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.

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.

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.

Analysis of Respiratory Sinus Arrhythmia with Respect to Respiratory Phase

2000 ◽  
Vol 39 (02) ◽  
pp. 153-156 ◽  
Author(s):  
K. Kotani ◽  
I. Hidaka ◽  
Y. Yamamoto ◽  
S. Ozono
Keyword(s):  
Respiratory Sinus Arrhythmia ◽  
Spontaneous Breathing ◽  
Breath Holding ◽  
Breathing Patterns ◽  
Sinus Arrhythmia ◽  
Paced Breathing ◽  
Phase Domain ◽  
Volume Curve ◽  
Respiratory Phase ◽  
Respiratory Modulation

Abstract:We evaluated the respiratory modulation of heart rate, i.e., respiratory sinus arrhythmia (RSA), with respect to respiratory phase derived from an analytic signal from the lung volume curve, during spontaneous breathing and paced breathing with different patterns. The magnitudes and waveforms of RSA in the phase domain were similar regardless of breathing pattern, even including spontaneous breathing. An examination of the occurrence of heart beats with respect to the respiratory phase revealed that synchronized patterns recently reported in the literature (Nature 392: 239, 1998) were observed during paced breathing with breath holding periods whereby the respiratory phase advanced more slowly. It was concluded that the phase domain approach might be useful in extracting RSA during spontaneous breathing and for elucidating detailed mechanisms for RSA. However, the use of this technique for studies investigating cardio-respiratory coupling should be approached cautiously, as the results may be influenced by breathing patterns.

Abstract P3056: The Effect of Device Guided Slow Breathing With Biofeedback on Pulse Transit Time and Respiratory Sinus Arrhythmia

Hypertension ◽  
2019 ◽  
Vol 74 (Suppl_1) ◽  
Author(s):  
Thomas Mengden ◽  
Martin Bachler ◽  
Christopher C Mayer ◽  
Ines Mikisek ◽  
Walter Sehnert ◽  
...  
Keyword(s):  
Transit Time ◽  
Respiratory Sinus Arrhythmia ◽  
Pulse Transit Time ◽  
Sinus Arrhythmia ◽  
Slow Breathing

Influence of breathing frequency on the pattern of respiratory sinus arrhythmia and blood pressure: old questions revisited

2010 ◽  
Vol 298 (5) ◽  
pp. H1588-H1599 ◽  
Author(s):  
P. Y. W. Sin ◽  
D. C. Galletly ◽  
Y. C. Tzeng
Keyword(s):  
Blood Pressure ◽  
Respiratory Sinus Arrhythmia ◽  
Pattern Analysis ◽  
Time Interval ◽  
Adrenergic Blockade ◽  
Breathing Frequency ◽  
Sinus Arrhythmia ◽  
Temporal Relationships ◽  
Sympathetic Modulation ◽  
Slow Breathing

Respiratory sinus arrhythmia (RSA) is classically described as a vagally mediated increase and decrease in heart rate concurrent with inspiration and expiration, respectively. However, although breathing frequency is known to alter this temporal relationship, the precise nature of this phase dependency and its relationship to blood pressure remains unclear. In 16 subjects we systematically examined the temporal relationships between respiration, RSA, and blood pressure by graphically portraying cardiac interval (R-R) and systolic blood pressure (SBP) variations as a function of the respiratory cycle (pattern analysis), during incremental stepwise paced breathing. The principal findings were 1) the time interval between R-R maximum and expiration onset remained the same (∼2.5–3.0 s) irrespective of breathing frequency ( P = 0.10), whereas R-R minimum progressively shifted from expiratory onset into midinspiration with slower breathing ( P < 0.0001); 2) there is a clear qualitative distinction between pre- versus postinspiratory cardiac acceleration during slow (0.10 Hz) but not fast (0.20 Hz) breathing; 3) the time interval from inspiration onset to SBP minimum ( P = 0.16) and from expiration onset to SBP maximum ( P = 0.26) remained unchanged across breathing frequencies; 4) SBP maximum and R-R maximum maintained an unchanged temporal alignment of ∼1.1 s irrespective of breathing frequency ( P = 0.84), whereas the alignment between SBP minimum and R-R minimum was inconstant ( P > 0.0001); and 5) β1-adrenergic blockade did not influence the respiration-RSA relationships or distinct RSA patterns observed during slow breathing, suggesting that temporal dependencies associated with alterations in breathing frequency are unrelated to cardiac sympathetic modulation. Collectively, these results illustrate nonlinear respiration-RSA-blood pressure relationships that may yield new insights to the fundamental mechanism of RSA in humans.

