Abstract
Background and Aims: The changes of autonomic nervous activity during
bronchoscopic procedures are closely related to the development of cardiovascular
complications. We aimed to evaluate the changes of autonomic nervous activity
during bronchoscopic procedures using R-R interval variability from electrocardiograms
(ECGs) obtained during diagnostic bronchoscopy.
Methods: Twenty-four patients who underwent bronchoscopy were included.Continuous
ECG was recorded prior to, during and after the bronchoscopic procedure.
Time and frequency domain analyses of heart rate variability were performed.
Results: Heart rate increased significantly after pre-medication compared with that
before pre-medication and increased further during bronchoscopy. The coefficient
of variation (CVRR) values after pre-medication and during bronchoscopy were
significantly higher than those before pre-medication (P = 0.031 and P = 0.041,
respectively). The low frequency (LF) power decreased during bronchoscopy. LF
powers obtained after bronchoscopy were significantly lower than those obtained
before bronchoscopy (P < 0.041). The high-frequency (HF) power was found to be
decreased during bronchoscopy. In particular, HF powers obtained after
bronchoscopy were significantly lower than those obtained before bronchoscopy
(P < 0.019). Although the LF/HF ratios increased after pre-medication, they
decreased temporarily during the bronchoscope insertion.
Conclusions: This study shows for the first time that Holter ECG monitoring
during diagnostic bronchoscopy was associated with activation of cardiac sympathetic
and withdrawal of cardiac parasympathetic regulation, which may contribute
to the occurrence of cardiac events during bronchoscopic procedures. So,
Holter ECG monitoring during bronchoscopic procedures may confer reduction in
cardiovascular events.