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Spyros Zakynthinos - One of the best experts on this subject based on the ideXlab platform.
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Respiratory Muscle Blood Flow Measured by Near-Infrared Spectroscopy (NIRS) and Indocyanine Green Dye (ICG)
Mechanics of Breathing, 2014Co-Authors: Zafeiris Louvaris, Spyros Zakynthinos, Ioannis VogiatzisAbstract:The ability to measure intercostal Muscle Blood Flow in humans has implications for understanding Blood Flow distribution patterns and circulatory regulation during exercise. Accordingly, the advantage of performing actual Muscle Blood Flow measurements is that it provides an insight into the “Blood Flow competition” theory, based on which it is proposed that the respiratory Muscles compete with the locomotor Muscles for the available Blood Flow. Until very recently it was impossible to measure respiratory Muscle Blood Flow in humans during exercise owing to several difficulties. Near-infrared spectroscopy (NIRS) combined with indocyanine green dye (ICG) is a new valid and minimally invasive technique for measuring respiratory Muscle Blood Flow during exercise in humans allowing for continuous and variable frequency data collection. On the basis of tracer principles of mass conservation, the NIRS–ICG technique makes it possible to quantify Blood Flow because the rate of accumulation of ICG in a given tissue reflects perfusion in the specified tissue of interest. Respiratory Muscle Blood Flow measurements by NIRS–ICG technique primarily reflect the internal and external intercostal Muscles and only to a lesser extent the costal part of the diaphragm. However, while the diaphragm acts as the primary Flow generator during exercise, the role of the intercostal Muscles is also important as they develop the necessary pressure to move the rib cage. This chapter focuses on the intercostal Muscle perfusion measured by the NIRS–ICG technique in healthy individuals and patients with chronic obstructive pulmonary disease (COPD) during exercise who often experience greater work of breathing than healthy subjects both at rest and during exercise.
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intercostal Muscle Blood Flow limitation during exercise in chronic obstructive pulmonary disease
American Journal of Respiratory and Critical Care Medicine, 2010Co-Authors: Ioannis Vogiatzis, Dimitris Athanasopoulos, Helmut Habazettl, Harrieth Wagner, Charis Roussos, Peter D Wagner, Zafeiris Louvaris, Andrea Aliverti, Evgenia Cherouveim, Spyros ZakynthinosAbstract:Rationale: It has been hypothesized that, because of the high work of breathing sustained by patients with chronic obstructive pulmonary disease (COPD) during exercise, Blood Flow may increase in favor of the respiratory Muscles, thereby compromising locomotor Muscle Blood Flow.Objectives: To test this hypothesis by investigating whether, at the same work of breathing, intercostal Muscle Blood Flow during exercise is as high as during resting isocapnic hyperpnea when respiratory and locomotor Muscles do not compete for the available Blood Flow.Methods: Intercostal and vastus lateralis Muscle perfusion was measured simultaneously in 10 patients with COPD (FEV1 = 50.5 ± 5.5% predicted) by near-infrared spectroscopy using indocyanine green dye.Measurements and Main Results: Measurements were made at several exercise intensities up to peak work rate (WRpeak) and subsequently during resting hyperpnea at minute ventilation levels up to those at WRpeak. During resting hyperpnea, intercostal Muscle Blood Flow inc...
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intercostal Muscle Blood Flow limitation in athletes during maximal exercise
The Journal of Physiology, 2009Co-Authors: Ioannis Vogiatzis, Dimitris Athanasopoulos, Helmut Habazettl, Wolfgang M Kuebler, Harrieth Wagner, Charis Roussos, Peter D Wagner, Spyros ZakynthinosAbstract:We investigated whether, during maximal exercise, intercostal Muscle Blood Flow is as high as during resting hyperpnoea at the same work of breathing. We hypothesized that during exercise, intercostal Muscle Blood Flow would be limited by competition from the locomotor Muscles. Intercostal (probe over the 7th intercostal space) and vastus lateralis Muscle perfusion were measured simultaneously in ten trained cyclists by near-infrared spectroscopy using indocyanine green dye. Measurements were made at several exercise intensities up to maximal (WRmax) and subsequently during resting isocapnic hyperpnoea at minute ventilation levels up to those at WRmax. During resting hyperpnoea, intercostal Muscle Blood Flow increased linearly with the work of breathing (R2= 0.94) to 73.0 ± 8.8 ml min−1 (100 g)−1 at the ventilation seen at WRmax (work of breathing ∼550–600 J min−1), but during exercise it peaked at 80% WRmax (53.4 ± 10.3 ml min−1 (100 g)−1), significantly falling to 24.7 ± 5.3 ml min−1 (100 g)−1 at WRmax. At maximal ventilation intercostal Muscle vascular conductance was significantly lower during exercise (0.22 ± 0.05 ml min−1 (100 g)−1 mmHg−1) compared to isocapnic hyperpnoea (0.77 ± 0.13 ml min−1 (100 g)−1 mmHg−1). During exercise, both cardiac output and vastus lateralis Muscle Blood Flow also plateaued at about 80% WRmax (the latter at 95.4 ± 11.8 ml min−1 (100 g)−1). In conclusion, during exercise above 80% WRmax in trained subjects, intercostal Muscle Blood Flow and vascular conductance are less than during resting hyperpnoea at the same minute ventilation. This suggests that the circulatory system is unable to meet the demands of both locomotor and intercostal Muscles during heavy exercise, requiring greater O2 extraction and likely contributing to respiratory Muscle fatigue.
