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Sample records for breathing cardiovascular variability

  1. Positive end-expiratory pressure may alter breathing cardiovascular variability and baroreflex gain in mechanically ventilated patients.

    PubMed

    Van de Louw, Andry; Médigue, Claire; Papelier, Yves; Cottin, François

    2010-04-19

    Baroreflex allows to reduce sudden rises or falls of arterial pressure through parallel RR interval fluctuations induced by autonomic nervous system. During spontaneous breathing, the application of positive end-expiratory pressure (PEEP) may affect the autonomic nervous system, as suggested by changes in baroreflex efficiency and RR variability. During mechanical ventilation, some patients have stable cardiorespiratory phase difference and high-frequency amplitude of RR variability (HF-RR amplitude) over time and others do not. Our first hypothesis was that a steady pattern could be associated with reduced baroreflex sensitivity and HF-RR amplitude, reflecting a blunted autonomic nervous function. Our second hypothesis was that PEEP, widely used in critical care patients, could affect their autonomic function, promoting both steady pattern and reduced baroreflex sensitivity. We tested the effect of increasing PEEP from 5 to 10 cm H2O on the breathing variability of arterial pressure and RR intervals, and on the baroreflex. Invasive arterial pressure, ECG and ventilatory flow were recorded in 23 mechanically ventilated patients during 15 minutes for both PEEP levels. HF amplitude of RR and systolic blood pressure (SBP) time series and HF phase differences between RR, SBP and ventilatory signals were continuously computed by complex demodulation. Cross-spectral analysis was used to assess the coherence and gain functions between RR and SBP, yielding baroreflex-sensitivity indices. At PEEP 10, the 12 patients with a stable pattern had lower baroreflex gain and HF-RR amplitude of variability than the 11 other patients. Increasing PEEP was generally associated with a decreased baroreflex gain and a greater stability of HF-RR amplitude and cardiorespiratory phase difference. Four patients who exhibited a variable pattern at PEEP 5 became stable at PEEP 10. At PEEP 10, a stable pattern was associated with higher organ failure score and catecholamine dosage. During

  2. Positive End-Expiratory Pressure may alter breathing cardiovascular variability and baroreflex gain in mechanically ventilated patients

    PubMed Central

    2010-01-01

    Background Baroreflex allows to reduce sudden rises or falls of arterial pressure through parallel RR interval fluctuations induced by autonomic nervous system. During spontaneous breathing, the application of positive end-expiratory pressure (PEEP) may affect the autonomic nervous system, as suggested by changes in baroreflex efficiency and RR variability. During mechanical ventilation, some patients have stable cardiorespiratory phase difference and high-frequency amplitude of RR variability (HF-RR amplitude) over time and others do not. Our first hypothesis was that a steady pattern could be associated with reduced baroreflex sensitivity and HF-RR amplitude, reflecting a blunted autonomic nervous function. Our second hypothesis was that PEEP, widely used in critical care patients, could affect their autonomic function, promoting both steady pattern and reduced baroreflex sensitivity. Methods We tested the effect of increasing PEEP from 5 to 10 cm H2O on the breathing variability of arterial pressure and RR intervals, and on the baroreflex. Invasive arterial pressure, ECG and ventilatory flow were recorded in 23 mechanically ventilated patients during 15 minutes for both PEEP levels. HF amplitude of RR and systolic blood pressure (SBP) time series and HF phase differences between RR, SBP and ventilatory signals were continuously computed by complex demodulation. Cross-spectral analysis was used to assess the coherence and gain functions between RR and SBP, yielding baroreflex-sensitivity indices. Results At PEEP 10, the 12 patients with a stable pattern had lower baroreflex gain and HF-RR amplitude of variability than the 11 other patients. Increasing PEEP was generally associated with a decreased baroreflex gain and a greater stability of HF-RR amplitude and cardiorespiratory phase difference. Four patients who exhibited a variable pattern at PEEP 5 became stable at PEEP 10. At PEEP 10, a stable pattern was associated with higher organ failure score and

  3. Slow breathing and cardiovascular disease

    PubMed Central

    Chaddha, Ashish

    2015-01-01

    Cardiovascular disease is the leading cause of death for both men and women worldwide. Much emphasis has been placed on the primary and secondary prevention of cardiovascular disease. While depression and anxiety increase the risk of developing cardiovascular disease, cardiovascular disease also increases the risk of developing anxiety and depression. Thus, promoting optimal mental health may be important for both primary and secondary prevention of cardiovascular disease. Like lowering blood pressure, lipids, and body weight, lowering anger and hostility and improving depression and anxiety may also be an important intervention in preventive cardiology. As we strive to further improve cardiovascular outcomes, the next bridge to cross may be one of offering patients nonpharmacologic means for combating daily mental stress and promoting mental health, such as yoga and pranayama. Indeed, the best preventive cardiovascular medicine may be a blend of both Western and Eastern medicine. PMID:26170595

  4. Slow breathing and cardiovascular disease.

    PubMed

    Chaddha, Ashish

    2015-01-01

    Cardiovascular disease is the leading cause of death for both men and women worldwide. Much emphasis has been placed on the primary and secondary prevention of cardiovascular disease. While depression and anxiety increase the risk of developing cardiovascular disease, cardiovascular disease also increases the risk of developing anxiety and depression. Thus, promoting optimal mental health may be important for both primary and secondary prevention of cardiovascular disease. Like lowering blood pressure, lipids, and body weight, lowering anger and hostility and improving depression and anxiety may also be an important intervention in preventive cardiology. As we strive to further improve cardiovascular outcomes, the next bridge to cross may be one of offering patients nonpharmacologic means for combating daily mental stress and promoting mental health, such as yoga and pranayama. Indeed, the best preventive cardiovascular medicine may be a blend of both Western and Eastern medicine.

  5. Sleep-disordered breathing and cardiovascular disease

    PubMed Central

    Anker, Stefan D.; von Haehling, Stephan; Germany, Robin

    2016-01-01

    Sleep-disordered breathing (SDB) is a common comorbidity in a number of cardiovascular diseases, and mounting clinical evidence demonstrates that it has important implications in the long-term outcomes of patients with cardiovascular disease (CVD). While recognition among clinicians of the role of SDB in CVD is increasing, it too often remains neglected in the routine care of patients with CVD, and therefore remains widely undiagnosed and untreated. In this article, we provide an overview of SDB and its relationship to CVD, with the goal of helping cardiovascular clinicians better recognize and treat this important comorbidity in their patients. We will describe the two major types of SDB and discuss the pathophysiologic, diagnostic, and therapeutic considerations of SDB in patients with CVD. PMID:27056657

  6. Controlled breathing protocols probe human autonomic cardiovascular rhythms

    NASA Technical Reports Server (NTRS)

    Cooke, W. H.; Cox, J. F.; Diedrich, A. M.; Taylor, J. A.; Beightol, L. A.; Ames, J. E. 4th; Hoag, J. B.; Seidel, H.; Eckberg, D. L.

    1998-01-01

    The purpose of this study was to determine how breathing protocols requiring varying degrees of control affect cardiovascular dynamics. We measured inspiratory volume, end-tidal CO2, R-R interval, and arterial pressure spectral power in 10 volunteers who followed the following 5 breathing protocols: 1) uncontrolled breathing for 5 min; 2) stepwise frequency breathing (at 0.3, 0.25, 0.2, 0.15, 0.1, and 0.05 Hz for 2 min each); 3) stepwise frequency breathing as above, but with prescribed tidal volumes; 4) random-frequency breathing (approximately 0.5-0.05 Hz) for 6 min; and 5) fixed-frequency breathing (0.25 Hz) for 5 min. During stepwise breathing, R-R interval and arterial pressure spectral power increased as breathing frequency decreased. Control of inspired volume reduced R-R interval spectral power during 0.1 Hz breathing (P < 0.05). Stepwise and random-breathing protocols yielded comparable coherence and transfer functions between respiration and R-R intervals and systolic pressure and R-R intervals. Random- and fixed-frequency breathing reduced end-tidal CO2 modestly (P < 0.05). Our data suggest that stringent tidal volume control attenuates low-frequency R-R interval oscillations and that fixed- and random-rate breathing may decrease CO2 chemoreceptor stimulation. We conclude that autonomic rhythms measured during different breathing protocols have much in common but that a stepwise protocol without stringent control of inspired volume may allow for the most efficient assessment of short-term respiratory-mediated autonomic oscillations.

  7. Variables influencing cardiovascular function.

    PubMed

    Fitzsimmons, L; Shively, M; Verderber, A

    1991-07-01

    Two studies are reviewed, one regarding the effects of music therapy on psychophysiologic stress in coronary care unit patients and one regarding the effects of age and gender on cardiovascular autonomic reactivity in healthy adults. Music therapy is determined to be safe for coronary care unit patients and effective in modulating the psychophysiologic manifestations of stress. The second study suggests that age--gender interactions may influence autonomic cardiovascular responsiveness. It is suggested that older adults be taught methods to reduce straining, so that rapid transient changes in blood pressure are avoided.

  8. The importance of sleep-disordered breathing in cardiovascular disease.

    PubMed

    Linz, Dominik; Woehrle, Holger; Bitter, Thomas; Fox, Henrik; Cowie, Martin R; Böhm, Michael; Oldenburg, Olaf

    2015-09-01

    Obstructive sleep apnoea and central sleep apnoea/Cheyne-Stokes respiration are collectively referred to as sleep-disordered breathing (SDB). Rapidly accumulating evidence suggests that both forms of SDB, and often a combination of both, are highly prevalent in patients with a wide variety of cardiovascular diseases, including hypertension, heart failure, arrhythmias, coronary artery disease, acute coronary syndrome and stroke. The presence of SDB in these patients is independently associated with worse cardiac function and exercise tolerance, recurrent arrhythmias, infarct expansion, decreased quality of life and increased mortality. Recent data suggest positive effects of positive airway pressure (PAP) therapy on quality of life and cardiovascular function. In addition, ongoing clinical trials may soon provide first definitive data on PAP therapy of SDB on hard outcomes such as mortality. This review presents current data highlighting links between SDB and a variety of cardiovascular conditions, the importance of recognising and diagnosing SDB in patients with cardiovascular disease, and the effects of effective SDB treatment on cardiovascular endpoints.

  9. A computational physiology approach to personalized treatment models: the beneficial effects of slow breathing on the human cardiovascular system.

    PubMed

    Fonoberova, Maria; Mezić, Igor; Buckman, Jennifer F; Fonoberov, Vladimir A; Mezić, Adriana; Vaschillo, Evgeny G; Mun, Eun-Young; Vaschillo, Bronya; Bates, Marsha E

    2014-10-01

    Heart rate variability biofeedback intervention involves slow breathing at a rate of ∼6 breaths/min (resonance breathing) to maximize respiratory and baroreflex effects on heart period oscillations. This intervention has wide-ranging clinical benefits and is gaining empirical support as an adjunct therapy for biobehavioral disorders, including asthma and depression. Yet, little is known about the system-level cardiovascular changes that occur during resonance breathing or the extent to which individuals differ in cardiovascular benefit. This study used a computational physiology approach to dynamically model the human cardiovascular system at rest and during resonance breathing. Noninvasive measurements of heart period, beat-to-beat systolic and diastolic blood pressure, and respiration period were obtained from 24 healthy young men and women. A model with respiration as input was parameterized to better understand how the cardiovascular processes that control variability in heart period and blood pressure change from rest to resonance breathing. The cost function used in model calibration corresponded to the difference between the experimental data and model outputs. A good match was observed between the data and model outputs (heart period, blood pressure, and corresponding power spectral densities). Significant improvements in several modeled cardiovascular functions (e.g., blood flow to internal organs, sensitivity of the sympathetic component of the baroreflex, ventricular elastance) were observed during resonance breathing. Individual differences in the magnitude and nature of these dynamic responses suggest that computational physiology may be clinically useful for tailoring heart rate variability biofeedback interventions for the needs of individual patients. Copyright © 2014 the American Physiological Society.

  10. A computational physiology approach to personalized treatment models: the beneficial effects of slow breathing on the human cardiovascular system

    PubMed Central

    Fonoberova, Maria; Mezić, Igor; Buckman, Jennifer F.; Fonoberov, Vladimir A.; Mezić, Adriana; Vaschillo, Evgeny G.; Mun, Eun-Young; Vaschillo, Bronya

    2014-01-01

    Heart rate variability biofeedback intervention involves slow breathing at a rate of ∼6 breaths/min (resonance breathing) to maximize respiratory and baroreflex effects on heart period oscillations. This intervention has wide-ranging clinical benefits and is gaining empirical support as an adjunct therapy for biobehavioral disorders, including asthma and depression. Yet, little is known about the system-level cardiovascular changes that occur during resonance breathing or the extent to which individuals differ in cardiovascular benefit. This study used a computational physiology approach to dynamically model the human cardiovascular system at rest and during resonance breathing. Noninvasive measurements of heart period, beat-to-beat systolic and diastolic blood pressure, and respiration period were obtained from 24 healthy young men and women. A model with respiration as input was parameterized to better understand how the cardiovascular processes that control variability in heart period and blood pressure change from rest to resonance breathing. The cost function used in model calibration corresponded to the difference between the experimental data and model outputs. A good match was observed between the data and model outputs (heart period, blood pressure, and corresponding power spectral densities). Significant improvements in several modeled cardiovascular functions (e.g., blood flow to internal organs, sensitivity of the sympathetic component of the baroreflex, ventricular elastance) were observed during resonance breathing. Individual differences in the magnitude and nature of these dynamic responses suggest that computational physiology may be clinically useful for tailoring heart rate variability biofeedback interventions for the needs of individual patients. PMID:25063789

  11. Cardiovascular Disease and Sleep-Disordered Breathing in Acromegaly.

    PubMed

    Powlson, Andrew S; Gurnell, Mark

    2016-01-01

    Treatment goals in acromegaly include symptom relief, tumour control and reversal of the excess morbidity and mortality associated with the disorder. Cardiovascular complications include concentric biventricular hypertrophy and cardiomyopathy, hypertension, valvular heart disease and arrhythmias, while metabolic disturbance (insulin resistance/diabetes mellitus, dyslipidaemia) further increases the risk of cardiovascular and cerebrovascular events. Sleep-disordered breathing (in the form of sleep apnoea) is also common in patients with acromegaly and may exacerbate cardiovascular dysfunction, in addition to contributing to impaired quality of life. Accordingly, and in keeping with evidence that cardiorespiratory complications in acromegaly are not automatically reversed/ameliorated simply through the attainment of 'safe' growth hormone and insulin-like growth factor 1 levels, recent guidelines have emphasised the need not only to achieve stringent biochemical control, but also to identify and independently treat these comorbidities. It is important, therefore, that patients with acromegaly are systematically screened at diagnosis, and periodically thereafter, for the common cardiovascular and respiratory manifestations and that biochemical targets do not become the only treatment goal. © 2015 S. Karger AG, Basel.

  12. Essential Hypertension: Cardiovascular Response to Breath Hold Combined with Exercise.

    PubMed

    Hoffmann, U; Urban, P; Koschate, J; Drescher, U; Pfister, R; Michels, G

    2015-07-01

    Essential hypertension (EH) is a widespread disease and might be prevalent in apnea divers and master athletes. Little is known about the influence of EH and the antihypertensive drugs (AHD) on cardiovascular reactions to combined breath hold (BH) and exercise. In this pilot study, healthy divers (HCON) were compared with treated hypertensive divers with regard to heart rate (HR) and mean blood-pressure (MAP) responses to BH, exercise and the combination of both. Ten subjects with EH and ten healthy divers were tested. 3 different 20 s stimuli were applied: BH combined with 30 W or 150 W and 150 W without BH. The time-charts during the stress intervals and during recovery were compared. Subjects treated with an angiotensin-converting enzyme (ACE) inhibitor showed higher changes for MAP values if breath hold was performed. HR responses were obviously changed if a β-blocker was part of the medication. One subject showed extreme MAP responses to all stimuli and conspicuous HR if BH was involved. The modulation of HR-/MAP-response in EH subjects depends on the mechanisms of antihypertensive agents. The combination of an ACE inhibitor and a β-blocker may give the best protection. It is recommended to include short apnea tests in the fitness-to-dive examination to individually predict potential endangerment.

  13. Heart rate variability with deep breathing as a clinical test of cardiovagal function.

    PubMed

    Shields, Robert W

    2009-04-01

    Research into heart rate variability (HRV) and respiration over the past 150 years has led to the insight that HRV with deep breathing (HRVdb) is a highly sensitive measure of cardiovagal or parasympathetic cardiac function. This sensitivity makes HRVdb an important part of the battery of cardiovascular autonomic function tests used in clinical autonomic laboratories. HRVdb is a reliable and sensitive clinical test for early detection of cardiovagal dysfunction in a wide range of autonomic disorders.

  14. Beat to beat variability in cardiovascular variables: noise or music?

    NASA Technical Reports Server (NTRS)

    Appel, M. L.; Berger, R. D.; Saul, J. P.; Smith, J. M.; Cohen, R. J.

    1989-01-01

    Cardiovascular variables such as heart rate, arterial blood pressure, stroke volume and the shape of electrocardiographic complexes all fluctuate on a beat to beat basis. These fluctuations have traditionally been ignored or, at best, treated as noise to be averaged out. The variability in cardiovascular signals reflects the homeodynamic interplay between perturbations to cardiovascular function and the dynamic response of the cardiovascular regulatory systems. Modern signal processing techniques provide a means of analyzing beat to beat fluctuations in cardiovascular signals, so as to permit a quantitative, noninvasive or minimally invasive method of assessing closed loop hemodynamic regulation and cardiac electrical stability. This method promises to provide a new approach to the clinical diagnosis and management of alterations in cardiovascular regulation and stability.

  15. Beat to beat variability in cardiovascular variables: noise or music?

    NASA Technical Reports Server (NTRS)

    Appel, M. L.; Berger, R. D.; Saul, J. P.; Smith, J. M.; Cohen, R. J.

    1989-01-01

    Cardiovascular variables such as heart rate, arterial blood pressure, stroke volume and the shape of electrocardiographic complexes all fluctuate on a beat to beat basis. These fluctuations have traditionally been ignored or, at best, treated as noise to be averaged out. The variability in cardiovascular signals reflects the homeodynamic interplay between perturbations to cardiovascular function and the dynamic response of the cardiovascular regulatory systems. Modern signal processing techniques provide a means of analyzing beat to beat fluctuations in cardiovascular signals, so as to permit a quantitative, noninvasive or minimally invasive method of assessing closed loop hemodynamic regulation and cardiac electrical stability. This method promises to provide a new approach to the clinical diagnosis and management of alterations in cardiovascular regulation and stability.

  16. Infant breathing rate counter based on variable resistor for pneumonia

    NASA Astrophysics Data System (ADS)

    Sakti, Novi Angga; Hardiyanto, Ardy Dwi; La Febry Andira R., C.; Camelya, Kesa; Widiyanti, Prihartini

    2016-03-01

    Pneumonia is one of the leading causes of death in new born baby in Indonesia. According to WHO in 2002, breathing rate is very important index to be the symptom of pneumonia. In the Community Health Center, the nurses count with a stopwatch for exactly one minute. Miscalculation in Community Health Center occurs because of long time concentration and focus on two object at once. This calculation errors can cause the baby who should be admitted to the hospital only be attended at home. Therefore, an accurate breathing rate counter at Community Health Center level is necessary. In this work, resistance change of variable resistor is made to be breathing rate counter. Resistance change in voltage divider can produce voltage change. If the variable resistance moves periodically, the voltage will change periodically too. The voltage change counted by software in the microcontroller. For the every mm shift at the variable resistor produce average 0.96 voltage change. The software can count the number of wave generated by shifting resistor.

  17. Heart Rate Variability Dynamics for the Prognosis of Cardiovascular Risk

    PubMed Central

    Ramirez-Villegas, Juan F.; Lam-Espinosa, Eric; Ramirez-Moreno, David F.; Calvo-Echeverry, Paulo C.; Agredo-Rodriguez, Wilfredo

    2011-01-01

    Statistical, spectral, multi-resolution and non-linear methods were applied to heart rate variability (HRV) series linked with classification schemes for the prognosis of cardiovascular risk. A total of 90 HRV records were analyzed: 45 from healthy subjects and 45 from cardiovascular risk patients. A total of 52 features from all the analysis methods were evaluated using standard two-sample Kolmogorov-Smirnov test (KS-test). The results of the statistical procedure provided input to multi-layer perceptron (MLP) neural networks, radial basis function (RBF) neural networks and support vector machines (SVM) for data classification. These schemes showed high performances with both training and test sets and many combinations of features (with a maximum accuracy of 96.67%). Additionally, there was a strong consideration for breathing frequency as a relevant feature in the HRV analysis. PMID:21386966

  18. Heart rate variability and stroke volume variability to detect central hypovolemia during spontaneous breathing and supported ventilation in young, healthy volunteers.

    PubMed

    Elstad, Maja; Walløe, Lars

    2015-04-01

    Cardiovascular oscillations exist in many different variables and may give important diagnostic and prognostic information in patients. Variability in cardiac stroke volume (SVV) is used in clinical practice for diagnosis of hypovolemia, but currently is limited to patients on mechanical ventilation. We investigated if SVV and heart rate variability (HRV) could detect central hypovolemia in spontaneously breathing humans: We also compared cardiovascular variability during spontaneous breathing with supported mechanical ventilation.Ten subjects underwent simulated central hypovolemia by lower body negative pressure (LBNP) with >10% reduction of cardiac stroke volume. The subjects breathed spontaneously and with supported mechanical ventilation. Heart rate, respiratory frequency and mean arterial blood pressure were measured. Stroke volume (SV) was estimated by ModelFlow (Finometer). Respiratory SVV was calculated by: 1) SVV% = (SVmax - SVmin)/SVmean during one respiratory cycle, 2) SVIntegral from the power spectra (Fourier transform) at 0.15-0.4 Hz and 3) SVV_norm = (√SVIntegral)/SVmean. HRV was calculated by the same methods.During spontaneous breathing two measures of SVV and all three measures of HRV were reduced during hypovolemia compared to baseline. During spontaneous breathing SVIntegral and HRV% were best to detect hypovolemia (area under receiver operating curve 0.81). HRV% ≤ 11% and SVIntegral ≤ 12 ml(2) differentiated between hypovolemia and baseline during spontaneous breathing.During supported mechanical ventilation, none of the three measures of SVV changed and two of the HRV measures were reduced during hypovolemia. Neither measures of SVV nor HRV were classified as a good detector of hypovolemia.We conclude that HRV% and SVIntegral detect hypovolemia during spontaneous breathing and both are candidates for further clinical testing.

