TY - JOUR
T1 - Voluntary control of breathing does not alter vagal modulation of heart rate
AU - Patwardhan, A. R.
AU - Evans, J. M.
AU - Bruce, E. N.
AU - Eckberg, D. L.
AU - Knapp, C. F.
PY - 1995
Y1 - 1995
N2 - Variations in respiratory pattern influence the heart rate spectrum. It has been suggested, hence, that metronomic respiration should be used to correctly assess vagal modulation of heart rate by using spectral analysis. On the other hand, breathing to a metronome has been reported to increase heart rate spectral power in the high- or respiratory frequency region; this finding has led to the suggestion that metronomic respiration enhances vagal tone or alters vagal modulation of heart rate. To investigate whether metronomic breathing complicates the interpretation of heart rate spectra by altering vagal modulation, we recorded the electrocardiogram and respiration from eight volunteers during three breathing trials of 10 min each: 1) spontaneous breathing (mean rate of 14.4 breaths/min); 2) breathing to a metronome at the rate of 15, 18, and 21 breaths/min for 2, 6, and 2 min, respectively; and 3) breathing to a metronome at the rate of 18 breaths/ rain for 10 min. Data were also collected from eight volunteers who breathed spontaneously for 20 min and breathed metroheroically at each subject's mean spontaneous breathing frequency for 20 min. Results from the three 10-min breathing trials showed that heart rate power in the respiratory frequency region was smaller during metronemic breathing than during spontaneous breathing. This decrease could be explained fully by the higher breathing frequencies used during trials 2 and 3 of metronomic breathing. When the subjects breathed metronomically at each subject's mean breathing frequency, the heart rate powers during metronomic breathing were similar to those during spontaneous breathing. Our results suggest that vagal modulation of heart rate is not altered and vagal tone is not enhanced during metronomic breathing.
AB - Variations in respiratory pattern influence the heart rate spectrum. It has been suggested, hence, that metronomic respiration should be used to correctly assess vagal modulation of heart rate by using spectral analysis. On the other hand, breathing to a metronome has been reported to increase heart rate spectral power in the high- or respiratory frequency region; this finding has led to the suggestion that metronomic respiration enhances vagal tone or alters vagal modulation of heart rate. To investigate whether metronomic breathing complicates the interpretation of heart rate spectra by altering vagal modulation, we recorded the electrocardiogram and respiration from eight volunteers during three breathing trials of 10 min each: 1) spontaneous breathing (mean rate of 14.4 breaths/min); 2) breathing to a metronome at the rate of 15, 18, and 21 breaths/min for 2, 6, and 2 min, respectively; and 3) breathing to a metronome at the rate of 18 breaths/ rain for 10 min. Data were also collected from eight volunteers who breathed spontaneously for 20 min and breathed metroheroically at each subject's mean spontaneous breathing frequency for 20 min. Results from the three 10-min breathing trials showed that heart rate power in the respiratory frequency region was smaller during metronemic breathing than during spontaneous breathing. This decrease could be explained fully by the higher breathing frequencies used during trials 2 and 3 of metronomic breathing. When the subjects breathed metronomically at each subject's mean breathing frequency, the heart rate powers during metronomic breathing were similar to those during spontaneous breathing. Our results suggest that vagal modulation of heart rate is not altered and vagal tone is not enhanced during metronomic breathing.
KW - metronomic breathing
KW - spectral analysis
KW - vagal tone
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U2 - 10.1152/jappl.1995.78.6.2087
DO - 10.1152/jappl.1995.78.6.2087
M3 - Article
C2 - 7665403
AN - SCOPUS:0029055693
SN - 8750-7587
VL - 78
SP - 2087
EP - 2094
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
IS - 6
ER -