, where is the identity tensor. The concentric growth, on the other hand, induces parallel deposition of the sarcomeres. The growth of cardiomyocyte is in the transverse direction, and thus the concentric growth tensor is expressed as: , where is the vector perpendicular to tangent plane of the cardiac wall. There are different hypothesis on the growth laws governing the growth multipliers and . Motivated by the observation that eccentric growth is induced by volume-overload, strain-driven growth laws are applied to the . For the concentric growth, which is induced by pressure-overload, both stress-driven and strain-driven growth laws have been investigated and tested using computational finite element method. The biomechanical model based on continuum theories of growth can be used to predict the progression of the disease, and therefore can potentially help developing treatments to pathological hypertrophy. Diagnosis Quantification Hypertrophy of the ventricle can be measured with a number of techniques. Electrocardiogram (EKG), a non-invasive assessment of the electrical system of the heart, can be useful in determining the degree of hypertrophy, as well as subsequent dysfunction it may precipitate. Specifically, an increase in Q wave size, abnormalities in the P wave, as well as giant inverted T waves, are indicative of significant concentric hypertrophy. Specific changes in repolarization and depolarization events are indicative of different underlying causes of hypertrophy and can assist in the appropriate management of the condition. Changes are common in both eccentric and concentric hypertrophy, though are substantially different from one another. In either condition fewer than 10% of patients with significant hypertrophy display a normal EKG. Transthoracic echocardiography, a similarly non-invasive assessment of cardiac morphology, is also important in determining both the degree of hypertrophy, underlying pathologies (such as aortic coarction), and degree of cardiac dysfunction. Important considerations in echocardiography of the hypertrophied heart include lateral and septal wall thickness, degree of outflow tract obstruction, and systolic anterior wall motion (SAM) of the mitral valve, which can exacerbate outflow obstruction. It is not uncommon to undergo cardiopulmonary exercise testing (CPET), which measures the heart's response to exercise, to assess the functional impairment caused by hypertrophy, and to prognosticate outcomes. In other animals In most situations, described above, the increase in ventricular wall thickness is a slow process. However, in some instances hypertrophy may be "dramatic and rapid." In the Burmese python, consumption of a large meal is associated with an increase in metabolic work by