scholarly journals The Effect of Breathing Patterns Common to Competitive Swimming on Gas Exchange and Muscle Deoxygenation During Heavy-Intensity Fartlek Exercise

2021 ◽  
Vol 12 ◽  
Author(s):  
Kevin J. Grossman ◽  
David J. Lim ◽  
Juan M. Murias ◽  
Glen R. Belfry
Keyword(s):  
Near Infrared ◽  
Head Rotation ◽  
Free Breathing ◽  
Gas Analysis ◽  
Breath Hold ◽  
Breathing Patterns ◽  
Competitive Swimming ◽  
Change Of Direction ◽  
Muscle Deoxygenation ◽  
Total Hemoglobin

During competitive freestyle swimming, the change of direction requires a turn followed by ∼15 m of underwater kicking at various intensities that require a ∼5 s breath-hold (BH). Upon surfacing, breathing must be regulated, as head rotation is necessary to facilitate the breath while completing the length of the pool (∼25 s). This study compared the respiratory and muscle deoxygenation responses of regulated breathing vs. free breathing, during these 25–5 s cycles. It was hypothesized that with the addition of a BH and sprint during heavy-intensity (HVY) exercise, oxygen uptake (VO2) and oxygen saturation (SatO2) would decrease, and muscle deoxygenation ([HHb]) and total hemoglobin ([Hbtot]) would increase. Ten healthy male participants (24 ± 3 years) performed 4–6 min trials of HVY cycling in the following conditions: (1) continuous free breathing (CONLD); (2) continuous with 5 s BH every 25 s (CONLD-BH); (3) Fartlek (FLK), a 5 s sprint followed by 25 s of HVY; and (4) a combined Fartlek and BH (FLK-BH). Continuous collection of VO2 and SatO2, [Hbtot], and [HHb] via breath-by-breath gas analysis and near-infrared spectroscopy (normalized to baseline) was performed. Breathing frequency and tidal volumes were matched between CONLD and CONLD-BH and between FLK and FLK-BH. As a result, VO2 was unchanged between CONLD (2.12 ± 0.35 L/min) and CONLD-BH (2.15 ± 0.42 L/min; p = 0.116) and between FLK (2.24 ± 0.40 L/min) and FLK-BH (2.20 ± 0.45 L/min; p = 0.861). SatO2 was higher in CONLD (63 ± 1.9%) than CONLD-BH (59 ± 3.3%; p < 0.001), but was unchanged between FLK (61 ± 2.2%) and FLK-BH (62 ± 3.1%; p = 0.462). Δ[Hbtot] is higher in CONLD (3.3 ± 1.6 μM) than CONLD-BH (-2.5 ± 1.2 μM; Δ177%; p < 0.001), but was unchanged between FLK (2.0 ± 1.6 μM) and FLK-BH (0.82 ± 1.4 μM; p = 0.979). Δ[HHb] was higher in CONLD (7.3 ± 1.8μM) than CONLD-BH (7.0 ± 2.0μM; Δ4%; p = 0.011) and lower in FLK (6.7 ± 1.8μM) compared to FLK-BH (8.7 ± 2.4 μM; p < 0.001). It is suggested that the unchanged VO2 between CONLD and CONLD-BH was supported by increased deoxygenation as reflected by decreased Δ[Hbtot] and blunted Δ[HHb], via apneic-driven redistribution of blood flow away from working muscles, which was reflected by the decreased SatO2. However, the preserved VO2 during FLK-BH vs. FLK has been underpinned by an increase in [HHb].

scholarly journals Muscle O2 extraction reserve during intense cycling is site-specific

2014 ◽  
Vol 117 (10) ◽  
pp. 1199-1206 ◽  
Author(s):  
Matthew D. Spencer ◽  
Tatsuro Amano ◽  
Narihiko Kondo ◽  
John M. Kowalchuk ◽  
Shunsaku Koga
Keyword(s):  
Near Infrared ◽  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Moderate Intensity ◽  
Time Resolved ◽  
Site Specific ◽  
Muscle Deoxygenation ◽  
Total Hemoglobin ◽  
O2 Extraction ◽  
Gas Exchange Threshold