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Intercostal Muscle Blood Flow limitation in athletes during maximal exercise.
The Journal of physiology, 2009Co-Authors: Ioannis Vogiatzis, Dimitris Athanasopoulos, Helmut Habazettl, Wolfgang M Kuebler, Harrieth Wagner, Charis Roussos, Peter D Wagner, Spyros ZakynthinosAbstract:We investigated whether, during maximal exercise, intercostal Muscle Blood Flow is as high as during resting hyperpnoea at the same work of breathing. We hypothesized that during exercise, intercostal Muscle Blood Flow would be limited by competition from the locomotor Muscles. Intercostal (probe over the 7th intercostal space) and vastus lateralis Muscle perfusion were measured simultaneously in ten trained cyclists by near-infrared spectroscopy using indocyanine green dye. Measurements were made at several exercise intensities up to maximal (WRmax) and subsequently during resting isocapnic hyperpnoea at minute ventilation levels up to those at WRmax. During resting hyperpnoea, intercostal Muscle Blood Flow increased linearly with the work of breathing (R2 = 0.94) to 73.0 +/- 8.8 ml min-1 (100 g)-1 at the ventilation seen at WRmax (work of breathing approximately 550-600 J min-1), but during exercise it peaked at 80% WRmax (53.4 +/- 10.3 ml min-1 (100 g)-1), significantly falling to 24.7 +/- 5.3 ml min-1 (100 g)-1 at WRmax. At maximal ventilation intercostal Muscle vascular conductance was significantly lower during exercise (0.22 +/- 0.05 ml min-1 (100 g)-1 mmHg-1) compared to isocapnic hyperpnoea (0.77 +/- 0.13 ml min-1 (100 g)-1 mmHg-1). During exercise, both cardiac output and vastus lateralis Muscle Blood Flow also plateaued at about 80% WRmax (the latter at 95.4 +/- 11.8 ml min-1 (100 g)-1). In conclusion, during exercise above 80% WRmax in trained subjects, intercostal Muscle Blood Flow and vascular conductance are less than during resting hyperpnoea at the same minute ventilation. This suggests that the circulatory system is unable to meet the demands of both locomotor and intercostal Muscles during heavy exercise, requiring greater O2 extraction and likely contributing to respiratory Muscle fatigue.
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human respiratory Muscle Blood Flow measured by near infrared spectroscopy and indocyanine green
Journal of Applied Physiology, 2008Co-Authors: Jordan A Guenette, Ioannis Vogiatzis, Harrieth Wagner, Charis Roussos, Spyros Zakynthinos, Dimitrios Athanasopoulos, Maria Koskolou, Spyretta Golemati, Maroula Vasilopoulou, Peter D WagnerAbstract:Measurement of respiratory Muscle Blood Flow (RMBF) in humans has important implications for understanding patterns of Blood Flow distribution during exercise in healthy individuals and those with ...
Ioannis Vogiatzis - One of the best experts on this subject based on the ideXlab platform.
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Respiratory and locomotor Muscle Blood Flow during exercise in health and chronic obstructive pulmonary disease.
Experimental Physiology, 2020Co-Authors: Ioannis Vogiatzis, Zafeiris Louvaris, Peter D WagnerAbstract:NEW FINDINGS: Using an approach we developed to measure Muscle Blood Flow by indocyanine green dye detected by near infrared spectroscopy, we have found that isocapnic hyperpnoea at rest leads to an increase in respiratory Muscle Blood Flow that is proportional to the respiratory Muscle work required. Surprisingly, cycling exercise interferes with respiratory Muscle Blood Flow, especially in COPD, but even in health athletes. Intercostal Muscle Blood Flow during exercise fails to reach Flow rates observed at the same minute ventilation as during isocapnic hyperpnoea, and in COPD, intercostal Muscle Blood Flow during exercise actually falls below Flow during resting breathing. No evidence is found in intact subjects for redistribution of Blood Flow from the legs to the respiratory Muscles during heavy exercise in health or COPD. Evidence of decrease in leg Blood Flow and increase in respiratory Muscle Flow was found only when imposing expiratory Flow limitation (EFL) during exercise in healthy individuals. However, because EFL caused substantial physiological derangement, these results cannot be projected onto normal exercise. ABSTRACT: We have developed an indicator-dilution method to measure Muscle Blood Flow at rest and during exercise using the light absorbing tracer indocyanine green dye (ICG) injected as an intravenous bolus, with surface optodes placed over Muscles of interest to record the ICG signal by near-infrared spectroscopy. Here we review findings for both quadriceps and intercostal Muscle Blood Flow (measured simultaneously) in trained cyclists and in patients with COPD. During resting hyperpnoea in both athletes and patients, intercostal Muscle Blood Flow increased with ventilation, correlating closely and linearly with the work of breathing, with no change in quadriceps Flow. During graded exercise in athletes, intercostal Flow at first increased, but then began to fall approaching peak effort. Unexpectedly, in COPD, intercostal Muscle Blood Flow during exercise fell progressively from resting values, contrasting sharply with the response to resting hyperpnoea. During exercise at peak intensity, we found no quadriceps Blood Flow reduction in favour of the respiratory Muscles in either athletes or patients. In COPD at peak exercise, when patients breathed 21% oxygen in helium or 100% oxygen, there was no redistribution of Blood Flow observed between legs and respiratory Muscles in either direction. Evidence of decrease in leg Blood Flow and increase in respiratory Muscle Flow was found only when imposing expiratory Flow limitation (EFL) during exercise in healthy individuals. However, because EFL caused substantial physiological derangement, lowering arterial oxygen saturation and raising end-tidal PCO2 and heart rate, these results cannot be projected onto normal exercise. This article is protected by copyright. All rights reserved.
