PubMed1975
7 children from 7-15 years of age, who had a large VSD with pulmonary arterial hypertension, were investigated on a bicycle ergometer during stepwise increasing load. In 5 cases a pulmonary artery banding had been performed earlier in spite of distinctly increased pulmonary vascular resistance. In two cases with Eisenmenger-syndrome no operative measures had been attempted. The measurements, which were carried out at rest and during two submaximal loads, comprised beside determination of oxygen uptake and heart frequency also the arteriovenous oxygen difference as well as mean arterial pressure in the pulmonary and the systemic circuit so that flow and resistance could be calculated for both circuits. During exercise a linear increase of flow in the pulmonary circuit was achieved in all cases, accompanied by a distinct rise of the mean pulmonary arterial pressure. The pulmonary vascular resistance stayed, however, generally constant. Systemic vascular resistance, on the contrary, decreased to about one third of the resting values so that the ratio of pulmonary arterial to systemic vascular resistance increased considerably. The result was a progressive increase of the right to left shunt during exercise, and in 3 cases with predominant left to right shunt at rest in spite of the band, a reversed shunt resulted, partially due to the effectiveness of the band, but substantially brought about by the undiminished high pulmonary vascular resistance. The results show that ergometric investigations in children with pulmonary arterial hypertension may contribute to clarify the indication for surgery, but they also confirm that generally a final operation is not possible in children whose banding-operation has been performed at the age of more than 2 years.