  19. Breath-to-breath variability of exhaled CO2 as a marker of lung dysmaturity in infancy.

    PubMed

    Fouzas, Sotirios; Theodorakopoulos, Ilias; Delgado-Eckert, Edgar Wilfried; Latzin, Philipp; Frey, Urs

    2017-09-07

    The concept of diffusional screening implies that breath-to-breath variations in CO2 clearance, when related to the variability of breathing, may contain information on the quality and utilization of the available alveolar surface. We explored the validity of the above hypothesis in a cohort of young infants of comparable post-menstrual age but born at different stages of lung maturity, namely, in term-born infants (N = 128), preterm-born infants without chronic lung disease of infancy (CLDI) (N = 53) and preterm infants with moderate/severe CLDI (N = 87). Exhaled CO2 volume (VE,CO2) and concentration (FE,CO2) were determined by volumetric capnography, while their variance was assessed by linear and non-linear variability metrics. The relationship between relative breath-to-breath change of VE,CO2 (ΔVE,CO2) and the corresponding change of tidal volume (VT), was also analyzed. Non-linear FE,CO2 variability was lower in CLDI compared to term and non-CLDI preterm group (P<0.001 for both comparisons). In CLDI infants, most of the VE,CO2 variability was attributed to the variability of VT (R(2) 0.749), while in term and healthy preterm infants this relationship was weaker (R(2) 0.507 and 0.630, respectively). The ΔVE,CO2-ΔVT slope was less steep in the CLDI group (1.06 ± 0.07) compared to non-CLDI preterm (1.16 ± 0.07; P <0.001) and term infants (1.20 ± 0.10; P <0.001), suggesting that the more dysmature the infant lung the less efficiently it eliminates CO2 under tidal breathing conditions. We conclude that the temporal variation of CO2 clearance may be related to the degree of lung dysmaturity in early infancy. Copyright © 2017, Journal of Applied Physiology.

  20. Low-frequency heart rate variability is related to the breath-to-breath variability in the respiratory pattern.

    PubMed

    Beda, Alessandro; Simpson, David M; Carvalho, Nadja C; Carvalho, Alysson Roncally S

    2014-02-01

    Changes in heart rate variability (HRV) at "respiratory" frequencies (0.15-0.5 Hz) may result from changes in respiration rather than autonomic control. We now investigate if the differences in HRV power in the low-frequency (LF) band (0.05-0.15 Hz, HRV(LF)) can also be predicted by respiration variability, quantified by the fraction of tidal volume power in the LF (V(LF,n)). Three experimental protocols were considered: paced breathing, mental effort tasks, and a repeated attentional task. Significant intra- and interindividual correlations were found between changes in HRV(LF) and V(LF,n) despite all subjects having a respiratory frequency above the LF band. Respiratory parameters (respiratory period, tidal volume, and V(LF,n)) could predict up to 79% of HRV(LF) differences in some cases. This suggests that respiratory variability is another mechanism of HRV(LF) generation, which should be always monitored, assessed, and considered in the interpretation of HRV changes.

  1. An integrative model of respiratory and cardiovascular control in sleep-disordered breathing

    PubMed Central

    Cheng, Limei; Ivanova, Olga; Fan, Hsing-Hua; Khoo, Michael C. K.

    2010-01-01

    While many physiological control models exist in the literature, none thus far has focused on characterizing the interactions among the respiratory, cardiovascular and sleep-wake regulation systems that occur in sleep-disordered breathing. The model introduced in this study integrates the autonomic control of the cardiovascular system, chemoreflex and state-related control of respiration, including respiratory and upper airway mechanics, along with a model of circadian and sleep-wake regulation. The integrative model provides realistic predictions of the physiological responses under a variety of conditions including: the sleep-wake cycle, hypoxia-induced periodic breathing, Cheyne-Stokes respiration in chronic heart failure, and obstructive sleep apnoea (OSA). It can be used to investigate the effects of a variety of interventions, such as isocapnic and hypercapnic and/or hypoxic gas administration, the Valsalva and Mueller maneuvers, and the application of continuous positive airway pressure on OSA subjects. By being able to delineate the influences of the various interacting physiological mechanisms, the model is useful in providing a more lucid understanding of the complex dynamics that characterize state-cardiorespiratory control in the different forms of sleep-disordered breathing. PMID:20542148

  2. Tai Chi Chuan modulates heart rate variability during abdominal breathing in elderly adults.

    PubMed

    Wei, Gao-Xia; Li, You-Fa; Yue, Xiao-Lin; Ma, Xiao; Chang, Yu-Kai; Yi, Long-Yan; Li, Jing-Cheng; Zuo, Xi-Nian

    2016-03-01

    Tai Chi Chuan (TCC) practice is currently intentionally applied in clinical populations, especially those with cardiovascular diseases because of its potential benefits on the autonomic nervous system. The long-term effect of TCC practice on heart rate variability (HRV) remains largely unknown. In this study, we recruited 23 TCC practitioners whose experience averaged approximately 21 years and 19 controls matched by age, sex and education to examine the effect of TCC practice on the autonomic nervous system during a resting state and during an abdominal breathing state. HRV was measured by traditional electrocardiogram (ECG) recording. The results showed that the low frequency, total power frequency, and normalized low frequency components and the low-frequency/high-frequency ratio were significantly higher, whereas the normalized high frequency was significantly lower in the TCC practitioners relative to controls during the abdominal breathing state. However, we did not detect any significant difference in the HRV measures during the resting state between the two groups. Additionally, TCC experience did not correlate with HRV components either in the abdominal state or the resting state in the TCC group. Considering all of these findings, we suggest that TCC improves vagal activity and the balance between sympathetic and parasympathetic activity during the relaxation state. This study also provides direct physiological evidence for the role of TCC practice in relaxation.

  3. Phase Synchronization of Hemodynamic Variables at Rest and after Deep Breathing Measured during the Course of Pregnancy

    PubMed Central

    Papousek, Ilona; Roessler, Andreas; Hinghofer-Szalkay, Helmut; Lang, Uwe; Kolovetsiou-Kreiner, Vassiliki

    2013-01-01

    Background The autonomic nervous system plays a central role in the functioning of systems critical for the homeostasis maintenance. However, its role in the cardiovascular adaptation to pregnancy-related demands is poorly understood. We explored the maternal cardiovascular systems throughout pregnancy to quantify pregnancy-related autonomic nervous system adaptations. Methodology Continuous monitoring of heart rate (R-R interval; derived from the 3-lead electrocardiography), blood pressure, and thoracic impedance was carried out in thirty-six women at six time-points throughout pregnancy. In order to quantify in addition to the longitudinal effects on baseline levels throughout gestation the immediate adaptive heart rate and blood pressure changes at each time point, a simple reflex test, deep breathing, was applied. Consequently, heart rate variability and blood pressure variability in the low (LF) and high (HF) frequency range, respiration and baroreceptor sensitivity were analyzed in resting conditions and after deep breathing. The adjustment of the rhythms of the R-R interval, blood pressure and respiration partitioned for the sympathetic and the parasympathetic branch of the autonomic nervous system were quantified by the phase synchronization index γ, which has been adopted from the analysis of weakly coupled chaotic oscillators. Results Heart rate and LF/HF ratio increased throughout pregnancy and these effects were accompanied by a continuous loss of baroreceptor sensitivity. The increases in heart rate and LF/HF ratio levels were associated with an increasing decline in the ability to flexibly respond to additional demands (i.e., diminished adaptive responses to deep breathing). The phase synchronization index γ showed that the observed effects could be explained by a decreased coupling of respiration and the cardiovascular system (HF components of heart rate and blood pressure). Conclusions/Significance The findings suggest that during the course of

  4. Heart rate variability and muscle sympathetic nerve activity response to acute stress: the effect of breathing

    PubMed Central

    DeBeck, Lindsay D.; Petersen, Stewart R.; Jones, Kelvin E.; Stickland, Michael K.

    2016-01-01

    Previous research has suggested a relationship between low-frequency power of heart rate variability (HRV; LF in normalized units, LFnu) and muscle sympathetic nerve activity (MSNA). However, investigations have not systematically controlled for breathing, which can modulate both HRV and MSNA. Accordingly, the aims of this experiment were to investigate the possibility of parallel responses in MSNA and HRV (LFnu) to selected acute stressors and the effect of controlled breathing. After data were obtained at rest, 12 healthy males (28 ± 5 yr) performed isometric handgrip exercise (30% maximal voluntary contraction) and the cold pressor test in random order, and were then exposed to hypoxia (inspired fraction of O2 = 0.105) for 7 min, during randomly assigned spontaneous and controlled breathing conditions (20 breaths/min, constant tidal volume, isocapnic). MSNA was recorded from the peroneal nerve, whereas HRV was calculated from ECG. At rest, controlled breathing did not alter MSNA but decreased LFnu (P < 0.05 for all) relative to spontaneous breathing. MSNA increased in response to all stressors regardless of breathing. LFnu increased with exercise during both breathing conditions. During cold pressor, LFnu decreased when breathing was spontaneous, whereas in the controlled breathing condition, LFnu was unchanged from baseline. Hypoxia elicited increases in LFnu when breathing was controlled, but not during spontaneous breathing. The parallel changes observed during exercise and controlled breathing during hypoxia suggest that LFnu may be an indication of sympathetic outflow in select conditions. However, since MSNA and LFnu did not change in parallel with all stressors, a cautious approach to the use of LFnu as a marker of sympathetic activity is warranted. PMID:20410469

  5. Heart rate variability and muscle sympathetic nerve activity response to acute stress: the effect of breathing.

    PubMed

    DeBeck, Lindsay D; Petersen, Stewart R; Jones, Kelvin E; Stickland, Michael K

    2010-07-01

    Previous research has suggested a relationship between low-frequency power of heart rate variability (HRV; LF in normalized units, LFnu) and muscle sympathetic nerve activity (MSNA). However, investigations have not systematically controlled for breathing, which can modulate both HRV and MSNA. Accordingly, the aims of this experiment were to investigate the possibility of parallel responses in MSNA and HRV (LFnu) to selected acute stressors and the effect of controlled breathing. After data were obtained at rest, 12 healthy males (28 +/- 5 yr) performed isometric handgrip exercise (30% maximal voluntary contraction) and the cold pressor test in random order, and were then exposed to hypoxia (inspired fraction of O(2) = 0.105) for 7 min, during randomly assigned spontaneous and controlled breathing conditions (20 breaths/min, constant tidal volume, isocapnic). MSNA was recorded from the peroneal nerve, whereas HRV was calculated from ECG. At rest, controlled breathing did not alter MSNA but decreased LFnu (P < 0.05 for all) relative to spontaneous breathing. MSNA increased in response to all stressors regardless of breathing. LFnu increased with exercise during both breathing conditions. During cold pressor, LFnu decreased when breathing was spontaneous, whereas in the controlled breathing condition, LFnu was unchanged from baseline. Hypoxia elicited increases in LFnu when breathing was controlled, but not during spontaneous breathing. The parallel changes observed during exercise and controlled breathing during hypoxia suggest that LFnu may be an indication of sympathetic outflow in select conditions. However, since MSNA and LFnu did not change in parallel with all stressors, a cautious approach to the use of LFnu as a marker of sympathetic activity is warranted.

  6. Investigations on the variability of breath gas sampling using PTR-MS.

    PubMed

    Thekedar, B; Szymczak, W; Höllriegl, V; Hoeschen, C; Oeh, U

    2009-06-01

    Breath gas analysis is a promising technology in the frame of medical diagnostics. By identifying disease-specific biomarkers in the breath of patients, a non-invasive and easy method for early diagnosis or therapy monitoring might be developed. However, to verify this potential and develop diagnostic tools based on breath gas analysis one essential prerequisite is a low variability in measurement of exhaled volatile organic compounds. Therefore, a study has been undertaken in order to identify possible artefacts within the application of a breath gas test in practice, for which the breath gas is analysed by proton transfer reaction-mass spectrometry (PTR-MS). After validating the low instrumental variability by repeatedly measuring standard gas, the variability of breath gas sampling has been evaluated. The latter has been carried out by measuring single breath gas samples (mixed expiratory breath) collected over different periods of time such as 1 min (10 volunteers, 4 breath gas samples each), 1 h (10 volunteers, 11 breath gas samples each) and several days (11 volunteers, 10 breath gas samples each). The breath gas samples were collected in Teflon bags and consecutively measured with PTR-MS. It was found that those samples collected within 1 min and 1 h show a low variability. This was, however, not the case for samples being collected over longer periods of time (15-70 days). Under these circumstances, many volatile organic compounds (VOCs) showed significant day-to-day variation in concentration, although the breath collection had been performed under the same conditions (similar sampling time, sampling technique, sample storage time, measurement conditions, etc). This large variation might be assigned to the influence of room air VOCs, which have been investigated in this work, or with other parameters which will be discussed. It was also found that the variability in the measurement of exhaled concentrations of methanol, acetone and isoprene within

  7. Patent foramen ovale: a novel cardiovascular risk factor in patients with sleep disordered breathing and high altitude dwellers?

    PubMed

    Rexhai, Emrush; Scherrer, Urs; Rimoldi, Stefano F

    2016-01-01

    Diseases associated with chronic hypoxaemia are a leading cause of morbidity and mortality in Western countries. Epidemiological data indicate that cardiovascular diseases contribute substantially to this problem, but the underlying mechanisms are incompletely understood. Sleep disordered breathing and high altitude exposure are frequent conditions associated with hypoxaemia. Recent evidence suggests that in these conditions the concomitant presence of a patent foramen ovale plays an important pathogenic role. For example, in patients with obstructive sleep apnoea the presence of a patent foramen ovale is associated with more severe sleep disordered breathing, nocturnal oxygen desaturation, generalised endothelial dysfunction and arterial hypertension. After patent foramen ovale closure, both sleep disordered breathing and cardiovascular phenotype improve, suggesting the existence of a possible causal link. During short-term high altitude exposure, the presence of a patent foramen ovale, by aggravating altitude-induced hypoxaemia, facilitates exaggerated pulmonary hypertension. Interestingly, there is increasing evidence showing that in high-altitude dwellers a patent foramen ovale also alters the cardiovascular phenotype. In this article we will summarise recent evidence demonstrating how a patent foramen ovale alters the cardiovascular phenotype and increases cardiovascular risk in patients with sleep disordered breathing and high-altitude dwellers.

  8. Increased variability in respiratory parameters heralds obstructive events in children with sleep disordered breathing.

    PubMed

    Immanuel, Sarah A; Kohler, Mark; Pamula, Yvonne; Kabir, Muammar M; Saint, David A; Baumert, Mathias

    2013-01-01

    Sleep disordered breathing (SDB) is characterized by repeated episodes of central or obstructive apneas, disturbing respiratory patterns. The purpose of this study is to quantify respiratory variability associated with apneic/hypopneic events by computing respiratory parameters and thoraco-abdominal asynchrony (TAA) over sleep periods preceding the occurrence of obstructive events in children with SDB. One minute artifact-free epochs of ribcage (RC) and abdominal (AB) signals were extracted from the respiratory inductive plethysmograph (RIP) channel of the PSG prior to the onset of each obstruction. Breath-by-breath values of TAA were computed using a Hilbert transform based technique that measures the phase shift between the RC and AB signals. In addition, the following parameters were computed breath-by-breath from the RC signal: inspiratory time (Ti), expiratory time (Te), total time (Ttot), and the inspiratory duty cycle (DC=Ti/Ttot). Standard deviation of the parameters (SD_TAA, SD_Ti, SD_Te, SD_Ttot, SD_DC) over each 1 min epoch were calculated and averaged over each subject with respect to sleep stage. For comparison, similar measures were computed from within quiet breathing periods of each subject. We found that breaths immediately before apnea/hypopneas were associated with a high degree of variability in respiratory timing and TAA. The proposed variability analysis of RIP signals may be useful for detecting acute epochs of respiratory instability in children with SDB.

  9. Variability of the breathing pattern in newborn rats: effects of ambient temperature in normoxia or hypoxia.

    PubMed

    Cameron, Y L; Merazzi, D; Mortola, J P

    2000-06-01

    We hypothesized that the inter-breath variability of the breathing pattern in newborn rats varied with temperature and oxygenation. Breathing pattern was recorded in 4-day-old rats by airflow plethysmography, during normoxia in warm (control) and cold conditions, or during hypoxia (inspired O2 = 10%) in warm or cold conditions, each lasting 15 min. The warm phase (36 degrees C) either preceded or followed the cold (24 degrees C). Time-domain analysis was applied to 500 continuous breaths recorded toward the end of each phase. All parameters describing the breathing pattern (instantaneous ventilation, tidal volume, and inspiratory and expiratory time) had lower variability when the condition differed from control i.e. in cold or hypoxia, with no correlation with the absolute level of ventilation. The difference in variability between warm-normoxia and the other conditions was reduced when cold preceded the warm phase. Gaseous metabolism was increased in cold because of thermogenesis. When the cold preceded the warm phase the increased thermogenesis partly persisted into the warm phase, raising the metabolic level. We conclude that the variability of the breathing pattern in newborn rats 1) does not depend on the absolute level of ventilation, and 2) is reduced by the increased chemical stimuli occurring during cold-hypermetabolism or hypoxia. In normoxia in warm condition metabolic and chemical stimuli are low, and the variability is the highest. The results are in agreement with the clinical observations of a higher incidence of apneic episodes in infants during warm conditions.

  10. Correlated Variability in the Breathing Pattern and End-Expiratory Lung Volumes in Conscious Humans

    PubMed Central

    Dellaca, Raffaele L.; Aliverti, Andrea; Lo Mauro, Antonella; Lutchen, Kenneth R.; Pedotti, Antonio; Suki, Bela

    2015-01-01

    In order to characterize the variability and correlation properties of spontaneous breathing in humans, the breathing pattern of 16 seated healthy subjects was studied during 40 min of quiet breathing using opto-electronic plethysmography, a contactless technology that measures total and compartmental chest wall volumes without interfering with the subjects breathing. From these signals, tidal volume (VT), respiratory time (TTOT) and the other breathing pattern parameters were computed breath-by-breath together with the end-expiratory total and compartmental (pulmonary rib cage and abdomen) chest wall volume changes. The correlation properties of these variables were quantified by detrended fluctuation analysis, computing the scaling exponentα. VT, TTOT and the other breathing pattern variables showed α values between 0.60 (for minute ventilation) to 0.71 (for respiratory rate), all significantly lower than the ones obtained for end-expiratory volumes, that ranged between 1.05 (for rib cage) and 1.13 (for abdomen) with no significant differences between compartments. The much stronger long-range correlations of the end expiratory volumes were interpreted by a neuromechanical network model consisting of five neuron groups in the brain respiratory center coupled with the mechanical properties of the respiratory system modeled as a simple Kelvin body. The model-based α for VT is 0.57, similar to the experimental data. While the α for TTOT was slightly lower than the experimental values, the model correctly predicted α for end-expiratory lung volumes (1.045). In conclusion, we propose that the correlations in the timing and amplitude of the physiological variables originate from the brain with the exception of end-expiratory lung volume, which shows the strongest correlations largely due to the contribution of the viscoelastic properties of the tissues. This cycle-by-cycle variability may have a significant impact on the functioning of adherent cells in the

  11. Correlated variability in the breathing pattern and end-expiratory lung volumes in conscious humans.

    PubMed

    Dellaca, Raffaele L; Aliverti, Andrea; Lo Mauro, Antonella; Lutchen, Kenneth R; Pedotti, Antonio; Suki, Bela

    2015-01-01

    In order to characterize the variability and correlation properties of spontaneous breathing in humans, the breathing pattern of 16 seated healthy subjects was studied during 40 min of quiet breathing using opto-electronic plethysmography, a contactless technology that measures total and compartmental chest wall volumes without interfering with the subjects breathing. From these signals, tidal volume (VT), respiratory time (TTOT) and the other breathing pattern parameters were computed breath-by-breath together with the end-expiratory total and compartmental (pulmonary rib cage and abdomen) chest wall volume changes. The correlation properties of these variables were quantified by detrended fluctuation analysis, computing the scaling exponenta. VT, TTOT and the other breathing pattern variables showed α values between 0.60 (for minute ventilation) to 0.71 (for respiratory rate), all significantly lower than the ones obtained for end-expiratory volumes, that ranged between 1.05 (for rib cage) and 1.13 (for abdomen) with no significant differences between compartments. The much stronger long-range correlations of the end expiratory volumes were interpreted by a neuromechanical network model consisting of five neuron groups in the brain respiratory center coupled with the mechanical properties of the respiratory system modeled as a simple Kelvin body. The model-based α for VT is 0.57, similar to the experimental data. While the α for TTOT was slightly lower than the experimental values, the model correctly predicted α for end-expiratory lung volumes (1.045). In conclusion, we propose that the correlations in the timing and amplitude of the physiological variables originate from the brain with the exception of end-expiratory lung volume, which shows the strongest correlations largely due to the contribution of the viscoelastic properties of the tissues. This cycle-by-cycle variability may have a significant impact on the functioning of adherent cells in the

  12. Effects of breathing patterns and light exercise on linear and nonlinear heart rate variability.

    PubMed

    Weippert, Matthias; Behrens, Kristin; Rieger, Annika; Kumar, Mohit; Behrens, Martin

    2015-08-01

    Despite their use in cardiac risk stratification, the physiological meaning of nonlinear heart rate variability (HRV) measures is not well understood. The aim of this study was to elucidate effects of breathing frequency, tidal volume, and light exercise on nonlinear HRV and to determine associations with traditional HRV indices. R-R intervals, blood pressure, minute ventilation, breathing frequency, and respiratory gas concentrations were measured in 24 healthy male volunteers during 7 conditions: voluntary breathing at rest, and metronome guided breathing (0.1, 0.2 and 0.4 Hz) during rest, and cycling, respectively. The effect of physical load was significant for heart rate (HR; p < 0.001) and traditional HRV indices SDNN, RMSSD, lnLFP, and lnHFP (p < 0.01 for all). It approached significance for sample entropy (SampEn) and correlation dimension (D2) (p < 0.1 for both), while HRV detrended fluctuation analysis (DFA) measures DFAα1 and DFAα2 were not affected by load condition. Breathing did not affect HR but affected all traditional HRV measures. D2 was not affected by breathing; DFAα1 was moderately affected by breathing; and DFAα2, approximate entropy (ApEn), and SampEn were strongly affected by breathing. DFAα1 was strongly increased, whereas DFAα2, ApEn, and SampEn were decreased by slow breathing. No interaction effect of load and breathing pattern was evident. Correlations to traditional HRV indices were modest (r from -0.14 to -0.67, p < 0.05 to <0.01). In conclusion, while light exercise does not significantly affect short-time HRV nonlinear indices, respiratory activity has to be considered as a potential contributor at rest and during light dynamic exercise.

  13. Photoplethysmography as a single source for analysis of sleep-disordered breathing in patients with severe cardiovascular disease.

    PubMed

    Amir, Offer; Barak-Shinar, Deganit; Henry, Antonietta; Smart, Frank W

    2012-02-01

    Sleep-disordered breathing and Cheyne-Stokes breathing are often not diagnosed, especially in cardiovascular patients. An automated system based on photoplethysmographic signals might provide a convenient screening and diagnostic solution for patient evaluation at home or in an ambulatory setting. We compared event detection and classification obtained by full polysomnography (the 'gold standard') and by an automated new algorithm system in 74 subjects. Each subject underwent overnight polysomnography, 60 in a hospital cardiology department and 14 while being tested for suspected sleep-disordered breathing in a sleep laboratory. The sleep-disordered breathing and Cheyne-Stokes breathing parameters measured by a new automated algorithm system correlated very well with the corresponding results obtained by full polysomnography. The sensitivity of the Cheyne-Stokes breathing detected from the system compared to full polysomnography was 92% [95% confidence interval (CI): 78.6-98.3%] and specificity 94% (95% CI: 81.3-99.3%). Comparison of the Apnea Hyponea Index with a cutoff level of 15 shows a sensitivity of 98% (95% CI: 87.1-99.6%) and specificity of 96% (95% CI: 79.8-99.3%). The detection of respiratory events showed agreement of approximately 80%. Regression and Bland-Altman plots revealed good agreement between the two methods. Relative to gold-standard polysomnography, the simply used automated system in this study yielded an acceptable analysis of sleep- and/or cardiac-related breathing disorders. Accordingly, and given the convenience and simplicity of its application, this system can be considered as a suitable platform for home and ambulatory screening and diagnosis of sleep-disordered breathing in patients with cardiovascular disease.

