1. A method for automatically analyzing a long-axis image of a heart, said method comprising the steps of: (a) generating an image frame of the myocardium, interventricular septum, and mitral valve annulus of said heart, said image frame comprising a plurality of rows and a plurality of columns of pixels in a digital format; (b) determining an approximate position of said interventricular septum from said diagnostic image comprising: (i) passing a filter through the image to determine a maximum mean pixel intensity, wherein said maximum is a first approximate position of said interventricular septum; (ii) defining a second approximate position of said interventricular septum with a series of straight line filters; (iii) obtaining a best fit line through the second approximate position from the upper portion of said series of straight line filters; (c) determining an approximate position of a medial border of said mitral valve annulus by passing a right-angle filter down the best fit line determined from step (b)(iii) until a maximum mean pixel intensity is determined, wherein said maximum is indicative of the approximate position of said mitral valve annulus; (d) defining a registration point as the point at which said best fit line intersects the approximatepositionof said mitral valve annulus; (e) locating one or more regions of the myocardium in relation to said registration point; and (f) calculating the mean pixel intensity in each of the regions of the myocardium, wherein said mean pixel intensity provides an analysis of the long axis image of the heart.