Atrioventricular discordance in situs inversus

We retrospectively analysed the records of 23 patients with atrioventricular discordance in situs inversus and compared them with 121 cases of atrioventricular discordance in situs solitus seen during preceding four years. One hundred and two (70.8%) patients were male. The mean age was 9.3 +/- 10.1 years (range 1 day-48 years). Overall, a ventricular septal defect with pulmonic stenosis (Fallot's physiology) was seen in 76 (56.7%) cases, ventricular septal defect without pulmonic stenosis in 26 (18.1%) cases, atrioventricular valve regurgitation in 25 (17.3%) cases and complete heart block in 13 (9%) cases. Double outlet right ventricle and Fallot's physiology were significantly more common (74.0% vs 32.3% and 91.3% vs 45.0%, respectively; p < 0.005), whereas atrioventricular valve regurgitation and complete heart block were less common (4.3% vs 19.8% and 0% vs 10.7%, respectively; p < 0.05) in patients with situs inversus and atrioventricular discordance as compared to patients with situs solitus. These differences may influence the natural history and treatment options selected for patients with atrioventricular discordance.