Two cases of left-sided tricuspid atresia with situs solitus L-bulboventricular loop and L-transposition of the great arteries.

Two cases of extremely rare type of tricuspid atresia are presented. Both possessed left-sided tricuspid atresia, situs solitus of viscera and atria, 1-bulboventricular loop and 1-transposition of the great arteries. These anomalies are typical tricuspid atresia with 1-transpositions. The importance of bulboventricular loop in tricuspid atresia is emphasized because the atretic tricuspid valve is right-sided in the heart with solitus and d-loop, and is left-sided in the heart with solitus and 1-loop.