282
A. V. Tankanag et al.
nervous system [8, 11]. The formation of respiratory-related oscillations in vascular
blood flow is due to at least two mechanisms: a) passive spread of respiratory modulation of blood pressure, b) vasomotor reflexes caused by respiratory modulation of
sympathetic nerve activity. Such oscillations were successfully recorded by means
of laser Doppler flowmetry (LDF). Apart from spontaneous breathing, controlled
one is of particular interest due to its influence on respiratory-related cardiovascular
oscillations. Our previous study demonstrated that deep controlled breathing affects
skin blood flow oscillation spectra [9]. Other authors reported that a deep inspiratory
gasp induces almost complete shut-down of a microvascular blood flow which manifests itself as a decrease in LDF signals [1]. Thus, the respiratory-cardiovascular
coupling is a complicated and timely problem. It is known that it depends on the
frequency and deepness of breathing. In this work, we present a study of the influence of deep controlled breathing on phase coherence of respiratory-related skin
blood flow oscillations of left and right finger-pad forefingers.
18.2 Methodology
18.2.1 Participants
29 healthy normotensive young females aged from 18 to 25 years (weight 58 ± 10 kg,
height 166 ± 4 cm, arterial blood pressure 117 ± 11/69 ± 6 mm Hg, heart rate 71
± 9 bpm) participated in the study. The participants had not taken any drugs for at
least one week before the study. None of the participants smoked and they abstained
from any alcohol- or caffeine-containing drinks for at least 12 h before the study.
The exclusion criteria were previous history of cardiovascular diseases, diabetes and
other acute and chronic illnesses. The study was approved by the local Committee
for Human Biomedical Research Ethics and was carried out in accordance with
the principles outlined in the 2002 Declaration of Helsinki of the World Medical
Association. The study protocol and its purpose were explained in detail to each
subject and informed consent was obtained from all subjects.
18.2.2 Measurements
The registration was initiated following a 20-min adaptation period. During the
measurements the subjects were in sitting position in a quiet room at constant room
temperature of 23 ± 1 °C. For each participant 7 successive recording sessions were
carried out: first and last, at spontaneous breathing rate before and after all controlled
regimes; and the five, in the regime of controlled breathing with different rates of
enforced breathing and fixed depth. The following rates of controlled breathing were
used: 0.25, 0.16, 0.1, 0.07 and 0.05 Hz. In the present study the breathing depth was
A. V. Tankanag et al.
nervous system [8, 11]. The formation of respiratory-related oscillations in vascular
blood flow is due to at least two mechanisms: a) passive spread of respiratory modulation of blood pressure, b) vasomotor reflexes caused by respiratory modulation of
sympathetic nerve activity. Such oscillations were successfully recorded by means
of laser Doppler flowmetry (LDF). Apart from spontaneous breathing, controlled
one is of particular interest due to its influence on respiratory-related cardiovascular
oscillations. Our previous study demonstrated that deep controlled breathing affects
skin blood flow oscillation spectra [9]. Other authors reported that a deep inspiratory
gasp induces almost complete shut-down of a microvascular blood flow which manifests itself as a decrease in LDF signals [1]. Thus, the respiratory-cardiovascular
coupling is a complicated and timely problem. It is known that it depends on the
frequency and deepness of breathing. In this work, we present a study of the influence of deep controlled breathing on phase coherence of respiratory-related skin
blood flow oscillations of left and right finger-pad forefingers.
18.2 Methodology
18.2.1 Participants
29 healthy normotensive young females aged from 18 to 25 years (weight 58 ± 10 kg,
height 166 ± 4 cm, arterial blood pressure 117 ± 11/69 ± 6 mm Hg, heart rate 71
± 9 bpm) participated in the study. The participants had not taken any drugs for at
least one week before the study. None of the participants smoked and they abstained
from any alcohol- or caffeine-containing drinks for at least 12 h before the study.
The exclusion criteria were previous history of cardiovascular diseases, diabetes and
other acute and chronic illnesses. The study was approved by the local Committee
for Human Biomedical Research Ethics and was carried out in accordance with
the principles outlined in the 2002 Declaration of Helsinki of the World Medical
Association. The study protocol and its purpose were explained in detail to each
subject and informed consent was obtained from all subjects.
18.2.2 Measurements
The registration was initiated following a 20-min adaptation period. During the
measurements the subjects were in sitting position in a quiet room at constant room
temperature of 23 ± 1 °C. For each participant 7 successive recording sessions were
carried out: first and last, at spontaneous breathing rate before and after all controlled
regimes; and the five, in the regime of controlled breathing with different rates of
enforced breathing and fixed depth. The following rates of controlled breathing were
used: 0.25, 0.16, 0.1, 0.07 and 0.05 Hz. In the present study the breathing depth was