Cardiac load and function in hypertension. Ultrasonic and hemodynamic study.

On the basis of echocardiographic measurements, 46 patients with established, uncomplicated primary hypertension (diastolic pressure = 100 mm Hg) were classified as: those with a normal-sized heart (Group I, 13 patients); those with left ventricular concentric hypertrophy (Group II, 19 patients); and those with left ventricular hypertrophy and enlargement (Group III, 14 patients). Eighteen age-matched healthy subjects were investigated as the controls. The function of both the left and right ventricle, evaluated by the stroke index-filling pressure relation and by the mean rate of ejection, was maintained in Group I, augmented in Group II and reduced in Group III, in comparison with the controls. Left ventricular mean rate of circumferential fiber shortening (Vcf) was normal in Group I, significantly augmented in Group II and definitely reduced in Group III. It could not be established whether the divergent variation from normal of the Vcf in Groups II and III reflected opposite changes in ventricular contractility or in afterload (wall stress during ejection), or both. However, the parallel functional pattern of the right and left ventricle in these two groups suggests a functional interdependence of the two sides which cannot be interpreted in terms of afterload but is best explained by changes in the contractile state of the whole heart.