The present study compared peak muscle deoxygenation ([HHb]peak) responses at three quadriceps sites during occlusion (OCC), ramp incremental (RI), severe- (SVR) and moderate-intensity (MOD) exercise. Seven healthy men (25 ± 4 yr) each completed a stationary cycling RI (20 W/min) test to determine [HHb]peak [at distal and proximal vastus lateralis (VLD and VLP) and rectus femoris (RF)], peak V̇o2 (V̇o2peak), gas exchange threshold (GET), and peak work rate (WRpeak). Subjects also completed MOD (WR = 80% GET) and SVR exercise (WR corresponding to 120% V̇o2peak) with absolute [HHb] (quantified by multichannel, time-resolved near-infrared spectroscopy) and pulmonary VO2 (V̇o2p) monitored continuously. Additionally, [HHb] and total hemoglobin ([Hb]tot) were monitored at rest and during subsequent OCC (250 mmHg). Site-specific adipose tissue thickness was assessed (B-mode ultrasound), and its relationship with resting [Hb]tot was used to correct absolute [HHb]. For VLD and RF, [HHb]peak was higher ( P < 0.05) during OCC (VLD = 111 ± 38, RF = 114 ± 26 μM) than RI (VLD 64 ± 14, RF = 85 ± 20) and SVR (VLD = 63 ± 13, RF = 81 ± 18). [HHb]peak was similar ( P > 0.05) across these conditions at the VLP (OCC = 67 ± 17, RI = 69 ± 17, SVR = 63 ± 17 μM). [HHb] peaked and then decreased prior to exercise cessation during SVR at all three muscle sites. [HHb]peak during MOD was consistently lower than other conditions at all sites. A “[HHb] reserve” exists during intense cycling at the VLD and RF, likely implying either sufficient blood flow to meet oxidative demands or insufficient diffusion time for complete equilibration. In VLP this [HHb] reserve was absent, suggesting that a critical Po2 may be challenged during intense cycling.

Comparison of breath-hold and free-breathing quantitative pulmonary perfusion MRI

Pneumologie ◽  
2012 ◽  
Vol 66 (06) ◽  
Author(s):  
D Maxien ◽  
M Ingrisch ◽  
F Meinel ◽  
S Thieme ◽  
MF Reiser ◽  
...  
Keyword(s):  
Free Breathing ◽  
Perfusion Mri ◽  
Breath Hold ◽  
Pulmonary Perfusion

Efficacy of Near-Infrared Spectrometry for Monitoring the Cerebral Effects of Severe Dilutional Anemia

2014 ◽  
Vol 17 (3) ◽  
pp. 154 ◽  
Author(s):  
Arıtürk Cem ◽  
Ustalar Serpil ◽  
Toraman Fevzi ◽  
Ökten Murat ◽  
Güllü Ümit ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Surgery ◽  
Blood Lactate ◽  
Near Infrared ◽  
Bypass Graft ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Infrared Spectrometry ◽  
Control Group ◽  
Near Infrared Spectrometry

<p><strong>Introduction:</strong> Clear guidelines for red cell transfusion during cardiac surgery have not yet been established. The current focus on blood conservation during cardiac surgery has increased the urgency to determine the minimum safe hematocrit for these patients. The aim of this study was to determine whether monitoring of cerebral regional oxygen saturation (rSO<sub>2</sub>) via near-infrared spectrometry (NIRS) is effective for assessing the cerebral effects of severe dilutional anemia during elective coronary arterial bypass graft surgery (CABG).</p><p><strong>Methods:</strong> The prospective observational study involved patients who underwent cerebral rSO<sub>2</sub> monitoring by NIRS during elective isolated first-time CABG: an anemic group (<em>N</em>=15) (minimum Hemoglobin (Hb) N=15) (Hb &gt;8 g/dL during CPB). Mean arterial pressure (MAP), pump blood flow, blood lactate level, pCO<sub>2</sub>, pO<sub>2</sub> at five time points and cross-clamp time, extracorporeal circulation time were recorded for each patient. Group results statistically were compared.</p><p><strong>Results:</strong> The anemic group had significantly lower mean preoperative Hb than the control group (10.3 mg/dL versus 14.2 mg/dL; <em>P</em> = .001). The lowest Hb levels were observed in the hypothermic period of CPB in the anemic group. None of the controls exhibited a &gt;20% decrease in cerebral rSO<sub>2</sub>. Eleven (73.3%) of the anemic patients required an increase in pump blood flow to raise their cerebral rSO<sub>2</sub>.</p><p><strong>Conclusions:</strong> In this study, the changes in cerebral rSO<sub>2</sub> in the patients with low Hb were within acceptable limits, and this was in concordance with the blood lactate levels and blood-gas analysis. It can be suggested that NIRS monitoring of cerebral rSO<sub>2</sub> can assist in decision making related to blood transfusion and dilutional anemia during CPB.</p>

scholarly journals Deep-inspirational breath-hold (DIBH) technique in left-sided breast cancer: various aspects of clinical utility