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Respiratory Muscle Blood Flow Measured by Near-Infrared Spectroscopy (NIRS) and Indocyanine Green Dye (ICG)
Mechanics of Breathing, 2014Co-Authors: Zafeiris Louvaris, Spyros Zakynthinos, Ioannis VogiatzisAbstract:The ability to measure intercostal Muscle Blood Flow in humans has implications for understanding Blood Flow distribution patterns and circulatory regulation during exercise. Accordingly, the advantage of performing actual Muscle Blood Flow measurements is that it provides an insight into the “Blood Flow competition” theory, based on which it is proposed that the respiratory Muscles compete with the locomotor Muscles for the available Blood Flow. Until very recently it was impossible to measure respiratory Muscle Blood Flow in humans during exercise owing to several difficulties. Near-infrared spectroscopy (NIRS) combined with indocyanine green dye (ICG) is a new valid and minimally invasive technique for measuring respiratory Muscle Blood Flow during exercise in humans allowing for continuous and variable frequency data collection. On the basis of tracer principles of mass conservation, the NIRS–ICG technique makes it possible to quantify Blood Flow because the rate of accumulation of ICG in a given tissue reflects perfusion in the specified tissue of interest. Respiratory Muscle Blood Flow measurements by NIRS–ICG technique primarily reflect the internal and external intercostal Muscles and only to a lesser extent the costal part of the diaphragm. However, while the diaphragm acts as the primary Flow generator during exercise, the role of the intercostal Muscles is also important as they develop the necessary pressure to move the rib cage. This chapter focuses on the intercostal Muscle perfusion measured by the NIRS–ICG technique in healthy individuals and patients with chronic obstructive pulmonary disease (COPD) during exercise who often experience greater work of breathing than healthy subjects both at rest and during exercise.
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intercostal Muscle Blood Flow limitation during exercise in chronic obstructive pulmonary disease
American Journal of Respiratory and Critical Care Medicine, 2010Co-Authors: Ioannis Vogiatzis, Dimitris Athanasopoulos, Helmut Habazettl, Harrieth Wagner, Charis Roussos, Peter D Wagner, Zafeiris Louvaris, Andrea Aliverti, Evgenia Cherouveim, Spyros ZakynthinosAbstract:Rationale: It has been hypothesized that, because of the high work of breathing sustained by patients with chronic obstructive pulmonary disease (COPD) during exercise, Blood Flow may increase in favor of the respiratory Muscles, thereby compromising locomotor Muscle Blood Flow.Objectives: To test this hypothesis by investigating whether, at the same work of breathing, intercostal Muscle Blood Flow during exercise is as high as during resting isocapnic hyperpnea when respiratory and locomotor Muscles do not compete for the available Blood Flow.Methods: Intercostal and vastus lateralis Muscle perfusion was measured simultaneously in 10 patients with COPD (FEV1 = 50.5 ± 5.5% predicted) by near-infrared spectroscopy using indocyanine green dye.Measurements and Main Results: Measurements were made at several exercise intensities up to peak work rate (WRpeak) and subsequently during resting hyperpnea at minute ventilation levels up to those at WRpeak. During resting hyperpnea, intercostal Muscle Blood Flow inc...
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intercostal Muscle Blood Flow limitation in athletes during maximal exercise
The Journal of Physiology, 2009Co-Authors: Ioannis Vogiatzis, Dimitris Athanasopoulos, Helmut Habazettl, Wolfgang M Kuebler, Harrieth Wagner, Charis Roussos, Peter D Wagner, Spyros ZakynthinosAbstract:We investigated whether, during maximal exercise, intercostal Muscle Blood Flow is as high as during resting hyperpnoea at the same work of breathing. We hypothesized that during exercise, intercostal Muscle Blood Flow would be limited by competition from the locomotor Muscles. Intercostal (probe over the 7th intercostal space) and vastus lateralis Muscle perfusion were measured simultaneously in ten trained cyclists by near-infrared spectroscopy using indocyanine green dye. Measurements were made at several exercise intensities up to maximal (WRmax) and subsequently during resting isocapnic hyperpnoea at minute ventilation levels up to those at WRmax. During resting hyperpnoea, intercostal Muscle Blood Flow increased linearly with the work of breathing (R2= 0.94) to 73.0 ± 8.8 ml min−1 (100 g)−1 at the ventilation seen at WRmax (work of breathing ∼550–600 J min−1), but during exercise it peaked at 80% WRmax (53.4 ± 10.3 ml min−1 (100 g)−1), significantly falling to 24.7 ± 5.3 ml min−1 (100 g)−1 at WRmax. At maximal ventilation intercostal Muscle vascular conductance was significantly lower during exercise (0.22 ± 0.05 ml min−1 (100 g)−1 mmHg−1) compared to isocapnic hyperpnoea (0.77 ± 0.13 ml min−1 (100 g)−1 mmHg−1). During exercise, both cardiac output and vastus lateralis Muscle Blood Flow also plateaued at about 80% WRmax (the latter at 95.4 ± 11.8 ml min−1 (100 g)−1). In conclusion, during exercise above 80% WRmax in trained subjects, intercostal Muscle Blood Flow and vascular conductance are less than during resting hyperpnoea at the same minute ventilation. This suggests that the circulatory system is unable to meet the demands of both locomotor and intercostal Muscles during heavy exercise, requiring greater O2 extraction and likely contributing to respiratory Muscle fatigue.