  14. Breathing Maneuvers as a Vasoactive Stimulus for Detecting Inducible Myocardial Ischemia – An Experimental Cardiovascular Magnetic Resonance Study

    PubMed Central

    Fischer, Kady; Guensch, Dominik P; Shie, Nancy; Lebel, Julie; Friedrich, Matthias G

    2016-01-01

    Background Breathing maneuvers can elicit a similar vascular response as vasodilatory agents like adenosine; yet, their potential diagnostic utility in the presence of coronary artery stenosis is unknown. The objective of the study is to investigate if breathing maneuvers can non-invasively detect inducible ischemia in an experimental animal model when the myocardium is imaged with oxygenation-sensitive cardiovascular magnetic resonance (OS-CMR). Methods and Findings In 11 anesthetised swine with experimentally induced significant stenosis (fractional flow reserve <0.75) of the left anterior descending coronary artery (LAD) and 9 control animals, OS-CMR at 3T was performed during two different breathing maneuvers, a long breath-hold; and a combined maneuver of 60s of hyperventilation followed by a long breath-hold. The resulting change of myocardial oxygenation was compared to the invasive measurements of coronary blood flow, blood gases, and oxygen extraction. In control animals, all breathing maneuvers could significantly alter coronary blood flow as hyperventilation decreased coronary blood flow by 34±23%. A long breath-hold alone led to an increase of 97±88%, while the increase was 346±327% (p<0.001), when the long breath-hold was performed after hyperventilation. In stenosis animals, the coronary blood flow response was attenuated after both hyperventilation and the following breath-hold. This was matched by the observed oxygenation response as breath-holds following hyperventilation consistently yielded a significant difference in the signal of the MRI images between the perfusion territory of the stenosis LAD and remote myocardium. There was no difference between the coronary territories during the other breathing maneuvers or in the control group at any point. Conclusion In an experimental animal model, the response to a combined breathing maneuver of hyperventilation with subsequent breath-holding is blunted in myocardium subject to significant coronary

  15. Breathing Maneuvers as a Vasoactive Stimulus for Detecting Inducible Myocardial Ischemia - An Experimental Cardiovascular Magnetic Resonance Study.

    PubMed

    Fischer, Kady; Guensch, Dominik P; Shie, Nancy; Lebel, Julie; Friedrich, Matthias G

    2016-01-01

    Breathing maneuvers can elicit a similar vascular response as vasodilatory agents like adenosine; yet, their potential diagnostic utility in the presence of coronary artery stenosis is unknown. The objective of the study is to investigate if breathing maneuvers can non-invasively detect inducible ischemia in an experimental animal model when the myocardium is imaged with oxygenation-sensitive cardiovascular magnetic resonance (OS-CMR). In 11 anesthetised swine with experimentally induced significant stenosis (fractional flow reserve <0.75) of the left anterior descending coronary artery (LAD) and 9 control animals, OS-CMR at 3T was performed during two different breathing maneuvers, a long breath-hold; and a combined maneuver of 60s of hyperventilation followed by a long breath-hold. The resulting change of myocardial oxygenation was compared to the invasive measurements of coronary blood flow, blood gases, and oxygen extraction. In control animals, all breathing maneuvers could significantly alter coronary blood flow as hyperventilation decreased coronary blood flow by 34±23%. A long breath-hold alone led to an increase of 97±88%, while the increase was 346±327% (p<0.001), when the long breath-hold was performed after hyperventilation. In stenosis animals, the coronary blood flow response was attenuated after both hyperventilation and the following breath-hold. This was matched by the observed oxygenation response as breath-holds following hyperventilation consistently yielded a significant difference in the signal of the MRI images between the perfusion territory of the stenosis LAD and remote myocardium. There was no difference between the coronary territories during the other breathing maneuvers or in the control group at any point. In an experimental animal model, the response to a combined breathing maneuver of hyperventilation with subsequent breath-holding is blunted in myocardium subject to significant coronary artery stenosis. This maneuver may allow

  16. The Impact of Resonance Frequency Breathing on Measures of Heart Rate Variability, Blood Pressure, and Mood.

    PubMed

    Steffen, Patrick R; Austin, Tara; DeBarros, Andrea; Brown, Tracy

    2017-01-01

    Heart rate variability biofeedback (HRVB) significantly improves heart rate variability (HRV). Breathing at resonance frequency (RF, approximately 6 breaths/min) constitutes a key part of HRVB training and is hypothesized to be a pathway through which biofeedback improves HRV. No studies to date, however, have experimentally examined whether RF breathing impacts measures of HRV. The present study addressed this question by comparing three groups: the RF group breathed at their determined RF for 15 min; the RF + 1 group breathed at 1 breath/min higher than their determined RF for 15 min; and the third group sat quietly for 15 min. After this 15-min period, all groups participated in the Paced Auditory Serial Addition Task (PASAT) for 8 min, and then sat quietly during a 10-min recovery period. HRV, blood pressure, and mood were measured throughout the experiment. Groups were not significantly different on any of the measures at baseline. After the breathing exercise, the RF group reported higher positive mood than the other two groups and a significantly higher LF/HF HRV ratio relative to the control group, a key goal in HRVB training (p < 0.05). Additionally, the RF group showed lower systolic blood pressure during the PASAT and during the recovery period relative to the control group, with the RF + 1 group not being significantly different from either group (p < 0.05). Overall, RF breathing appears to play an important role in the positive effect HRVB has on measures of HRV.

  17. The Impact of Resonance Frequency Breathing on Measures of Heart Rate Variability, Blood Pressure, and Mood

    PubMed Central

    Steffen, Patrick R.; Austin, Tara; DeBarros, Andrea; Brown, Tracy

    2017-01-01

    Heart rate variability biofeedback (HRVB) significantly improves heart rate variability (HRV). Breathing at resonance frequency (RF, approximately 6 breaths/min) constitutes a key part of HRVB training and is hypothesized to be a pathway through which biofeedback improves HRV. No studies to date, however, have experimentally examined whether RF breathing impacts measures of HRV. The present study addressed this question by comparing three groups: the RF group breathed at their determined RF for 15 min; the RF + 1 group breathed at 1 breath/min higher than their determined RF for 15 min; and the third group sat quietly for 15 min. After this 15-min period, all groups participated in the Paced Auditory Serial Addition Task (PASAT) for 8 min, and then sat quietly during a 10-min recovery period. HRV, blood pressure, and mood were measured throughout the experiment. Groups were not significantly different on any of the measures at baseline. After the breathing exercise, the RF group reported higher positive mood than the other two groups and a significantly higher LF/HF HRV ratio relative to the control group, a key goal in HRVB training (p < 0.05). Additionally, the RF group showed lower systolic blood pressure during the PASAT and during the recovery period relative to the control group, with the RF + 1 group not being significantly different from either group (p < 0.05). Overall, RF breathing appears to play an important role in the positive effect HRVB has on measures of HRV. PMID:28890890

  18. Use of Variable Pressure Suits, Intermittent Recompression and Nitrox Breathing Mixtures during Lunar Extravehicular Activities

    NASA Technical Reports Server (NTRS)

    Gernhardt, Michael L.; Abercromby, Andrew F.

    2009-01-01

    This slide presentation reviews the use of variable pressure suits, intermittent recompression and Nitrox breathing mixtures to allow for multiple short extravehicular activities (EVAs) at different locations in a day. This new operational concept of multiple short EVAs requires short purge times and shorter prebreathes to assure rapid egress with a minimal loss of the vehicular air. Preliminary analysis has begun to evaluate the potential benefits of the intermittent recompression, and Nitrox breathing mixtures when used with variable pressure suits to enable reduce purges and prebreathe durations.

  19. Relationship between heart rate variability, blood pressure and arterial wall properties during air and oxygen breathing in healthy subjects.

    PubMed

    Graff, Beata; Szyndler, Anna; Czechowicz, Krzysztof; Kucharska, Wiesława; Graff, Grzegorz; Boutouyrie, Pierre; Laurent, Stephane; Narkiewicz, Krzysztof

    2013-11-01

    Previous studies reported that normobaric hyperoxia influences heart rate, arterial pressure, cardiac output and systemic vascular resistance, but the mechanisms underlying these changes are still not fully understood. Several factors are considered including degeneration of endothelium-derived nitric oxide by reactive oxygen species, the impact of oxygen-free radicals on tissues and alterations of autonomic nervous system function. Recently, new devices for the detailed non-invasive assessment of large and small arteries have been developed. Therefore, the aim of our study was to assess heart rate variability (HRV) as a potential indicator of autonomic balance and its relation to blood pressure and vascular properties during medical air (MAB) and 100% oxygen breathing (OXB) in healthy volunteers. In 12 healthy subjects we assessed heart rate and blood pressure variability, baroreflex sensitivity, respiratory frequency, common carotid artery diameter and its wall distensibility, as well as changes in the digital artery pulse waveform, stroke index and systemic vascular resistance during MAB and OXB. Mean and systolic blood pressure have increased significantly while digital pulse amplitude and carotid artery diameter were significantly lower during hyperoxia. Heart rate variability measures did not differ during MAB and OXB. However, the correlations between spectral HRV components and those hemodynamic parameters which have changed due to hyperoxia varied substantially during MAB (correlated significantly) and OXB (no significant correlations were noted). Our findings suggest that autonomic nervous system might not be the main mediator of the cardiovascular changes during 100% oxygen breathing in healthy subjects. It seems that the direct vascular responses are initial consequences of hyperoxia and other cardiovascular parameter alterations are secondary to them. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Mathematical models of periodic breathing and their usefulness in understanding cardiovascular and respiratory disorders.

    PubMed

    Cherniack, Neil S; Longobardo, Guy S

    2006-03-01

    Periodic breathing is an unusual form of breathing with oscillations in minute ventilations and with repetitive apnoeas or near apnoeas. Reported initially in patients with heart failure or stroke, it was later recognized to occur especially during sleep. The recurrent hypoxia and surges of sympathetic activity that often occur during the apnoeas have serious health consequences. Mathematical models have helped greatly in the understanding of the causes of recurrent apnoeas. It is unlikely that every instance of periodic breathing has the same cause, but many result from instability in the feedback control involved in the chemical regulation of breathing caused by increased controller and plant gains and delays in information transfer. Even when it is not the main cause of the periodic breathing, unstable control modifies the ventilatory pattern and sometimes intensifies the recurrent apnoeas. The characteristics of disturbances to breathing and their interaction with the control system can be critical in determining ventilation responses and the occurrence of periodic breathing. Large abrupt changes in ventilation produced, for example, in the transition from waking to sleep and vice versa, or in the transition from breathing to apnoea, are potent factors causing periodic breathing. Mathematical models show that periodic breathing is a 'systems disorder' produced by the interplay of multiple factors. Multiple factors contribute to the occurrence of periodic breathing in congestive heart failure and cerebrovascular disease, increasing treatment options.

  1. Using a respiratory navigator significantly reduces variability when quantifying left ventricular torsion with cardiovascular magnetic resonance.

    PubMed

    Hamlet, Sean M; Haggerty, Christopher M; Suever, Jonathan D; Wehner, Gregory J; Andres, Kristin N; Powell, David K; Charnigo, Richard J; Fornwalt, Brandon K

    2017-03-01

    Left ventricular (LV) torsion is an important indicator of cardiac function that is limited by high inter-test variability (50% of the mean value). We hypothesized that this high inter-test variability is partly due to inconsistent breath-hold positions during serial image acquisitions, which could be significantly improved by using a respiratory navigator for cardiovascular magnetic resonance (CMR) based quantification of LV torsion. We assessed respiratory-related variability in measured LV torsion with two distinct experimental protocols. First, 17 volunteers were recruited for CMR with cine displacement encoding with stimulated echoes (DENSE) in which a respiratory navigator was used to measure and then enforce variability in end-expiratory position between all LV basal and apical acquisitions. From these data, we quantified the inter-test variability of torsion in the absence and presence of enforced end-expiratory position variability, which established an upper bound for the expected torsion variability. For the second experiment (in 20 new, healthy volunteers), 10 pairs of cine DENSE basal and apical images were each acquired from consecutive breath-holds and consecutive navigator-gated scans (with a single acceptance position). Inter-test variability of torsion was compared between the breath-hold and navigator-gated scans to quantify the variability due to natural breath-hold variation. To demonstrate the importance of these variability reductions, we quantified the reduction in sample size required to detect a clinically meaningful change in LV torsion with the use of a respiratory navigator. The mean torsion was 3.4 ± 0.2°/cm. From the first experiment, enforced variability in end-expiratory position translated to considerable variability in measured torsion (0.56 ± 0.34°/cm), whereas inter-test variability with consistent end-expiratory position was 57% lower (0.24 ± 0.16°/cm, p < 0.001). From the second experiment, natural

  2. Assessment of heart rate variability in breath holding children by 24 hour Holter monitoring.

    PubMed

    Yilmaz, Osman; Ciftel, Murat; Ozturk, Kezban; Kilic, Omer; Kahveci, Hasan; Laloğlu, Fuat; Ceylan, Ozben

    2015-02-01

    Previous studies have shown that the underlying pathophysiologic mechanism in children with breath holding may be generalised autonomic dysregulation. Thus, we performed cardiac rhythm and heart rate variability analyses using 24-hour Holter monitoring to evaluate the cardiac effects of autonomic dysregulation in children with breath-holding spells. We performed cardiac rhythm and heart rate analyses using 24-hour Holter monitors to evaluate the cardiac effects of autonomic dysregulation in children during a breath-holding spell. Our study group consisted of 68 children with breath-holding spells - 56 cyanotic type and 12 pallid type - and 39 healthy controls. Clinical and heart rate variability results were compared between each spell type - cyanotic or pallid - and the control group; significant differences (p<0.05) in standard deviation of all NN intervals, mean of the standard deviations of all NN intervals for all 5-minute segments, percentage of differences between adjacent RR intervals >50 ms, and square root of the mean of the sum of squares of the differences between adjacent NN intervals values were found between the pallid and cyanotic groups. Holter monitoring for 24 hours and heart rate variability parameters, particularly in children with pallid spells, are crucial for evaluation of cardiac rhythm changes.

  3. Blood Pressure and Heart Rate Variability during Yoga-Based Alternate Nostril Breathing Practice and Breath Awareness

    PubMed Central

    Telles, Shirley; Sharma, Sachin Kumar; Balkrishna, Acharya

    2014-01-01

    Background Previous research has shown a reduction in blood pressure (BP) immediately after the practice of alternate nostril yoga breathing (ANYB) in normal healthy male volunteers and in hypertensive patients of both sexes. The BP during ANYB has not been recorded. Material/Methods Participants were 26 male volunteers (group mean age ±SD, 23.8±3.5 years). We assessed (1) heart rate variability, (2) non-invasive arterial BP, and (3) respiration rate, during (a) ANYB and (b) breath awareness (BAW) sessions. Each session was 25 minutes. We performed assessments at 3 time points: Pre (5 minutes), during (15 minutes; for ANYB or BAW) and Post (5 minutes). A naïve-to-yoga control group (n=15 males, mean age ±SD 26.1±4.0 years) were assessed while seated quietly for 25 minutes. Results During ANYB there was a significant decrease (repeated measures ANOVA) in systolic BP and respiration rate; while RMSSD (the square root of the mean of the sum of squares of differences between adjacent NN intervals) and NN50 (the number of interval differences of successive normal to normal intervals greater than 50 ms) significantly increased. During BAW respiration rate decreased. In contrast, respiration rate increased during the control state. ANYB and BAW were significantly different (2-factor ANOVA) in RMSSD and respiration rate. BAW and control were different with respect to respiration rate. Conclusions The results suggest that vagal activity increased during and after ANYB, which could have contributed to the decrease in BP and changes in the HRV. PMID:25408140

  4. Vagal-dependent nonlinear variability in the respiratory pattern of anesthetized, spontaneously breathing rats

    PubMed Central

    Dhingra, R. R.; Jacono, F. J.; Fishman, M.; Loparo, K. A.; Rybak, I. A.

    2011-01-01

    Physiological rhythms, including respiration, exhibit endogenous variability associated with health, and deviations from this are associated with disease. Specific changes in the linear and nonlinear sources of breathing variability have not been investigated. In this study, we used information theory-based techniques, combined with surrogate data testing, to quantify and characterize the vagal-dependent nonlinear pattern variability in urethane-anesthetized, spontaneously breathing adult rats. Surrogate data sets preserved the amplitude distribution and linear correlations of the original data set, but nonlinear correlation structure in the data was removed. Differences in mutual information and sample entropy between original and surrogate data sets indicated the presence of deterministic nonlinear or stochastic non-Gaussian variability. With vagi intact (n = 11), the respiratory cycle exhibited significant nonlinear behavior in templates of points separated by time delays ranging from one sample to one cycle length. After vagotomy (n = 6), even though nonlinear variability was reduced significantly, nonlinear properties were still evident at various time delays. Nonlinear deterministic variability did not change further after subsequent bilateral microinjection of MK-801, an N-methyl-d-aspartate receptor antagonist, in the Kölliker-Fuse nuclei. Reversing the sequence (n = 5), blocking N-methyl-d-aspartate receptors bilaterally in the dorsolateral pons significantly decreased nonlinear variability in the respiratory pattern, even with the vagi intact, and subsequent vagotomy did not change nonlinear variability. Thus both vagal and dorsolateral pontine influences contribute to nonlinear respiratory pattern variability. Furthermore, breathing dynamics of the intact system are mutually dependent on vagal and pontine sources of nonlinear complexity. Understanding the structure and modulation of variability provides insight into disease effects on respiratory

  5. Pre-analytic variability in cardiovascular biomarker testing

    PubMed Central

    Daves, Massimo

    2015-01-01

    The impact of laboratory medicine on clinical cardiology has dramatically increased over the years and a lot of cardiovascular biomarkers have been recently proposed. In order to avoid clinical mistakes, physicians should be well aware of all the aspects, which could affect the quality of laboratory results, remembering that pre-analytic variability is an often overlooked significant source of bias, determining the vast majority of laboratory errors. This review addresses the determinants of pre-analitycal variability in cardiovascular biomarker testing, focusing on the most widespread biomarkers, which are cardiac troponins and natriuretic peptides. PMID:26623116

  6. Characterization of the fetal diaphragmatic magnetomyogram and the effect of breathing movements on cardiac metrics of rate and variability.

    PubMed

    Gustafson, Kathleen M; Allen, John J B; Yeh, Hung-Wen; May, Linda E

    2011-07-01

    Breathing movements are one of the earliest fetal motor behaviors to emerge and are a hallmark of fetal well-being. Fetal respiratory sinus arrhythmia (RSA) has been documented but efforts to quantify the influence of breathing on heart rate (HR) and heart rate variability (HRV) are difficult due to the episodic nature of fetal breathing activity. We used a dedicated fetal biomagnetometer to acquire the magnetocardiogram (MCG) between 36 and 38 weeks gestational age (GA). We identified and characterized a waveform observed in the raw data and independent component decomposition that we attribute to fetal diaphragmatic movements during breathing episodes. RSA and increased high frequency power in a time-frequency analysis of the IBI time-series was observed during fetal breathing periods. Using the diaphragmatic magnetomyogram (dMMG) as a marker, we compared time and frequency domain metrics of heart rate and heart rate variability between breathing and non-breathing epochs. Fetal breathing activity resulted in significantly lower HR, increased high frequency power, greater sympathovagal balance, increased short-term HRV and greater parasympathetic input relative to non-breathing episodes confirming the specificity of fetal breathing movements on parasympathetic cardiac influence. No significant differences between breathing and non-breathing epochs were found in two metrics reflecting total HRV or very low, low and intermediate frequency bands. Using the fetal dMMG as a marker, biomagnetometry can help to elucidate the electrophysiologic mechanisms associated with diaphragmatic motor function and may be used to study the longitudinal development of human fetal cardiac autonomic control and breathing activity.

  7. Characterization of the Fetal Diaphragmatic Magnetomyogram and the Effect of Breathing Movements on Cardiac Metrics of Rate and Variability

    PubMed Central

    Gustafson, Kathleen M.; Allen, John J. B.; Yeh, Hung-wen; May, Linda E.

    2011-01-01

    Breathing movements are one of the earliest fetal motor behaviors to emerge andare ahallmark of fetal well-being. Fetal respiratory sinus arrhythmia (RSA) has been documented but efforts to quantify the influence of breathing on heart rate (HR) and heart rate variability (HRV) are difficult due to the episodic nature of fetal breathing activity. We used a dedicated fetal biomagnetometer to acquire the magnetocardiogram (MCG) between 36-38 weeks gestational age (GA). We identified and characterized a waveform observed in the raw data and independent component decomposition that we attribute to fetal diaphragmatic movements during breathing episodes. RSA and increased high frequency power in a time-frequency analysis of the IBI time-series was observed during fetal breathing periods. Using the diaphragmatic magnetomyogram (dMMG) as a marker, we compared time and frequency domain metrics of heartrate and heart rate variability between breathing and non-breathing epochs. Fetal breathing activity resulted in significantly lower HR, increased high frequency power, greater sympathovagal balance, increased short-term HRV andgreater parasympathetic input relative to non-breathing episodesconfirming the specificity of fetal breathing movements on parasympathetic cardiac influence. No significant differences between breathing and non-breathing epochs were found in two metrics reflecting total HRVor very low, low and intermediate frequency bands. Using the fetal dMMG as a marker, biomagnetometry can help to elucidate the electrophysiologic mechanisms associated with diaphragmatic motor function and may be used to study the longitudinal development of human fetal cardiac autonomic control and breathing activity. PMID:21497027

  8. Alternate Nostril Breathing at Different Rates and its Influence on Heart Rate Variability in Non Practitioners of Yoga.

    PubMed

    Subramanian, Rajam Krishna; P R, Devaki; P, Saikumar

    2016-01-01

    Heart rate variability is a measure of modulation in autonomic input to the heart and is one of the markers of autonomic functions. Though there are many studies on the long term influence of breathing on HRV (heart rate variability) there are only a few studies on the immediate effect of breathing especially alternate nostril breathing on HRV. This study focuses on the immediate effects of alternate nostril breathing and the influence of different breathing rates on HRV. The study was done on 25 subjects in the age group of 17-35 years. ECG and respiration were recorded before intervention and immediately after the subjects were asked to perform alternate nostril breathing for five minutes. Low frequency (LF) which is a marker of sympathetic activity increased, high frequency (HF) which is a marker of parasympathetic activity decreased and their ratio LF/HF which is a marker of sympatho/vagal balance increased immediately after 6 and 12 minutes in comparison to baseline values whereas there was no significant difference in the means of these components when both 6 and 12 minutes were compared. Immediate effects of alternate nostril breathing on HRV in non practitioners of yogic breathing are very different from the long term influence of yogic breathing on HRV which show a predominant parasympathetic influence on the heart.

