Morphometric analysis of cardiac hypertrophy: left ventricular shape and number of muscle-fiber layers across left ventricular wall.

Left ventricular hypertrophy was quantitatively analysed in reference to the relation of ventricular shape and intramyocardial muscle-fiber arrangement. The shape of the ventricle was defined by VL/WL, left ventricular capacity ratio. The ratio was depressed in concentric hypertrophy due to pressure overload and elevated in eccentric hypertrophy due to volume overload. Moreover, VL/WL was reversely correlated with Nf, number of muscle-fiber layers across the left ventricular wall. The results supported the following view on the morphogenesis of left ventricular hypertrophy: The muscle fibers show the strained piling vertically across the ventricular wall to cause wall thickening and cavity narrowing in concentric hypertrophy. On the other hand, the muscle fibers are piled strongly in parallel to the ventricular surface in eccentric hypertrophy to result in attenuation of the wall thickness and dilatation of the ventricular cavity.