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Intercostal Muscle Blood Flow limitation in athletes during maximal exercise.
The Journal of physiology, 2009Co-Authors: Ioannis Vogiatzis, Dimitris Athanasopoulos, Helmut Habazettl, Wolfgang M Kuebler, Harrieth Wagner, Charis Roussos, Peter D Wagner, Spyros ZakynthinosAbstract:We investigated whether, during maximal exercise, intercostal Muscle Blood Flow is as high as during resting hyperpnoea at the same work of breathing. We hypothesized that during exercise, intercostal Muscle Blood Flow would be limited by competition from the locomotor Muscles. Intercostal (probe over the 7th intercostal space) and vastus lateralis Muscle perfusion were measured simultaneously in ten trained cyclists by near-infrared spectroscopy using indocyanine green dye. Measurements were made at several exercise intensities up to maximal (WRmax) and subsequently during resting isocapnic hyperpnoea at minute ventilation levels up to those at WRmax. During resting hyperpnoea, intercostal Muscle Blood Flow increased linearly with the work of breathing (R2 = 0.94) to 73.0 +/- 8.8 ml min-1 (100 g)-1 at the ventilation seen at WRmax (work of breathing approximately 550-600 J min-1), but during exercise it peaked at 80% WRmax (53.4 +/- 10.3 ml min-1 (100 g)-1), significantly falling to 24.7 +/- 5.3 ml min-1 (100 g)-1 at WRmax. At maximal ventilation intercostal Muscle vascular conductance was significantly lower during exercise (0.22 +/- 0.05 ml min-1 (100 g)-1 mmHg-1) compared to isocapnic hyperpnoea (0.77 +/- 0.13 ml min-1 (100 g)-1 mmHg-1). During exercise, both cardiac output and vastus lateralis Muscle Blood Flow also plateaued at about 80% WRmax (the latter at 95.4 +/- 11.8 ml min-1 (100 g)-1). In conclusion, during exercise above 80% WRmax in trained subjects, intercostal Muscle Blood Flow and vascular conductance are less than during resting hyperpnoea at the same minute ventilation. This suggests that the circulatory system is unable to meet the demands of both locomotor and intercostal Muscles during heavy exercise, requiring greater O2 extraction and likely contributing to respiratory Muscle fatigue.
Peter D Wagner - One of the best experts on this subject based on the ideXlab platform.
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Respiratory and locomotor Muscle Blood Flow during exercise in health and chronic obstructive pulmonary disease.
Experimental Physiology, 2020Co-Authors: Ioannis Vogiatzis, Zafeiris Louvaris, Peter D WagnerAbstract:NEW FINDINGS: Using an approach we developed to measure Muscle Blood Flow by indocyanine green dye detected by near infrared spectroscopy, we have found that isocapnic hyperpnoea at rest leads to an increase in respiratory Muscle Blood Flow that is proportional to the respiratory Muscle work required. Surprisingly, cycling exercise interferes with respiratory Muscle Blood Flow, especially in COPD, but even in health athletes. Intercostal Muscle Blood Flow during exercise fails to reach Flow rates observed at the same minute ventilation as during isocapnic hyperpnoea, and in COPD, intercostal Muscle Blood Flow during exercise actually falls below Flow during resting breathing. No evidence is found in intact subjects for redistribution of Blood Flow from the legs to the respiratory Muscles during heavy exercise in health or COPD. Evidence of decrease in leg Blood Flow and increase in respiratory Muscle Flow was found only when imposing expiratory Flow limitation (EFL) during exercise in healthy individuals. However, because EFL caused substantial physiological derangement, these results cannot be projected onto normal exercise. ABSTRACT: We have developed an indicator-dilution method to measure Muscle Blood Flow at rest and during exercise using the light absorbing tracer indocyanine green dye (ICG) injected as an intravenous bolus, with surface optodes placed over Muscles of interest to record the ICG signal by near-infrared spectroscopy. Here we review findings for both quadriceps and intercostal Muscle Blood Flow (measured simultaneously) in trained cyclists and in patients with COPD. During resting hyperpnoea in both athletes and patients, intercostal Muscle Blood Flow increased with ventilation, correlating closely and linearly with the work of breathing, with no change in quadriceps Flow. During graded exercise in athletes, intercostal Flow at first increased, but then began to fall approaching peak effort. Unexpectedly, in COPD, intercostal Muscle Blood Flow during exercise fell progressively from resting values, contrasting sharply with the response to resting hyperpnoea. During exercise at peak intensity, we found no quadriceps Blood Flow reduction in favour of the respiratory Muscles in either athletes or patients. In COPD at peak exercise, when patients breathed 21% oxygen in helium or 100% oxygen, there was no redistribution of Blood Flow observed between legs and respiratory Muscles in either direction. Evidence of decrease in leg Blood Flow and increase in respiratory Muscle Flow was found only when imposing expiratory Flow limitation (EFL) during exercise in healthy individuals. However, because EFL caused substantial physiological derangement, lowering arterial oxygen saturation and raising end-tidal PCO2 and heart rate, these results cannot be projected onto normal exercise. This article is protected by copyright. All rights reserved.
