Abstract: A rate adaptive pacemaker of the type having a variable rate cardiac stimulating pulse generator and a sensor for monitoring some physiologic parameter whereby the pulse generator stimulating rate can be adjusted to meet physiologic demand is further provided with a hemodynamic sensor which is operative to provide an output signal representing the pumping performance of the heart in response to the pacing stimulation. The signal from the hemodynamic sensor is processed and then used in an algorithm to determine whether further rate increase should be permitted based upon whether the rate increase would be accompanied by a further increase in cardiac output, a plateau or a decrease in cardiac output. Hence, the adaptive rate pacemaker is provided with a real-time, hemodynamic maximum pacing rate instead of a preprogrammed, fixed, maximum rate.

Abstract: A method of graphically displaying cardiopulmonary function data by providing a plurality of axes radially projecting from a common point of origin, there being one such axis for each cardiopulmonary parameter to be plotted, each axis having scale markings thereon whereby the normal value for each parameter will lie an equal distance from said point of origin, and straight line segments connected between said normal values on adjacent axes will form a generally regular polygon. The cardiopulmonary function data to be displayed are then plotted on the same appropriate axis and to the same scale such that deviations of any such data from normal will result in an irregular polygon when the segments are joined between plotted values on adjacent axis. Deviations of the irregular polygon from the regular polygon thus provides a clinician with a readily visible display of possible cardiopulmonary disfunction.