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Szilvia Gaál ◽  
Zsuzsanna Kahán ◽  
Viktor Paczona ◽  
Renáta Kószó ◽  
Rita Drencsényi ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Side Effects ◽  
Clinical Utility ◽  
Prospective Trial ◽  
Conformal Radiotherapy ◽  
Free Breathing ◽  
Left Breast ◽  
Breath Hold ◽  
Ipsilateral Lung ◽  
Breast Cancer Radiotherapy

Abstract Background Studying the clinical utility of deep-inspirational breath-hold (DIBH) in left breast cancer radiotherapy (RT) was aimed at focusing on dosimetry and feasibility aspects. Methods In this prospective trial all enrolled patients went through planning CT in supine position under both DIBH and free breathing (FB); in whole breast irradiation (WBI) cases prone CT was also taken. In 3-dimensional conformal radiotherapy (3DCRT) plans heart, left anterior descending coronary artery (LAD), ipsilateral lung and contralateral breast doses were analyzed. The acceptance of DIBH technique as reported by the patients and the staff was analyzed; post-RT side-effects including radiation lung changes (visual scores and lung density measurements) were collected. Results Among 130 enrolled patients 26 were not suitable for the technique while in 16, heart or LAD dose constraints were not met in the DIBH plans. Among 54 and 34 patients receiving WBI and postmastectomy/nodal RT, respectively with DIBH, mean heart dose (MHD) was reduced to < 50%, the heart V25 Gy to < 20%, the LAD mean dose to < 40% and the LAD maximum dose to about 50% as compared to that under FB; the magnitude of benefit was related to the relative increase of the ipsilateral lung volume at DIBH. Nevertheless, heart and LAD dose differences (DIBH vs. FB) individually varied. Among the WBI cases at least one heart/LAD dose parameter was more favorable in the prone or in the supine FB plan in 15 and 4 cases, respectively; differences were numerically small. All DIBH patients completed the RT, inter-fraction repositioning accuracy and radiation side-effects were similar to that of other breast RT techniques. Both the patients and radiographers were satisfied with the technique. Conclusions DIBH is an excellent heart sparing technique in breast RT, but about one-third of the patients do not benefit from that otherwise laborious procedure or benefit less than from an alternative method. Trial registration: retrospectively registered under ISRCTN14360721 (February 12, 2021)

Kinetics of muscle deoxygenation and microvascular Po2 during contractions in rat: comparison of optical spectroscopy and phosphorescence-quenching techniques

2012 ◽  
Vol 112 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Shunsaku Koga ◽  
Yutaka Kano ◽  
Thomas J. Barstow ◽  
Leonardo F. Ferreira ◽  
Etsuko Ohmae ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Visible Light ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Fiber Type ◽  
Type I ◽  
Phosphorescence Quenching ◽  
Mean Response Time ◽  
Muscle Deoxygenation ◽  
Visible Light Spectroscopy

The overarching presumption with near-infrared spectroscopy measurement of muscle deoxygenation is that the signal reflects predominantly the intramuscular microcirculatory compartment rather than intramyocyte myoglobin (Mb). To test this hypothesis, we compared the kinetics profile of muscle deoxygenation using visible light spectroscopy (suitable for the superficial fiber layers) with that for microvascular O2 partial pressure (i.e., PmvO2, phosphorescence quenching) within the same muscle region (0.5∼1 mm depth) during transitions from rest to electrically stimulated contractions in the gastrocnemius of male Wistar rats ( n = 14). Both responses could be modeled by a time delay (TD), followed by a close-to-exponential change to the new steady level. However, the TD for the muscle deoxygenation profile was significantly longer compared with that for the phosphorescence-quenching PmvO2 [8.6 ± 1.4 and 2.7 ± 0.6 s (means ± SE) for the deoxygenation and PmvO2, respectively; P < 0.05]. The time constants (τ) of the responses were not different (8.8 ± 4.7 and 11.2 ± 1.8 s for the deoxygenation and PmvO2, respectively). These disparate (TD) responses suggest that the deoxygenation characteristics of Mb extend the TD, thereby increasing the duration (number of contractions) before the onset of muscle deoxygenation. However, this effect was insufficient to increase the mean response time. Somewhat differently, the muscle deoxygenation response measured using near-infrared spectroscopy in the deeper regions (∼5 mm depth) (∼50% type I Mb-rich, highly oxidative fibers) was slower (τ = 42.3 ± 6.6 s; P < 0.05) than the corresponding value for superficial muscle measured using visible light spectroscopy or PmvO2 and can be explained on the basis of known fiber-type differences in PmvO2 kinetics. These data suggest that, within the superficial and also deeper muscle regions, the τ of the deoxygenation signal may represent a useful index of local O2 extraction kinetics during exercise transients.

