[Correlation between the mass and diameter of the left ventricle. Physiologic and physiopathologic consequences]

109 echocardiograms were recorded in 109 subjects, consisting of 51 hypertensive patients and 58 normal subjects, in order to study the correlation between hypertrophy and dilatation. The correlation between the left ventricular mass (LVM) and the end-diastolic left ventricular diameter (Dd) is highly significant (r = 0.72; p less than 0.001). This relation follows a sigmoid curve with two asymptotes for y (LVM) = 0 and y = M (M : estimated upper limit of the reaction of the left ventricle to hypertrophy, expressed in g) with the following formula: (Formula: see text). This relation reflects the adaptation of the LVM to a defined end-diastolic volume in physiological and pathological situations. This adaptation tends to maintain the stress exerted on the left ventricular wall at a constant value. On the basis of this relation, we can define three types of response of the LVM to the diameter: adequate hypertrophy follows the relation in normal limits (+/- 2 SD); inadequate hypertrophy, where the LVM is insufficient in relation to the Dd and inappropriate hypertrophy, where the LVM is exaggerated. Most of the subjects were distributed along the curve, below the point of inflection (corresponding to a Dd of 6.25 cm). Only a few hypertensive subjects were found above this point. The presence of inadequate hypertrophy seems to imply an intrinsic disease of the myocardium which limits normal regulation. Finally, if the stimulus responsible for hypertrophy is removed, the reaction should be reversible, at least to a certain degree.