Cloose Loop Stimulation (CLS) algorithm is a form of rate adaptive pacing, able to provide an effective pacing rate profile not only during physical
exercise but although during mental stress. To test this hypothesis CLS or accelerometers sensor (AS) rate response was compared intraindividually
during a mental stress test. Methods: 36 patients (mean age 76 ± 9)implanted with a VVI-CLS Cylos Biotronik underwentmental stress test in different
pacing configuration: non-rate adaptive mode (VVI), accelerometer sensor (AS) mode (VVIR), and CLS respectively. A modified Stroop test was used in order to induce mental stress. Heart rate
(HR), systolic and diastolic blood pressure and pacing percentage burden were collected for 5 minutes before, during and 5minutes after the test.
Results: Our study show that the average peak HR during mental stress test was significantly higher
in CLS configuration than in AS and non adaptive mode. Further the average HR increase (calculated as the difference in minimum HR and the HR
peak) during mental stress test was wider in CLS configuration than in VVIR and VVI. Finally, the percentage of pacing beats during mental stress
test was higher in CLS configuration than with the other algorithms.
Conclusion: CLS showed to be more effective than AS mode in providing a rate-adaptive pacing during mental stress. Results support the issue
that CLS algorithm can detect an hemodynamic demand due to an emotional upheaval and supply a proper heart rate increase
