal

Echocardiogram:

• Shows the defect with no pulmonary hypertension

Question 5

How do you manage a small VSD?

Answer 5

• These lesions will close spontaneously
• Confirmed by the disappearance of the murmer with a normal ECG and by a normal echo
• While the VSD is present, prevention of bacterial endocarditis is by maintaining good dental hygiene

Question 6

What are the symptoms (3) and physical signs (5) of a large VSD?

Answer 6

Symptoms:

• Heart failure with breathlessness
• Failure to thrive after 1 week old
• Recurrent chest infections

Signs:

• ​Heart failure signs:
  
  • Tachypnoea
  • Tachycardia
  • Enlarged liver
• Active precordium should be felt (volume overload)
• Soft pansystolic murmer (large defect) heard at LLSE
• Apical mid-diastolic murmer will present (due to increased flow across the mitral valve from blood leaving the lungs)
• Loud pulmonary second sound due to raised pulmonary arterial pressure

Question 7

What investigations for large VSD?

What would they show?

Answer 7

Chest X-ray:

• Cardiomegaly
• Enlarged pulmonary arteries
• Increased pulmonary vascular markings
• Pulmonary oedema

ECG:

• Biventricular hypertrophy by 2 months of age (upright T-wave - pulmonary hypertension)

Echo:

• Shows defect

Question 8

How should a large VSD be managed?

Answer 8

• Drug therapy for heart failure is with diuretic, often combined with captopril
• Additional calorie input is required
• Surgery usually preformed at 3-6 months of age

(There is always pulmonary hypertension with a large VSD and left to right shunt. This will ultimately lead to irreverisble damage and Eisenmenger syndrome)