  9. Effects of slow breathing exercise on cardiovascular functions, pulmonary functions & galvanic skin resistance in healthy human volunteers - a pilot study.

    PubMed

    Turankar, A V; Jain, S; Patel, S B; Sinha, S R; Joshi, A D; Vallish, B N; Mane, P R; Turankar, S A

    2013-05-01

    Regular practice of slow breathing has been shown to improve cardiovascular and respiratory functions and to decrease the effects of stress. This pilot study was planned to evaluate the short term effects of pranayama on cardiovascular functions, pulmonary functions and galvanic skin resistance (GSR) which mirrors sympathetic tone, and to evaluate the changes that appear within a short span of one week following slow breathing techniques. Eleven normal healthy volunteers were randomized into Pranayama group (n=6) and a non-Pranayama control group (n=5); the pranayama volunteers were trained in pranayama, the technique being Anuloma-Viloma pranayama with Kumbhak. All the 11 volunteers were made to sit in similar environment for two sessions of 20 min each for seven days, while the pranayama volunteers performed slow breathing under supervision, the control group relaxed without conscious control on breathing. Pulse, GSR, blood pressure (BP) and pulmonary function tests (PFT) were measured before and after the 7-day programme in all the volunteers. While no significant changes were observed in BP and PFT, an overall reduction in pulse rate was observed in all the eleven volunteers; this reduction might have resulted from the relaxation and the environment. Statistically significant changes were observed in the Pranayama group volunteers in the GSR values during standing phases indicating that regular practice of Pranayama causes a reduction in the sympathetic tone within a period as short as 7 days. Beneficial effects of pranayama started appearing within a week of regular practice, and the first change appeared to be a reduction in sympathetic tone.

  10. Heart Rate Variability and Cardiovascular Reactivity in Panic Disorder

    DTIC Science & Technology

    1999-04-01

    heart rate reactivity to cold pressor , CO2 and mental arithmetic (Roth et aI., 1992) and orthostatic... heart rates in panic disorder are inconsistent. The decreased heart rate responses to commonly used stressors, such as cold pressor , may indicate that...cardiovascular activation and heart rate variability during naturalistic anxiety and panic. Specific hypotheses to be tested included: HyPOthesis

  11. Consciously controlled breathing decreases the high-frequency component of heart rate variability by inhibiting cardiac parasympathetic nerve activity.

    PubMed

    Sasaki, Konosuke; Maruyama, Ryoko

    2014-01-01

    Heart rate variability (HRV), the beat-to-beat alterations in heart rate, comprises sympathetic and parasympathetic nerve activities of the heart. HRV analysis is used to quantify cardiac autonomic regulation. Since respiration could be a confounding factor in HRV evaluation, some studies recommend consciously controlled breathing to standardize the method. However, it remains unclear whether controlled breathing affects HRV measurement. We compared the effects of controlled breathing on HRV with those of spontaneous breathing. In 20 healthy volunteers, we measured respiratory frequency (f), tidal volume, and blood pressure (BP) and recorded electrocardiograms during spontaneous breathing (14.8 ± 0.7 breaths/min) and controlled breathing at 15 (0.25 Hz) and 6 (0.10 Hz) breaths/min. Compared to spontaneous breathing, controlled breathing at 0.25 Hz showed a higher heart rate and a lower high-frequency (HF) component, an index of parasympathetic nerve activity, although the f was the same. During controlled breathing at 0.10 Hz, the ratio of the low frequency (LF) to HF components (LF/HF), an index of sympathetic nerve activity, increased greatly and HF decreased, while heart rate and BP remained almost unchanged. Thus, controlled breathing at 0.25 Hz, which requires mental concentration, might inhibit parasympathetic nerve activity. During controlled breathing at 0.10 Hz, LF/HF increases because some HF subcomponents are synchronized with f and probably move into the LF band. This increment leads to misinterpretation of the true autonomic nervous regulation. We recommend that the respiratory pattern of participants should be evaluated before spectral HRV analysis to correctly understand changes in autonomic nervous regulation.

  12. Sleep-Disordered Breathing and Cardiovascular Correlates in College Football Players.

    PubMed

    Kim, Jonathan H; Hollowed, Casey; Irwin-Weyant, Morgan; Patel, Keyur; Hosny, Kareem; Aida, Hiroshi; Gowani, Zaina; Sher, Salman; Gleason, Patrick; Shoop, James L; Galante, Angelo; Clark, Craig; Ko, Yi-An; Quyyumi, Arshed A; Collop, Nancy A; Baggish, Aaron L

    2017-07-25

    This study sought to determine the cardiovascular physiologic correlates of sleep-disordered breathing (SDB) in American-style football (ASF) participants using echocardiography, vascular applanation tonometry, and peripheral arterial tonometry. Forty collegiate ASF participants were analyzed at pre- and postseason time points with echocardiography and vascular applanation tonometry. WatchPAT (inclusive of peripheral arterial tonometry) used to assess for SDB was then performed at the postseason time point. Twenty-two of 40 (55%) ASF participants demonstrated SDB with an apnea-hypopnea index (pAHI) ≥5. ASF participants with SDB were larger (109 ± 20 vs 92 ± 14 kg, p = 0.004) and more likely linemen position players (83% vs 50%, p = 0.03). Compared with those without SDB, ASF participants with SDB demonstrated relative impairments in left ventricular diastolic and vascular function as reflected by lower lateral e' (14 ± 3 vs 17 ± 3 cm/s, p = 0.007) and septal e' (11 ± 2 vs 13 ± 2 cm/s, p = 0.009) tissue velocities and higher pulse wave velocity (5.4 ± 0.9 vs 4.8 ± 0.5 m/s, p = 0.02). In the total cohort, there were significant positive correlations between pAHI and pulse wave velocity (r = 0.42, p = 0.008) and inverse correlations between pAHI and the averaged e' tissue velocities (r = -0.42, p = 0.01). In conclusion, SDB is highly prevalent in youthful collegiate ASF participants and associated with relative impairments in cardiac and vascular function. Targeted efforts to identify youthful populations with SDB, including ASF participants, and implement SDB treatment algorithms, represent important future clinical directives. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Breathing variability and brainstem serotonergic loss in a genetic model of multiple system atrophy.

    PubMed

    Flabeau, Olivier; Meissner, Wassilios G; Ozier, Annaig; Berger, Patrick; Tison, François; Fernagut, Pierre-Olivier

    2014-03-01

    Breathing disorders like sleep apnea, stridor, and dysrythmic breathing are frequent in patients with multiple system atrophy (MSA). These observations have been related to neurodegeneration in several pontomedullary respiratory nuclei and may explain the occurrence of sudden death. In this study, we sought to determine whether these functional and neuropathological characteristics could be replicated in a transgenic model of MSA. Mice expressing human wild-type α-synuclein under the control of the proteolipid promoter (PLP-αSYN) were compared with age-matched controls. Using whole-body, unrestrained plethysmography, the following breathing parameters were measured: inspiratory and expiratory times, tidal volume, expiratory volume, peak inspiratory and expiratory flows, and respiratory frequency. For each category, the mean, coefficient of variation, and irregularity score were analyzed. Brains were then processed for stereological cell counts of pontomedullary respiratory nuclei. A significant increase in the coefficient of variation and irregularity score was observed for inspiratory time, tidal volume, and expiratory volume in PLP-αSYN mice (P < 0.05). Glial cytoplasmic inclusions were found in the medullary raphe of PLP-αSYN mice, together with a loss of serotonergic immunoreactivity in the raphe obscurus (P < 0.001) and pallidus (P < 0.01). There was a negative correlation between α-synuclein burden and raphe pallidus cell counts (P < 0.05). There was no significant neuronal loss in the pre-Botzinger complex. The PLP-αSYN mouse model replicates the breathing variability and part of the neuronal depletion in pontomedullary respiratory nuclei observed in patients with MSA. Our findings support the use of this model for future candidate drugs in the breathing disorders observed in MSA. © 2014 International Parkinson and Movement Disorder Society.

  14. Variability of exhaled breath condensate (EBC) volume and pH using a feedback regulated breathing pattern

    EPA Science Inventory

    Exhaled breath condensate (EBC) is a valuable biological medium for non-invasively measuring biomarkers with the potential to reflect organ systems responses to environmental and dietary exposures and disease processes. Collection of EBC has typically been with spontaneous breat...

  15. Variability of exhaled breath condensate (EBC) volume and pH using a feedback regulated breathing pattern

    EPA Science Inventory

    Exhaled breath condensate (EBC) is a valuable biological medium for non-invasively measuring biomarkers with the potential to reflect organ systems responses to environmental and dietary exposures and disease processes. Collection of EBC has typically been with spontaneous breat...

  16. Response of nasal airway and heart rate variability to controlled nasal breathing.

    PubMed

    Fan, W-H; Ko, J-H; Lee, M-J; Xu, G; Lee, Guo-She

    2011-04-01

    To investigate the responses of nasal airway and autonomic nervous system (ANS) under controlled nasal breathings. Ten healthy volunteers, aged between 21 and 37 years, were enrolled. The participants breathed either through bilateral nostrils (BNB) or unilaterally through the left nostril (UNB) at 0.25 Hz for 5 min. The electrocardiography was simultaneously recorded and the ANS activities were evaluated using heart rate variability analysis. Nasal airway resistance and related factors were measured by rhinomanometry. The results showed that the mean heartbeat interval during UNB was significantly greater than during BNB. The sympathetic modulation decreased significantly during UNB. The correlations between nasal airway resistance and mean heartbeat interval were significant for both UNB and BNB. The increase of heartbeat intervals during UNB was associated with the decrease of cardiac sympathetic activities. The changes of ANS activities and nasal airway resistance during UNB are similar to the changes caused by a prolonged lying.

  17. An automated and reliable method for breath detection during variable mask pressures in awake and sleeping humans.

    PubMed

    Nguyen, Chinh D; Amatoury, Jason; Carberry, Jayne C; Eckert, Danny J

    2017-01-01

    Accurate breath detection is crucial in sleep and respiratory physiology research and in several clinical settings. However, this process is technically challenging due to measurement and physiological artifacts and other factors such as variable leaks in the breathing circuit. Recently developed techniques to quantify the multiple causes of obstructive sleep apnea, require intermittent changes in airway pressure applied to a breathing mask. This presents an additional unique challenge for breath detection. Traditional algorithms often require drift correction. However, this is an empirical operation potentially prone to human error. This paper presents a new algorithm for breath detection during variable mask pressures in awake and sleeping humans based on physiological landmarks detected in the airflow or epiglottic pressure signal (Pepi). The algorithms were validated using simulated data from a mathematical model and against the standard visual detection approach in 4 healthy individuals and 6 patients with sleep apnea during variable mask pressure conditions. Using the flow signal, the algorithm correctly identified 97.6% of breaths with a mean difference±SD in the onsets of respiratory phase compared to expert visual detection of 23±89ms for inspiration and 6±56ms for expiration during wakefulness and 10±74ms for inspiration and 3±28 ms for expiration with variable mask pressures during sleep. Using the Pepi signal, the algorithm correctly identified 89% of the breaths with accuracy of 31±156ms for inspiration and 9±147ms for expiration compared to expert visual detection during variable mask pressures asleep. The algorithm had excellent performance in response to baseline drifts and noise during variable mask pressure conditions. This new algorithm can be used for accurate breath detection including during variable mask pressure conditions which represents a major advance over existing time-consuming manual approaches.

  18. Analysis of heart rate variability and skin blood flow oscillations under deep controlled breathing.

    PubMed

    Krasnikov, Gennady V; Tyurina, Miglena Y; Tankanag, Arina V; Piskunova, Galina M; Chemeris, Nikolai K

    2013-02-01

    The effect of deep breathing controlled in both rate (0.25, 0.16, 0.1, 0.07, 0.05 and 0.03 Hz) and amplitude on the heart rate variability (HRV) and respiration-dependent oscillations of forearm/finger skin blood flow (SBF) has been studied in 29 young healthy volunteers. The influence of sympathovagal balance on the respiratory sinus arrhythmia (RSA) amplitude and respiratory SBF oscillations has been studied. The subjects with predominant parasympathetic tonus had statistically significant higher RSA amplitudes in the breathing rate region of 0.03-0.07 Hz than the subjects with predominant sympathetic tonus. In the finger-cushion zone, having a well-developed sympathetic vascular innervations, the amplitudes of respiratory SBF oscillations at breathing rates 0.05 and 0.07 Hz were higher in the group of subjects with predominant parasympathetic tonus. In the forearm skin, where the density of sympathetic innervations is low comparatively to that in the finger skin, no statistically significant differences in the amplitude of respiratory SBF oscillations were found concerning the two groups of subjects.

  19. Cardiovascular variability and introversion/extroversion, neuroticism and psychoticism.

    PubMed

    Burdick, J A; Van Dyck, B; Von Bargen, W J

    1982-01-01

    Forty-eight subjects were measured during a 10 min rest period for pulse wave velocity (PWV) and heart rate (HR) level and variability, using a Cyborg BL 907 instrument. These subjects were also evaluated by means of the Eysenck Personality Questionnaire for I-E, N, P and L. These data were factor analyzed. Five factors were identified which were accounted for 80.6% of the variance. These factors were: 'cardiovascular lability', 'heart rate time trends', 'cardiovascular balance', 'sex effects' and 'self reports'. The EPQ measurements separated from the physiological measurements in the factor analysis and none were found to be significantly loaded on any physiological variables. On the other hand, significant physiological correlations were found with N. This study adds a possible blood pressure and heart rate descripter to N.

  20. High spatial and temporal resolution retrospective cine cardiovascular magnetic resonance from shortened free breathing real-time acquisitions.

    PubMed

    Xue, Hui; Kellman, Peter; Larocca, Gina; Arai, Andrew E; Hansen, Michael S

    2013-11-14

    Cine cardiovascular magnetic resonance (CMR) is challenging in patients who cannot perform repeated breath holds. Real-time, free-breathing acquisition is an alternative, but image quality is typically inferior. There is a clinical need for techniques that achieve similar image quality to the segmented cine using a free breathing acquisition. Previously, high quality retrospectively gated cine images have been reconstructed from real-time acquisitions using parallel imaging and motion correction. These methods had limited clinical applicability due to lengthy acquisitions and volumetric measurements obtained with such methods have not previously been evaluated systematically. This study introduces a new retrospective reconstruction scheme for real-time cine imaging which aims to shorten the required acquisition. A real-time acquisition of 16-20s per acquired slice was inputted into a retrospective cine reconstruction algorithm, which employed non-rigid registration to remove respiratory motion and SPIRiT non-linear reconstruction with temporal regularization to fill in missing data. The algorithm was used to reconstruct cine loops with high spatial (1.3-1.8 × 1.8-2.1 mm²) and temporal resolution (retrospectively gated, 30 cardiac phases, temporal resolution 34.3 ± 9.1 ms). Validation was performed in 15 healthy volunteers using two different acquisition resolutions (256 × 144/192 × 128 matrix sizes). For each subject, 9 to 12 short axis and 3 long axis slices were imaged with both segmented and real-time acquisitions. The retrospectively reconstructed real-time cine images were compared to a traditional segmented breath-held acquisition in terms of image quality scores. Image quality scoring was performed by two experts using a scale between 1 and 5 (poor to good). For every subject, LAX and three SAX slices were selected and reviewed in the random order. The reviewers were blinded to the reconstruction approach and acquisition protocols and

  1. High spatial and temporal resolution retrospective cine cardiovascular magnetic resonance from shortened free breathing real-time acquisitions

    PubMed Central

    2013-01-01

    Background Cine cardiovascular magnetic resonance (CMR) is challenging in patients who cannot perform repeated breath holds. Real-time, free-breathing acquisition is an alternative, but image quality is typically inferior. There is a clinical need for techniques that achieve similar image quality to the segmented cine using a free breathing acquisition. Previously, high quality retrospectively gated cine images have been reconstructed from real-time acquisitions using parallel imaging and motion correction. These methods had limited clinical applicability due to lengthy acquisitions and volumetric measurements obtained with such methods have not previously been evaluated systematically. Methods This study introduces a new retrospective reconstruction scheme for real-time cine imaging which aims to shorten the required acquisition. A real-time acquisition of 16-20s per acquired slice was inputted into a retrospective cine reconstruction algorithm, which employed non-rigid registration to remove respiratory motion and SPIRiT non-linear reconstruction with temporal regularization to fill in missing data. The algorithm was used to reconstruct cine loops with high spatial (1.3-1.8 × 1.8-2.1 mm2) and temporal resolution (retrospectively gated, 30 cardiac phases, temporal resolution 34.3 ± 9.1 ms). Validation was performed in 15 healthy volunteers using two different acquisition resolutions (256 × 144/192 × 128 matrix sizes). For each subject, 9 to 12 short axis and 3 long axis slices were imaged with both segmented and real-time acquisitions. The retrospectively reconstructed real-time cine images were compared to a traditional segmented breath-held acquisition in terms of image quality scores. Image quality scoring was performed by two experts using a scale between 1 and 5 (poor to good). For every subject, LAX and three SAX slices were selected and reviewed in the random order. The reviewers were blinded to the reconstruction approach and

  2. PLASTICS AND CARDIOVASCULAR HEALTH: PHTHALATES MAY DISRUPT HEART RATE VARIABILITY AND CARDIOVASCULAR REACTIVITY.

    PubMed

    Jaimes, Rafael; Swiercz, Adam; Sherman, Meredith; Muselimyan, Narine; Marvar, Paul; Posnack, Nikki Gillum

    2017-08-25

    Plastics have revolutionized medical device technology, transformed hematological care, and facilitated modern cardiology procedures. Despite these advances, studies have shown that phthalate chemicals migrate out of plastic products, and that these chemicals are bioactive. Recent epidemiological and research studies suggest that phthalate exposure adversely affects cardiovascular function. To assess the safety and biocompatibility of phthalate chemicals, and resolve the impact on cardiovascular and autonomic physiology. Adult mice were implanted with radiofrequency transmitters to monitor heart rate variability, blood pressure, and autonomic regulation in response to di-2-ethylhexyl-phthalate (DEHP) exposure. DEHP-treated animals displayed a decrease in heart rate variability (-17% SDNN, -36% high frequency power) and an exaggerated mean arterial pressure (MAP) response to ganglionic blockade (31.5% via chlorisondamine). In response to a conditioned stressor, DEHP-treated animals displayed enhanced cardiovascular reactivity (-56% SD2, standard deviation, major axis Poincarè plot) and prolonged blood pressure recovery. Alterations in cardiac gene expression of endothelin-1, angiotensin converting enzyme, and nitric oxide synthase may partly explain these cardiovascular alterations. This is the first study to show an association between phthalate chemicals that are used in medical devices with alterations in autonomic regulation, heart rate variability and cardiovascular reactivity. Since changes in autonomic balance often precede clinical manifestations of hypertension, atherosclerosis and conduction abnormalities - future studies are warranted to assess the downstream impact of plastic chemical exposure on end-organ function in sensitive patient populations. This study also highlights the importance of adopting safer biomaterials, chemicals, and/or surface coatings for use in medical devices. Copyright © 2017, American Journal of Physiology-Heart and Circulatory

  3. Override of spontaneous respiratory pattern generator reduces cardiovascular parasympathetic influence

    NASA Technical Reports Server (NTRS)

    Patwardhan, A. R.; Vallurupalli, S.; Evans, J. M.; Bruce, E. N.; Knapp, C. F.

    1995-01-01

    We investigated the effects of voluntary control of breathing on autonomic function in cardiovascular regulation. Variability in heart rate was compared between 5 min of spontaneous and controlled breathing. During controlled breathing, for 5 min, subjects voluntarily reproduced their own spontaneous breathing pattern (both rate and volume on a breath-by-breath basis). With the use of this experimental design, we could unmask the effects of voluntary override of the spontaneous respiratory pattern generator on autonomic function in cardiovascular regulation without the confounding effects of altered respiratory pattern. Results from 10 subjects showed that during voluntary control of breathing, mean values of heart rate and blood pressure increased, whereas fractal and spectral powers in heart rate in the respiratory frequency region decreased. End-tidal PCO2 was similar during spontaneous and controlled breathing. These results indicate that the act of voluntary control of breathing decreases the influence of the vagal component, which is the principal parasympathetic influence in cardiovascular regulation.

  4. Feedback control of multiple hemodynamic variables with multiple cardiovascular drugs.

    PubMed

    Sugimachi, Masaru; Uemura, Kazunori; Kamiya, Atsunori; Shimizu, Shuji; Inagaki, Masashi; Shishido, Toshiaki

    2009-01-01

    The ultimate goal of disease treatment is to control the biological system beyond the native regulation to combat pathological process. To maximize the advantage of drugs, we attempted to pharmacologically control the biological system at will, e.g., control multiple hemodynamic variables with multiple cardiovascular drugs. A comprehensive physiological cardiovascular model enabled us to evaluate cardiovascular properties (pump function, vascular resistance, and blood volume) and the feedback control of these properties. In 12 dogs, with dobutamine (5+/-3 mug.kg(-1).min(-1)), nitroprusside (4+/-2 mug.kg(-1).min(-1)), dextran (2+/-2 ml.kg(-1)), and furosemide (10 mg in one, 20 mg in one), rapid, sufficient and stable control of pump function, vascular resistance and blood volume resulted in similarly quick and stable control of blood pressure, cardiac output and left atrial pressure in 5+/-7, 7+/-5, and 12+/-10 minutes, respectively. These variables remained stable for 60 minutes (RMS 4+/-3 mmHg, 5+/-2 ml.min(-1).kg(-1), 0.8+/-0.6 mmHg, respectively).

  5. Breathing exercise combined with cognitive behavioural intervention improves sleep quality and heart rate variability in major depression.

