Respiratory sinus arrhythmia is associated with efficiency of pulmonary gas exchange in healthy humans

2003 ◽  
Vol 284 (5) ◽  
pp. H1585-H1591 ◽  
Author(s):  
Nicholas D. Giardino ◽  
Robb W. Glenny ◽  
Soo Borson ◽  
Leighton Chan
Keyword(s):  
Heart Rate ◽  
Gas Exchange ◽  
Tidal Volume ◽  
Respiration Rate ◽  
Respiratory Sinus Arrhythmia ◽  
Minute Ventilation ◽  
Pulmonary Gas Exchange ◽  
Sinus Arrhythmia ◽  
Paced Breathing ◽  
Healthy Humans

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.

Human sinus arrhythmia: inconsistencies of a teleological hypothesis

2009 ◽  
Vol 296 (1) ◽  
pp. H65-H70 ◽  
Author(s):  
Y. C. Tzeng ◽  
P. Y. W. Sin ◽  
D. C. Galletly
Keyword(s):  
Gas Exchange ◽  
Respiratory Sinus Arrhythmia ◽  
Spline Interpolation ◽  
Human Subjects ◽  
Pulmonary Gas Exchange ◽  
Respiratory Cycle ◽  
Sinus Arrhythmia ◽  
Paced Breathing ◽  
Phase Domain ◽  
Slow Breathing

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.

Direct effect of PaCO2 on respiratory sinus arrhythmia in conscious humans

2002 ◽  
Vol 282 (3) ◽  
pp. H973-H976 ◽  
Author(s):  
Nobuko Sasano ◽  
Alex E. Vesely ◽  
Junichiro Hayano ◽  
Hiroshi Sasano ◽  
Ron Somogyi ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Direct Effect ◽  
Respiratory Sinus Arrhythmia ◽  
Random Order ◽  
Mean Amplitude ◽  
Frequency Component ◽  
Pulmonary Gas Exchange ◽  
High Frequency Component ◽  
Sinus Arrhythmia ◽  
End Tidal

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.

Augmentation of respiratory sinus arrhythmia in response to progressive hypercapnia in conscious dogs

2001 ◽  
Vol 280 (5) ◽  
pp. H2336-H2341 ◽  
Author(s):  
Fumihiko Yasuma ◽  
Jun-Ichiro Hayano
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Blood Pressure ◽  
Respiratory Sinus Arrhythmia ◽  
Physiological Response ◽  
Minute Ventilation ◽  
Control Level ◽  
Conscious Dogs ◽  
Sinus Arrhythmia ◽  
Arterial Blood

Respiratory sinus arrhythmia (RSA) may serve to enhance pulmonary gas exchange efficiency by matching pulmonary blood flow with lung volume within each respiratory cycle. We examined the hypothesis that RSA is augmented as an active physiological response to hypercapnia. We measured electrocardiograms and arterial blood pressure during progressive hypercapnia in conscious dogs that were prepared with a permanent tracheostomy and an implanted blood pressure telemetry unit. The intensity of RSA was assessed continuously as the amplitude of respiratory fluctuation of heart rate using complex demodulation. In a total of 39 runs of hypercapnia in 3 dogs, RSA increased by 38 and 43% of the control level when minute ventilation reached 10 and 15 l/min, respectively ( P < 0.0001 for both), and heart rate and mean arterial pressure showed no significant change. The increases in RSA were significant even after adjustment for the effects of increased tidal volume, respiratory rate, and respiratory fluctuation of arterial blood pressure ( P < 0.001). These observations indicate that increased RSA during hypercapnia is not the consequence of altered autonomic balance or respiratory patterns and support the hypothesis that RSA is augmented as an active physiological response to hypercapnia.

