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Lookup NU author(s): Dr Luigi Di Marco,
Dr Ding Chang Zheng,
Emeritus Professor Alan MurrayORCiD
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The aim of this study was to investigate the effects of deep breathing on blood pressure parameters: systolic (SBP), diastolic (DBP) and pulse pressure, mean pulse rate (MPR), and the amplitude of Korotkoff sounds.Manual SBP and DBP were measured from 20 healthy subjects (age: 44 +/- 13 years) during normal (NB) and deep (DB) breathing. A chest magnetometer was used to acquire the respiratory depth, and an electronic stethoscope for the Korotkoff sound. All data were sampled at 2 kHz. MPR was derived from the oscillometric pulse waveform. For each oscillometric pulse, time-frequency analysis of the Korotkoff sound located the time of the peak energy (Tp), and Korotkoff sounds amplitude was defined as the maximum peak-to-peak amplitude in the window T-P +/- 50ms. The respiratory rate was calculated from both the magnetometer (f(R)) and Korotkoff amplitude series (f(K)) for the period between the manually measured SBP and DBP, with a power spectral density resolution of 0.016 Hz in the physiological respiratory frequency range at rest.DB compared to NB increased respiratory regularity (quantified by spectral concentration) by 9 +/- 10% (mean +/- SD, p<0.005), and decreased fR from 0.24 +/- 0.06 to 0.20 +/- 0.05 Hz (p<0.0005). SBP and pulse pressure also decreased, from 116 +/- 12 to 113 +/- 11 mmHg (p<0.005) and 41 +/- 9 to 37 +/- 9 mmHg (p<0.01) respectively, and MPR increased from 64 +/- 8 to 68 +/- 9 pulse/min (p<0.0005). In 70% of recordings fR differed from fK by 0.05 Hz or less. The results show an effect of DB on blood pressure, and the presence of a modulating effect of respiration on the Korotkoff sound.
Author(s): Di Marco LY, Zheng DC, Murray A
Publication type: Conference Proceedings (inc. Abstract)
Publication status: Published
Conference Name: 2012 Computing in Cardiology
Year of Conference: 2012
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