    PubMed

    Chien, Hui-Ching; Chung, Yu-Chu; Yeh, Mei-Ling; Lee, Jia-Fu

    2015-11-01

    The aim of this study was to investigate the effects of a cognitive behavioural intervention combined with a breathing relaxation exercise on sleep quality and heart rate variability in patients with major depression. Depression is a long-lasting illness with significant effects not only in individuals themselves, but on their family, work and social relationships as well. Cognitive behavioural therapy is considered to be an effective treatment for major depression. Breathing relaxation may improve heart rate variability, but few studies have comprehensively examined the effect of a cognitive behavioural intervention combined with relaxing breathing on patients with major depression. An experimental research design with a repeated measure was used. Eighty-nine participants completed this study and entered data analysed. The experimental group (n = 43) received the cognitive behavioural intervention combined with a breathing relaxation exercise for four weeks, whereas the control group (n = 46) did not. Sleep quality and heart rate variability were measured at baseline, posttest1, posttest2 and follow-up. Data were examined by chi-square tests, t-tests and generalised estimating equations. After adjusting for age, socioeconomic status, severity of disease and psychiatric history, the quality of sleep of the experimental group improved, with the results at posttest achieving significance. Heart rate variability parameters were also significantly improved. This study supported the hypothesis that the cognitive behavioural intervention combined with a breathing relaxation exercise could improve sleep quality and heart rate variability in patients with major depression, and the effectiveness was lasting. The cognitive behavioural intervention combined with a breathing relaxation exercise that included muscle relaxation, deep breathing and sleep hygiene could be provided with major depression during hospitalisation. Through group practice and experience sharing

  6. Slow breathing influences cardiac autonomic responses to postural maneuver: Slow breathing and HRV.

    PubMed

    Vidigal, Giovanna Ana de Paula; Tavares, Bruna S; Garner, David M; Porto, Andrey A; Carlos de Abreu, Luiz; Ferreira, Celso; Valenti, Vitor E

    2016-05-01

    Chronic slow breathing has been reported to improve Heart Rate Variability (HRV) in patients with cardiovascular disorders. However, it is not clear regarding its acute effects on HRV responses on autonomic analysis. We evaluated the acute effects of slow breathing on cardiac autonomic responses to postural change manoeuvre (PCM). The study was conducted on 21 healthy male students aged between 18 and 35 years old. In the control protocol, the volunteer remained at rest seated for 15 min under spontaneous breathing and quickly stood up within 3 s and remained standing for 15 min. In the slow breathing protocol, the volunteer remained at rest seated for 10 min under spontaneous breath, then performed slow breathing for 5 min and rapidly stood up within 3 s and remained standing for 15 min. Slow breathing intensified cardiac autonomic responses to postural maneuver.

  7. Effects of ion channel noise on neural circuits: an application to the respiratory pattern generator to investigate breathing variability.

    PubMed

    Yu, Haitao; Dhingra, Rishi R; Dick, Thomas E; Galán, Roberto F

    2017-01-01

    Neural activity generally displays irregular firing patterns even in circuits with apparently regular outputs, such as motor pattern generators, in which the output frequency fluctuates randomly around a mean value. This "circuit noise" is inherited from the random firing of single neurons, which emerges from stochastic ion channel gating (channel noise), spontaneous neurotransmitter release, and its diffusion and binding to synaptic receptors. Here we demonstrate how to expand conductance-based network models that are originally deterministic to include realistic, physiological noise, focusing on stochastic ion channel gating. We illustrate this procedure with a well-established conductance-based model of the respiratory pattern generator, which allows us to investigate how channel noise affects neural dynamics at the circuit level and, in particular, to understand the relationship between the respiratory pattern and its breath-to-breath variability. We show that as the channel number increases, the duration of inspiration and expiration varies, and so does the coefficient of variation of the breath-to-breath interval, which attains a minimum when the mean duration of expiration slightly exceeds that of inspiration. For small channel numbers, the variability of the expiratory phase dominates over that of the inspiratory phase, and vice versa for large channel numbers. Among the four different cell types in the respiratory pattern generator, pacemaker cells exhibit the highest sensitivity to channel noise. The model shows that suppressing input from the pons leads to longer inspiratory phases, a reduction in breathing frequency, and larger breath-to-breath variability, whereas enhanced input from the raphe nucleus increases breathing frequency without changing its pattern.

  8. Free breathing three-dimensional late gadolinium enhancement cardiovascular magnetic resonance using outer volume suppressed projection navigators

    PubMed Central

    Menon, Rajiv G.; Miller, G.W.; Jeudy, Jean; Rajagopalan, Sanjay; Shin, Taehoon

    2017-01-01

    Purpose To develop a free-breathing, 3D late gadolinium enhancement (3D FB-LGE) cardiovascular magnetic resonance (CMR) technique and to compare it with clinically used 2D breath-hold LGE (2D BH-LGE). Methods The proposed 3D FB-LGE method consisted of inversion preparation, inversion delay, fat saturation, outer volume suppression, 1D-projection navigators, and a segmented stack of spirals acquisition. The 3D FB-LGE and 2D BH-LGE scans were performed on 29 cardiac patients. Qualitative analysis and quantitative analysis (in patients with scar) were performed. Results No significant differences were noted between the 3D FB-LGE and 2D BH-LGE datasets in terms of overall image quality score (2D: 4.69 ± 0.60 versus 3D: 4.55 ± 0.51, P = 0.46) and image artifact score (2D: 1.10 ± 0.31 versus 3D: 1.17 ± 0.38; P = 0.63). The average difference in fractional scar volume between the 3D and 2D methods was 1.9 % (n = 5). Acquisition time was significantly shorter for the 3D FB-LGE over 2D BH-LGE by a factor of 2.83 ± 0.77 (P < 0.0001). Conclusions The 3D FB-LGE is a viable option for patients, particularly in acute settings or in patients who are unable to comply with breath-hold instructions. PMID:27122450

  9. Accurate derivation of heart rate variability signal for detection of sleep disordered breathing in children.

    PubMed

    Chatlapalli, S; Nazeran, H; Melarkod, V; Krishnam, R; Estrada, E; Pamula, Y; Cabrera, S

    2004-01-01

    The electrocardiogram (ECG) signal is used extensively as a low cost diagnostic tool to provide information concerning the heart's state of health. Accurate determination of the QRS complex, in particular, reliable detection of the R wave peak, is essential in computer based ECG analysis. ECG data from Physionet's Sleep-Apnea database were used to develop, test, and validate a robust heart rate variability (HRV) signal derivation algorithm. The HRV signal was derived from pre-processed ECG signals by developing an enhanced Hilbert transform (EHT) algorithm with built-in missing beat detection capability for reliable QRS detection. The performance of the EHT algorithm was then compared against that of a popular Hilbert transform-based (HT) QRS detection algorithm. Autoregressive (AR) modeling of the HRV power spectrum for both EHT- and HT-derived HRV signals was achieved and different parameters from their power spectra as well as approximate entropy were derived for comparison. Poincare plots were then used as a visualization tool to highlight the detection of the missing beats in the EHT method After validation of the EHT algorithm on ECG data from the Physionet, the algorithm was further tested and validated on a dataset obtained from children undergoing polysomnography for detection of sleep disordered breathing (SDB). Sensitive measures of accurate HRV signals were then derived to be used in detecting and diagnosing sleep disordered breathing in children. All signal processing algorithms were implemented in MATLAB. We present a description of the EHT algorithm and analyze pilot data for eight children undergoing nocturnal polysomnography. The pilot data demonstrated that the EHT method provides an accurate way of deriving the HRV signal and plays an important role in extraction of reliable measures to distinguish between periods of normal and sleep disordered breathing (SDB) in children.

  10. Head-down bed rest reduces the breathing rate short-term variability in subjects with orthostatic intolerance.

    PubMed

    Balocchi, R; Menicucci, D; Varanini, M; Chillemi, S; Legramante, J M; Saltini, C; Raimondi, G

    2004-07-01

    Orthostatic intolerance is the most serious symptom of cardiovascular deconditioning induced by microgravity. We have showed that in symptomatic subjects the baroreflex control of sinus node is affected by short term simulated microgravity. At present the influence of the respiration on the cardiovascular system in this condition is not clear. The aim of the present study was to examine the behaviour of the Breathing Rate (BR) in 5 Non-Symptomatic (NS) and 3 Symptomatic (S) subjects before and after 4 hours of head-down bed rest (HD).

  11. Effect of breakfast on selected serum and cardiovascular variables

    NASA Technical Reports Server (NTRS)

    Frey, Mary A. B.; Merz, Marion P.; Hoffler, G. W.

    1992-01-01

    In view of the objections of many subjects to overnight fasting prior to their blood being drawn for analyses, the effect of eating breakfast on the results of subsequent blood analyses of selected blood constituents and on cardiovascular variables was investigated in 47 men and 34 women who were subjected to blood analyses on two occasions, one week apart: once fasting and once after breakfast. Results suggest that subjects need not fast overnight before blood is being drawn for determinations of the HDL-C levels, hemoglobin, hematocrit, total cholesterol, or phosphorus. However, based on other studies, it is suggested breakfast should not have a high content of fat.

  12. Effect of breakfast on selected serum and cardiovascular variables

    NASA Technical Reports Server (NTRS)

    Frey, Mary A. B.; Merz, Marion P.; Hoffler, G. W.

    1992-01-01

    In view of the objections of many subjects to overnight fasting prior to their blood being drawn for analyses, the effect of eating breakfast on the results of subsequent blood analyses of selected blood constituents and on cardiovascular variables was investigated in 47 men and 34 women who were subjected to blood analyses on two occasions, one week apart: once fasting and once after breakfast. Results suggest that subjects need not fast overnight before blood is being drawn for determinations of the HDL-C levels, hemoglobin, hematocrit, total cholesterol, or phosphorus. However, based on other studies, it is suggested breakfast should not have a high content of fat.

  13. Loss of Breathing Modulation of Heart Rate Variability in Patients with Recent and Long Standing Diabetes Mellitus Type II.

    PubMed

    Rivera, Ana Leonor; Estañol, Bruno; Fossion, Ruben; Toledo-Roy, Juan C; Callejas-Rojas, José A; Gien-López, José A; Delgado-García, Guillermo R; Frank, Alejandro

    2016-01-01

    Healthy subjects under rhythmic breathing have heart interbeat intervals with a respiratory band in the frequency domain that can be an index of vagal activity. Diabetes Mellitus Type II (DM) affects the autonomic nervous system of patients, thus it can be expected changes on the vagal activity. Here, the influence of DM on the breathing modulation of the heart rate is evaluated by analyzing in the frequency domain heart interbeat interval (IBI) records obtained from 30 recently diagnosed, 15 long standing DM patients, and 30 control subjects during standardized clinical tests of controlled breathing at 0.1 Hz, supine rest and standing upright. Fourier spectral analysis of IBI records quantifies heart rate variability in different regions: low-frequencies (LF, 0.04-0.15 Hz), high-frequencies (HF, 0.15-0.4 Hz), and a controlled breathing peak (RP, centered around 0.1 Hz). Two new parameters are introduced: the frequency radius rf (square root of the sum of LF and HF squared) and β (power of RP divided by the sum of LF and HF). As diabetes evolves, the controlled breathing peak loses power and shifts to smaller frequencies, indicating that heart rate modulation is slower in diabetic patients than in controls. In contrast to the traditional parameters LF, HF and LF/HF, which do not show significant differences between the three populations in neither of the clinical tests, the new parameters rf and β, distinguish between control and diabetic subjects in the case of controlled breathing. Sympathetic activity that is driven by the baroreceptor reflex associated with the 0.1 Hz breathing modulations is affected in DM patients. Diabetes produces not only a rigid heartbeat with less autonomic induced variability (rf diminishes), but also alters the coupling between breathing and heart rate (reduced β), due to a progressive decline of vagal and sympathetic activity.

  14. Loss of Breathing Modulation of Heart Rate Variability in Patients with Recent and Long Standing Diabetes Mellitus Type II

    PubMed Central

    Estañol, Bruno; Fossion, Ruben; Toledo-Roy, Juan C.; Callejas-Rojas, José A.; Gien-López, José A.; Delgado-García, Guillermo R.; Frank, Alejandro

    2016-01-01

    Healthy subjects under rhythmic breathing have heart interbeat intervals with a respiratory band in the frequency domain that can be an index of vagal activity. Diabetes Mellitus Type II (DM) affects the autonomic nervous system of patients, thus it can be expected changes on the vagal activity. Here, the influence of DM on the breathing modulation of the heart rate is evaluated by analyzing in the frequency domain heart interbeat interval (IBI) records obtained from 30 recently diagnosed, 15 long standing DM patients, and 30 control subjects during standardized clinical tests of controlled breathing at 0.1 Hz, supine rest and standing upright. Fourier spectral analysis of IBI records quantifies heart rate variability in different regions: low-frequencies (LF, 0.04–0.15 Hz), high-frequencies (HF, 0.15–0.4 Hz), and a controlled breathing peak (RP, centered around 0.1 Hz). Two new parameters are introduced: the frequency radius rf (square root of the sum of LF and HF squared) and β (power of RP divided by the sum of LF and HF). As diabetes evolves, the controlled breathing peak loses power and shifts to smaller frequencies, indicating that heart rate modulation is slower in diabetic patients than in controls. In contrast to the traditional parameters LF, HF and LF/HF, which do not show significant differences between the three populations in neither of the clinical tests, the new parameters rf and β, distinguish between control and diabetic subjects in the case of controlled breathing. Sympathetic activity that is driven by the baroreceptor reflex associated with the 0.1 Hz breathing modulations is affected in DM patients. Diabetes produces not only a rigid heartbeat with less autonomic induced variability (rf diminishes), but also alters the coupling between breathing and heart rate (reduced β), due to a progressive decline of vagal and sympathetic activity. PMID:27802329

  15. Effects of heart rate variability biofeedback on cardiovascular responses and autonomic sympathovagal modulation following stressor tasks in prehypertensives.

    PubMed

    Chen, S; Sun, P; Wang, S; Lin, G; Wang, T

    2016-02-01

    Autonomic dysfunction is implicated in prehypertension, and previous studies have suggested that therapies that improve modulation of sympathovagal balance, such as biofeedback and slow abdominal breathing, are effective in patients with prehypertension at rest. However, considering that psychophysiological stressors may be associated with greater cardiovascular risk in prehypertensives, it is important to investigate whether heart rate variability biofeedback (HRV-BF) results in equivalent effects on autonomic cardiovascular responses control during stressful conditions in prehypertensives. A total of 32 college students with prehypertension were enrolled and randomly assigned to HRV-BF (n=12), slow abdominal breathing (SAB, n=10) or no treatment (control, n=10) groups. Then, a training experiment consisting of 15 sessions was employed to compare the effect of each intervention on the following cardiovascular response indicators before and after intervention: heart rate (HR); heart rate variability (HRV) components; blood volume pulse amplitude (BVPamp); galvanic skin response; respiration rate (RSP); and blood pressure. In addition, the cold pressor test and the mental arithmetic challenge test were also performed over two successive days before and after the invention as well as after 3 months of follow-up. A significant decrease in HR and RSP and a significant increase in BVPamp were observed after the HRV-BF intervention (P<0.001). For the HRV analysis, HRV-BF significantly reduced the ratio of low-frequency power to high-frequency power (the LF/HF ratio, P<0.001) and increased the normalized high-frequency power (HFnm) (P<0.001) during the stress tests, and an added benefit over SAB by improving HRV was also observed. In the 3-month follow-up study, similar effects on RSP, BVPamp, LF/HF and HFnm were observed in the HRV-BF group compared with the SAB group. HRV-BF training contributes to the beneficial effect of reducing the stress-related cardiovascular

  16. Variability of breath condensate pH may contribute to the better understanding of non-allergic seasonal respiratory diseases

    NASA Astrophysics Data System (ADS)

    Kullmann, Tamás; Szipőcs, Annamária

    2017-07-01

    The seasonal variability of certain non-allergic respiratory diseases is not clearly understood. Analysis of the breath condensate, the liquid that can be collected by breathing into a cold tube, has been proposed to bring closer to the understanding of airway pathologies. It has been assumed, that (1) airway lining fluid was a stable body liquid and (2) the breath condensate samples were representative of the airway lining fluid. Research was focussed on the identification of biomarkers indicative of respiratory pathologies. Despite 30 years of extended investigations breath condensate analysis has not gained any clinical implementation so far. The pH of the condensate is the characteristic that can be determined with the highest reproducibility. The present paper shows, that contrary to the initial assumptions, breath condensate is not a representative of the airway lining fluid, and the airway lining fluid is not a stable body liquid. Condensate pH shows baseline variability and it is influenced by drinking and by the ambient temperature. The changes in condensate pH are linked to changes in airway lining fluid pH. The variability of airway lining fluid pH may explain seasonal incidence of certain non-allergic respiratory diseases such as the catching of a common cold and the increased incidence of COPD exacerbations and exercise-induced bronchoconstriction in cold periods.

  17. Variability of breath condensate pH may contribute to the better understanding of non-allergic seasonal respiratory diseases

    NASA Astrophysics Data System (ADS)

    Kullmann, Tamás; Szipőcs, Annamária

    2017-09-01

    The seasonal variability of certain non-allergic respiratory diseases is not clearly understood. Analysis of the breath condensate, the liquid that can be collected by breathing into a cold tube, has been proposed to bring closer to the understanding of airway pathologies. It has been assumed, that (1) airway lining fluid was a stable body liquid and (2) the breath condensate samples were representative of the airway lining fluid. Research was focussed on the identification of biomarkers indicative of respiratory pathologies. Despite 30 years of extended investigations breath condensate analysis has not gained any clinical implementation so far. The pH of the condensate is the characteristic that can be determined with the highest reproducibility. The present paper shows, that contrary to the initial assumptions, breath condensate is not a representative of the airway lining fluid, and the airway lining fluid is not a stable body liquid. Condensate pH shows baseline variability and it is influenced by drinking and by the ambient temperature. The changes in condensate pH are linked to changes in airway lining fluid pH. The variability of airway lining fluid pH may explain seasonal incidence of certain non-allergic respiratory diseases such as the catching of a common cold and the increased incidence of COPD exacerbations and exercise-induced bronchoconstriction in cold periods.

  18. Influence of deep breathing exercise on spontaneous respiratory rate and heart rate variability: a randomised controlled trial in healthy subjects.

    PubMed

    Tharion, Elizabeth; Samuel, Prasanna; Rajalakshmi, R; Gnanasenthil, G; Subramanian, Rajam Krishna

    2012-01-01

    Studies show that yogic type of breathing exercises reduces the spontaneous respiratory rate. However, there are no conclusive studies on the effects of breathing exercise on heart rate variability. We investigated the effects of non-yogic breathing exercise on respiratory rate and heart rate variability. Healthy subjects (21-33 years, both genders) were randomized into the intervention group (n=18), which performed daily deep breathing exercise at 6 breaths/min (0.1 Hz) for one month, and a control group (n=18) which did not perform any breathing exercise. Baseline respiratory rate and short-term heart rate variability indices were assessed in both groups. Reassessment was done after one month and the change in the parameters from baseline was computed for each group. Comparison of the absolute changes [median (inter-quartile ranges)] of the parameters between the intervention and control group showed a significant difference in the spontaneous respiratory rate [intervention group -2.50 (-4.00, -1.00), control group 0.00 (-1.00, 1.00), cycles/min, P<0.001], mean arterial pressure [intervention group -0.67 (-6.67, 1.33), control group 0.67 (0.00, 6.67), mmHg, (P<0.05)], high frequency power [intervention group 278.50 (17.00, 496.00), control group -1.00 (-341.00, 196.00), ms2 P<0.05] and sum of low and high frequency powers [intervention group 512.00 (-73.00, 999.00), control group 51.00 (-449.00, 324.00), ms2, P<0.05]. Neither the mean of the RR intervals nor the parameters reflecting sympatho-vagal balance were significantly different across the groups. In conclusion, the changes produced by simple deep slow breathing exercise in the respiratory rate and cardiac autonomic modulation of the intervention group were significant, when compared to the changes in the control group. Thus practice of deep slow breathing exercise improves heart rate variability in healthy subjects, without altering their cardiac autonomic balance. These findings have implications in the

  19. Obesity accentuates circadian variability in breathing during sleep in mice but does not predispose to apnea.

    PubMed

    Davis, Eric M; Locke, Landon W; McDowell, Angela L; Strollo, Patrick J; O'Donnell, Christopher P

    2013-08-15

    Obesity is a primary risk factor for the development of obstructive sleep apnea in humans, but the impact of obesity on central sleep apnea is less clear. Given the comorbidities associated with obesity in humans, we developed techniques for long-term recording of diaphragmatic EMG activity and polysomnography in obese mice to assess breathing patterns during sleep and to determine the effect of obesity on apnea generation. We hypothesized that genetically obese ob/ob mice would exhibit less variability in breathing across the 24-h circadian cycle, be more prone to central apneas, and be more likely to exhibit patterns of increased diaphragm muscle activity consistent with obstructive apneas compared with lean mice. Unexpectedly, we found that obese mice exhibited a greater circadian impact on respiratory rate and diaphragmatic burst amplitude than lean mice, particularly during rapid eye movement (REM) sleep. Central apneas were more common in REM sleep (42 ± 17 h(-1)) than non-REM (NREM) sleep (14 ± 5 h(-1)) in obese mice (P < 0.05), but rates were not different between lean and obese mice in either sleep state. Even after experimentally enhancing central apnea generation by acute withdrawal of hypoxic chemoreceptor activation during sleep, central apnea rates remained comparable between lean and obese mice. Last, we were unable to detect patterns of diaphragmatic burst activity suggestive of obstructive apnea events in obese mice. In summary, obesity does not predispose mice to increased occurrence of central or obstructive apneas during sleep, but does lead to a more pronounced circadian variability in respiration.

  20. Assessment of slow-breathing relaxation technique in acute stressful tasks using a multipurpose non-invasive beat-by-beat cardiovascular monitoring system.

    PubMed

    Nogawa, Masamichi; Yamakoshi, Takehiro; Ikarashi, Akira; Tanaka, Shinobu; Yamakoshi, Ken-ichi

    2007-01-01

    Recently, several studies revealed that daily slow-breathing exercise lowered blood pressure and increased baroreflex sensitivity. With this interesting finding, we have been contemplating to design a compact breath-controllable device for relaxation to stress reaction during daily living for home as well as ambulatory use, as a final goal, towards reduction of cognitive hemodynamic disorders, hypertension, and acute stress-induced hemodynamic disorders. The present study thereby describes, as a first step, to design a prototype system combining a compact multipurpose non-invasive beat-by-beat cardiovascular monitor developed previously with a wrist-type vibrator to make a respiration rhythm, and to assess an effect of slow-breathing relaxation on the cardiovascular hemodynamics in response to acute stressful conditions. The cardiovascular hemodynamic monitor can measure beat-by-beat systolic (SBP), mean (MBP) and diastolic (DBP) pressure in a finger based on the volume-compensation method, cardiac output (CO) by the electrical admittance method and the other hemodynamic-related parameters (e.g., total peripheral resistance (TPR=MBP/CO), heart rate (HR), respiratory rate, pulse wave velocity, etc.). The wrist-type vibrator can give various breathing rhythms quietly to a subject using a small vibration motor. The stressful tasks loaded to healthy volunteers (3 males, 23-34 yrs.) in the experiments were cold pressor and arithmetic ones as a representative of daily passive and active coping tasks, respectively, under conditions with (respiratory rate of 6 1/min) and without breath control.. The results showed that the slow-breathing technique could have a significant effect on improvement of the hemodynamic changes following the acute stressful tasks, especially in the passive coping task.

  1. Complexity Variability Assessment of Nonlinear Time-Varying Cardiovascular Control

    NASA Astrophysics Data System (ADS)

    Valenza, Gaetano; Citi, Luca; Garcia, Ronald G.; Taylor, Jessica Noggle; Toschi, Nicola; Barbieri, Riccardo

    2017-02-01

    The application of complex systems theory to physiology and medicine has provided meaningful information about the nonlinear aspects underlying the dynamics of a wide range of biological processes and their disease-related aberrations. However, no studies have investigated whether meaningful information can be extracted by quantifying second-order moments of time-varying cardiovascular complexity. To this extent, we introduce a novel mathematical framework termed complexity variability, in which the variance of instantaneous Lyapunov spectra estimated over time serves as a reference quantifier. We apply the proposed methodology to four exemplary studies involving disorders which stem from cardiology, neurology and psychiatry: Congestive Heart Failure (CHF), Major Depression Disorder (MDD), Parkinson’s Disease (PD), and Post-Traumatic Stress Disorder (PTSD) patients with insomnia under a yoga training regime. We show that complexity assessments derived from simple time-averaging are not able to discern pathology-related changes in autonomic control, and we demonstrate that between-group differences in measures of complexity variability are consistent across pathologies. Pathological states such as CHF, MDD, and PD are associated with an increased complexity variability when compared to healthy controls, whereas wellbeing derived from yoga in PTSD is associated with lower time-variance of complexity.

