Double-horned or caplike right ventricle: Diagnosis and operative treatment

Background. Three patients reported here and 4 from the literature serve as background for the state-of-art diagnostic and operative considerations for an unusual congenital cardiac malformation—double-horned or caplike right ventricle. Methods. This is a retrospective analysis of cardiac catheterization, cineangiography, and two-dimensional echocardiography findings, as well as palliative and corrective operations in 3 previously unreported patients. Four patients from the literature are reviewed. Results. Characteristic morphologic features recognizable by invasive and noninvasive imaging distinguish double-horned right ventricle from complex malformations such as criss-cross hearts, superior-inferior ventricles, and univentricular hearts with a small outflow chamber. Conclusion. Double-horned or caplike right ventricle is a congenital malformation characterized by an unusual ventricular morphology, which may be the result of incomplete development of the right ventricle. The two-horned appearance may be secondary to an absence of the apical trabeculated compartment, with the left ventricle wedged between the two horns. It is invariably associated with double right ventricular outlet. Surgical experience so far suggests that most patients with typical double-horned right ventricle should be considered for anatomic surgical correction.