Abstract
Four cases of congenital heart disease of the cyanotic type (morbus caeruleus) are presented in an attempt to help differentiate them from the more common tetralogy of Fallot. These 4 cases were (1) tricuspid atresia, (2) Eisenmenger''s complex, (3) single ventricle, and (4) transposition of the great vessels. The first 3 cases had in common a systolic murmur audible in variable degrees of intensity; the last case showed no murmur. Tricuspid atresia alone presented left axis deviation in the electrocardiogram.