scholarly journals EP-1316: Prone breast radiotherapy in prone: free breathing, deep inspiration breath hold and inspiration gating

2015 ◽  
Vol 115 ◽  
pp. S710
Author(s):  
M. Swimberge ◽  
V. Remouchamps ◽  
L. Veldeman ◽  
T. Mulliez ◽  
B. Speelers ◽  
...  
Keyword(s):  
Free Breathing ◽  
Breath Hold ◽  
Deep Inspiration ◽  
Breast Radiotherapy ◽  
Deep Inspiration Breath Hold

Deep-inspiration breath hold radiotherapy in patients with left-sided breast cancer after partial mastectomy

2021 ◽  
Vol 100 (4) ◽  
Keyword(s):  
Breast Cancer ◽  
Radiation Dose ◽  
Organs At Risk ◽  
Left Lung ◽  
Free Breathing ◽  
Partial Mastectomy ◽  
Breath Hold ◽  
Deep Inspiration ◽  
Deep Inspiration Breath Hold ◽  
Dose Volume Histograms

Introduction: The purpose of this study was to compare the radiation dose to organs at risk for deep-inspiration breath hold (DIBH) and free-breathing (FB) radiotherapy in patients with lef-sided breast cancer undergoing adjuvant radiotherapy after partial mastectomy. Methods: One hundred patients with left-sided breast cancer underwent DIBH and FB planning computed tomography scans, and the 2 techniques were compared. Dose-volume histograms were analyzed for heart, left anterior descending coronary artery (LAD), and left lung. Results: Radiation dose to heart, LAD, and left lung was significantly lower for DIBH than for free breathing plans. The median mean heart dose for DIBH technique in comparison with FB was 1.21 Gy, and 3.22 Gy respectively; for LAD, 4.67 versus 24.71 Gy; and for left lung 8.32 Gy versus 9.99 Gy. Conclusion: DIBH is an effective technique to reduce cardiac and lung radiation exposure.

Time-course of V̇O2 kinetics responses during moderate-intensity exercise subsequent to HIIT vs moderate-intensity continuous training in type 2 diabetes.

2021 ◽  
Author(s):  
Norita Gildea ◽  
Adam McDermott ◽  
Joel Rocha ◽  
Donal O'Shea ◽  
Simon Green ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Time Course ◽  
Near Infrared ◽  
Vastus Lateralis ◽  
Moderate Intensity ◽  
Vastus Lateralis Muscle ◽  
Maximal Heart Rate ◽  
Continuous Training ◽  
Muscle Deoxygenation

We assessed the time course of changes in oxygen uptake (V̇O2) and muscle deoxygenation (i.e., deoxygenated haemoglobin and myoglobin, [HHb+Mb]) kinetics during transitions to moderate-intensity cycling following 12-weeks of low-volume high-intensity interval training (HIIT) vs. moderate-intensity continuous training (MICT) in adults with type 2 diabetes (T2D). Participants were randomly assigned to MICT (n=10, 50 min of moderate-intensity cycling), HIIT (n=9, 10x1 min at ~90% maximal heart rate) or non-exercising control (n=9) groups. Exercising groups trained 3 times per week and measurements were taken every 3 weeks. [HHb+Mb] kinetics were measured by near-infrared spectroscopy at the vastus lateralis muscle. The local matching of O2 delivery to O2 utilization was assessed by the Δ[HHb+Mb]/ΔV̇O2ratio. The pretraining time constant of the primary phase of V̇O2 (τV̇O2p ) decreased (P<0.05) at wk 3 of training in both MICT (from 44±12 to 32±5 s) and HIIT (from 42±8 to 32 ± 4 s) with no further changes thereafter; while no changes were reported in controls. The pretraining overall dynamic response of muscle deoxygenation (τ'[HHb+Mb]) was faster than τV̇O2p in all groups, resulting in Δ[HHb+Mb]/V̇O2p showing a transient "overshoot" relative to the subsequent steady-state level. After 3 wks, the Δ[HHb+Mb]/V̇O2p overshoot was eliminated only in the training groups, so that τ'[HHb+Mb] was not different to τV̇O2p in MICT and HIIT. The enhanced V̇O2 kinetics response consequent to both MICT and HIIT in T2D was likely attributed to a training-induced improvement in matching of O2 delivery to utilization.

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