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Darrel P Francis - One of the best experts on this subject based on the ideXlab platform.

  • real time dynamic carbon dioxide administration a novel treatment strategy for stabilization of Periodic Breathing with potential application to central sleep apnea
    Journal of the American College of Cardiology, 2010
    Co-Authors: Alberto Giannoni, Michele Emdin, Keith Willson, Yoseph Mebrate, Charlotte Manisty, Resham Baruah, Jamil Mayet, Alun D Hughes, Darrel P Francis
    Abstract:

    Objectives This study targeted carbon dioxide (CO2) oscillations seen in oscillatory ventilation with dynamic pre-emptive CO2administration. Background Oscillations in end-tidal CO2(et-CO2) drive the ventilatory oscillations of Periodic Breathing (PB) and central sleep apnea in heart failure (HF). Methods Seven healthy volunteers simulated PB, while undergoing dynamic CO2administration delivered by an automated algorithm at different concentrations and phases within the PB cycle. The algorithm was then tested in 7 patients with HF and PB. Results In voluntary PB, the greatest reduction (74%, p Conclusions Dynamic CO2administration, delivered at an appropriate time during PB, can almost eliminate oscillations in et-CO2and ventilation. This dynamic approach might be developed to treat central sleep apnea, as well as minimizing undesirable increases in et-CO2and ventilation.

  • real time dynamic co2 administration a novel treatment strategy for Periodic Breathing
    American Thoracic Society International Conference, 2010
    Co-Authors: Resham Baruah, Alberto Giannoni, Michele Emdin, Keith Willson, Yoseph Mebrate, Charlotte Manisty, Jamil Mayet, Darrel P Francis
    Abstract:

    Objectives and background: Oscillations in end-tidal carbon dioxide (et-CO2) drive the characteristic ventilatory oscillations of Periodic Breathing (PB) and Cheyne-Stokes respiration (CSR) in heart failure (HF). Exogenous CO2 administration (constant concentration, constant flow) successfully avoids apnoeas but is associated with significantly increased et-CO2 which may contribute to sympathetic hyperactivity.

  • dynamic co2 therapy in Periodic Breathing a modeling study to determine optimal timing and dosage regimes
    Journal of Applied Physiology, 2009
    Co-Authors: Yoseph Mebrate, Keith Willson, Charlotte Manisty, Resham Baruah, Jamil Mayet, Alun D Hughes, Kim H Parker, Darrel P Francis
    Abstract:

    We examine the potential to treat unstable ventilatory control (seen in Periodic Breathing, Cheyne-Stokes respiration, and central sleep apnea) with carefully controlled dynamic administration of supplementary CO(2), aiming to reduce ventilatory oscillations with minimum increment in mean CO(2). We used a standard mathematical model to explore the consequences of phasic CO(2) administration, with different timing and dosing algorithms. We found an optimal time window within the ventilation cycle (covering approximately 1/6 of the cycle) during which CO(2) delivery reduces ventilatory fluctuations by >95%. Outside that time, therapy is dramatically less effective: indeed, for more than two-thirds of the cycle, therapy increases ventilatory fluctuations >30%. Efficiency of stabilizing ventilation improved when the algorithm gave a graded increase in CO(2) dose (by controlling its duration or concentration) for more severe Periodic Breathing. Combining gradations of duration and concentration further increased efficiency of therapy by 22%. The (undesirable) increment in mean end-tidal CO(2) caused was 300 times smaller with dynamic therapy than with static therapy, to achieve the same degree of ventilatory stabilization (0.0005 vs. 0.1710 kPa). The increase in average ventilation was also much smaller with dynamic than static therapy (0.005 vs. 2.015 l/min). We conclude that, if administered dynamically, dramatically smaller quantities of CO(2) could be used to reduce Periodic Breathing, with minimal adverse effects. Algorithms adjusting both duration and concentration in real time would achieve this most efficiently. If developed clinically as a therapy for Periodic Breathing, this would minimize excess acidosis, hyperventilation, and sympathetic overactivation, compared with static treatment.

