MESSUNG DES HERZSCHLAGINTERVALLS EINES STIMULIERTEN HERZES, SICH ANPASSENDER HERZSCHRITTMACHER UND BETRIEBSART

A pacemaker (16) allows the rate at which the pacemaker delivers electrical stimulation pulses to the heart, or the escape interval during which a natural heart event must occur before an electrical stimulation pulse is delivered, to be adjusted as needed in order to satisfy the body's physiological needs by using the time interval between an atrial stimulation pulse and the responsive atrial or ventricle depolarization or between a ventricular stimulation pulse and the responsive ventricular depolarization as determined by an interval measurement circuit (71), as an indication of the physiological demands placed on the heart. Atrial depolarization is sensed at electrodes (24, 26) by detecting a P-wave, and ventricular depolarization at electrodes (46, 46a) by detecting an R-wave. P-wave and R-wave sense amplifiers (48, 54, 56), connected to an atrial pacing/sense lead (22) and a ventricular pacing/sense lead (30), are used to conduct the sensed signals to the pacemaker (16). The A-P, A-R, or V-R intervals thus measured are processed in a physiological detector (73) in order to ascertain if these intervals are increasing or decreasing. If, over several heart cycles or beats, an increase or decrease in these measurements is detected, the pacing interval set by the pacemaker's pulse generator logic (42) is adjusted in an appropriate direction in order to adjust the heart beat rate accordingly.