Two-dimensional echocardiographic anatomy in crisscross heart.

The anatomy of crisscross heart was studied in 14 patients, aged 2 days to 26 years, using 2-dimensional (2-D) echocardiography. The visceroatrial situs was solitus in all 14 patients. Crossing of the atrioventricular (AV) valves could be seen in each case by scanning in a subxiphoid or apical 4-chamber view. The subpulmonary infundibulum was deficient in 13 of the 14 patients, resulting in approximation of the pulmonary and tricuspid valves. Subpulmonary stenosis, seen in 11 patients, resulted from proximity of the infundibular septum, the tricuspid valve and the subpulmonary infundibular free wall. A subaortic infundibulum, present in all cases, was well developed in 13 patients, who had malposition of the great arteries, and was short in 1 patient, with nearly normally related great arteries. In cases that conformed to the inverse loop rule (segmental combination (S,D,L) or (S,L,D)), the pulmonary valve was posterior to the tricuspid valve and wedged between the AV valves. In 3 patients (double outlet right ventricle (S,D,L)) the mitral valve straddled into a large, left-sided subaortic infundibulum. In both patients with arterial malposition who did not follow the inverse loop rule, the pulmonary trunk was anterior to the tricuspid valve and well separated from the mitral valve. In patients with crisscross heart the ventricles appeared to have been rotated about their long axes without concomitant motion of the AV valve anuli, producing actual crossing of the ventricular inflow tracts. The right ventricular sinus was significantly smaller and the infundibulum significantly larger in the patients with crisscross heart than in age-matched control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)