  • impact of Periodic Breathing on measurement of oxygen uptake and respiratory exchange ratio during cardiopulmonary exercise testing
    Clinical Science, 2002
    Co-Authors: Darrel P Francis, Ceri L Davies, Keith Willson, Roland Wensel, Piotr Ponikowski, Andrew J S Coats, Massimo F Piepoli
    Abstract:

    Metabolic exercise testing is valuable in patients with chronic heart failure (CHF), but Periodic Breathing may confound the measurements. We aimed to examine the effects of Periodic Breathing on the measurement of oxygen uptake ( V*O(2)) and respiratory exchange ratio (RER). First, we measured the effects of different averaging procedures on peak V*O(2) and RER values in 122 patients with CHF undergoing cardiopulmonary exercise testing. Secondly, we studied the effects of Periodic Breathing on V*O2) and RER in healthy volunteers performing computer-guided Periodic Breathing. Thirdly, we used a Fourier analysis to study the effects of Periodic Breathing on gas exchange measurements. The first part of the study showed that 1 min moving window gave a mean peak V*O(2) of 13.8 ml.min(-1).kg(-1) for the CHF patients. A 15 s window gave significantly higher values. The difference averaged 1.0 ml.min(-1).kg(-1) ( P <0.0001), but varied widely: 41% of subjects showed a difference greater than 1.0 ml.min(-1).kg(-1). RER values were also higher by an average of 0.09 ( P <0.0001); in 20% of subjects the difference was greater than 0.10. In the second part of the study, we found artefactual elevations of peak V*O(2) (without averaging) of 2.9 ml.min(-1).kg(-1) ( P <0.01) and of peak RER of 0.13 ( P <0.001), which were still significant when 30 s averaging was applied [delta(peak V*O(2))=1.8 ml.min(-1).kg(-1), P <0.01; deltaRER=0.08, P <0.001]. The third, theoretical, part of the study showed that values of carbon dioxide output and V*O(2) oscillate with different phases and amplitudes, resulting in oscillations in their ratio, RER. Averaging over 15 s or 30 s can be expected to give only 10% or 36% attenuation respectively. Thus Periodic Breathing causes variable artefactual elevations of measured peak V*O(2) and RER, which can be attenuated by using longer averaging periods. Clinical reports and research publications describing peak V*O(2) in CHF should be accompanied by details of the averaging technique used.

  • quantitative general theory for Periodic Breathing in chronic heart failure and its clinical implications
    Circulation, 2000
    Co-Authors: Darrel P Francis, Ceri L Davies, Keith Willson, Andrew J S Coats, Massimo F Piepoli
    Abstract:

    Background—In patients with chronic heart failure (CHF), Periodic Breathing (PB) predicts poor prognosis. Clinical studies have identified numerous risk factors for PB (which also includes Cheyne-S...

Michele Emdin - One of the best experts on this subject based on the ideXlab platform.

  • roles of Periodic Breathing and isocapnic buffering period during exercise in heart failure
    European Journal of Preventive Cardiology, 2020
    Co-Authors: Piergiuseppe Agostoni, Michele Emdin, Anna Apostolo, Mauro Contini, Fabiana De Martino, Marco Mase, Cosimo Carriere, Carlo Vignati, Gianfranco Sinagra
    Abstract:

    In heart failure, exercise – induced Periodic Breathing and end tidal carbon dioxide pressure value during the isocapnic buffering period are two features identified at cardiopulmonary exercise tes...

  • persistence of Periodic Breathing cheyne stokes respiration after tilt table test during short term respiratory monitoring in patients with systolic heart failure
    Journal of the American College of Cardiology, 2018
    Co-Authors: Chiara Borrelli, Claudio Passino, Michele Emdin, Francesco Gentile, Paolo Sciarrone, Federico Rossari, Gianluca Mirizzi, Francesca Bramanti, Giovanni Iudice, Alberto Giannoni
    Abstract:

    Although Periodic Breathing (PB: hyperventilation/hypopneas) and Cheyne-Stokes respiration (CSR: hyperventilation/apneas) are usually considered to occur in lying and sleeping conditions in patients with heart failure (HF), there are recent evidences that both phenomena may spread throughout the 24-

  • targeting Periodic Breathing in heart failure patients and treating it gently
    Journal of Cardiac Failure, 2014
    Co-Authors: Michele Emdin, Claudio Passino
    Abstract:

