Our Experience with Dual Sensor Rate-adaptive Permanent Pacemakers

In this study we present the rate-adaptive behavior of a new developed dual sensor rate responsive pacemaker (PM) combining QT interval and activity. We tested this dual sensor (DS) PM in 5 patients (56±8 yrs) with implanted Topaz model 515. We compared the DS rate response to that of the individual sensors during three treadmill exercise stress tests. The DS rate response showed a fast onset of the rate response. After the first minute of exercise, the rate increase was proportional to the level of exercise. During rest the rate decreased gradually. We conclude that at onset of exercise DS showed rate response due to activity sensor. Then the rate increase and rate decay was achieved by QT interval iriformation.