TY - JOUR
T1 - Negative respiratory sinus arrhythmia (nRSA) in the MRI-scanner - a physiologic phenomenon observed during elevated anxiety in healthy persons
AU - Rassler, Beate
AU - Schwerdtfeger, Andreas
AU - Schwarz, Gerhard
AU - Pfurtscheller, Gert
N1 - Funding Information:
We like to thank David Fink for support in data acquisition and Clemens Brunner for support in data processing (all University of Graz). The authors confirm that they have not received funding.
Publisher Copyright:
© 2021 Elsevier Inc.
PY - 2022/3/1
Y1 - 2022/3/1
N2 - Recently, we reported on a rare manifestation of respiratory sinus arrhythmia (RSA), namely the “switched-off” RSA (Rassler et al., 2018), also called negative RSA (nRSA). It was found in a minority of healthy persons during elevated fMRI-related anxiety characterized by slow spontaneous breathing and synchronous slow beat-to-beat interval (RRI) oscillations. From 23 healthy scanner naïve participants of an fMRI study consisting of 4 resting states, we selected resting states with highest state anxiety (AS) from 10 participants (AS=24.6±2.5) and compared them to those with lowest AS of the same participants (AS=15.1±3.8, p<0.001). During elevated anxiety, the percentage of nRSA (nRSA%) was more than twice of RSA (p=0.045), while RSA prevailed during low anxiety. This indicates that nRSA might be related to elevated anxiety. Interestingly, nRSA was not only associated with slow RRI and breathing oscillations, but also occurred at “normal” breathing rates in the 0.20-0.35 Hz range. We often observed coupled RRI oscillations at 0.1 or 0.15 Hz and respiration at 0.3 Hz (rate ratio 1:3 or 1:2) with respiration-synchronous 0.3 Hz-wavelets in the RRI rhythm (termed “superposition”) indicating a reduced dominance of the respiratory rhythm over the RRI rhythm. This novel finding is supported by the work of Perlitz et al., (2004) on a “0.15 Hz rhythm” in brainstem. The concept behind such a 1:n ratio is a pacemaker-like rhythm in the brainstem that “drives” the cardiac RRI signal and secondarily also respiration as reflected in the 1:n rate ratio.
AB - Recently, we reported on a rare manifestation of respiratory sinus arrhythmia (RSA), namely the “switched-off” RSA (Rassler et al., 2018), also called negative RSA (nRSA). It was found in a minority of healthy persons during elevated fMRI-related anxiety characterized by slow spontaneous breathing and synchronous slow beat-to-beat interval (RRI) oscillations. From 23 healthy scanner naïve participants of an fMRI study consisting of 4 resting states, we selected resting states with highest state anxiety (AS) from 10 participants (AS=24.6±2.5) and compared them to those with lowest AS of the same participants (AS=15.1±3.8, p<0.001). During elevated anxiety, the percentage of nRSA (nRSA%) was more than twice of RSA (p=0.045), while RSA prevailed during low anxiety. This indicates that nRSA might be related to elevated anxiety. Interestingly, nRSA was not only associated with slow RRI and breathing oscillations, but also occurred at “normal” breathing rates in the 0.20-0.35 Hz range. We often observed coupled RRI oscillations at 0.1 or 0.15 Hz and respiration at 0.3 Hz (rate ratio 1:3 or 1:2) with respiration-synchronous 0.3 Hz-wavelets in the RRI rhythm (termed “superposition”) indicating a reduced dominance of the respiratory rhythm over the RRI rhythm. This novel finding is supported by the work of Perlitz et al., (2004) on a “0.15 Hz rhythm” in brainstem. The concept behind such a 1:n ratio is a pacemaker-like rhythm in the brainstem that “drives” the cardiac RRI signal and secondarily also respiration as reflected in the 1:n rate ratio.
KW - 0.15-Hz rhythm
KW - anxiety processing
KW - central pacemaker
KW - functional magnetic resonance imaging
KW - heart rate variability
KW - respiratory sinus arrhythmia
UR - http://www.scopus.com/inward/record.url?scp=85121470500&partnerID=8YFLogxK
U2 - 10.1016/j.physbeh.2021.113676
DO - 10.1016/j.physbeh.2021.113676
M3 - Article
C2 - 34919919
AN - SCOPUS:85121470500
VL - 245
JO - Physiology & Behavior
JF - Physiology & Behavior
SN - 0031-9384
M1 - 113676
ER -