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intercostal Muscle Blood Flow limitation during exercise in chronic obstructive pulmonary disease
American Journal of Respiratory and Critical Care Medicine, 2010Co-Authors: Ioannis Vogiatzis, Dimitris Athanasopoulos, Helmut Habazettl, Harrieth Wagner, Charis Roussos, Peter D Wagner, Zafeiris Louvaris, Andrea Aliverti, Evgenia Cherouveim, Spyros ZakynthinosAbstract:Rationale: It has been hypothesized that, because of the high work of breathing sustained by patients with chronic obstructive pulmonary disease (COPD) during exercise, Blood Flow may increase in favor of the respiratory Muscles, thereby compromising locomotor Muscle Blood Flow.Objectives: To test this hypothesis by investigating whether, at the same work of breathing, intercostal Muscle Blood Flow during exercise is as high as during resting isocapnic hyperpnea when respiratory and locomotor Muscles do not compete for the available Blood Flow.Methods: Intercostal and vastus lateralis Muscle perfusion was measured simultaneously in 10 patients with COPD (FEV1 = 50.5 ± 5.5% predicted) by near-infrared spectroscopy using indocyanine green dye.Measurements and Main Results: Measurements were made at several exercise intensities up to peak work rate (WRpeak) and subsequently during resting hyperpnea at minute ventilation levels up to those at WRpeak. During resting hyperpnea, intercostal Muscle Blood Flow inc...
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intercostal Muscle Blood Flow limitation in athletes during maximal exercise
The Journal of Physiology, 2009Co-Authors: Ioannis Vogiatzis, Dimitris Athanasopoulos, Helmut Habazettl, Wolfgang M Kuebler, Harrieth Wagner, Charis Roussos, Peter D Wagner, Spyros ZakynthinosAbstract:We investigated whether, during maximal exercise, intercostal Muscle Blood Flow is as high as during resting hyperpnoea at the same work of breathing. We hypothesized that during exercise, intercostal Muscle Blood Flow would be limited by competition from the locomotor Muscles. Intercostal (probe over the 7th intercostal space) and vastus lateralis Muscle perfusion were measured simultaneously in ten trained cyclists by near-infrared spectroscopy using indocyanine green dye. Measurements were made at several exercise intensities up to maximal (WRmax) and subsequently during resting isocapnic hyperpnoea at minute ventilation levels up to those at WRmax. During resting hyperpnoea, intercostal Muscle Blood Flow increased linearly with the work of breathing (R2= 0.94) to 73.0 ± 8.8 ml min−1 (100 g)−1 at the ventilation seen at WRmax (work of breathing ∼550–600 J min−1), but during exercise it peaked at 80% WRmax (53.4 ± 10.3 ml min−1 (100 g)−1), significantly falling to 24.7 ± 5.3 ml min−1 (100 g)−1 at WRmax. At maximal ventilation intercostal Muscle vascular conductance was significantly lower during exercise (0.22 ± 0.05 ml min−1 (100 g)−1 mmHg−1) compared to isocapnic hyperpnoea (0.77 ± 0.13 ml min−1 (100 g)−1 mmHg−1). During exercise, both cardiac output and vastus lateralis Muscle Blood Flow also plateaued at about 80% WRmax (the latter at 95.4 ± 11.8 ml min−1 (100 g)−1). In conclusion, during exercise above 80% WRmax in trained subjects, intercostal Muscle Blood Flow and vascular conductance are less than during resting hyperpnoea at the same minute ventilation. This suggests that the circulatory system is unable to meet the demands of both locomotor and intercostal Muscles during heavy exercise, requiring greater O2 extraction and likely contributing to respiratory Muscle fatigue.
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Intercostal Muscle Blood Flow limitation in athletes during maximal exercise.