    Cheyne and Stokes first described 2 centuries ago that patients with heart failure experience Periodic Breathing, characterized by waxing and waning of ventilation, with cycling apnea and hyperpnea phases, yet this observation has been for a long time disregarded in clinical practice. However, the most recent guidelines on HF management have outlined the evidence that a high percentage of heart failure patients present with disordered Breathing, associated with sleep fragmentation, adrenergic overactivation, and increased mortality, and that a specific treatment can be beneficial to improve left ventricular systolic function and functional status. Currently, the literature mostly refers to the occurrence of central apneas only during sleep (‘‘sleep apnea’’) and recommends polysomnography as the criterion diagnostic test and noninvasive mechanical ventilation (continuous positive airway pressure and, more recently, servoventilation) as the standard treatment. However, Periodic Breathing occurs frequently, even at daytime in awake patients, as demonstrated by laboratory or ambulatory polygraphy, and may be present even during effort, showing an independent and additive prognostic value compared with sleep apnea. Finally, noninvasive mechanical ventilation acts downstream on apneas only in asleep patients, with a poor compliance and a doubtful effect on survival, and it has no effect upstream on recognized pathophysiologic triggers and, therefore, is not able to treat daytime episodes of apnea. Several attempts have been made to cure Periodic Breathing, by targeting circulatory delay or altered chemoreflex sensitivity to hypoxia and/or hypercapnia, which both

  • real time dynamic carbon dioxide administration a novel treatment strategy for stabilization of Periodic Breathing with potential application to central sleep apnea
    Journal of the American College of Cardiology, 2010
    Co-Authors: Alberto Giannoni, Michele Emdin, Keith Willson, Yoseph Mebrate, Charlotte Manisty, Resham Baruah, Jamil Mayet, Alun D Hughes, Darrel P Francis
    Abstract:

    Objectives This study targeted carbon dioxide (CO2) oscillations seen in oscillatory ventilation with dynamic pre-emptive CO2administration. Background Oscillations in end-tidal CO2(et-CO2) drive the ventilatory oscillations of Periodic Breathing (PB) and central sleep apnea in heart failure (HF). Methods Seven healthy volunteers simulated PB, while undergoing dynamic CO2administration delivered by an automated algorithm at different concentrations and phases within the PB cycle. The algorithm was then tested in 7 patients with HF and PB. Results In voluntary PB, the greatest reduction (74%, p Conclusions Dynamic CO2administration, delivered at an appropriate time during PB, can almost eliminate oscillations in et-CO2and ventilation. This dynamic approach might be developed to treat central sleep apnea, as well as minimizing undesirable increases in et-CO2and ventilation.

  • real time dynamic co2 administration a novel treatment strategy for Periodic Breathing
    American Thoracic Society International Conference, 2010
    Co-Authors: Resham Baruah, Alberto Giannoni, Michele Emdin, Keith Willson, Yoseph Mebrate, Charlotte Manisty, Jamil Mayet, Darrel P Francis
    Abstract:

    Objectives and background: Oscillations in end-tidal carbon dioxide (et-CO2) drive the characteristic ventilatory oscillations of Periodic Breathing (PB) and Cheyne-Stokes respiration (CSR) in heart failure (HF). Exogenous CO2 administration (constant concentration, constant flow) successfully avoids apnoeas but is associated with significantly increased et-CO2 which may contribute to sympathetic hyperactivity.

Herbert Hamilton - One of the best experts on this subject based on the ideXlab platform.

  • mechanism of sleep induced Periodic Breathing in convalescing stroke patients and healthy elderly subjects
    Chest, 1993
    Co-Authors: David W Hudgel, Prema Devadatta, Mustafa Quadri, Eulogio R Sioson, Herbert Hamilton
    Abstract:

    Cerebral vascular ischemic strokes are known to precipitate Cheyne-Stokes Periodic Breathing. Interestingly, Cheyne-Stokes-like Breathing during sleep may be associated with obstructive sleep apnea (OSA) in some individuals. Therefore, it was reasoned that stroke patients with Periodic Breathing in sleep would be susceptible to OSA. Because oscillations in upper airway resistance can occur as a component of sleep-induced Periodic Breathing, we hypothesized that stroke patients with sleep-induced Periodic Breathing would have oscillations in upper airway resistance. These oscillations in resistance would be expected to contribute to OSA. We studied stroke patients with sleep-induced Periodic Breathing and control subjects to evaluate the relationship between upper airway resistance and ventilation in Periodic Breathing in sleep. Ventilation and upper airway resistance were measured in presleep wakefulness and in stage 2 NREM sleep. Mean tidal volume, minute ventilation, respiratory cycle timing variables, and upper airway resistance were not different between stroke and control subjects, either awake or asleep. Upper airway resistance increased and ventilation volume decreased from wakefulness to sleep in both groups. In an equivalent number of subjects from each group, reciprocal patterned oscillations in tidal volume and upper airway resistance were present at a 5 to 12.5 breath frequency during sleep. As upper airway resistance increased, tidal volume decreased. Stroke patients had wider fluctuations in upper airway resistance than control subjects, likely contributing to the higher number of sleep-disordered Breathing events observed in the stroke patients.

