Palliative balloon pulmonary valvuloplasty in tetralogy of Fallot: Echocardiographic predictors of successful outcome

Although balloon pulmonary valvuloplasty (BPV) has been advocated as a mean s of palliating patients with tetralogy of Fallot (TOF), the results of thi s procedure were not uniformly good in this patient population. The purpose of this study was to review our institution's experience with BPV in patie nts with TOF, and to determine whether echocardiographic criteria exist tha t may be used to identify patients likely to derive prolonged benefit from this procedure. Between 1991 and 1999, nine patients with TOF, ages 0.4-26. 1 weeks (mean, 7.4 +/- 7.6 weeks) underwent BPV due to cyanosis and other a ssociated medical conditions (e.g., coronary artery anomalies, small size) that rendered immediate surgical intervention undesirable. Data from the ca theterization and pre-BPV echocardiograms were analyzed. All patients had a t least transient improvement in oxygen saturation. However, 4 patients (Gr oup 1) required intervention (1 open-heart repair, 3 palliative shunts) wit hin 5 weeks of BPV due to recurrent desaturation. In the remaining 5 patien ts (Group 2), open-heart repair was delayed 8-36 weeks (mean, 23 +/- 13 wee ks). Groups 1 and 2 did not differ regarding pulmonary valve annulus, main pulmonary artery or branch pulmonary artery diameter. However, the diastoli c diameter of the right ventricular outflow tract (RVOT) was significantly smaller in Group 1 (18.3 +/- 3,5 mm/m(2) versus 24.4 +/- 4.1 mm/m(2) in Gro up 2; p < 0.05). Pour out of five patients with a RVOT diameter < 23 mm/m(2 ) were in Group 1, and all patients with RVOT diameter greater than 25 mm/m (2) were in Group 2. We conclude that BPV can effectively palliate patients with TOF whose RVOT diastolic diameter is >25 mm/m(2). However, patients w ith a diastolic RVOT diameter < 23 mm/m(2) are unlikely to have sustained i mprovement following BPV.