Percutaneous balloon dilatation of the atrial septum: immediate and midterm results.

OBJECTIVES To assess the effectiveness of atrial septostomy by percutaneous balloon dilatation in patients with congenital heart defects or primary pulmonary hypertension. PATIENTS AND DESIGN Twenty three patients (15 boys, eight girls; aged 10 days to 10 years; 17 with congenital heart defects and six with primary pulmonary hypertension), all haemodynamically unstable under optimal medical treatment, underwent atrial septostomy by percutaneous balloon dilatation. INTERVENTIONS The balloon catheter entered the left atrium through a patent foramen ovale (n = 14) or via transseptal puncture in cases with an intact atrial septum (n = 9). The size of the balloons used ranged from 13 to 18 mm. RESULTS There were no complications. The interatrial communication (mm) increased (P < 0.05) after dilatation and remained unchanged (P = NS) during a 16.6 (13.8) month follow up (2 (1.7) v 8.8 (1.4) v 8.2 (1.1), respectively). Transatrial gradient (mm Hg) fell and arterial oxygenation (%) improved both in patients with transposition (6.3 (0.8) v 0.8 (1) (P = 0.0001) and 40.6 (4.2) v 76.5 (4.8) (P = 0.0001), respectively) and in those with mitral atresia (13.4 (1.9) v 2 (1.4) (P = 0.0001) and 77.1 (3.9) v 81.5 (4.2) (P = 0.008), respectively). There were two failures, one early and one late, both in the group of patients with mitral atresia or stenosis. A decrease in arterial oxygenation (94.8 (1.5) v 83 (2.4), P = 0.004) and an increase in left atrial pressure (6.8 (0.9) v 8.3 (1.2), P = 0.02) and cardiac index (2.3 (0.2) v 3.1 (0.2) l/min/m2, P = 0.002) was observed in patients with primary pulmonary hypertension. CONCLUSIONS Percutaneous balloon dilatation is an effective and safe procedure for creating an adequate interatrial communication that can be used as an alternative to blade septostomy.