scholarly journals Respiratory sinus arrhythmia and pulmonary gas exchange efficiency: time for a reappraisal

2010 ◽  
Vol 95 (7) ◽  
pp. 767-767 ◽  
Author(s):  
Martin Buchheit
2002 ◽  
Vol 282 (3) ◽  
pp. H973-H976 ◽  
Author(s):  
Nobuko Sasano ◽  
Alex E. Vesely ◽  
Junichiro Hayano ◽  
Hiroshi Sasano ◽  
Ron Somogyi ◽  
...  

Respiratory sinus arrhythmia (RSA) may improve the efficiency of pulmonary gas exchange by matching the pulmonary blood flow to lung volume during each respiratory cycle. If so, an increased demand for pulmonary gas exchange may enhance RSA magnitude. We therefore tested the hypothesis that CO2directly affects RSA in conscious humans even when changes in tidal volume (VT) and breathing frequency ( F B), which indirectly affect RSA, are prevented. In seven healthy subjects, we adjusted end-tidal Pco 2 (Pet CO2 ) to 30, 40, or 50 mmHg in random order at constant VT and F B. The mean amplitude of the high-frequency component of R-R interval variation was used as a quantitative assessment of RSA magnitude. RSA magnitude increased progressively with Pet CO2 ( P < 0.001). Mean R-R interval did not differ at Pet CO2 of 40 and 50 mmHg but was less at 30 mmHg ( P < 0.05). Because VT and F B were constant, these results support our hypothesis that increased CO2directly increases RSA magnitude, probably via a direct effect on medullary mechanisms generating RSA.


2009 ◽  
Vol 296 (1) ◽  
pp. H65-H70 ◽  
Author(s):  
Y. C. Tzeng ◽  
P. Y. W. Sin ◽  
D. C. Galletly

Respiratory sinus arrhythmia (RSA) may serve an inherent function in optimizing pulmonary gas exchange efficiency via clustering and scattering of heart beats during the inspiratory and expiratory phases of the respiratory cycle. This study sought to determine whether physiological levels of RSA, enhanced by slow paced breathing, caused more heart beats to cluster in inspiration. In 12 human subjects, we analyzed the histogram distribution of heart beats throughout the respiratory cycle during paced breathing at 12, 9, and 6 breaths/min (br/min). The inspiratory period-to-respiratory period ratio was fixed at ∼0.5. RSA and its relationship with respiration was characterized in the phase domain by average cubic-spline interpolation of electrocardiographic R wave-to-R wave interval fluctuations throughout all respiratory cycles. Although 6 br/min breathing was associated with a significant increase in RSA amplitude ( P < 0.01), we observed no significant increase in the proportion of heart beats in inspiration ( P = 0.34). Contrary to assumptions in the literature, we observed no significant clustering of heart beats even with high levels of RSA enhanced by slow breathing. The results of this study do not support the hypothesis that RSA optimizes pulmonary gas exchange efficiency via clustering of heart beats in inspiration.


2003 ◽  
Vol 284 (5) ◽  
pp. H1585-H1591 ◽  
Author(s):  
Nicholas D. Giardino ◽  
Robb W. Glenny ◽  
Soo Borson ◽  
Leighton Chan

Respiratory sinus arrhythmia (RSA) may be associated with improved efficiency of pulmonary gas exchange by matching ventilation to perfusion within each respiratory cycle. Respiration rate, tidal volume, minute ventilation (V˙e), exhaled carbon dioxide (V˙co 2), oxygen consumption (V˙o 2), and heart rate were measured in 10 healthy human volunteers during paced breathing to test the hypothesis that RSA contributes to pulmonary gas exchange efficiency. Cross-spectral analysis of heart rate and respiration was computed to calculate RSA and the coherence and phase between these variables. Pulmonary gas exchange efficiency was measured as the average ventilatory equivalent of CO2(V˙e/V˙co 2) and O2(V˙e/V˙o 2). Across subjects and paced breathing periods, RSA was significantly associated with CO2 (partial r = −0.53, P = 0.002) and O2 (partial r = −0.49, P = 0.005) exchange efficiency after controlling for the effects of age, respiration rate, tidal volume, and average heart rate. Phase between heart rate and respiration was significantly associated with CO2 exchange efficiency (partial r = 0.40, P = 0.03). These results are consistent with previous studies and further support the theory that RSA may improve the efficiency of pulmonary gas exchange.


