Comparison between Normal Function Sinus Rhythm and Minute-Ventilation Blended Sensor during Exercise: Case Report

Background: Rate-response functions of pacing devices for the chronotropic Incompetence patient have been proposed in various ways. Conventional acceleration sensor has limitation to react physiologically. A further improvement of the rate-response function is expected. Method: The case is 80 years old female who had implanted the pacemaker (ALTRUA60; Boston Scientific) for the diagnosis of atrioventricular block. Atrial pacing dependant has documented in clinical (60 pace per minute). We examined the utility of Minute-Ventilation blended sensor by the Cardio Pulmonary Exercise test (CPX) with CO/CI monitoring and 6 minutes walking, with and without the rate-response function. Result: Unexpectedly, sinus node function was normal in this case. Therefore, we could exam the reaction of Minute-Ventilation blended sensor comparing with the physiological normal sinus response. In the hard situation to react with the acceleration sensor only, such as CPX, Minute-Ventilation sensor showed the response closer to the sinus response than the acceleration sensor. Minute-Ventilation blended sensor showed the Pacing curve closer to the physiologic sinus reaction in 6 minutes walking. Conclusion: Pacing curve of MV blend sensor was close to the physiologic sinus response in ether exam compared with acceleration sensor only.