[Anesthesia-induced changes in the preload-dependent circulatory reactions in patients with coronary heart disease]

The influence of preload changes (table tilt) on the hemodynamic regulation before and after induction of neuroleptanalgesia was studied in 31 patients with coronary heart disease. The induced preload changes are balanced in the awake patient for the maintenance of normal arterial pressure by regulation of stroke volume and peripheral vascular resistance. This regulation does not exist after induction of anaesthesia. Splitting the patients into sub-groups with good or poor left ventricular function, different ventricular function curves were obtained before and after the induction of anaesthesia. The pharmacologic and ventilatory reasons for the changed regulation of circulation are discussed. For investigations into hemodynamic changes produced by intervention in anaesthesia and intensive therapy, it is recommended to define more exactly the cardiovascular status of patients and the study conditions.