In many parts of the world, mostly low- and middle-income countries, timely diagnosis and repair of congenital heart diseases (CHDs) is not feasible for a variety of reasons. In these regions, economic growth has enabled the development of cardiac units that manage patients with CHD presenting later than would be ideal, often after the window for early stabilisation – transposition of the great arteries, coarctation of the aorta – or for lower-risk surgery in infancy – left-to-right shunts or cyanotic conditions. As a result, patients may have suffered organ dysfunction, manifest signs of pulmonary vascular disease, or the sequelae of profound cyanosis and polycythaemia. Late presentation poses unique clinical and ethical challenges in decision making regarding operability or surgical candidacy, surgical strategy, and perioperative intensive care management.

Anomalous origin of a pulmonary artery from the ascending aorta is a congenital defect that can be complicated by pulmonary arterial hypertension, typically due to vascular disease if the anomaly is left uncorrected past 6 months of age. We describe a unique case of severe pulmonary arterial hypertension with this defect in a 1-month-old infant unexpectedly caused instead by bronchial compression from her dilated left pulmonary artery.

A right-sided modified Blalock-Taussig anastomosis was created using a 5 mm Gore-Tex tube in a 4½ month old infant with unilateral “absence” of the right pulmonary artery. Wide patency of the shunt was confirmed shortly after by angiography, but rarefaction of the peripheral right pulmonary arteries was seen at the age of 2½ years, when corrective surgery was performed. Postoperative hypoperfusion of the right lung, along with severe pulmonary vascular abnormalities seen in a lung biopsy, indicated failure of the two-stage correction in spite of appropriate surgery.

Lung biopsies were taken from 30 children aged three months to 15 years (median, 11 months) who had pulmonary hypertensive congenital heart disease and were living at an altitude of 1750 meters. They had either a ventricular septal defect and/or patency of the arterial duct, atrioventricular septal defect or complete transposition with a ventricular septal defect. Biopsies were studied using quantitative morphometric light microscopic techniques. All patients with a ventricular septal defect with or without patency of the arterial duct showed a significant increase in mean percentage arterial medial thickness of both pre- and intraacinar pulmonary arteries compared with those of normal children of similar age living at sea level (p<0.001 for both pre- and intraacinar vessels) and with children with a ventricular septal defect living at sea level (p<0.001 for both pre- and intraacinar vessels). Extension of muscle to more peripheral pulmonary arteries was also greater. Intimal proliferation and fibrosis was seen in 10 patients, in three of whom it was severe. Intimal proliferation occurred more frequently than in children with a ventricular septal defect living at sea level. The findings were similar in patients with atrioventricular septal defect and complete transposition with ventricular septal defect. These findings suggest that patients with congenital heart disease who live at a relatively high altitude develop pulmonary vascular disease more rapidly than do those living at sea level.

Recent studies of intravascular ultrasound of the pulmonary arteries suggest that the technique can detect intimal and medial thickening in patients with pulmonary hypertension, potentially providing a method of assessing severity of pulmonary vascular disease in life. A major drawback of the technique is that only the elastic pulmonary arteries are accessible to current ultrasound catheters. The aim of this study was to determine whether morphological changes in vessels accessible to intravascular imaging reflect severity of pulmonary vascular disease and are of a sufficient degree to be detectable by current ultrasound catheters. Morphometric studies of the elastic pulmonary arteries were performed in specimens of lungs from 24 patients who had died with pulmonary hypertension (aged 3 weeks–9 years) and compared with measurements from infants who had died from sudden infant death syndrome. Morphological changes evident in the elastic pulmonary arteries in pulmonary hypertension included luminal dilation and medial thickening but these changes were too variable to be predictive of the severity of peripheral pulmonary vascular disease. Intimal thickening and atherosclerosis were present only in those with advanced pulmonary hypertensive disease. The changes of medial thickening and luminal dilation, nonetheless, are too variable to be predictive of the severity of peripheral pulmonary vascular disease. Thus, imaging by intravascular ultrasound may help confirm advanced pulmonary vascular disease, but is unlikely to differentiate less severe pulmonary vascular disease when the patient may still potentially be operable.

Introduction: Pulmonary arterial hypertension, both primary and secondary, continues to pose a therapeutic problem. In this study, we evaluate the efficacy and safety of a low-dose of oral sildenafil in 10 patients with pulmonary arterial hypertension. Methods: We administered a single daily dose of 0.5 milligrams per kilogram of sildenafil for 3 months to 10 patients with pulmonary arterial hypertension. Their average age was 26.8 years. Diagnoses were primary pulmonary arterial hypertension in 3 patients, and secondary pulmonary arterial hypertension due to congenital cardiac disease in the remaining 7 patients. Outcome measures included the clinical state, the mean pulmonary arterial pressure, and the indexed pulmonary vascular resistance; the latter two assessed at the beginning and at the end of the treatment period by cardiac catheterization. We also analysed the cost of the treatment. Results: Oral treatment was well tolerated, and resulted in an improvement of the functional capacity in 9 of the 10 patients. Pulmonary arterial pressure decreased from 70 to 60 millimetres of mercury (p equal to 0.05), and indexed pulmonary vascular resistance decreased from 21.8 to 15.8 Wood units per square metre (p equal to 0.006). The mean cost per patient for 3 months on oral treatment with sildenafil was 120.99 American dollars. Conclusions: A low dose of 0.5 milligrams per kilogram per day of oral sildenafil, instead of 1 to 4 milligrams per kilogram per day, provided early clinical and haemodynamic improvements, and proved less expensive. Additional experience is now required to define more reliably the true long-term benefits of this therapy.

A 9-year-old boy, with significant left-to-right shunting across a large duct in the context of rubella syndrome, was tested during catheterization to establish the feasability of occluding the duct with a device. The testing, including temporary closure of the duct and monitoring of pulmonary vascular reactivity to vasodilative substances, lead to the decision to implant an Amplatzer occluder. Sixteen months later, there was no residual shunting across the duct, and pulmonary arterial pressures had normalised. It remains unclear why the patient had not developed irreversible pulmonary vascular disease.

Pulmonary vascular disease is a risk factor for the surgical management of common arterial trunk. Surgical repair, therefore, is usually performed in early infancy, before irreversible changes can occur in the epulmonary vasculature. Because of this, there has been an increasing tendency to dispense with cardiac catheterisation as a means of assessing pulmonary vascular disease. Cardiac catheterisation, nonetheless, is still performed when there is a risk of pulmonary vascular disease, such as in older children. There are no clear guidelines, however, as to who should be catheterised. We have developed a simple screening test to help make this decision.