lifesaving procedure Infants with large unrestrictive defects frequently develop pulmonary hypertension as a consequence and are the group at greatest risk for the development of pulmonary vascular disease.63 This becomes established and irreversible in the majority before the age of 2 years, again supporting the strategy for repair in the first year of life in those with evidence of congestive heart failure refractory to medical management.64 Patients who have experienced little or no fall in pulmonary vascular resistance after birth form the remainder of the subjects at high risk Tragically, this last group may escape detection until cyanosis supervenes It is important, therefore, to recognize that irreversible and progressive pulmonary vascular disease is present in the affected patients long before they become cyanosed The prognosis of patients with ventricular septal defect and pulmonary vascular disease is poor, but survival into adult life is common Death usually occurs before 40 years of age in affected patients In females with pulmonary vascular disease, pregnancy poses a particular risk, and avoidance of such is advised This is because loss of blood of even moderate degree, as may occur at delivery, can precipitate an irreversible state of low cardiac output If the female patient becomes pregnant and strongly wishes to continue the pregnancy, she may be able deliver safely with careful supervision, although the maternal mortality may be as high as 50%.65,66 There are two other complications of isolated ventricular septal defect that can cause death before the age of 40 years The first is development of aortic regurgitation.67 The reported incidence varies from less than 1% to as high as 5% of patients.62,68 It occurs most commonly when the defect is doubly committed and juxtaarterial, when more than seven-tenths may have prolapse of the aortic valvar leaflets, with more than four-tenths having resultant aortic regurgitation,69 or when the defect is perimembranous.70 It can also occur in the presence of muscular outlet defects when the muscular outlet septum is hypoplastic.71 Almost always it is the right coronary aortic leaflet that prolapses through the defect In perimembranous defects, the noncoronary leaflet and rarely the left may also be involved It is often recommended that surgical treatment be offered as soon as significant aortic regurgitation is recognized.72 It is now known that the condition is well tolerated during childhood in the majority of patients It can occasionally precipitate cardiac failure refractory to medical treatment during childhood, but this complication is more frequently encountered during adult life The second complication is infective endocarditis The incidence is approximately 1 to 2 per 1000 patient-years The complication is more likely to arise in an adult than during childhood This represents a risk of approximately 1 in 10 of developing infective endocarditis before the age of 70 years.59,73–75 The size of the defect has no influence on its incidence.74 Most patients who develop infective endocarditis today are successfully treated Closure of the defect does not eliminate the chance of contracting this infection Indeed, the cumulative incidence of infective endocarditis after repair of isolated ventricular septal defects remains near 3%.76 Avoidance of infective endocarditis cannot, therefore, be proposed as an indication for the closure of ventricular septal defects Recent data, summarized by the American Heart Association,77 recommend that, as in previous guidelines, those with isolated acyanotic ventricular septal defects do not require antibiotic coverage, citing evidence that prior antibiotic coverage in this situation was not universally effective Prophylaxis was deemed reasonable only for patients with the highest risk of developing an adverse outcome, including administration for 6 months following patch closure or device placement and in those with a residual lesion along the patch margin Management When presentation occurs in early infancy, the outcome is always in doubt For example, an asymptomatic infant presenting with a murmur at 1 month of age may be in intractable heart failure by the age of 3 months Similarly, spontaneous closure of ventricular septal defect may occur even when the defect has been large enough to cause cardiac failure in infancy The prognosis must always, therefore, be guarded during the first few months of life Asymptomatic infants should be closely followed clinically to assess for symptoms of congestive heart failure and resulting failure to thrive, as well as by using echocardiography to assess the anatomy and the gradient from the left to the right ventricle Those who remain asymptomatic, with no signs or investigations suggesting pulmonary overcirculation or pulmonary hypertension, require no treatment, including no measures against infective endocarditis These infants have small restrictive defects Infants with congestive cardiac failure should be treated medically If the cardiac failure is intractable to medical treatment, then surgical intervention is indicated These infants usually have unrestrictive defects Intractability of the cardiac failure can be deemed to be present when, despite maximal medical treatment with diuretics and afterload reduction, the infant fails to thrive despite high-calorie feeding regimes Subsequent to closure, improvement in growth is almost universal.78 Infants responding to medical treatment may have unrestrictive defects in the context of high pulmonary vascular resistance or a very compliant left ventricle and lungs Nevertheless, they usually have large and restrictive ones In either event, the pulmonary arterial pressure will be elevated in early infancy but may fall to normal by 6 months of age should the defect become smaller Closure is indicated in these patients if Doppler echocardiography fails to show a fall in right ventricular pressure to less than 60% of the left ventricular pressure by 5 to 6 months of age and the baby is failing to grow adequately This is because such babies are at risk for the development of irreversible pulmonary vascular disease If the Doppler velocity indicates a lower right ventricular pressure, conservative management should be continued A basic assumption behind this policy is that pulmonary vascular disease can be prevented or reversed in its early stages, although this may not always be the case These recommendations give the best chance of achieving this aim at present.79 It should be recognized that, in some