Respiratory sinus arrhythmia in humans: how breathing pattern modulates heart rate

1981 ◽  
Vol 241 (4) ◽  
pp. H620-H629 ◽  
Author(s):  
J. A. Hirsch ◽  
B. Bishop
Keyword(s):  
Heart Rate ◽  
Tidal Volume ◽  
Respiratory Sinus Arrhythmia ◽  
Spontaneous Breathing ◽  
Low Frequency ◽  
Corner Frequency ◽  
Breath Hold ◽  
Breathing Frequency ◽  
Quiet Breathing ◽  
Sinus Arrhythmia

The relationship of respiratory sinus arrhythmia amplitude (RSA) to tidal volume and breathing frequency was quantified during voluntarily controlled tidal volume and breathing frequency and spontaneous quiet breathing. Seventeen seated subjects breathed via mouthpiece and nose-clip, maintaining constant tidal volumes at each of several breathing frequencies. Inspiratory breath hold was zero frequency. Log RSA was plotted vs. log frequency for each tidal volume. The large stable RSA for frequencies less than 6 cycles/min was called low-frequency intercept (LFI, 20 +/- 5 beats/min). Low-frequency intercept was inversely proportional to a subject's age only to 35 yr. At higher breathing frequencies above a characteristic corner frequency (fC, 7.2 +/- 1.5 cycles/min) RSA decreased with constant slope (roll-off; 21 +/- 3.4 dB/decade). The RSA-volume relationship was linear permitting normalization of RSA-frequency curves for tidal volume to yield one curve. Spontaneous breathing data points fell on this curve. Voluntarily coupling of heart rate to breathing frequency in integer ratios reduced breath-by-breath variability of RSA without changing mean RSA. In conclusion, low-frequency intercept, corner frequency, and roll-off characterize an individual's RSA-frequency relationship during both voluntarily controlled and spontaneous breathing.

scholarly journals QUANTIFICATION OF RESPIRATORY SINUS ARRHYTHMIA WITH HIGH-FRAMERATE ELECTRICAL IMPEDANCE TOMOGRAPHY

2013 ◽  
Vol 53 (6) ◽  
pp. 854-861
Author(s):  
Christoph Hoog Antink ◽  
Steffen Leonhardt
Keyword(s):  
Heart Rate ◽  
Quantitative Analysis ◽  
Tidal Volume ◽  
Electrical Impedance Tomography ◽  
Respiratory Sinus Arrhythmia ◽  
Electrical Impedance ◽  
Cardiac Activity ◽  
Patient Specific ◽  
Impedance Tomography ◽  
Sinus Arrhythmia

Respiratory Sinus Arrhythmia, the variation in the heart rate synchronized with the breathing cycle, forms an interconnection between cardiac-related and respiratory-related signals. It can be used by itself for diagnostic purposes, or by exploiting the redundancies it creates, for example by extracting respiratory rate from an electrocardiogram (ECG). To perform quantitative analysis and patient specific modeling, however, simultaneous information about ventilation as well as cardiac activity needs to be recorded and analyzed. The recent advent of medically approved Electrical Impedance Tomography (EIT) devices capable of recording up to 50 frames per second facilitates the application of this technology. This paper presents the automated selection of a cardiac-related signal from EIT data and quantitative analysis of this signal. It is demonstrated that beat-to-beat intervals can be extracted with a median absolute error below 20 ms. A comparison between ECG and EIT data shows a variation in peak delay time that requires further analysis. Finally, the known coupling of heart rate variability and tidal volume can be shown and quantified using global impedance as a surrogate for tidal volume.

scholarly journals Physiological Responses during Competitive Sports Aerobics Exercise

2018 ◽  
Vol 3 (57) ◽  
Author(s):  
Roma Aleksandravičienė ◽  
Arvydas Stasiulis
Keyword(s):  
Heart Rate ◽  
Gas Exchange ◽  
Oxygen Uptake ◽  
Aerobic Capacity ◽  
Minute Ventilation ◽  
Pulmonary Ventilation ◽  
Pulmonary Gas Exchange ◽  
Treadmill Test ◽  
Lactate Accumulation ◽  
National Team

