Of concern in the paper is a theoretical study of the effect of ventricular structure and mechanics on left ventricular aneurysm. A mathematical model has been developed by considering the left ventricle as an ellipsoidal shell. The structural non-homogeneity of the ventricle has been taken into account by considering the three distinct layers that exist in the left ventricle. The study pertains to an early stage of formation of the aneurysm (bulging), when the damage area is not too large. In view of this,it is assumed that the ellipsoidal geometry of the left ventricle is preserved, even after the formation of the aneurysm and also that the volumes of the three individual muscle layers after infarction remain equal to the respective volumes before infarction. The theoretical study has been performed by employing suitable analytical methods. The derived analytical expressions have been computed, by taking appropriate values of different parameters involved in the study. The results have been validated in a proper way.