Impact of the Systemic-Pulmonary Shunt and Fontan Operation on Ventricular Geometry in Functionally Single Ventricle

In order to evaluate the effect of the systemic-pulmonary shunt and Fontan operation on ventricular geometry, the diameter, volume, shape and mass of the ventricle were determined echocardiographically in patients with functionally single ventricle. Three groups, 10 patients (group II) aged 4.77±3.48 years having no operation, 12 patients (group III) between 12.34±11.18 years of age with systemic-pulmonary artery shunt and 20 patients with performed Fontan operation aged 11.42±6.95 years constituted our study population. At a mean age of 6.56±2.87 years, 21 children having no cardiac disease were accepted as the control group. In the evaluation of the ventricular shape, the ratio of ventricular diameter to length was determined. Ventricular mass has been standardized according to patient's body surface area and ventricular volume. Ventricular diameter and volume were greater for patients with single ventricle than for the control group. The morphology of the main ventricular chamber and cardiac pathology had no influence on these parameters. Although no statistical diameter and volume were found in patients with systemic-pulmonary shunt, and these parameters were closest to the normal in the group IV patients. Ventricular mass was also greater for patients with single ventricle than for the control group. In the cases with right ventricular main chamber, the ventricular mass was the greatest and this was sttistically significant. In patients with single ventricle the ventricular shape was spheric while in normal children it was ellipsoid. Also the ventricular shape in patients with Fontan operation was more like an ellipsoid than other patient groups. The main ventricular morphology and cardiac pathology had no influence on this finding. In conclusion, in patients with functionally single ventricle, ventricular shape is spheric, and ventricular diameter, volume and mass are considerably greater than those of normals. With Fontan operation the ventricle becomes more ellipsoid and significant reduction in ventricular diameter, volume and mass are achieved. Since the ventricular diameter, volume, mass and shape were not unchanged in the patients with single ventricle, hemodynamic status and patient's age had affected these parameters, and these parameters also influenced the ventricular systolic and diastolic funcctions, echocardigraphic follow-up is useful, safe and necessary.