[Echocardiographic study of the left ventricular mass-dilatation ratio in hypertensive disease].

The object of this work is the exhaustive interpretation of 52 echocardiograms of hypertensive African subjects. The following parameters were measured on the echocardiogram: Dd (left ventricular end diastolic dimension), Ds (left ventricular end systolic dimension), DSd (interventricular end diastolic dimension), DEd (left ventricular posterior wall end diastolic thickness). Left ventricular performance was evaluated with the calculated Vcf, FR (fractional shortening) and EF (ejection fraction). A ratio "R" was estimated as he ratio of the left ventricular mass (MVG) measured with Bennett's formula: [(Dsd + DEd + Dd)3-Dd3] x 1,05] to the left ventricular end diastolic dimension. A carotid pulse and phonocardiogram were simultaneously recorded and systolic time intervals were measured and corrected for heart rate, using regression equations corresponding to African subjects. The analysis of the "R" ratio has led us to put forward a new concept of the progression of the hypertensive cardiomyopathy. It has been shown, in this study, that the hypertensive heart becomes hypertrophic, even under treatment and after return of blood pressure to normal. It appears that hypertrophy is a reaction tending to keep normal or almost normal the telediastolic left ventricular dimension and consequently to prevent left ventricular dilatation. This can be explained by the tendency of myocardial hypertrophy to reduce wall stress and oxygen consumption. The analysis of the correlation between MVG and Dd (good), TAM (mean arterial blood pressure) and Dd (poor) and TAM and MVG (nil) has les us to the conclusion that the stimulus to hypertrophy lies in the left ventricular dilatation.(ABSTRACT TRUNCATED AT 250 WORDS)