Postural-induced phase shift of respiratory sinus arrhythmia and blood pressure variations: insight from respiratory-phase domain analysis

2008 ◽  
Vol 294 (3) ◽  
pp. H1481-H1489 ◽  
Author(s):  
Kiyoshi Kotani ◽  
Kiyoshi Takamasu ◽  
Yasuhiko Jimbo ◽  
Yoshiharu Yamamoto
Keyword(s):  
Blood Pressure ◽  
Phase Shift ◽  
Respiratory Sinus Arrhythmia ◽  
Domain Analysis ◽  
Standing Position ◽  
Sitting Position ◽  
Sinus Arrhythmia ◽  
Phase Domain ◽  
Healthy Humans ◽  
Respiratory Phase

The purpose of this study is to evaluate the multiple effects of respiration on cardiovascular variability in different postures, by analyzing respiratory sinus arrhythmia (RSA) and respiratory-related blood pressure (BP) variations for systolic BP (SBP), diastolic BP (DBP), and pulse pressure (PP) in the respiratory-phase domain. The measurements were conducted for 420 s on healthy humans in the sitting and standing positions, while the subjects were continuously monitored for heart rate and BP variability and instantaneous lung volume. The waveforms of RSA and respiratory-related BP variations were extracted as a function of the respiratory phase. In the standing position, the waveforms of the BP variations for SBP, DBP, and PP show their maxima at around the end of expiration (π rad) and the minima at around the end of inspiration (2 π rad), while the waveform of RSA is delayed by ∼0.35 π rad compared with the BP waveforms. On the other hand, in the sitting position, the phase of the DBP waveform (1.69 π rad) greatly and significantly ( P < 0.01) differs from that in the standing position (1.20 π rad). Also, the phase of PP is delayed and that of RSA is advanced in the sitting position ( P < 0.01). In particular, the phase shift of the DBP waveform is sufficiently large to alter whole hemodynamic fluctuations, affecting the amplitudes of SBP and PP variations. We conclude that the postural change associated with an altered autonomic balance affects not only the amplitude of RSA, but also the phases of RSA and BP variations in a complicated manner, and the respiratory-phase domain analysis used in this study is useful for elucidating the dynamic mechanisms of RSA.

Mutual interactions of respiratory sinus arrhythmia and the carotid baroreceptor-heart rate reflex

1992 ◽  
Vol 82 (2) ◽  
pp. 139-145 ◽  
Author(s):  
S. J. Cross ◽  
M. R. Cowie ◽  
J. M. Rawles
Keyword(s):  
Heart Rate ◽  
Respiratory Sinus Arrhythmia ◽  
Cycle Length ◽  
Respiratory Cycle ◽  
Reflex Response ◽  
Sinus Arrhythmia ◽  
Carotid Baroreceptor ◽  
Cycle Lengths ◽  
Interval Response ◽  
Algebraic Summation

1. In six healthy subjects the amplitude and phase of respiratory sinus arrhythmia were determined at five different respiratory cycle lengths ranging from 3 to 9.5 s. 2. At each respiratory cycle length the carotid baroreceptor-heart rate reflex response was determined by cyclical neck suction at −40 mmHg at five different cycle lengths covering the same range of 3–9.5 s. 3. The application of cyclical neck suction increased the amplitude of respiratory sinus arrhythmia in all but the longest respiratory cycle lengths. 4. With increasing respiratory cycle length the amplitude of sinus arrhythmia increased, and R-R intervals were at their longest at an earlier phase of the respiratory cycle. Similarly, with increasing suction cycle length the amplitude of the cardiac interval response increased and the phase angle decreased. 5. The cardiac interval responses to respiration and to neck suction at different frequencies were independent of each other, the heart rate at any moment resulting from the algebraic summation of the two responses.

scholarly journals Pulmonary gas exchange capacity is reduced during normovolaemic haemodilution in healthy human subjects

1996 ◽  
Vol 43 (7) ◽  
pp. 672-677 ◽  
Author(s):  
Charles Le Merre ◽  
Michel Dauzat ◽  
Patrice Poupard ◽  
Rémi Targhetta ◽  
Christine Fabre ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Human Subjects ◽  
Exchange Capacity ◽  
Pulmonary Gas Exchange ◽  
Healthy Human ◽  
Healthy Human Subjects
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