Effect of moderate hyperglycaemia on left-ventricular systolic time intervals during submaximal exercise of steady workload in healthy subjects.

The effect of submaximal exercise at steady workload on left-ventricular systolic time intervals (STI) was studied in healthy subjects. In group I (22 subjects) 20% glucose solution was injected intravenously in a dose of 2.5 ml/kg of body weight before the exercise. In group II (20 subjects) the same exercise was preceded by intravenous injection of normal saline 2.5 ml/kg of body weight. The left ventricular systolic time intervals were determined by the polycardiographic metod of Blumberger modified by Holldack and Weissler. It was found that glucose administration before the exercise improved myocardial contractility during the exercise. During hyperglycaemia the secondary impairment of myocardial contractility was less pronounced than in the control group. Postexercise changes in left ventricular systolic function regressed more rapidly in the group receiving glucose than in controls.