[Pulmonary atresia with intact ventricular septum. Natural development of the right ventricle].

A case of pulmonary atresia with intact ventricular septum and a hypoplastic right ventricle, with three wall formed portions, that became naturally well developed until 2 years of age, is related. A Blalock-Taussig shunt had been performed early in life. Z value of tricuspid valve of 0.3 and left ventricular in ECG has been changed to a well developed tricuspid annulus of 22 mm diameter and to a right ventricle overload after 2 years of follow-up, being possible surgical correction at that time. This observation, until today unknown, the natural increase of a congenitally hypoplastic cardiac chamber, favors the possibility to postpone the corrective operation to a better stage in this anomaly, when the risk becomes lower.