  2. Complexity Variability Assessment of Nonlinear Time-Varying Cardiovascular Control.

    PubMed

    Valenza, Gaetano; Citi, Luca; Garcia, Ronald G; Taylor, Jessica Noggle; Toschi, Nicola; Barbieri, Riccardo

    2017-02-20

    The application of complex systems theory to physiology and medicine has provided meaningful information about the nonlinear aspects underlying the dynamics of a wide range of biological processes and their disease-related aberrations. However, no studies have investigated whether meaningful information can be extracted by quantifying second-order moments of time-varying cardiovascular complexity. To this extent, we introduce a novel mathematical framework termed complexity variability, in which the variance of instantaneous Lyapunov spectra estimated over time serves as a reference quantifier. We apply the proposed methodology to four exemplary studies involving disorders which stem from cardiology, neurology and psychiatry: Congestive Heart Failure (CHF), Major Depression Disorder (MDD), Parkinson's Disease (PD), and Post-Traumatic Stress Disorder (PTSD) patients with insomnia under a yoga training regime. We show that complexity assessments derived from simple time-averaging are not able to discern pathology-related changes in autonomic control, and we demonstrate that between-group differences in measures of complexity variability are consistent across pathologies. Pathological states such as CHF, MDD, and PD are associated with an increased complexity variability when compared to healthy controls, whereas wellbeing derived from yoga in PTSD is associated with lower time-variance of complexity.

  3. Complexity Variability Assessment of Nonlinear Time-Varying Cardiovascular Control

    PubMed Central

    Valenza, Gaetano; Citi, Luca; Garcia, Ronald G.; Taylor, Jessica Noggle; Toschi, Nicola; Barbieri, Riccardo

    2017-01-01

    The application of complex systems theory to physiology and medicine has provided meaningful information about the nonlinear aspects underlying the dynamics of a wide range of biological processes and their disease-related aberrations. However, no studies have investigated whether meaningful information can be extracted by quantifying second-order moments of time-varying cardiovascular complexity. To this extent, we introduce a novel mathematical framework termed complexity variability, in which the variance of instantaneous Lyapunov spectra estimated over time serves as a reference quantifier. We apply the proposed methodology to four exemplary studies involving disorders which stem from cardiology, neurology and psychiatry: Congestive Heart Failure (CHF), Major Depression Disorder (MDD), Parkinson’s Disease (PD), and Post-Traumatic Stress Disorder (PTSD) patients with insomnia under a yoga training regime. We show that complexity assessments derived from simple time-averaging are not able to discern pathology-related changes in autonomic control, and we demonstrate that between-group differences in measures of complexity variability are consistent across pathologies. Pathological states such as CHF, MDD, and PD are associated with an increased complexity variability when compared to healthy controls, whereas wellbeing derived from yoga in PTSD is associated with lower time-variance of complexity. PMID:28218249

  4. Compressed sensing real-time cine cardiovascular magnetic resonance: accurate assessment of left ventricular function in a single-breath-hold.

    PubMed

    Kido, Tomoyuki; Kido, Teruhito; Nakamura, Masashi; Watanabe, Kouki; Schmidt, Michaela; Forman, Christoph; Mochizuki, Teruhito

    2016-08-24

    Cardiovascular cine magnetic resonance (CMR) accelerated by compressed sensing (CS) is used to assess left ventricular (LV) function. However, it is difficult for prospective CS cine CMR to capture the complete end-diastolic phase, which can lead to underestimation of the end-diastolic volume (EDV), stroke volume (SV), and ejection fraction (EF), compared to retrospective standard cine CMR. This prospective study aimed to evaluate the diagnostic quality and accuracy of single-breath-hold full cardiac cycle CS cine CMR, acquired over two heart beats, to quantify LV volume in comparison to multi-breath-hold standard cine CMR. Eighty-one participants underwent standard segmented breath-hold cine and CS real-time cine CMR examinations to obtain a stack of eight contiguous short-axis images with same high spatial (1.7 × 1.7 mm(2)) and temporal resolution (41 ms). Two radiologists independently performed qualitative analysis of image quality (score, 1 [i.e., "nondiagnostic"] to 5 [i.e., "excellent"]) and quantitative analysis of the LV volume measurements. The total examination time was 113 ± 7 s for standard cine CMR and 24 ± 4 s for CS cine CMR (p < 0.0001). The CS cine image quality was slightly lower than standard cine (4.8 ± 0.5 for standard vs. 4.4 ± 0.5 for CS; p < 0.0001). However, all image quality scores for CS cine were above 4 (i.e., good). No significant differences existed between standard and CS cine MR for all quantitative LV measurements. The mean differences with 95 % confidence interval (CI), based on Bland-Altman analysis, were 1.3 mL (95 % CI, -14.6 - 17.2) for LV end-diastolic volume, 0.2 mL (95 % CI, -9.8 to10.3) for LV end-systolic volume, 1.1 mL (95 % CI, -10.5 to 12.7) for LV stroke volume, 1.0 g (95 % CI, -11.2 to 13.3) for LV mass, and 0.4 % (95 % CI, -4.8 - 5.6) for LV ejection fraction. The interobserver and intraobserver variability for CS cine MR ranged from -4.8 - 1.6 % and from -7.3 - 9.3

  5. Subject-specific estimation of respiratory navigator tracking factor for free-breathing cardiovascular MR.

    PubMed

    Moghari, Mehdi H; Hu, Peng; Kissinger, Kraig V; Goddu, Beth; Goepfert, Lois; Ngo, Long; Manning, Warren J; Nezafat, Reza

    2012-06-01

    A mean respiratory navigator tracking factor of 0.6 is commonly used to estimate the respiratory motion of the heart from the displacement of the right hemi-diaphragm. A constant tracking factor can generate significant residual error in estimation of the respiratory motion of the heart for the cases where the actual tracking factor highly deviates from 0.6. In this study, we implemented and evaluated a robust method to calculate a subject-specific tracking factor for free-breathing high resolution cardiac MR. The subject-specific tracking factor was calculated from two consecutive navigator signals placed on the right hemi-diaphragm and the basal left ventricle in a training phase. To verify the accuracy of the estimated subject-specific tracking factor, nineteen subjects were recruited for comparing the estimated tracking factor in real-time with an image-based tracking factor, calculated off-line. Subsequently, in seven adult subjects, whole-heart or targeted coronary artery MR images were acquired using the estimated subject-specific tracking factor and visually compared with those acquired using a constant (0.6) tracking factor. It was shown that the proposed method can accurately estimate the subject-specific tracking factor and improve the quality of coronary images when the subject-specific tracking factor differs from 0.6. Copyright © 2011 Wiley-Liss, Inc.

  6. Heart Rate Variability and Sleep-Related Breathing Disorders in the General Population.

    PubMed

    Aeschbacher, Stefanie; Bossard, Matthias; Schoen, Tobias; Schmidlin, Delia; Muff, Christoph; Maseli, Anna; Leuppi, Jörg D; Miedinger, David; Probst-Hensch, Nicole M; Schmidt-Trucksäss, Arno; Risch, Martin; Risch, Lorenz; Conen, David

    2016-09-15

    Obstructive sleep apnea seems to have an important influence on the autonomic nervous system. In this study, we assessed the relations of sleep apnea-related parameters with 24-hour heart rate variability (HRV) in a large population of young and healthy adults. Participants aged 25 to 41 years with a body mass index <35 kg/m(2) and without known obstructive sleep apnea were included in a prospective population-based cohort study. HRV was assessed using 24-hour electrocardiographic monitoring. The SD of all normal RR intervals (SDNN) was used as the main HRV variable. Apnea-Hypopnea Index (AHI) and oxygen desaturation index (ODI) were obtained from nighttime pulse oximetry with nasal airflow measurements. We defined sleep-related breathing disorders as an AHI ≥5 or an ODI ≥5. Multivariable regression models were constructed to assess the relation of HRV with either AHI or ODI. Median age of the 1,255 participants was 37 years, 47% were men, and 9.6% had an AHI ≥5. Linear inverse associations of SDNN across AHI and ODI groups were found (p for trend = 0.006 and 0.0004, respectively). The β coefficients (95% CI) for the relation between SDNN and elevated AHI were -0.20 (-0.40 to -0.11), p = 0.04 and -0.29 (-0.47 to -0.11), p = 0.002 for elevated ODI. After adjustment for 24-hour heart rate, the same β coefficients (95% CI) were -0.06 (-0.22 to 0.11), p = 0.51 and -0.14 (-0.30 to 0.01), p = 0.07, respectively. In conclusion, even early stages of sleep-related breathing disorders are inversely associated with HRV in young and healthy adults, suggesting that they are tightly linked with autonomic dysfunction. However, HRV and 24-hour heart rate seem to have common information. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. The effect of formulation variables and breathing patterns on the site of nasal deposition in an anatomically correct model.

    PubMed

    Guo, Yang; Laube, Beth; Dalby, Richard

    2005-11-01

    This study was conducted to evaluate the effect of formulation variables and breathing patterns on aerosol distribution in the nasal cavity. Placebo nasal spray formulations containing 0.25% w/v Avicel CL611 (viscosity = 4 cP) and 2% w/v methylcellulose (MC; viscosity = 18.2 cP) were radiolabeled with (99m)Technicium. Following spraying into a silicone nose model, through which air was drawn at one of three constant rates (0, 10, and 20 L/min) or one of two breathing profiles (representing fast and slow inhalations), aerosol deposition in the model was quantified by gamma scintigraphy. Regional deposition was expressed as horizontal[inner, middle (h), outer] and vertical distribution [upper, middle (v), lower] in the nose model. Compared to 2% MC, Avicel CL611 significantly increased aerosol deposition in the middle (h) region of the nasal cavity under all breathing conditions, and in the inner region at 0 and 20 L/min and with a slow inhalation. The different breathing rates showed no effect on deposition of 2% MC. However, 10 L/min significantly increased the upper deposition of Avicel compared to 0 and 20 L/min. Nasal sprays with a low viscosity provided greater surface coverage of the nasal mucosa than higher viscosity formulations. Changes in breathing profiles did not affect aerosol deposition in this nose model.

  8. Reliability of transfer function estimates in cardiovascular variability analysis.

    PubMed

    Pinna, G D; Maestri, R

    2001-05-01

    Transfer function (TF) analysis is a widely diffused technique in the assessment of the relationship between short-term cardiovascular variability signals, particularly blood pressure, heart rate and respiration. To guarantee the reliability of the estimates, a conventional threshold of 0.5 on the magnitude squared coherence (MSC) is commonly used, although (i) other analysis parameters play a role and (ii) lower values of MSC are frequently unavoidable in physiological systems. In this study, computer simulations are performed to assess the dependency of the bias and standard deviation (SD) of TF estimates on record length (RL), spectral window bandwidth (Bw) and MSC; to evaluate the accuracy of theoretical expressions for the computation of the confidence interval (CI) of the estimates; and to assess, in some representative situations, how faithfully observed TF shapes reproduce the underlying true functions in conditions of very low MSC. The accuracy of TF estimates increases non-linearly with increasing RL, and the benefit over 7 min is small. Using this RL, the relative bias for the TF modulus is < 10% for MSC > 0.2. Estimates of TF phase are unbiased. The SD of both the modulus and phase increases linearly as the MSC decrease to 0.4 and then, for lower MSC, increases markedly with nonlinear behaviour. Bw= 0.03Hz appears to be most suitable to reduce the error, preserving spectral resolution. CIs for the TF phase are highly reliable, whereas those for the modulus tend to be slightly narrower than the nominal value at high coherence values. Major features of the TF shape appear to be preserved in simulations with very low MSC. The major problem in TF estimation is the sharp increase in the variability of the measurements as the coherence decreases towards the lowest values. The combination of RL > or = 420s and Bw= 0.03Hz should be suggested in short-term cardiovascular variability studies. Although basic features of the true TF can be recovered even when the

  9. Cardiovascular and respiratory effect of yogic slow breathing in the yoga beginner: what is the best approach?

    PubMed

    Mason, Heather; Vandoni, Matteo; Debarbieri, Giacomo; Codrons, Erwan; Ugargol, Veena; Bernardi, Luciano

    2013-01-01

    Slow breathing increases cardiac-vagal baroreflex sensitivity (BRS), improves oxygen saturation, lowers blood pressure, and reduces anxiety. Within the yoga tradition slow breathing is often paired with a contraction of the glottis muscles. This resistance breath "ujjayi" is performed at various rates and ratios of inspiration/expiration. To test whether ujjayi had additional positive effects to slow breathing, we compared BRS and ventilatory control under different breathing patterns (equal/unequal inspiration/expiration at 6 breath/min, with/without ujjayi), in 17 yoga-naive young healthy participants. BRS increased with slow breathing techniques with or without expiratory ujjayi (P < 0.05 or higher) except with inspiratory + expiratory ujjayi. The maximal increase in BRS and decrease in blood pressure were found in slow breathing with equal inspiration and expiration. This corresponded with a significant improvement in oxygen saturation without increase in heart rate and ventilation. Ujjayi showed similar increase in oxygen saturation but slightly lesser improvement in baroreflex sensitivity with no change in blood pressure. The slow breathing with equal inspiration and expiration seems the best technique for improving baroreflex sensitivity in yoga-naive subjects. The effects of ujjayi seems dependent on increased intrathoracic pressure that requires greater effort than normal slow breathing.

  10. Deep breathing heart rate variability is associated with inspiratory muscle weakness in chronic heart failure.

    PubMed

    Reis, Michel Silva; Arena, Ross; Archiza, Bruno; de Toledo, Carlos Fischer; Catai, Aparecida Maria; Borghi-Silva, Audrey

    2014-03-01

    There is a synchronism between the respiratory and cardiac cycles. However, the relationship of inspiratory muscle weakness in chronic heart failure (CHF) on cardiac autonomic modulation is unknown. The purpose of the present investigation was to evaluate the impact of inspiratory muscle strength on the magnitude of respiratory sinus arrhythmia. Ten CHF (62 ± 7 years--left ventricle eject fraction of 40 ± 5% and New York Heart Association class I-III) and nine matched-age healthy volunteers (64 ± 5 years) participated in this study. Heart rate variability (HRV) was obtained at rest and during deep breathing manoeuvre (DB-M) by electrocardiograph. CHF patients demonstrated impaired cardiac autonomic modulation at rest and during DB-M when compared with healthy subjects (p < 0.05). Moreover, significant and positive correlations between maximal inspiratory pressure and inspiratory-expiratory differences (r = 0.79), expiratory/inspiratory ratio (r = 0.83), root mean square of the successive differences (r = 0.77), standard deviation of NN intervals (r = 0.77), low frequency (r = 0.77), and high frequency (r = 0.70) were found during DB-M. At rest, significant correlations were found also. Patients with CHF presented impaired cardiac autonomic modulation at rest. In addition, cardiac autonomic control of heart rate was associated with inspiratory muscle weakness in CHF. Based on this evidence, recommendations for future research applications of respiratory muscle training can bring to light a potentially valuable target for rehabilitation. Copyright © 2013 John Wiley & Sons, Ltd.

  11. Sleep-disordered breathing in patients with COPD and mild hypoxemia: prevalence and predictive variables.

    PubMed

    Silva, José Laerte Rodrigues; Conde, Marcus Barreto; Corrêa, Krislainy de Sousa; Rabahi, Helena; Rocha, Arthur Alves; Rabahi, Marcelo Fouad

    2017-01-01

    To infer the prevalence and variables predictive of isolated nocturnal hypoxemia and obstructive sleep apnea (OSA) in patients with COPD and mild hypoxemia. This was a cross-sectional study involving clinically stable COPD outpatients with mild hypoxemia (oxygen saturation = 90-94%) at a clinical center specializing in respiratory diseases, located in the city of Goiânia, Brazil. The patients underwent clinical evaluation, spirometry, polysomnography, echocardiography, arterial blood gas analysis, six-minute walk test assessment, and chest X-ray. The sample included 64 patients with COPD and mild hypoxemia; 39 (61%) were diagnosed with sleep-disordered breathing (OSA, in 14; and isolated nocturnal hypoxemia, in 25). Correlation analysis showed that PaO2 correlated moderately with mean sleep oxygen saturation (r = 0.45; p = 0.0002), mean rapid eye movement (REM) sleep oxygen saturation (r = 0.43; p = 0.001), and mean non-REM sleep oxygen saturation (r = 0.42; p = 0.001). A cut-off point of PaO2 ≤ 70 mmHg in the arterial blood gas analysis was significantly associated with sleep-disordered breathing (OR = 4.59; 95% CI: 1.54-13.67; p = 0.01). The model showed that, for identifying sleep-disordered breathing, the cut-off point had a specificity of 73.9% (95% CI: 51.6-89.8%), a sensitivity of 63.4% (95% CI: 46.9-77.9%), a positive predictive value of 81.3% (95% CI: 67.7-90.0%), and a negative predictive value of 53.1% (95% CI: 41.4-64.4%), with an area under the ROC curve of 0.69 (95% CI: 0.57-0.80), correctly classifying the observations in 67.2% of the cases. In our sample of patients with COPD and mild hypoxemia, the prevalence of sleep-disordered breathing was high (61%), suggesting that such patients would benefit from sleep studies. Inferir a prevalência e as variáveis preditivas de hipoxemia noturna e apneia obstrutiva do sono (AOS) em pacientes portadores de DPOC com hipoxemia leve. Estudo transversal realizado em pacientes ambulatoriais, clinicamente est

  12. Sleep-related breathing disorders and gait variability: a cross-sectional preliminary study.

    PubMed

    Celle, Sébastien; Annweiler, Cédric; Camicioli, Richard; Barthélémy, Jean-Claude; Roche, Frédéric; Beauchet, Olivier

    2014-08-23

    Sleep-related breathing disorders (SRBDs) provoke cognitive and structural brain disorders. Because these disorders have been associated with unsafe gait characterized by an increase in stride-to-stride variability of stride time (STV), we hypothesised that SRBDs could be associated with an increased STV. The aim of this study was to examine the association between SRBDs and STV in French healthy older community-dwellers. A total of 49 participants (mean age 69.6 ± 0.8 years; 65.2% female) were included in this cross-sectional study. All participants, who were free of clinically diagnosed SRBDs before their inclusion, had a nocturnal unattended home-sleep assessment. There were separated in three group based on apnea + hypopnea index (AHI): AHI <15 defining the absence of SRBD, AHI between 15-30 defining mild SRBD, and AHI >30 defining moderate-to-severe SRBD. Coefficient of variation of stride time, which is a measure of STV, was recorded while usual walking using SMTEC® footswitches system. Digit span score was used as a measure of executive performance. Age, gender, body mass index (BMI), number of drugs daily taken, vision, proprioception, history of falls, depression symptoms, global cognitive functioning were also recorded. STV and BMI were higher in participants with mild SRBDs (P = 0.031 and P = 0.020) and moderate-to-severe SRBDs (P = 0.004 and P = 0.002) compared to non-SRBDs. STV positively correlated with AHI (P = 0.036). Lower (i.e., better) STV was associated with the absence of SRBDs (P = 0.021), while greater (i.e., worse) STV was associated with moderate-to-severe SRBD (P < 0.045) but not with mild SRBD (P > 0.06). Our results show a positive association between STV and SRBDs, with moderate-to-severe SRBD being associated with greater gait variability. This association opens new perspectives for understanding gait disorders in older adults with SRBDs and opens the door to treatments options since SRBDs are potential treatable factors.

  13. Range of control of cardiovascular variables by the hypothalamus

    NASA Technical Reports Server (NTRS)

    Smith, O. A.; Stephenson, R. B.; Randall, D. C.

    1974-01-01

    New methodologies were utilized to study the influence of the hypothalamus on the cardiovascular system. The regulation of myocardial activity was investigated in monkeys with hypothalamic lesions that eliminate cardiovascular responses. Observations showed that a specific part of the hypothalamus regulates changes in myocardial contractility that accompanies emotion. Studies of the hypothalamus control of renal blood flow showed the powerful potential control of this organ over renal circulation.

  14. Range of control of cardiovascular variables by the hypothalamus

    NASA Technical Reports Server (NTRS)

    Smith, O. A.; Stephenson, R. B.; Randall, D. C.

    1974-01-01

    New methodologies were utilized to study the influence of the hypothalamus on the cardiovascular system. The regulation of myocardial activity was investigated in monkeys with hypothalamic lesions that eliminate cardiovascular responses. Observations showed that a specific part of the hypothalamus regulates changes in myocardial contractility that accompanies emotion. Studies of the hypothalamus control of renal blood flow showed the powerful potential control of this organ over renal circulation.

  15. Variables that Impact on the Results of Breath-Alcohol Tests

    ERIC Educational Resources Information Center

    Labianca, Dominick A.

    2004-01-01

    In a 2003 issue of the "Journal of Chemical Education," Kniesel and Bellamy describe a timely and pedagogically effective experiment involving breath-alcohol analysis using an FTIR (Fourier Transform Infrared Spectroscopy) spectrometer. The present article clarifies some of the information presented in the 2003 article.

  16. Variables that Impact on the Results of Breath-Alcohol Tests

    ERIC Educational Resources Information Center

    Labianca, Dominick A.

    2004-01-01

    In a 2003 issue of the "Journal of Chemical Education," Kniesel and Bellamy describe a timely and pedagogically effective experiment involving breath-alcohol analysis using an FTIR (Fourier Transform Infrared Spectroscopy) spectrometer. The present article clarifies some of the information presented in the 2003 article.

  17. Effect of short-term practice of pranayamic breathing exercises on cognition, anxiety, general well being and heart rate variability.

    PubMed

    Chandla, S S; Sood, S; Dogra, R; Das, S; Shukla, S K; Gupta, Sanjay

    2013-10-01

    There has been an increasing interest in pranayamic breathing exercises which have been known to improve the quality of life. Present study was conducted to find out the effect of Bhastrika and Anulom Vilom Pranayam and yogasana on heart rate variability, general well being, cognition and anxiety levels of the medical students. Ninety-six medical students were randomly divided into two groups. One group performed Bhastrika and Anulom Vilom Pranayam and the second Suryanamaskar for six weeks. The subjects were made to fill in PGI memory scale, Hamilton- anxiety scale and psychological general well being schedule and recording of heart rate variability parameters was done, before and after six weeks of pranayam practice. The results showed highly significant increase in high frequency (HF) components of heart rate variability and decrease in low frequency (LF) components and LF/HF inthe group practising pranayam. There was also highly significant improvement of cognition, general well being and anxiety as shown by the PGI memory scale, Hamilton- anxiety scale and psychological general well being schedule scores in this group. In the yogasana group no significant changes were observed in the heart rate variability, cognition and anxiety although psychological general well being schedule scores significantly improved after six weeks practice of yogasana. The study shows that practice of slow breathing type of pranayam for six weeks improves cognition, anxiety and general well being and Increases the parasympathetic activity. Whereas there was no effect of the yogasana on the above parameters except improvements in the general well being.

