Echocardiographic determinants of successful balloon dilation in pulmonary atresia with intact ventricular septum

Aims Pulmonary atresia with intact ventricular septum (PA–IVS) is a complex congenital heart malformation with multitude therapeutic approaches. Recently, balloon valvotomy has been used as an alternative to primary surgery. This study aimed to identify echocardiographic markers of balloon dilation success in PA–IVS. Methods and results The echocardiograms of 26 patients diagnosed with PA–IVS who underwent primary pulmonary balloon valvotomy were reviewed. Tricuspid annulus Z -score, pulmonary annulus Z -score, right ventricular (RV) to left ventricular (LV) length ratio, RV to LV transverse diameter ratio, and tricuspid valve (TV) to mitral valve (MV) annulus diameter ratio were measured. The tricuspid Z -score, pulmonary Z -score, RV/LV length ratio, RV/LV diameter ratio, and the TV/MV ratio were significantly different in the group which had successful balloon dilation compared with that failed. Based on decision trees using the Weka classifier package, only RV/LV diameter ratio >0.76 predicts a 92.3% success rate. In contrast, an RV/LV diameter ratio ≤0.76 associated with RV/LV length ratio ≤0.70 predicts 100% failure. Conclusion Successful balloon dilation in membranous type PA–IVS can be predicted by a scoring system using RV/LV diameter ratio and RV/LV length ratio.