2020 ◽  
Vol 224 (1) ◽  
pp. jeb234096
Author(s):  
Ashley M. Blawas ◽  
Douglas P. Nowacek ◽  
Austin S. Allen ◽  
Julie Rocho-Levine ◽  
Andreas Fahlman

ABSTRACTAmong the many factors that influence the cardiovascular adjustments of marine mammals is the act of respiration at the surface, which facilitates rapid gas exchange and tissue re-perfusion between dives. We measured heart rate (fH) in six adult male bottlenose dolphins (Tursiops truncatus) spontaneously breathing at the surface to quantify the relationship between respiration and fH, and compared this with fH during submerged breath-holds. We found that dolphins exhibit a pronounced respiratory sinus arrhythmia (RSA) during surface breathing, resulting in a rapid increase in fH after a breath followed by a gradual decrease over the following 15–20 s to a steady fH that is maintained until the following breath. RSA resulted in a maximum instantaneous fH (ifH) of 87.4±13.6 beats min−1 and a minimum ifH of 56.8±14.8 beats min−1, and the degree of RSA was positively correlated with the inter-breath interval (IBI). The minimum ifH during 2 min submerged breath-holds where dolphins exhibited submersion bradycardia (36.4±9.0 beats min−1) was lower than the minimum ifH observed during an average IBI; however, during IBIs longer than 30 s, the minimum ifH (38.7±10.6 beats min−1) was not significantly different from that during 2 min breath-holds. These results demonstrate that the fH patterns observed during submerged breath-holds are similar to those resulting from RSA during an extended IBI. Here, we highlight the importance of RSA in influencing fH variability and emphasize the need to understand its relationship to submersion bradycardia.


2019 ◽  
Vol 33 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Elizabeth M. Stoakley ◽  
Karen J. Mathewson ◽  
Louis A. Schmidt ◽  
Kimberly A. Cote

Abstract. Resting respiratory sinus arrhythmia (RSA) is related to individual differences in waking affective style and self-regulation. However, little is known about the stability of RSA between sleep/wake stages or the relations between RSA during sleep and waking affective style. We examined resting RSA in 25 healthy undergraduates during the waking state and one night of sleep. Stability of cardiac variables across sleep/wake states was highly reliable within participants. As predicted, greater approach behavior and lower impulsivity were associated with higher RSA; these relations were evident in early night Non-REM (NREM) sleep, particularly in slow wave sleep (SWS). The current research extends previous findings by establishing stability of RSA within individuals between wake and sleep states, and by identifying SWS as an optimal period of measurement for relations between waking affective style and RSA.


2011 ◽  
Vol 25 (4) ◽  
pp. 164-173 ◽  
Author(s):  
Brian Healy ◽  
Aaron Treadwell ◽  
Mandy Reagan

The current study was an attempt to determine the degree to which the suppression of respiratory sinus arrhythmia (RSA) and attentional control were influential in the ability to engage various executive processes under high and low levels of negative affect. Ninety-four college students completed the Stroop Test while heart rate was being recorded. Estimates of the suppression of RSA were calculated from each participant in response to this test. The participants then completed self-ratings of attentional control, negative affect, and executive functioning. Regression analysis indicated that individual differences in estimates of the suppression of RSA, and ratings of attentional control were associated with the ability to employ executive processes but only when self-ratings of negative affect were low. An increase in negative affect compromised the ability to employ these strategies in the majority of participants. The data also suggest that high attentional control in conjunction with attenuated estimates of RSA suppression may increase the ability to use executive processes as negative affect increases.


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