Nowadays magnetic resonance images (MRI) are being used to calculate important clinical parameters such as ejection fraction (EF), left ventricle myocardium mass (MM), and stroke volume (SV) which are crucial to estimate the cardiac function, surgical planning and create patient-specific heart models, therefore for quantifying accurately these parameters it is also necessary a good delimitation of cardiac structures. The proposed approach presents an automatic segmentation of the left ventricle (LV) and basically is composed by three steps: first, heart structure localization with template matching technique in coronal and sagittal view that is used to restrict axial analysis. Second, ellipsoidal approximation using the axial projection of previous coarse segmentation. Third, a conventional snake algorithm is performed to refine external myocardium boundaries in axial view. The strategy was evaluated using 100 cardiac MRI volumes provided by the ACDC 2017 MICCAI challenge which is composed of 4 different heart diseases, the strategy had an average Dice Score of 0.79.