The Journal of physiology, 2009Co-Authors: Ioannis Vogiatzis, Dimitris Athanasopoulos, Helmut Habazettl, Wolfgang M Kuebler, Harrieth Wagner, Charis Roussos, Peter D Wagner, Spyros ZakynthinosAbstract:We investigated whether, during maximal exercise, intercostal Muscle Blood Flow is as high as during resting hyperpnoea at the same work of breathing. We hypothesized that during exercise, intercostal Muscle Blood Flow would be limited by competition from the locomotor Muscles. Intercostal (probe over the 7th intercostal space) and vastus lateralis Muscle perfusion were measured simultaneously in ten trained cyclists by near-infrared spectroscopy using indocyanine green dye. Measurements were made at several exercise intensities up to maximal (WRmax) and subsequently during resting isocapnic hyperpnoea at minute ventilation levels up to those at WRmax. During resting hyperpnoea, intercostal Muscle Blood Flow increased linearly with the work of breathing (R2 = 0.94) to 73.0 +/- 8.8 ml min-1 (100 g)-1 at the ventilation seen at WRmax (work of breathing approximately 550-600 J min-1), but during exercise it peaked at 80% WRmax (53.4 +/- 10.3 ml min-1 (100 g)-1), significantly falling to 24.7 +/- 5.3 ml min-1 (100 g)-1 at WRmax. At maximal ventilation intercostal Muscle vascular conductance was significantly lower during exercise (0.22 +/- 0.05 ml min-1 (100 g)-1 mmHg-1) compared to isocapnic hyperpnoea (0.77 +/- 0.13 ml min-1 (100 g)-1 mmHg-1). During exercise, both cardiac output and vastus lateralis Muscle Blood Flow also plateaued at about 80% WRmax (the latter at 95.4 +/- 11.8 ml min-1 (100 g)-1). In conclusion, during exercise above 80% WRmax in trained subjects, intercostal Muscle Blood Flow and vascular conductance are less than during resting hyperpnoea at the same minute ventilation. This suggests that the circulatory system is unable to meet the demands of both locomotor and intercostal Muscles during heavy exercise, requiring greater O2 extraction and likely contributing to respiratory Muscle fatigue.
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human respiratory Muscle Blood Flow measured by near infrared spectroscopy and indocyanine green
Journal of Applied Physiology, 2008Co-Authors: Jordan A Guenette, Ioannis Vogiatzis, Harrieth Wagner, Charis Roussos, Spyros Zakynthinos, Dimitrios Athanasopoulos, Maria Koskolou, Spyretta Golemati, Maroula Vasilopoulou, Peter D WagnerAbstract:Measurement of respiratory Muscle Blood Flow (RMBF) in humans has important implications for understanding patterns of Blood Flow distribution during exercise in healthy individuals and those with ...
Harrieth Wagner - One of the best experts on this subject based on the ideXlab platform.
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intercostal Muscle Blood Flow limitation during exercise in chronic obstructive pulmonary disease
American Journal of Respiratory and Critical Care Medicine, 2010Co-Authors: Ioannis Vogiatzis, Dimitris Athanasopoulos, Helmut Habazettl, Harrieth Wagner, Charis Roussos, Peter D Wagner, Zafeiris Louvaris, Andrea Aliverti, Evgenia Cherouveim, Spyros ZakynthinosAbstract:Rationale: It has been hypothesized that, because of the high work of breathing sustained by patients with chronic obstructive pulmonary disease (COPD) during exercise, Blood Flow may increase in favor of the respiratory Muscles, thereby compromising locomotor Muscle Blood Flow.Objectives: To test this hypothesis by investigating whether, at the same work of breathing, intercostal Muscle Blood Flow during exercise is as high as during resting isocapnic hyperpnea when respiratory and locomotor Muscles do not compete for the available Blood Flow.Methods: Intercostal and vastus lateralis Muscle perfusion was measured simultaneously in 10 patients with COPD (FEV1 = 50.5 ± 5.5% predicted) by near-infrared spectroscopy using indocyanine green dye.Measurements and Main Results: Measurements were made at several exercise intensities up to peak work rate (WRpeak) and subsequently during resting hyperpnea at minute ventilation levels up to those at WRpeak. During resting hyperpnea, intercostal Muscle Blood Flow inc...
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intercostal Muscle Blood Flow limitation in athletes during maximal exercise
The Journal of Physiology, 2009Co-Authors: Ioannis Vogiatzis, Dimitris Athanasopoulos, Helmut Habazettl, Wolfgang M Kuebler, Harrieth Wagner, Charis Roussos, Peter D Wagner, Spyros ZakynthinosAbstract:We investigated whether, during maximal exercise, intercostal Muscle Blood Flow is as high as during resting hyperpnoea at the same work of breathing. We hypothesized that during exercise, intercostal Muscle Blood Flow would be limited by competition from the locomotor Muscles. Intercostal (probe over the 7th intercostal space) and vastus lateralis Muscle perfusion were measured simultaneously in ten trained cyclists by near-infrared spectroscopy using indocyanine green dye. Measurements were made at several exercise intensities up to maximal (WRmax) and subsequently during resting isocapnic hyperpnoea at minute ventilation levels up to those at WRmax. During resting hyperpnoea, intercostal Muscle Blood Flow increased linearly with the work of breathing (R2= 0.94) to 73.0 ± 8.8 ml min−1 (100 g)−1 at the ventilation seen at WRmax (work of breathing ∼550–600 J min−1), but during exercise it peaked at 80% WRmax (53.4 ± 10.3 ml min−1 (100 g)−1), significantly falling to 24.7 ± 5.3 ml min−1 (100 g)−1 at WRmax. At maximal ventilation intercostal Muscle vascular conductance was significantly lower during exercise (0.22 ± 0.05 ml min−1 (100 g)−1 mmHg−1) compared to isocapnic hyperpnoea (0.77 ± 0.13 ml min−1 (100 g)−1 mmHg−1). During exercise, both cardiac output and vastus lateralis Muscle Blood Flow also plateaued at about 80% WRmax (the latter at 95.4 ± 11.8 ml min−1 (100 g)−1). In conclusion, during exercise above 80% WRmax in trained subjects, intercostal Muscle Blood Flow and vascular conductance are less than during resting hyperpnoea at the same minute ventilation. This suggests that the circulatory system is unable to meet the demands of both locomotor and intercostal Muscles during heavy exercise, requiring greater O2 extraction and likely contributing to respiratory Muscle fatigue.