  18. Accounting for respiration is necessary to reliably infer Granger causality from cardiovascular variability series.

    PubMed

    Porta, Alberto; Bassani, Tito; Bari, Vlasta; Pinna, Gian D; Maestri, Roberto; Guzzetti, Stefano

    2012-03-01

    This study was designed to demonstrate the need of accounting for respiration (R) when causality between heart period (HP) and systolic arterial pressure (SAP) is under scrutiny. Simulations generated according to a bivariate autoregressive closed-loop model were utilized to assess how causality changes as a function of the model parameters. An exogenous (X) signal was added to the bivariate autoregressive closed-loop model to evaluate the bias on causality induced when the X source was disregarded. Causality was assessed in the time domain according to a predictability improvement approach (i.e., Granger causality). HP and SAP variability series were recorded with R in 19 healthy subjects during spontaneous and controlled breathing at 10, 15, and 20 breaths/min. Simulations proved the importance of accounting for X signals. During spontaneous breathing, assessing causality without taking into consideration R leads to a significantly larger percentage of closed-loop interactions and a smaller fraction of unidirectional causality from HP to SAP. This finding was confirmed during paced breathing and it was independent of the breathing rate. These results suggest that the role of baroreflex cannot be correctly assessed without accounting for R.

  19. Measuring Ventilatory Activity with Structured Light Plethysmography (SLP) Reduces Instrumental Observer Effect and Preserves Tidal Breathing Variability in Healthy and COPD

    PubMed Central

    Niérat, Marie-Cécile; Dubé, Bruno-Pierre; Llontop, Claudia; Bellocq, Agnès; Layachi Ben Mohamed, Lila; Rivals, Isabelle; Straus, Christian; Similowski, Thomas; Laveneziana, Pierantonio

    2017-01-01

    The use of a mouthpiece to measure ventilatory flow with a pneumotachograph (PNT) introduces a major perturbation to breathing (“instrumental/observer effect”) and suffices to modify the respiratory behavior. Structured light plethysmography (SLP) is a non-contact method of assessment of breathing pattern during tidal breathing. Firstly, we validated the SLP measurements by comparing timing components of the ventilatory pattern obtained by SLP vs. PNT under the same condition; secondly, we compared SLP to SLP+PNT measurements of breathing pattern to evaluate the disruption of breathing pattern and breathing variability in healthy and COPD subjects. Measurements were taken during tidal breathing with SLP alone and SLP+PNT recording in 30 COPD and healthy subjects. Measurements included: respiratory frequency (Rf), inspiratory, expiratory, and total breath time/duration (Ti, Te, and Tt). Passing-Bablok regression analysis was used to evaluate the interchangeability of timing components of the ventilatory pattern (Rf, Ti, Te, and Tt) between measurements performed under the following experimental conditions: SLP vs. PNT, SLP+PNT vs. SLP, and SLP+PNT vs. PNT. The variability of different ventilatory variables was assessed through their coefficients of variation (CVs). In healthy: according to Passing-Bablok regression, Rf, TI, TE and TT were interchangeable between measurements obtained under the three experimental conditions (SLP vs. PNT, SLP+PNT vs. SLP, and SLP+PNT vs. PNT). All the CVs describing “traditional” ventilatory variables (Rf, Ti, Te, Ti/Te, and Ti/Tt) were significantly smaller in SLP+PNT condition. This was not the case for more “specific” SLP-derived variables. In COPD: according to Passing-Bablok regression, Rf, TI, TE, and TT were interchangeable between measurements obtained under SLP vs. PNT and SLP+PNT vs. PNT, whereas only Rf, TE, and TT were interchangeable between measurements obtained under SLP+PNT vs. SLP. However, most discrete

  20. Variability of blood pressure in dialysis patients: a new marker of cardiovascular risk.

    PubMed

    Di Iorio, Biagio; Di Micco, Lucia; Torraca, Serena; Sirico, Maria Luisa; Guastaferro, Pasquale; Chiuchiolo, Luigi; Nigro, Filippo; De Blasio, Antonietta; Romano, Paolo; Pota, Andrea; Rubino, Roberto; Morrone, Luigi; Lopez, Teodoro; Casino, Francesco Gaetano

    2013-01-01

    Hemodialysis patients have a high cardiovascular mortality, and hypertension is the most prevalent treatable risk factor. We aimed to assess the predictive significance of dialysis-to-dialysis variability in blood pressure in hemodialysis patients. We performed a historical cohort study in 1,088 prevalent hemodialysis patients, followed up for 5 years. The risk of cardiovascular death was determined in relation to dialysis-to-dialysis variability in blood pressure, maximum blood pressure and pulse pressure. Variability in blood pressure was a predictor of cardiovascular death (hazard ratio [HR] = 1.242; 95% confidence interval [95% CI], 1.004-1.537; p=0.046). Also age (HR=1.021; 95% CI, 1.011-1.048; p=0.049), diabetes (HR=1.134; 95% CI, 1.128-1.451; p=0.035), creatinine (HR=0.837; 95% CI, 0.717-0.977; p=0.024) and albumin (HR=0.901; 95% CI, 0.821-0.924; p=0.022) influenced mortality. Maximum blood pressure and pulse pressure did not show any effect on cardiovascular death. Dialysis-to-dialysis variability in blood pressure is a predictor of cardiovascular mortality in hemodialysis patients, and blood pressure variability may be used in managing hypertension and predicting outcomes in dialysis patients.

  1. Increase in the heart rate variability with deep breathing in diabetic patients after 12-month exercise training.

    PubMed

    Sridhar, Bhagyalakshmi; Haleagrahara, Nagaraja; Bhat, Ramesh; Kulur, Anupama Bangra; Avabratha, Sridhar; Adhikary, Prabha

    2010-02-01

    Autonomic neuropathy in diabetes leads to impaired regulation of blood pressure and heart rate variability (HRV), which is due to a shift in cardiac autonomic balance towards sympathetic dominance. Lower HRV has been considered a predictor of cardiac mortality and morbidity. Deep breathing test is a simple method to measure HRV and it provides a sensitive measure of cardiac autonomic function. The effect of long-term physical activity on HRV in type-2 diabetes mellitus is inconclusive. We aimed to evaluate the effects of regular physical exercise on HRV with deep breathing in type 2 diabetes (n = 105). Thirty normotensive diabetic patients and 25 hypertensive diabetic patients underwent physical exercise program for 12 months, and the other 50 patients (22 normotensive and 28 hypertensive diabetic patients) were considered the non-exercised group. Electrocardiogram was recorded during deep breathing and HRV was measured. Regular exercise significantly increased HRV in diabetic patients with and without hypertension. The degree of the increase in HRV was greater in hypertensive diabetic patients (p < 0.01) than in normotensive diabetic patients (p < 0.05). After exercise, glycosylated hemoglobin levels were decreased in both groups of diabetic patients. Moreover, the hypertensive diabetic patients showed a decrease (p < 0.05) in blood pressure after regular exercise. Thus, regular exercise training increases HRV, suggesting that there is a shift in the cardiac sympathovagal balance in favor of parasympathetic dominance in diabetic patients. Long-term physical training may be an effective means to reverse the autonomic dysregulation seen in type 2 diabetes.

  2. Pulse oximetry-derived pleth variability index can predict dexmedetomidine-induced changes in blood pressure in spontaneously breathing patients.

    PubMed

    Sato, Makoto; Kunisawa, Takayuki; Kurosawa, Atsushi; Sasakawa, Tomoki

    2016-11-01

    Hypertension or hypotension in patients receiving continuous infusions of dexmedetomidine (DEX) is often due to changes in vascular resistance caused by α2 receptor stimulation. We investigated whether baseline perfusion index (PI) and pleth variability index (PVI), derived from pulse oximetry readings, could predict DEX-induced changes in the hemodynamic status in spontaneously breathing patients. Observational study. Operating room. Patients (American Society of Anesthesiologists performance status 1 or 2) scheduled to undergo lower extremity or abdominal procedures under regional anesthesia were approached. The PI and PVI were set as baseline upon arrival in theater and were then measured at 2.5-minute intervals. Upon attaining stable hemodynamic status under spontaneous breathing, intravenous administration of DEX was initiated at 6 μg kg(-1) h(-1) for 10minutes, followed by continuous infusion at 0.6 μg kg(-1) h(-1). Blood pressure, heart rate, PI, and PVI were measured. Hypertension was defined as an increase in systolic blood pressure (SBP) >15% and hypotension as a decrease in SBP <15% from baseline. Baseline PI and PVI correlated with the degree of change in SBP. The maximum percentage increase as well as the maximum percentage of decrease in SBP from baseline correlated with baseline PI (r=0.418 [P=.005] and r=0.507 [P<.001], respectively) and PVI (r=-0.658 [P<.001] and r=-0.438 [P=.003], respectively). PVI <15 identified DEX-induced hypertension (sensitivity 94%, specificity 85%) and PVI >16 identified DEX-induced hypotension (sensitivity 83%, specificity 64%). PVI may predict DEX-induced changes in blood pressure in spontaneously breathing patients. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Information domain analysis of cardiovascular variability signals: evaluation of regularity, synchronisation and co-ordination.

    PubMed

    Porta, A; Guzzetti, S; Montano, N; Pagani, M; Somers, V; Malliani, A; Baselli, G; Cerutti, S

    2000-03-01

    A unifying general approach to measure regularity, synchronisation and co-ordination is proposed. This approach is based on conditional entropy and is specifically designed to deal with a small amount of data (a few hundred samples). Quantitative and reliable indexes of regularity, synchronisation and co-ordination (ranging from 0 to 1) are derived in a domain (i.e. the information domain) different from time and frequency domains. The method is applied to evaluate regularity, synchronisation and co-ordination among cardiovascular beat-to-beat variability signals during sympathetic activation induced by head-up tilt (T), during the perturbing action produced by controlled respiration at 10, 15 and 20 breaths/min (CR10, CR15 and CR20), and after peripheral muscarinic blockade provoked by the administration of low and high doses of atropine (LD and HD). It is found that: (1) regularity of the RR interval series is around 0.209; (2) this increases during T, CR10 and HD; (3) the systolic arterial pressure (SAP) series is more regular (0.406) and its regularity is not affected by the specified experimental conditions; (4) the muscle sympathetic (MS) series is a complex signal (0.093) and its regularity is not influenced by HD and LD; (5) the RR interval and SAP series are significantly, though weakly, synchronised (0.093) and their coupling increases during T, CR10 and CR15; (6) the RR interval and respiration are coupled (0.152) and their coupling increases during CR10; (7) SAP and respiration are significantly synchronised (0.108) and synchronisation increases during CR10; (8) MS and respiration are uncoupled and become coupled (0.119) after HD; (9) the RR interval, SAP and respiration are significantly co-ordinated (0.118) and co-ordination increases during CR10 and CR15; (10) during HD the co-ordination among SAP, MS and the respiratory signal is larger than that among the RR interval, SAP, MS and the respiratory signal, thus indicating that the RR interval

  4. Associations between body fat variability and later onset of cardiovascular disease risk factors

    PubMed Central

    Takahashi, Osamu; Arioka, Hiroko; Kobayashi, Daiki

    2017-01-01

    Objective There is current debate regarding whether body weight variability is associated with cardiovascular events. Recently, high body fat percentage (BF%) has been shown to be a cardiovascular risk factor. We therefore hypothesized that BF% variability would present a stronger cardiovascular risk than body weight variability. Methods A single-center retrospective cohort study of medical check-up examinees aged 20 years or older at baseline (2005) was performed. Examinees were followed in 2007, 2009, and 2013–2014. BF% variability in 2005, 2007 and 2009 was calculated as the root-mean square error (RMSE) using a simple linear regression model. Multiple logistic regression models estimated the association between BF%-RMSE and new diagnoses of cardiovascular risk factors occurring between the 2009 and 2013–2014 visits. Results In total, 11,281 participants (mean age: 51.3 years old, 48.8% were male) were included in this study. The average BF%-RMSE of our subjects was 0.63, and the average BMI-RMSE was 0.24. The high BF%-RMSE group (76-100th percentile) had a higher incidence of hypertension and a lower incidence of diabetes mellitus than the low BF%-RMSE group (1-25th percentile). This tendency was particularly evident in male participants. BMI-RMSE was not associated with any cardiovascular risks in our study. Conclusions This study indicates that body fat variability has contrasting effects on cardiovascular risk factors, while body weight variability has no significant effects. PMID:28369119

  5. Home Blood Pressure Variability as Cardiovascular Risk Factor in the Population of Ohasama

    PubMed Central

    Asayama, Kei; Kikuya, Masahiro; Schutte, Rudolph; Thijs, Lutgarde; Hosaka, Miki; Satoh, Michihiro; Hara, Azusa; Obara, Taku; Inoue, Ryusuke; Metoki, Hirohito; Hirose, Takuo; Ohkubo, Takayoshi; Staessen, Jan A.; Imai, Yutaka

    2013-01-01

    Blood pressure variability based on office measurement predicts outcome in selected patients. We explored whether novel indices of blood pressure variability derived from the self-measured home blood pressure predicted outcome in a general population. We monitored mortality and stroke in 2421 Ohasama residents (Iwate Prefecture, Japan). At enrollment (1988–1995), participants (mean age, 58.6 years; 60.9% women; 27.1% treated) measured their blood pressure at home, using an oscillometric device. In multivariable-adjusted Cox models, we assessed the independent predictive value of the within-subject mean systolic blood pressure (SBP) and corresponding variability as estimated by variability independent of the mean, difference between maximum and minimum blood pressure, and average real variability. Over 12.0 years (median), 412 participants died, 139 of cardiovascular causes, and 223 had a stroke. In models including morning SBP, variability independent of the mean and average real variability (median, 26 readings) predicted total and cardiovascular mortality in all of the participants (P≤0.044); variability independent of the mean predicted cardiovascular mortality in treated (P=0.014) but not in untreated (P=0.23) participants; and morning maximum and minimum blood pressure did not predict any end point (P≥0.085). In models already including evening SBP, only variability independent of the mean predicted cardiovascular mortality in all and in untreated participants (P≤0.046). The R2 statistics, a measure for the incremental risk explained by adding blood pressure variability to models already including SBP and covariables, ranged from <0.01% to 0.88%. In a general population, new indices of blood pressure variability derived from home blood pressure did not incrementally predict outcome over and beyond mean SBP. PMID:23172933

  6. Feasibility of free-breathing late gadolinium-enhanced cardiovascular MRI for assessment of myocardial infarction: navigator-gated versus single-shot imaging.

    PubMed

    Matsumoto, Hidenari; Matsuda, Tetsuya; Miyamoto, Kenichi; Nakatsuma, Kenji; Sugahara, Masataka; Shimada, Toshihiko

    2013-09-20

    The aim of this study was to evaluate the feasibility of two free-breathing late gadolinium-enhanced cardiovascular magnetic resonance (LGE-CMR) techniques (two-dimensional segmented navigator-gated [NAV-LGE] and single-shot [SS-LGE]) by comparing with breath-hold LGE-CMR (BH-LGE) as reference. A total of 200 consecutive patients underwent the three LGE-CMR imaging techniques. BH patterns were assessed with dynamic navigator MR imaging. Image quality was graded on a 5-point scale (4=optimal; 0=not assessable). In patients with sufficient BH capability (diaphragmatic movement with a deviation of <3mm), hyperenhancement was scored with a 5-point scale, and global infarct size (%left ventricle) was quantified. Compared to free-breathing LGE-CMR, BH-LGE had higher image quality grade in patients with sufficient BH capability (P<0.01 [vs. NAV-LGE]; P<0.001 [vs. SS-LGE]) but poorer image quality in patients with insufficient BH capability (P<0.001 [vs. NAV-LGE]; P<0.01 [vs. SS-LGE]). NAV-LGE had higher sensitivity for infarct detection than SS-LGE (97.1% vs. 88.4%, P<0.05), but specificity was not significantly different (97.3% vs. 94.7%, P=0.37). By Bland-Altman analysis, the average differences in global infarct size were 0.4% and 1.2%, and the limits of agreement were ± 4.0% and ± 5.9% for NAV- and SS-LGE, respectively. Although both NAV- and SS-LGE improve the image quality in patients with insufficient BH capability, NAV-LGE is superior to SS-LGE in infarct detection and infarct size measurement. NAV-LGE can be a possible first-line technique for patients with inability to perform sufficient BH. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  7. May autonomic indices from cardiovascular variability help identify hypertension?

    PubMed

    Lucini, Daniela; Solaro, Nadia; Pagani, Massimo

    2014-02-01

    Altered profile of RR variability and reduced baroreflex gain, as autonomic proxies, are observed in hypertensive individuals. To assess whether using logistic models and cross-validation techniques autonomic proxies can be used to identify clinical hypertensive and normotensive groups. An observational study on 405 individuals (155 mild hypertensive and 250 controls). We used four steps for statistical analysis: preliminary descriptive statistics; logistic regression modelling; detection of best parsimonious set of variables; and concordance analysis between clinical and autonomic hypertension profile. Accuracy index (rate of correct identifications of normotensive and hypertensive states), computed on each of the four gradually more complex logistic models (from A to D), reached its highest value (82.7%), in the most complete model D, including autonomic nervous system indices (RR variability and baroreflex gain), age and sex. Measures of predictive performance increased from the simplest model to the most complex one [model D, positive predictive value (PPV) = 0.767, negative predictive value (NPV) = 0.866], with higher specificity than sensitivity. A parsimonious set of autonomic proxies (Mean RR, ΔRRLFnu - i.e. change from rest to standing up - baroreflex gain combined with age and sex) led to an accuracy index of 80.5%, thus proving to have discriminant and predictive powers in detecting hypertension very similar to the whole set of the explicative variables comprised in the complete model D. The clinical value of the observation that the information collectively carried by a small subset of indirect autonomic proxies may identify either hypertensive or normotensive groups needs to be further investigated.

  8. Baroreflex sensitivity assessed by complex demodulation of cardiovascular variability.

    PubMed

    Kim, S Y; Euler, D E

    1997-05-01

    We used complex demodulation of cardiac interval and systolic arterial blood pressure oscillations in the low-frequency band (0.04 to 0.14 Hz) to investigate baroreceptor control of heart rate. Baroreflex sensitivity was defined as the instantaneous amplitude of complex-demodulated oscillations in the RR interval divided by the instantaneous amplitude of complex-demodulated oscillations in systolic blood pressure. We evaluated the method using both simulated and actual data obtained from 33 healthy nonsmokers during supine and standing postures. To test the validity and reliability of the method, we compared the mean values of baroreflex sensitivity calculated using complex demodulation with the values obtained using power spectral analysis and sequential analysis of spontaneous variations in blood pressure and RR interval. All three methods applied to the simulated data yielded the same values of baroreceptor sensitivity. Mean values of baroreflex sensitivity assessed by complex demodulation of the actual data were similar to those calculated by both power spectral analysis and sequential analysis (13.9 +/- 5.2 versus 13.7 +/- 6.7 or 14.3 +/- 6.5 ms/mm Hg for supine and 7.3 +/- 2.8 versus 7.0 +/- 3.0 or 7.2 +/- 2.8 ms/mm Hg for standing, respectively). In addition, a significant correlation existed between the values obtained by complex demodulation and power spectral analysis (r = .97, P = .0001) and sequential analysis (r = .98, P = .0001). Furthermore, complex demodulation-derived baroreflex sensitivity fluctuated across time during both the supine and standing postures, and this could not be discerned by power spectral analysis. The results indicate that complex demodulation provides a dynamic assessment of baroreflex sensitivity and may be a useful tool in exploring reflex autonomic control of the cardiovascular system.

  9. Breastfeeding Status and Maternal Cardiovascular Variables Across the Postpartum

    PubMed Central

    Jevitt, Cecilia M.; Sahebzamani, Frances; Beckstead, Jason W.; Keefe, David L.

    2013-01-01

    Abstract Background There have been recent reports that lactational history is associated with long-term women's health benefits. Most of these studies are epidemiological. If particular cardiometabolic changes that occur during lactation ultimately influence women's health later is unknown. Methods Seventy-one healthy women participated in a prospective postpartum study that provided an opportunity to study anthropometric, endocrine, immune, and behavioral variables across time. Variables studied were heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), C-reactive protein, body mass index (BMI), perceived stress, and hormones. A cohort of women without a change in breastfeeding (N=22) or formula feeding (N=23) group membership for 5 months was used for analysis of effects of feeding status. The data were analyzed using factorial repeated measures analysis of variance and analysis of covariance. Results SBP and HR declined across the postpartum and were significantly lower in breastfeeding compared to formula feeding mothers (p<0.05). These differences remained statistically significant when BMI was added to the model. Other covariates of income, stress, marital status, and ethnicity were not significantly associated with these variables over time. DBP was also lower, but the significance was reduced by the addition of BMI as a covariate. Stress also was lower in breastfeeders, but this effect was reduced by the addition of income as a covariate. Conclusions These data suggest that there are important physiological differences in women during months of breastfeeding. These may have roles in influencing or programming later risks for a number of midlife diseases. PMID:23659484

  10. Variability in Ozone-Induced Pulmonary Injury and Inflammation in Healthy and Cardiovascular Compromised Rat Models

    EPA Science Inventory

    The molecular bases for variability in air pollutant-induced pulmonary injury due to underlying cardiovascular (CVD) and/or metabolic diseases are unknown. We hypothesized that healthy and genetic CVD-prone rat models will exhibit exacerbated response to acute ozone exposure depe...

  11. Variability in Ozone-Induced Pulmonary Injury and Inflammation in Healthy and Cardiovascular Compromised Rat Models

    EPA Science Inventory

    The molecular bases for variability in air pollutant-induced pulmonary injury due to underlying cardiovascular (CVD) and/or metabolic diseases are unknown. We hypothesized that healthy and genetic CVD-prone rat models will exhibit exacerbated response to acute ozone exposure depe...

  12. Classifying geometric variability by dominant eigenmodes of deformation in regressing tumours during active breath-hold lung cancer radiotherapy.

    PubMed

    Badawi, Ahmed M; Weiss, Elisabeth; Sleeman, William C; Hugo, Geoffrey D

    2012-01-21

    The purpose of this study is to develop and evaluate a lung tumour interfraction geometric variability classification scheme as a means to guide adaptive radiotherapy and improve measurement of treatment response. Principal component analysis (PCA) was used to generate statistical shape models of the gross tumour volume (GTV) for 12 patients with weekly breath hold CT scans. Each eigenmode of the PCA model was classified as 'trending' or 'non-trending' depending on whether its contribution to the overall GTV variability included a time trend over the treatment course. Trending eigenmodes were used to reconstruct the original semi-automatically delineated GTVs into a reduced model containing only time trends. Reduced models were compared to the original GTVs by analyzing the reconstruction error in the GTV and position. Both retrospective (all weekly images) and prospective (only the first four weekly images) were evaluated. The average volume difference from the original GTV was 4.3% ± 2.4% for the trending model. The positional variability of the GTV over the treatment course, as measured by the standard deviation of the GTV centroid, was 1.9 ± 1.4 mm for the original GTVs, which was reduced to 1.2 ± 0.6 mm for the trending-only model. In 3/13 cases, the dominant eigenmode changed class between the prospective and retrospective models. The trending-only model preserved GTV and shape relative to the original GTVs, while reducing spurious positional variability. The classification scheme appears feasible for separating types of geometric variability by time trend.