Alberto Giannoni - One of the best experts on this subject based on the ideXlab platform.

  • persistence of Periodic Breathing cheyne stokes respiration after tilt table test during short term respiratory monitoring in patients with systolic heart failure
    Journal of the American College of Cardiology, 2018
    Co-Authors: Chiara Borrelli, Claudio Passino, Michele Emdin, Francesco Gentile, Paolo Sciarrone, Federico Rossari, Gianluca Mirizzi, Francesca Bramanti, Giovanni Iudice, Alberto Giannoni
    Abstract:

    Although Periodic Breathing (PB: hyperventilation/hypopneas) and Cheyne-Stokes respiration (CSR: hyperventilation/apneas) are usually considered to occur in lying and sleeping conditions in patients with heart failure (HF), there are recent evidences that both phenomena may spread throughout the 24-

  • real time dynamic carbon dioxide administration a novel treatment strategy for stabilization of Periodic Breathing with potential application to central sleep apnea
    Journal of the American College of Cardiology, 2010
    Co-Authors: Alberto Giannoni, Michele Emdin, Keith Willson, Yoseph Mebrate, Charlotte Manisty, Resham Baruah, Jamil Mayet, Alun D Hughes, Darrel P Francis
    Abstract:

    Objectives This study targeted carbon dioxide (CO2) oscillations seen in oscillatory ventilation with dynamic pre-emptive CO2administration. Background Oscillations in end-tidal CO2(et-CO2) drive the ventilatory oscillations of Periodic Breathing (PB) and central sleep apnea in heart failure (HF). Methods Seven healthy volunteers simulated PB, while undergoing dynamic CO2administration delivered by an automated algorithm at different concentrations and phases within the PB cycle. The algorithm was then tested in 7 patients with HF and PB. Results In voluntary PB, the greatest reduction (74%, p Conclusions Dynamic CO2administration, delivered at an appropriate time during PB, can almost eliminate oscillations in et-CO2and ventilation. This dynamic approach might be developed to treat central sleep apnea, as well as minimizing undesirable increases in et-CO2and ventilation.

  • a Periodic Breathing novel experimental models to develop dynamic therapies
    Heart, 2010
    Co-Authors: R Baruah, Alberto Giannoni, Yoseph Mebrate, C Manisty, K Willson, A Kyriacou, S Sen, Mayooran Shanmuganathan, B Unsworth, H Yadav
    Abstract:

    Background Periodic Breathing (PB) is a common complication of heart failure (HF), characterised by oscillations in CO 2 and ventilation and associated with increased morbidity and mortality. Studying potential interventions for PB is difficult, because it is highly variable. We propose two experimental models and test two new dynamic therapies that target CO 2 oscillations directly. Methods and Results First, we aimed to produce a human model of PB using pacemakers. Pacemakers were manipulated in twelve pacemaker recipients, six with HF (EF=23.7±7.3%) and six without, to induce oscillations experimentally. Second, we applied a real-time algorithm of pre-emptive dynamic exogenous CO 2 administration, and tested different timings. We found that cardiac output alternation by pacemaker successfully induced CO 2 and ventilatory oscillations. Dynamic CO 2 therapy, when delivered coincident with hyperventilation, attenuated 64% of the experimentally-induced oscillations in end-tidal CO 2 : SD/mean 0.06±0.01 untreated vs 0.04±0.01 with treatment (p 2 did not significantly rise when dynamic CO2 was applied to the model (4.84±0.47 vs 4.91± 0.45 kPa, p=0.08). Furthermore, mean ventilation was also not significantly increased by dynamic CO 2 compared with untreated (0.13±0.02 vs 0.14±0.02 l/s, p=0.17). A second cohort of 14 patients with cardiac pacemakers (5 with HF (EF 27.6 ±13.9) and nine with normal systolic function) inhaled exogenous CO 2 that cycled from 0 to 4.25±1.8% every 30 s again inducing PB. In this group, cardiac output was then oscillated every 30 s in an attempt to alter the induced ventilatory oscillations. When cardiac output was oscillated from low too high every 30 s to coincide with peak ventilation, the degree of induced oscillation in et-CO 2 was reduced by 43% (SD/mean et-CO 2 during induced oscillations alone=0.08±0.02 vs SD/mean et-CO2 with alternation of cardiac output =0.05±0.02, p 2 , the degree of induced ventilatory oscillation was reduced 55% (SD/mean ventilation during induced oscillations alone=0.13±0.06 vs SD/mean ventilation with alternation of cardiac output=0.09±0.05, p Conclusion Both dynamic CO 2 administration and cardiac output modulation using a pacemaker, when correctly timed, successfully attenuated experimentally-induced ventilatory oscillations without increasing mean ventilation.

