Quantitative angiocardiographic recognition of atypical form of tetralogy of Fallot with absent pulmonic valve.

A 9-year-old boy is reported who had tetralogy of Fallot, rudimentary pulmonic valve, and supravalvar pulmonic stenosis. The patient lacked almost all of the clinical findings commonly encountered in this syndrome. Thus he never had signs of a large left-to-right shunt, or congestive heart failure. He had no murmur of pulmonic regurgitation and his pulmonary artery was not large on chest roentgenogram. Angiocardiography revealed moderate main pulmonary arterial dilation. The lack of the usual manifestations of tetralogy of Fallot with absent pulmonic valve was due to supravalvar pulmonic stenosis, acting as a natural pulmonary artery band. A quantitative angiocardiographic study was undertaken in order to find a clue for the diagnosis of these atypical cases. The ratio of the transverse diameters of the main pulmonary artery and the aortic root as measured on lateral angiocardiograms in 31 children with uncomplicated tetralogy of Fallot was 0.70 +/- 0.22, whereas this ratio was 1.70 in this particular patient (p less than 0.001). It is concluded that a quantitative evaluation of the ratio of the transverse diameter of the main pulmonary artery to the aortic root on lateral angiocardiogram allows differentiation of tetralogy of Fallot with absent pulmonic valve associated with supravalvular pulmonic stenosis from uncomplicated forms of tetralogy of Fallot.