100 QUESTIONS IN CARDIOLOGY

45 When and how should a ventricular septal

defect be closed in adults?

Seamus Cullen

Indications for surgical closure of a ventricular septal defect in

childhood include congestive cardiac failure, pulmonary hyper-

tension, severe aortic insufficiency and prior bacterial endo-

carditis. It is unlikely that a significant ventricular septal defect

will be missed in childhood and therefore ventricular septal

defects seen in adulthood tend to be small and isolated. In a small

number of patients with Eisenmenger syndrome, i.e. ventricular

septal defect with established pulmonary vascular disease, no

intervention is possible.

The natural history of small congenital ventricular septal

defects was thought to be favourable but longer follow up has

demonstrated that 25% of adults with small ventricular septal

defects may suffer from complications over longer periods of time.

The complications documented were: infective endocarditis,

aortic regurgitation, arrhythmias and myocardial dysfunction.

Whilst closure of a ventricular septal defect protects against

infective endocarditis, there are no data to suggest a protective

effect against the development of late arrhythmias, sudden death

or ventricular dysfunction.

The risk of bacterial endocarditis in patients with a ventricular

septal defect is low (14.5 per 10,000 patient years). Prior or

recurrent endocarditis on a ventricular septal defect would be

deemed an indication for surgical closure even though the risks of

endocarditis are low.

Whilst the majority of congenital ventricular septal defects are

in the perimembranous or trabecular septum, a small percentage

are found in the doubly committed subarterial position. This

small sub group may be complicated by aortic valve cusp

prolapse into the defect with development of subsequent aortic

regurgitation which may be progressive and severe. The detection

of aortic regurgitation in such a defect is considered an indication

for surgical closure in most centres.

The mortality for surgical closure of a post-infarction

ventricular septal defect may be up to 50%. Cardiogenic shock is

exacerbated by the acute left ventricular volume load from the

shunt through the ventricular septal defect. There is a small but