The aim of this study was to characterize heart rate (HR), oxygen uptake and pulmonary ventilation during competitiveaerobic gymnastics routine in a group of elite women athletes. The subjects were Lithuanian aerobic women gymnasts,members of national team (21.6, 4.4) years old). All subjects performed a maximal incremental treadmill test in thelaboratory and competitive aerobic gymnastics exercises in group category. Heart rate was continuously recordedusing the heart rate measurement equipment Polar ACCUREX-Plus. During the incremental treadmill test HRdeflection point and other parameters of aerobic capacity were determined from the relationship of HR to runningspeed. During the aerobic gymnastics routine pulmonary gas exchange parameters and heart rate were continuouslymeasured using the telemetric equipment Cortex 3B. The changes of HR, minute ventilation and oxygen uptake wereanalyzed by adopting monoexponential function.The results showed that HR values during the competitive aerobic gymnastics routine were higher than HR break pointwhich is near the lactate accumulation threshold (reaching 95.2 (4.2)% of maximal HR). Oxygen uptake duringcompetitive routine reached 81.3 (5.8)% of maximal oxygen uptake. Rather high blood lactate accumulation(7.50 mmol / l) at the third minute after exercise show the high intensity of exercise. These results allows us to considerthat aerobic gymnastics is a sport with high cardiorespiratory and metabolic demands, in which aerobic and anaerobicsources are intensely activated.Keywords: aerobic gymnastics, aerobic capacity, pulmonary gas exchange, lactate, heart rate deflection point.

scholarly journals Respiratory sinus arrhythmia and submersion bradycardia in bottlenose dolphins (Tursiops truncatus)

2020 ◽  
Vol 224 (1) ◽  
pp. jeb234096
Author(s):  
Ashley M. Blawas ◽  
Douglas P. Nowacek ◽  
Austin S. Allen ◽  
Julie Rocho-Levine ◽  
Andreas Fahlman
Keyword(s):  
Heart Rate ◽  
Gas Exchange ◽  
Respiratory Sinus Arrhythmia ◽  
Tursiops Truncatus ◽  
Marine Mammals ◽  
Bottlenose Dolphins ◽  
Sinus Arrhythmia ◽  
The Many ◽  
Spontaneously Breathing ◽  
The Relationship

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.

Cardiorespiratory demands of competitive rock climbing

2020 ◽  
Author(s):  
Nigel A Callender ◽  
Tara N Hayes ◽  
Nicholas B Tiller
Keyword(s):  
Heart Rate ◽  
Gas Exchange ◽  
Tidal Volume ◽  
Minute Ventilation ◽  
Pulmonary Ventilation ◽  
Rest Period ◽  
Rock Climbing ◽  
Treadmill Running ◽  
High Fraction ◽  
Physiological Demands

Rock climbing has become a mainstream sport, contested on the Olympic stage. The work/rest pattern of bouldering is unique among disciplines, and little is known about its physiological demands. This study characterized the cardiorespiratory responses to simulated competition. Eleven elite boulderers (7 male) volunteered to participate (age=23.3±4.5 y; mass=68.2±9.7 kg; stature=1.73±0.06 m; bodyfat %=10.4±5%). Subjects completed incremental treadmill running exercise to determine maximal capacities. On a separate day, they undertook a simulated Olympic-style competition comprising five boulder problems, each separated by 5-min rest. Pulmonary ventilation, gas exchange, and heart rate were assessed throughout. Total climbing time was 18.9±2.7 min. Bouldering elicited a peak V̇O2 of 35.8±7.3 mL∙kg−1∙min−1 (~75% of treadmill maximum) and a peak heart rate of 162±14 b∙min−1 (~88% of maximum). Subjects spent 22.9±8.6% of climbing time above the gas exchange threshold. At exercise cessation, there was an abrupt and significant increase in tidal volume (1.4±0.4 vs. 1.8±0.4 L; p=0.006, d=0.83) despite unchanged minute ventilation. Cardiorespiratory parameters returned to baseline within 4 min of the rest period. Competitive bouldering elicits substantial cardiorespiratory demand and evidence of tidal volume constraint. Further studies are warranted to explore the effect of cardiorespiratory training on climbing performance. Novelty bullets • Competitive bouldering evokes a high fraction of V̇O2max and prolonged periods above the GET • Climbing appears to impose a constraint on tidal volume expansion • Cardiorespiratory indices in elite climbers return to baseline within 2–4 min

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