Tricuspid atresia. Clinical course in 62 cases (1967--1974).

Sixty-two patients with tricuspid atresia admitted for cardiac catheterisation between 1967 and 1974 have been classified according to the anatomical and radiological findings into those with normally related great arteries (type I: 39 cases) and those with transposition of the great arteries (type II: 23 cases). These types were further subdivided into group A (reduced lung vascularity),groupB (normal or increased vascularity), and group C (increased vascularity initially, becoming reduced). Electrocardiograms showed a superior and leftward axis in 61b5 per cent of patients with type I and 22-7 per cent ofthose with type II tricuspid atresia. Correlations between P wave amplitude (> 0.25 mV) and the atrial pressures showed a better correlation with a wave gradient rather than with mean interatrial gradient. Analysis of the results of palliative operations showed a high mortality (44-4%) of the Waterston shunt procedure in neonates. A Blalock-Taussig shunt is therefore preferred though another shunt is invariably required later. Postoperative haemodynamic study never showed pulmonary hypertension after an arterial shunt procedure, and hence the survivors are suitable for the Fontan operation, as was done in 2 cases. It is suggested that, because multiple operative procedures are required with high mortality (30%),, it may be preferable to perform the Fontan procedure earlier. Pulmonary artery banding is recommended for patients with type II tricuspid atresia and increased pulmonary blood flow (type II B), as the initial step.