Spectrum of hearts with one underdeveloped and one dominant ventricle.

Hearts with one underdeveloped and one dominant ventricle form a spectrum of anomalies extending from the heart with two clearly adequate chambers to those with a true single ventricle. An angiographic concept of grouping such hearts is presented. 129 patients with unequal ventricles underwent catheterization and cineangiography between 1974 and 1983. The age at first catheterization ranged from one day to 24 years (mean 3.9 years). Male-female ratio was 2:1. Five groups of hearts (with their relative frequencies in the spectrum) were established: dominant left ventricle (53%); dominant right ventricle (20%), each with normally related chambers; dominant left ventricle (20%); dominant right ventricle (3%), each with ventricular inversion; true single ventricle (5%). The incidence of atrial anatomy, venous return, intracardiac connections and associated lesions within each group was assessed. From the standpoint of deranged physiology as well as surgical implications there are more similarities than differences among these hearts. The fact that one ventricle will not generate an adequate stroke volume after repair is overwhelmingly more important than most other considerations. For the diagnostic and surgical approach, we believe that the system offers many advantages.