COMPLIANCE IN ESSENTIAL HYPERTENSION/London

and may contribute further to lack of development of the RV as the patient grows. The absence of a hemodynamic explanation for ventricular hypoplasia makes the presence of a developmental factor such as markedly unequal relationship of the A-V valve to the ventricles probable and it may be that such a heart cannot be repaired by conventional techniques. In conclusion, our volumetric studies show that the LV, and to a lesser extent the RV, are enlarged in most cases of uncomplicated CAVC but normal in most cases with right ventricular outflow obstruction or PVO. LV dysfunction is more frequent than RV in both groups. RV hypoplasia is rare in CAVC but does occur in both uncomplicated forms and forms with RV obstruction. Further ventricular volume studies are needed in CAVC to confirm these findings and document the occurrence of LV hypoplasia, which was not found in this study. Although data concerning surgery in CAVC with ventricular hypoplasia are scanty, there is reason to believe that the surgical approach to these patients may need to be modified.