[Effects of anxiety on cardiorespiratory function]

The present study was undertaken to investigate the effect of anxiety on pulmonary function parameters and respiratory sinus arrhythmia (RSA) in healthy people under real-life conditions. This study consisted of two interrelated parts. During the first stage, eighty healthy students were examined in the following sequence: recording of heart rate variability (HRV) and respiration parameters at rest and shortly before real life stress. In a longitudinal study (the second stage), we assessed the profile of cardiorespiratory activity over 50 days in ten healthy women. Pulmonary function parameters like breath rate, tidal volume, forced expiratory volume in ones (FEV1), peak expiratory flow (PEF), forced expired flow at 25%, 50%, 75% of FVC, forced expired flow from 25-75% of FVC (FEF25-75%) and HRV measures (SDNN, RMSSD, pNN50, LF, HF, HFnorm, LF/HF ratio) of all subjects were tested. State anxiety was measured by Spielberger state anxiety inventory. Higher levels of state anxiety were associated with higher levels of breath rate, tidal volume and reduced HRV parameters, especially indicators of the RSA (HF and HFnorm) at baseline. These changes depend on the category of state anxiety: the group of students with a qualitative increase in state anxiety before examination has increased level of FEV1, PEF, forced expired flow at 25%, 50%, 75% of FVC, FEF25-75%. Less reactive students have no difference in respiratory parameters. We found a strong negative correlation between the level of HF at rest and state anxiety scores before examination. Longitudinal study found a negative correlation between RSA parameters and PEF, positive correlation between state anxiety and PEF of the majority those surveyed, except for two women with low levels of state anxiety and RSA indicators were in a narrow range. The variations of cardiorespiratory parameters during a longitudinal study depend on the changes of state anxiety. The higher level of state anxiety was associated with significant changes in RSA and the respiratory parameters. These results lend strong support to the notion that parasympathetic function is a critical physiological component of emotional processes.