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Intercostal Muscle Blood Flow limitation in athletes during maximal exercise.
The Journal of physiology, 2009Co-Authors: Ioannis Vogiatzis, Dimitris Athanasopoulos, Helmut Habazettl, Wolfgang M Kuebler, Harrieth Wagner, Charis Roussos, Peter D Wagner, Spyros ZakynthinosAbstract:We investigated whether, during maximal exercise, intercostal Muscle Blood Flow is as high as during resting hyperpnoea at the same work of breathing. We hypothesized that during exercise, intercostal Muscle Blood Flow would be limited by competition from the locomotor Muscles. Intercostal (probe over the 7th intercostal space) and vastus lateralis Muscle perfusion were measured simultaneously in ten trained cyclists by near-infrared spectroscopy using indocyanine green dye. Measurements were made at several exercise intensities up to maximal (WRmax) and subsequently during resting isocapnic hyperpnoea at minute ventilation levels up to those at WRmax. During resting hyperpnoea, intercostal Muscle Blood Flow increased linearly with the work of breathing (R2 = 0.94) to 73.0 +/- 8.8 ml min-1 (100 g)-1 at the ventilation seen at WRmax (work of breathing approximately 550-600 J min-1), but during exercise it peaked at 80% WRmax (53.4 +/- 10.3 ml min-1 (100 g)-1), significantly falling to 24.7 +/- 5.3 ml min-1 (100 g)-1 at WRmax. At maximal ventilation intercostal Muscle vascular conductance was significantly lower during exercise (0.22 +/- 0.05 ml min-1 (100 g)-1 mmHg-1) compared to isocapnic hyperpnoea (0.77 +/- 0.13 ml min-1 (100 g)-1 mmHg-1). During exercise, both cardiac output and vastus lateralis Muscle Blood Flow also plateaued at about 80% WRmax (the latter at 95.4 +/- 11.8 ml min-1 (100 g)-1). In conclusion, during exercise above 80% WRmax in trained subjects, intercostal Muscle Blood Flow and vascular conductance are less than during resting hyperpnoea at the same minute ventilation. This suggests that the circulatory system is unable to meet the demands of both locomotor and intercostal Muscles during heavy exercise, requiring greater O2 extraction and likely contributing to respiratory Muscle fatigue.
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human respiratory Muscle Blood Flow measured by near infrared spectroscopy and indocyanine green
Journal of Applied Physiology, 2008Co-Authors: Jordan A Guenette, Ioannis Vogiatzis, Harrieth Wagner, Charis Roussos, Spyros Zakynthinos, Dimitrios Athanasopoulos, Maria Koskolou, Spyretta Golemati, Maroula Vasilopoulou, Peter D WagnerAbstract:Measurement of respiratory Muscle Blood Flow (RMBF) in humans has important implications for understanding patterns of Blood Flow distribution during exercise in healthy individuals and those with ...
Charis Roussos - One of the best experts on this subject based on the ideXlab platform.
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intercostal Muscle Blood Flow limitation during exercise in chronic obstructive pulmonary disease
American Journal of Respiratory and Critical Care Medicine, 2010Co-Authors: Ioannis Vogiatzis, Dimitris Athanasopoulos, Helmut Habazettl, Harrieth Wagner, Charis Roussos, Peter D Wagner, Zafeiris Louvaris, Andrea Aliverti, Evgenia Cherouveim, Spyros ZakynthinosAbstract:Rationale: It has been hypothesized that, because of the high work of breathing sustained by patients with chronic obstructive pulmonary disease (COPD) during exercise, Blood Flow may increase in favor of the respiratory Muscles, thereby compromising locomotor Muscle Blood Flow.Objectives: To test this hypothesis by investigating whether, at the same work of breathing, intercostal Muscle Blood Flow during exercise is as high as during resting isocapnic hyperpnea when respiratory and locomotor Muscles do not compete for the available Blood Flow.Methods: Intercostal and vastus lateralis Muscle perfusion was measured simultaneously in 10 patients with COPD (FEV1 = 50.5 ± 5.5% predicted) by near-infrared spectroscopy using indocyanine green dye.Measurements and Main Results: Measurements were made at several exercise intensities up to peak work rate (WRpeak) and subsequently during resting hyperpnea at minute ventilation levels up to those at WRpeak. During resting hyperpnea, intercostal Muscle Blood Flow inc...
