Heart rate and body temperature sensitive diaphragm pacing.

Two ways of rate control for diaphragm pacing are proposed. One is rate control using only the patients' body temperature (method I). The other is rate control by both the patients' heart rate and body temperature (method II). To test the effectiveness of these methods, a diaphragm pacemaker which can be controlled by both heart rate and body temperature has been developed. It was applied to nine mongrel dogs. The pacing rate is controlled by atrial blood temperature (method I) or by both heart rate and temperature (method II). The animal's metabolism was elevated by the administration of a pyrogenic drug. It was found that method I is not suited to rapid changes in metabolism; however, it is useful in extreme metabolic elevation. An animal's metabolism was supported by using method II in all ranges of metabolism. This method proved more effective than method I for rate-responsive diaphragm pacing.