Making a generic heart deformable model to be able to analyze normal and pathological hearts is important. Such a generic model gives more stability and accuracy for segmentation, analysis and classsification. Due to the conflicting demands of shape generality and shape compactness, such a generic heart model is difficult to define. In order to be useful, a generic heart model should be defined with a few number of parameters. In all the previous work on the modeling of the LV-RV shape the deformable model is built from the given datasets. Therefore such methods have limitations that the quality of shape estimation are dependent on the quality of the datasets. In this paper, we introduce a blended deformable model approach with parameter functions which is generic enough to deal with the different heart shapes. Using a method we are able to model the 3D shape of the heart which include the left ventricle(LV) and the right ventricle(RV). We also include the inflow and outflow tract of the RV basal area, so that the full LV-RV shape can be estimated.