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intercostal Muscle Blood Flow limitation in athletes during maximal exercise
The Journal of Physiology, 2009Co-Authors: Ioannis Vogiatzis, Dimitris Athanasopoulos, Helmut Habazettl, Wolfgang M Kuebler, Harrieth Wagner, Charis Roussos, Peter D Wagner, Spyros ZakynthinosAbstract:We investigated whether, during maximal exercise, intercostal Muscle Blood Flow is as high as during resting hyperpnoea at the same work of breathing. We hypothesized that during exercise, intercostal Muscle Blood Flow would be limited by competition from the locomotor Muscles. Intercostal (probe over the 7th intercostal space) and vastus lateralis Muscle perfusion were measured simultaneously in ten trained cyclists by near-infrared spectroscopy using indocyanine green dye. Measurements were made at several exercise intensities up to maximal (WRmax) and subsequently during resting isocapnic hyperpnoea at minute ventilation levels up to those at WRmax. During resting hyperpnoea, intercostal Muscle Blood Flow increased linearly with the work of breathing (R2= 0.94) to 73.0 ± 8.8 ml min−1 (100 g)−1 at the ventilation seen at WRmax (work of breathing ∼550–600 J min−1), but during exercise it peaked at 80% WRmax (53.4 ± 10.3 ml min−1 (100 g)−1), significantly falling to 24.7 ± 5.3 ml min−1 (100 g)−1 at WRmax. At maximal ventilation intercostal Muscle vascular conductance was significantly lower during exercise (0.22 ± 0.05 ml min−1 (100 g)−1 mmHg−1) compared to isocapnic hyperpnoea (0.77 ± 0.13 ml min−1 (100 g)−1 mmHg−1). During exercise, both cardiac output and vastus lateralis Muscle Blood Flow also plateaued at about 80% WRmax (the latter at 95.4 ± 11.8 ml min−1 (100 g)−1). In conclusion, during exercise above 80% WRmax in trained subjects, intercostal Muscle Blood Flow and vascular conductance are less than during resting hyperpnoea at the same minute ventilation. This suggests that the circulatory system is unable to meet the demands of both locomotor and intercostal Muscles during heavy exercise, requiring greater O2 extraction and likely contributing to respiratory Muscle fatigue.
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Intercostal Muscle Blood Flow limitation in athletes during maximal exercise.
The Journal of physiology, 2009Co-Authors: Ioannis Vogiatzis, Dimitris Athanasopoulos, Helmut Habazettl, Wolfgang M Kuebler, Harrieth Wagner, Charis Roussos, Peter D Wagner, Spyros ZakynthinosAbstract:We investigated whether, during maximal exercise, intercostal Muscle Blood Flow is as high as during resting hyperpnoea at the same work of breathing. We hypothesized that during exercise, intercostal Muscle Blood Flow would be limited by competition from the locomotor Muscles. Intercostal (probe over the 7th intercostal space) and vastus lateralis Muscle perfusion were measured simultaneously in ten trained cyclists by near-infrared spectroscopy using indocyanine green dye. Measurements were made at several exercise intensities up to maximal (WRmax) and subsequently during resting isocapnic hyperpnoea at minute ventilation levels up to those at WRmax. During resting hyperpnoea, intercostal Muscle Blood Flow increased linearly with the work of breathing (R2 = 0.94) to 73.0 +/- 8.8 ml min-1 (100 g)-1 at the ventilation seen at WRmax (work of breathing approximately 550-600 J min-1), but during exercise it peaked at 80% WRmax (53.4 +/- 10.3 ml min-1 (100 g)-1), significantly falling to 24.7 +/- 5.3 ml min-1 (100 g)-1 at WRmax. At maximal ventilation intercostal Muscle vascular conductance was significantly lower during exercise (0.22 +/- 0.05 ml min-1 (100 g)-1 mmHg-1) compared to isocapnic hyperpnoea (0.77 +/- 0.13 ml min-1 (100 g)-1 mmHg-1). During exercise, both cardiac output and vastus lateralis Muscle Blood Flow also plateaued at about 80% WRmax (the latter at 95.4 +/- 11.8 ml min-1 (100 g)-1). In conclusion, during exercise above 80% WRmax in trained subjects, intercostal Muscle Blood Flow and vascular conductance are less than during resting hyperpnoea at the same minute ventilation. This suggests that the circulatory system is unable to meet the demands of both locomotor and intercostal Muscles during heavy exercise, requiring greater O2 extraction and likely contributing to respiratory Muscle fatigue.
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human respiratory Muscle Blood Flow measured by near infrared spectroscopy and indocyanine green
Journal of Applied Physiology, 2008Co-Authors: Jordan A Guenette, Ioannis Vogiatzis, Harrieth Wagner, Charis Roussos, Spyros Zakynthinos, Dimitrios Athanasopoulos, Maria Koskolou, Spyretta Golemati, Maroula Vasilopoulou, Peter D WagnerAbstract:Measurement of respiratory Muscle Blood Flow (RMBF) in humans has important implications for understanding patterns of Blood Flow distribution during exercise in healthy individuals and those with ...
