In a group of 34 men aged 30-59 years with essential hypertension of a mild or moderate degree the authors evaluated the behavior of the left ventricular ejection fraction and the rate of shortening of the circumferential fibre, using radionuclide ventriculography during exercise. The results were compared with a control group of 19 subjects lacking signs of cardiovascular disease. Asymptomatic hypertonic patients without signs complicating IHD have on average a small statistically insignificant reduction of values of the ejection fraction at rest and of the shortening of the circumferential fibre. However, they respond to a load by a significantly lower rise of the resting values than the control group. In 12% of the patients the authors found an abnormal reaction of the ejection fraction, i.e. a decline as compared with original values. The above differences can be ascribed to a reduction of left ventricular systolic function during chronic overload as a result of arterial hypertension. This functional reduction is not related to the values of the systolic or diastolic pressure at rest nor to the duration of hypertension.

Keywords: Adult; Heart Ventricles /physiopathology/; Humans; Hypertension /diagnostic imaging/; Male; Middle Aged; Myocardial Contraction; Physical Exertion; Radionuclide Ventriculography; Stroke Volume; Systole