  • real time dynamic co2 administration a novel treatment strategy for Periodic Breathing
    American Thoracic Society International Conference, 2010
    Co-Authors: Resham Baruah, Alberto Giannoni, Michele Emdin, Keith Willson, Yoseph Mebrate, Charlotte Manisty, Jamil Mayet, Darrel P Francis
    Abstract:

    Objectives and background: Oscillations in end-tidal carbon dioxide (et-CO2) drive the characteristic ventilatory oscillations of Periodic Breathing (PB) and Cheyne-Stokes respiration (CSR) in heart failure (HF). Exogenous CO2 administration (constant concentration, constant flow) successfully avoids apnoeas but is associated with significantly increased et-CO2 which may contribute to sympathetic hyperactivity.

Claudio Passino - One of the best experts on this subject based on the ideXlab platform.

  • persistence of Periodic Breathing cheyne stokes respiration after tilt table test during short term respiratory monitoring in patients with systolic heart failure
    Journal of the American College of Cardiology, 2018
    Co-Authors: Chiara Borrelli, Claudio Passino, Michele Emdin, Francesco Gentile, Paolo Sciarrone, Federico Rossari, Gianluca Mirizzi, Francesca Bramanti, Giovanni Iudice, Alberto Giannoni
    Abstract:

    Although Periodic Breathing (PB: hyperventilation/hypopneas) and Cheyne-Stokes respiration (CSR: hyperventilation/apneas) are usually considered to occur in lying and sleeping conditions in patients with heart failure (HF), there are recent evidences that both phenomena may spread throughout the 24-

  • targeting Periodic Breathing in heart failure patients and treating it gently
    Journal of Cardiac Failure, 2014
    Co-Authors: Michele Emdin, Claudio Passino
    Abstract:

    Cheyne and Stokes first described 2 centuries ago that patients with heart failure experience Periodic Breathing, characterized by waxing and waning of ventilation, with cycling apnea and hyperpnea phases, yet this observation has been for a long time disregarded in clinical practice. However, the most recent guidelines on HF management have outlined the evidence that a high percentage of heart failure patients present with disordered Breathing, associated with sleep fragmentation, adrenergic overactivation, and increased mortality, and that a specific treatment can be beneficial to improve left ventricular systolic function and functional status. Currently, the literature mostly refers to the occurrence of central apneas only during sleep (‘‘sleep apnea’’) and recommends polysomnography as the criterion diagnostic test and noninvasive mechanical ventilation (continuous positive airway pressure and, more recently, servoventilation) as the standard treatment. However, Periodic Breathing occurs frequently, even at daytime in awake patients, as demonstrated by laboratory or ambulatory polygraphy, and may be present even during effort, showing an independent and additive prognostic value compared with sleep apnea. Finally, noninvasive mechanical ventilation acts downstream on apneas only in asleep patients, with a poor compliance and a doubtful effect on survival, and it has no effect upstream on recognized pathophysiologic triggers and, therefore, is not able to treat daytime episodes of apnea. Several attempts have been made to cure Periodic Breathing, by targeting circulatory delay or altered chemoreflex sensitivity to hypoxia and/or hypercapnia, which both