[Metabolic parameters in the evaluation of frequency-adaptive sensors in pacemakers]

A comparison was made between metabolic parameters during exercise in patients with implanted dual sensor VVIR pacemakers. We analyzed two groups of patients with implanted dual sensor responsive pacemakers. The first group was composed of 14 patients (mean age 37.7 years) who had implanted Topaz pacemakers. The second group of 9 patients had a Legend Plus (mean age 44.7 years). A control group consisted of 54 healthy individuals (mean age 40.4 years). Testing was performed on treadmill, using a stepwise staircase loading CAEP protocol. Directly measured and mathematically calculated parameters used in assessment of metabolic impact of pacemaker function were: minute ventilation (MV), MV/body surface, MV/body mass unit, oxygen consumption, oxygen consumption/body surface, oxygen consumption/heart rate (oxygen pulse), oxygen consumption/body mass unit, carbon dioxide production, respiratory index. The majority of the observed parameters revealed no statistically significant difference between the control group and the patients with dual sensor or single sensor controlled rate response. However, oxygen pulse showed a statistically significant difference when comparing the group with single sensor controlled rate response with dual sensor controlled rate response and control group (p < 0.05). Other parameters indicating an advantage of dual sensor controlled rate were the time period of reaching anaerobic threshold (respiratory index) and exercise duration. They both displayed a statistically significant difference between dual sensor controlled rate response and single sensor rate response (p < 0.05) with no significant difference compared to control group (p > 0.05).