Hemodynamic Studies in Patients with Implanted Cardiac Pacemakers

Abstract
THE question of how well the compensated human heart with a fixed rate in the physiologic range is capable of adapting to the demands for increased cardiac output has very practical implications for the patient with an artificial pacemaker. The purpose of this study was to investigate several aspects of cardiac performance in patients with implanted cardiac pacemakers. The type of unit employed§ permitted the study of the effect of rate alone, as well as the effect of several interventions at a constant rate. The results of this investigation suggest that cardiac output in a basal patient with an implanted . . .