WHICH HEARTS ARE UNSUITABLE FOR BIVENTRICULAR CORRECTION

Background. The surgical option of biventricular repair requires two v entricles, each fully capable of supporting the systemic or pulmonary circulation. The morphologic substrates that may preclude some hearts from biventricular repair need to be assessed. Methods. Heart specimen s were reviewed to assess the morphologic mechanisms that produce an u nbalanced ventricular mass and to identify features that would, potent ially, be a contraindication for biventricular repair. Results. Hearts with solitary and indeterminate ventricles, and hearts with essential ly solitary ventricles, often have associated abnormalities of venoatr ial connections and arrangement of the atrioventricular valves. In the majority of hearts with univentricular atrioventricular connections, the rudimentary and incomplete ventricle of either right or left morph ology may be too small to support either the systemic or the pulmonary circulation. Straddling with overriding of the atrioventricular valve , unbalanced atrioventricular septal defect, and gross hypoplasia of o ne of the ventricles in hearts with biventricular connections are othe r mechanisms producing ventricular imbalance, which could preclude biv entricular repair. Conclusions. The morphologic mechanisms that result in ventricular imbalance are mainly related to the sizes and morpholo gy of the ventricles, septal malalignment, valvar morphology, and comp onent make-up of the ventricles. These features will influence decisio n-making in considering the option of biventricular repair. (C) 1998 b y The Society of Thoracic Surgeons.