Isolated ventricular inversion with double inlet left ventricle.

2 patients with viscero-atrial situs solitus, isolated ventricular inversion (IVI) and double inlet right-sided morphologic left ventricle are presented. Isolated ventricular inversion is a rare cardiac anomaly characterized by ventricular inversion, subpulmonary conus, and ventriculo-arterial concordance. Their angiocardiographic and pathologic features are presented, and the morphologic findings of the 9 patients in the literature with isolated ventricular inversion are reviewed. Of the 11 known patients with isolated ventricular inversion, levocardia was present in 10 and dextrocardia in 1; viscero-atrial situs solitus in 9 and inversus in 2; L-ventricular loop in 9 and D-loop in 2. The atrial septum was intact in 4. An intact ventricular septum was noted in only 2 patients while in 3, more than one ventricular septal defects were present, and 2 patients exhibited morphologic single ventricle. A solitary ventricular septal defect was noted in the remainder. Significant tricuspid valve abnormalities, including atresia, stenosis or hypoplasia with supravalvular fibrous ring were found in 7 patients. In 2 of these, both with significant obstruction at the tricuspid valve, both atrioventricular valves emptied into the morphologic left ventricle--thus isolated ventricular inversion with double inlet left ventricle. Pulmonary outflow tract obstruction was evident in only 3 patients. Total anomalous pulmonary venous return occurred twice and right juxtaposition of the atrial appendages once. Thus, while the patient with isolated ventricular iversion may present with clinical and hemodynamic features characteristic of classical transposition physiology the high frequency of significant associated anomalies would complicate this. Finally, the anomaly must be differentiated from the levo-transposition, isolated atrial inversion, and the anatomically corrected malpositions.