  13. Potential force dynamics of heart rate variability reflect cardiac autonomic modulation with respect to posture, age, and breathing pattern.

    PubMed

    Mahananto, Faizal; Igasaki, Tomohiko; Murayama, Nobuki

    2015-09-01

    Various physiological and pathological conditions are correlated with cardiac autonomic function. Heart rate variability is a marker of cardiac autonomic modulation and can be measured by several methods. However, the available methods are sensitive to breathing patterns. To quantify cardiac autonomic modulation by observing the potential force dynamics of the R-R interval time series in healthy individuals. We propose two "potentials of unbalanced complex kinetic" (PUCK) parameters to quantify the characteristics of the potential force dynamics of R-R interval time series: potential strength (slope) and fluctuation size (slope standard deviations [SSD1, SSD2]). We applied this method to the series of R-R intervals obtained from 30 healthy subjects in an experimental condition that elicited cardiac autonomic (i.e., sympathetic and vagal) activation (in supine, sitting, and standing positions). Subjects were categorized into three groups by decade (i.e., 20 s, 30 s, and 40 s) to verify the cardiac autonomic differences by age. Two respiration patterns were introduced to check the influence of the pattern into the analytical results. Sympathetic modulation activation significantly increased the slope and reduced SSD1 and SSD2; these trends were confirmed in all groups. The slope is concordant with the result of the low frequency/high frequency (LF/HF) ratio in frequency components as an indicator of sympathetic modulation. No trend was observed in slope among age groups. However, SSD1 and SSD2 in the 40 s group were significantly decreased in the supine and sitting positions. The results with respect to respiration frequency showed lower sympathetic modulation as shown in the LF/HF ratio and slope, whereas higher vagal modulation as shown in the HF appeared with a longer breathing rate. PUCK can quantify the cardiac autonomic modulation in the experimental conditions of different postures. SSD1 and SSD2 are more sensitive to age than frequency components and are

  14. Oscillons localized inside breathing periodical structures in a two-variable model of a one-dimensional infinite excitable reaction-diffusion system.

    PubMed

    Kawczyński, Andrzej L

    2010-08-19

    A two-variable model of a one-dimensional (1D), infinite, excitable, reaction-diffusion system describing oscillons localized inside an expanding breathing periodical structure emitting traveling impulses is presented. The model is based on two coupled catalytic (enzymatic) reactions.

  15. Breathing metabolic simulator

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G.; Hendricks, C. M.; Morison, W. B.

    1972-01-01

    The development of a breathing metabolic simulator (BMS) is reported. This BMS simulates all of the breathing and metabolic parameters required for complete evaluation and test of life support and resuscitation equipment. It is also useful for calibrating and validating mechanical and gaseous pulmonary function test procedures. Breathing rate, breathing depth, breath velocity contour, oxygen uptake, and carbon dioxide release are all variable over wide ranges simulating conditions from sleep to hard work with respiratory exchange ratios covering the range from hypoventilation. In addition, all of these parameters are remotely controllable to facilitate use of the device in hostile or remote environments. The exhaled breath is also maintained at body temperature and a high humidity. The simulation is accurate to the extent of having a variable functional residual capacity independent of other parameters.

  16. Comparison of sleep-disordered breathing and heart rate variability between hemodialysis and non-hemodialysis days in hemodialysis patients.

    PubMed

    Sukegawa, Mayo; Noda, Akiko; Soga, Taro; Adachi, Yuki; Tsuruta, Yoshinari; Ozaki, Norio; Koike, Yasuo

    2008-08-01

    Sleep disturbances manifesting as insomnia, daytime sleepiness, fatigue, and other symptoms are frequently found in patients with end-stage renal disease that is being treated with dialysis. Many factors, including neurosis, uremic symptoms, dialysis drugs, and sleep-wake rhythms have been suggested as potential causes for these sleep disturbances. We examined sleep apnea/hypopnea and heart rate variability (HRV) reflecting autonomic activity in hemodialysis patients on their hemodialysis and non-hemodialysis days using a home medical care device (Morpheus C, TEIJIN). Eleven hemodialysis patients and 14 healthy adults were enrolled in this study. We calculated the number of apnea/hypopnea episodes per hour (apnea/hypopnea index: AHI) and HRV (percentage of R-R intervals that differ by at least 50 ms from the previous interval: pNN50, very low frequency: VLF, low frequency: LF, high frequency: HF and LF/ HF). There was no significant difference in the AHI between hemodialysis and non-hemodialysis days. The heart rate in hemodialysis patients on non-hemodialysis days was significantly higher than in the controls, whereas the pNN50 was significantly lower in hemodialysis patients on non-hemodialysis days than in the controls. Although VLF was significantly lower in hemodialysis patients on non-hemodialysis days compared to the controls, there were no significant differences in LF, HF or LF/HF between the two groups. Hemodialysis itself might not be an important contributing factor in sleep-related breathing disturbances. The simultaneous analysis of HRV reflecting autonomic activity and sleep-disordered breathing on both hemodialysis and non-hemodialysis days provides important information.

  17. Systemic Hemodynamic Atherothrombotic Syndrome and Resonance Hypothesis of Blood Pressure Variability: Triggering Cardiovascular Events

    PubMed Central

    2016-01-01

    Blood pressure (BP) exhibits different variabilities and surges with different time phases, from the shortest beat-by-beat to longest yearly changes. We hypothesized that the synergistic resonance of these BP variabilites generates an extraordinarily large dynamic surge in BP and triggers cardiovascular events (the resonance hypothesis). The power of pulses is transmitted to the peripheral sites without attenuation by the large arteries, in individuals with stiffened arteries. Thus, the effect of a BP surge on cardiovascular risk would be especially exaggerated in high-risk patients with vascular disease. Based on this concept, our group recently proposed a new theory of systemic hemodynamic atherothromboltic syndrome (SHATS), a vicious cycle of hemodynamic stress and vascular disease that advances organ damage and triggers cardiovascular disease. Clinical phenotypes of SHATS are large-artery atherothombotic diseases such as stroke, coronary artery disease, and aortic and pheripheral artery disease; small-artery diseases, and microcirculation-related disease such as vascular cognitive dysfunction, heart failure, and chronic kidney disease. The careful consideration of BP variability and vascular diseases such as SHATS, and the early detection and management of SHATS, will achieve more effective individualized cardiovascular protection. In the near future, information and communication technology-based 'anticipation medicine' predicted by the changes of individual BP values could be a promising approach to achieving zero cardiovascular events. PMID:27482253

  18. Systemic Hemodynamic Atherothrombotic Syndrome and Resonance Hypothesis of Blood Pressure Variability: Triggering Cardiovascular Events.

    PubMed

    Kario, Kazuomi

    2016-07-01

    Blood pressure (BP) exhibits different variabilities and surges with different time phases, from the shortest beat-by-beat to longest yearly changes. We hypothesized that the synergistic resonance of these BP variabilites generates an extraordinarily large dynamic surge in BP and triggers cardiovascular events (the resonance hypothesis). The power of pulses is transmitted to the peripheral sites without attenuation by the large arteries, in individuals with stiffened arteries. Thus, the effect of a BP surge on cardiovascular risk would be especially exaggerated in high-risk patients with vascular disease. Based on this concept, our group recently proposed a new theory of systemic hemodynamic atherothromboltic syndrome (SHATS), a vicious cycle of hemodynamic stress and vascular disease that advances organ damage and triggers cardiovascular disease. Clinical phenotypes of SHATS are large-artery atherothombotic diseases such as stroke, coronary artery disease, and aortic and pheripheral artery disease; small-artery diseases, and microcirculation-related disease such as vascular cognitive dysfunction, heart failure, and chronic kidney disease. The careful consideration of BP variability and vascular diseases such as SHATS, and the early detection and management of SHATS, will achieve more effective individualized cardiovascular protection. In the near future, information and communication technology-based 'anticipation medicine' predicted by the changes of individual BP values could be a promising approach to achieving zero cardiovascular events.

  19. Cardiovascular

    NASA Image and Video Library

    Overview of Cardiovascular research which addresses risks of space flight, including adaptive changes to the cephalad fluid shift (such as reduced circulating blood volume), potential for heart rhy...

  20. Bad Breath

    MedlinePlus

    ... Emergency Room? What Happens in the Operating Room? Bad Breath KidsHealth > For Kids > Bad Breath A A ... visit your dentist or doctor . continue What Causes Bad Breath? Here are three common causes of bad ...

  1. Can Ambulatory Blood Pressure Variability Contribute to Individual Cardiovascular Risk Stratification?

    PubMed

    Magdás, Annamária; Szilágyi, László; Incze, Alexandru

    2016-01-01

    Objective. The aim of this study is to define the normal range for average real variability (ARV) and to establish whether it can be considered as an additional cardiovascular risk factor. Methods. In this observational study, 110 treated hypertensive patients were included and admitted for antihypertensive treatment adjustment. Circadian blood pressure was recorded with validated devices. Blood pressure variability (BPV) was assessed according to the ARV definition. Based on their variability, patients were classified into low, medium, and high variability groups using the fuzzy c-means algorithm. To assess cardiovascular risk, blood samples were collected. Characteristics of the groups were compared by ANOVA tests. Results. Low variability was defined as ARV below 9.8 mmHg (32 patients), medium as 9.8-12.8 mmHg (48 patients), and high variability above 12.8 mmHg (30 patients). Mean systolic blood pressure was 131.2 ± 16.7, 135.0 ± 12.1, and 141.5 ± 11.4 mmHg in the low, medium, and high variability groups, respectively (p = 0.0113). Glomerular filtration rate was 78.6 ± 29.3, 74.8 ± 26.4, and 62.7 ± 23.2 mL/min/1.73 m(2) in the low, medium, and high variability groups, respectively (p = 0.0261). Conclusion. Increased values of average real variability represent an additional cardiovascular risk factor. Therefore, reducing BP variability might be as important as achieving optimal BP levels, but there is need for further studies to define a widely acceptable threshold value.

  2. Is It Daily, Monthly, or Yearly Blood Pressure Variability that Enhances Cardiovascular Risk?

    PubMed

    Dolan, Eamon; O'Brien, Eoin

    2015-11-01

    Variability is a phenomenon common to most biological processes that we can measure and is a particular feature of blood pressure (BP). Variability causes concern for many physicians regarding its clinical meaning and potential impact on cardiovascular risk. In this review, we assess the role of different time periods of blood pressure variability (BPV) in cardiovascular risk stratification. We review the indices of BPV derived from ambulatory blood pressure measurement (ABPM), home blood pressure measurement (HBPM), or at the clinic setting with the intention of providing a clear message for clinical practice. BPV, either derived from ABPM or HBPM, does not consistently augment cardiovascular risk prediction over and beyond that of average BP, particularly in low-risk individuals. That said, it would seem that certain medications such as calcium channel blockers may have a beneficial effect on visit-to-visit BPV and perhaps reduce the associated cardiovascular risk. This highlights the benefits in using combination therapy which might couple a number of therapeutic benefits such as the reductions of mean blood pressure and BPV. Overall, we should remain aware that the average BP level remains the main modifiable risk factor derived from BP measurements and continue to improve the control of hypertension and adverse health outcomes.

  3. Reproducibility of heart rate variability during rest, paced breathing and light-to-moderate intense exercise in patients one month after stroke.

    PubMed

    Ginsburg, P; Bartur, G; Peleg, S; Vatine, J J; Katz-Leurer, M

    2011-01-01

    To examine test-retest reliability of time and frequency domain heart rate variability (HRV) in patients 1 month after stroke during rest, paced breathing and light-to-moderate physical activity. Fifteen patients up to 1 month after stroke underwent two measurements of HRV, with the measurements 4 days apart. Measurements took place under three conditions while sitting: (1) at rest with self-select breathing frequency, (2) paced breathing and (3) cycling while sitting. Reliability was assessed statistically by calculating intraclass correlation coefficients (ICC), standard error of measurement and coefficient of variance (CV). The relative reliability was found to be good-to-excellent for SDNN (ICC: 0.86-0.91), RMSSD (ICC: 0.81-0.87) and HF (ICC: 0.91-0.94) in all three conditions and poor for LF at rest and paced breathing (ICC: 0.43-0.47). The absolute reliability for all measures was found to be poor (CV >15%). HRV can be reliably assessed at rest, paced breathing and light-to-moderate physical activity for identifying differences between patients, while individual changes in autonomic functioning exhibited large random variations between test-retest measurements. Copyright © 2011 S. Karger AG, Basel.

  4. Biological correlates of blood pressure variability in elderly at high risk of cardiovascular disease.

    PubMed

    Poortvliet, Rosalinde K E; Lloyd, Suzanne M; Ford, Ian; Sattar, Naveed; de Craen, Anton J M; Wijsman, Liselotte W; Mooijaart, Simon P; Westendorp, Rudi G J; Jukema, J Wouter; de Ruijter, Wouter; Gussekloo, Jacobijn; Stott, David J

    2015-04-01

    Visit-to-visit variability in blood pressure is an independent predictor of cardiovascular disease. This study investigates biological correlates of intra-individual variability in blood pressure in older persons. Nested observational study within the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) among 3,794 male and female participants (range 70-82 years) with a history of, or risk factors for cardiovascular disease. Individual visit-to-visit variability in systolic and diastolic blood pressure and pulse pressure (expressed as 1 SD in mm Hg) was assessed using nine measurements over 2 years. Correlates of higher visit-to-visit variability were examined at baseline, including markers of inflammation, endothelial function, renal function and glucose homeostasis. Over the first 2 years, the mean intra-individual variability (1 SD) was 14.4mm Hg for systolic blood pressure, 7.7mm Hg for diastolic blood pressure, and 12.6mm Hg for pulse pressure. After multivariate adjustment a higher level of interleukin-6 at baseline was consistently associated with higher intra-individual variability of blood pressure, including systolic, diastolic, and pulse pressure. Markers of endothelial function (Von Willebrand factor, tissue plasminogen activator), renal function (glomerular filtration rate) and glucose homeostasis (blood glucose, homeostatic model assessment index) were not or to a minor extent associated with blood pressure variability. In an elderly population at risk of cardiovascular disease, inflammation (as evidenced by higher levels of interleukin-6) is associated with higher intra-individual variability in systolic, diastolic, and pulse pressure. © American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. On the nature of heart rate variability in a breathing normal subject: a stochastic process analysis.

    PubMed

    Buchner, Teodor; Petelczyc, Monika; Zebrowski, Jan J; Prejbisz, Aleksander; Kabat, Marek; Januszewicz, Andrzej; Piotrowska, Anna Justyna; Szelenberger, Waldemar

    2009-06-01

    Human heart rate is moderated by the autonomous nervous system acting predominantly through the sinus node (the main cardiac physiological pacemaker). One of the dominant factors that determine the heart rate in physiological conditions is its coupling with the respiratory rhythm. Using the language of stochastic processes, we analyzed both rhythms simultaneously taking the data from polysomnographic recordings of two healthy individuals. Each rhythm was treated as a sum of a deterministic drift term and a diffusion term (Kramers-Moyal expansion). We found that normal heart rate variability may be considered as the result of a bidirectional coupling of two nonlinear oscillators: the heart itself and the respiratory system. On average, the diffusion (noise) component measured is comparable in magnitude to the oscillatory (deterministic) term for both signals investigated. The application of the Kramers-Moyal expansion may be useful for medical diagnostics providing information on the relation between respiration and heart rate variability. This interaction is mediated by the autonomous nervous system, including the baroreflex, and results in a commonly observed phenomenon--respiratory sinus arrhythmia which is typical for normal subjects and often impaired by pathology.

  6. Does Vitamin D Deficiency Effect Heart Rate Variability in Low Cardiovascular Risk Population?

    PubMed Central

    Nalbant, Ahmet; Vatan, Mehmet Bulent; Varım, Perihan; Varım, Ceyhun; Kaya, Tezcan; Tamer, Ali

    2017-01-01

    AIM: This study aimed to evaluate the cardiac autonomic dysfunction and the cardiac arrhythmia risk using heart rate variability parameters in subjects with vitamin D deficiency and low cardiovascular risk. MATERIAL AND METHODS: One hundred five consecutive individuals, 54 patients with low vitamin D status and 51 healthy controls were enrolled in this study. The overall cardiac autonomic tone was quantified by using various heart rate variability parameters included mean RR interval, mean Heart Rate, mean of standard deviations of intervals for 24 hours (SDNN), standard deviation of averages of intervals (SDANN), mean of standard deviation of intervals for 5 minutes (SDNNI), root mean square of difference of successive intervals (rMSSD) and the proportion of intervals differing more than 50 ms (pNN50) values. The 12-lead ECG was recorded from each participant, and QT intervals were measured. RESULTS: Baseline demographic profiles were similar between two groups. The heart rate variability parameters such as mean RR interval, mean HR, SDNN, SDANN, SDNNI, rMSSD and pNN50 (%) values were not significantly different in patients with low vitamin D status compared to control group. The electrocardiography analysis revealed only slight but significant prolongation of corrected QT (QTc) intervals in the control group. CONCLUSION: HRV variables were not significantly altered in patients with vitamin D deficiency in low cardiovascular risk profile group. Further studies evaluating these findings in other cohorts with high cardiovascular risk are required. PMID:28507628

  7. Sleep-disordered breathing does not affect nocturnal dipping, as assessed by pulse transit time, in preschool children: evidence for early intervention to prevent adverse cardiovascular effects?

    PubMed

    Nisbet, Lauren C; Nixon, Gillian M; Yiallourou, Stephanie R; Biggs, Sarah N; Davey, Margot J; Trinder, John; Walter, Lisa M; Horne, Rosemary S C

    2014-04-01

    Sleep-disordered breathing (SDB) is associated with reduced nocturnal dipping of blood pressure (BP) and sleep disruption in adults, and these features confer an increased risk of cardiovascular events. As SDB prevalence in children peaks during the preschool years, we investigated nocturnal dipping and sleep fragmentation in preschool children with SDB. Children (3-5 years; n=163) grouped by obstructive apnoea hypopnoea index (OAHI): control, no snoring history and OAHI ≤1 event/h; primary snoring, OAHI ≤1 event/h; mild SDB, >1-≤5 events/h; moderate-severe SDB, >5 events/h. Pulse transit time (PTT), an inverse continuous indicator of BP changes, and heart rate (HR) during total sleep time and the first period of rapid eye movement (REM), non-REM (NREM)1/2 and NREM3/4 sleep were expressed as percentage change from wake before sleep onset. The sleep fragmentation index (SFI) was calculated as the number of sleep stage transitions or awakenings per hour of sleep. There were no group differences in the change in PTT or HR from wake to total sleep time or to individual sleep stages or in the proportion of children in the quartile with the smallest change in PTT during total sleep. Children with moderate-severe SDB had higher SFI than primary snoring (PS) or mild SDB groups (p<0.05 for both) and controls (p=0.07). In contrast to adults, nocturnal dipping is preserved in young children with SDB, despite increased sleep fragmentation. As there is evidence that nocturnal dipping is similarly preserved at the school age, childhood may pose a window of opportunity for resolution of SDB when the cardiovascular effects are less marked. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Sleep-Disordered Breathing in Chronic SCI: A Randomized Controlled Trial of Treatment Impact on Cognition, Quality of Life, and Cardiovascular Disease

    DTIC Science & Technology

    2014-10-01

    AWARD NUMBER: W81XWH-13-1-0479 TITLE: Sleep-Disordered Breathing in Chronic SCI: A...5a. CONTRACT NUMBER Sleep-Disordered Breathing in Chronic SCI: A Randomized Controlled Trial of Treatment Impact on Cognition...SCI. In this prospective randomized controlled trial, we will objectively measure sleep disordered breathing (SDB) in chronic SCI patients using

  9. Blood Pressure Variability: Can Nonlinear Dynamics Enhance Risk Assessment During Cardiovascular Surgery? A Feasibility Study

    PubMed Central

    Subramaniam, Balachundhar; Khabbaz, Kamal R.; Heldt, Thomas; Lerner, Adam B.; Mittleman, Murray A.; Davis, Roger B.; Goldberger, Ary L.; Costa, Madalena D.

    2014-01-01

    Brief Summary We propose that complex (nonlinear) fluctuations of hemodynamic variables (including systemic blood pressure parameters) during cardiovascular surgery contain information relevant to risk assessment and intraoperative management. Preliminary analysis of a pilot study supports the feasibility and potential merits of performing a larger, prospective study to assess the clinical utility of such new dynamical measures and to evaluate their potential role in enhancing contemporary approaches to risk assessment of major adverse events. PMID:24508020

  10. Contrasting effects of phentolamine and nitroprusside on neural and cardiovascular variability.

    PubMed

    van de Borne, P; Rahnama, M; Mezzetti, S; Montano, N; Porta, A; Degaute, J P; Somers, V K

    2001-08-01

    The relative contributions of a central neural oscillator and of the delay in alpha-adrenergic transmission within the baroreflex loop in the predominance of low-frequency (LF) cardiovascular variability during sympathetic activation in humans are unclear. We measured R-R interval (RR), muscle sympathetic nerve activity (MSNA), blood pressure (BP), and their variability in 10 normal subjects during sympathetic activation achieved by BP lowering with sodium nitroprusside (SNP) and alpha-adrenergic blockade using phentolamine. SNP and phentolamine induced comparable reductions in BP (P > 0.25). Despite tachycardia and sympathetic activation with both SNP and phentolamine, LF variability in RR, MSNA, and BP increased during SNP and decreased during phentolamine (SNP: RR +20 +/- 6%, MSNA +3 +/- 5%, systolic BP +9 +/- 6%, diastolic BP +7 +/- 5%; phentolamine: RR -2 +/- 7%, MSNA -34 +/- 6%, systolic BP -16 +/- 8%, diastolic BP -13 +/- 4%, P < 0.05 except systolic BP, where P = 0.09). Thus LF variability is reduced when sympathetic activation is induced by alpha-adrenergic blockade. This suggests that alpha-adrenergic transmission within the baroreflex loop may contribute importantly to the predominance of LF cardiovascular variability associated with sympathetic excitation in humans.

  11. Basic cardiovascular variability signals: mutual directed interactions explored in the information domain.

    PubMed

    Javorka, Michal; Krohova, Jana; Czippelova, Barbora; Turianikova, Zuzana; Lazarova, Zuzana; Javorka, Kamil; Faes, Luca

    2017-01-31

    The study of short-term cardiovascular interactions is classically performed through the bivariate analysis of the interactions between the beat-to-beat variability of heart period (RR interval from the ECG) and systolic blood pressure (SBP). Recent progress in the development of multivariate time series analysis methods is making it possible to explore how directed interactions between two signals change in the context of networks including other coupled signals. Exploiting these advances, the present study aims at assessing directional cardiovascular interactions among the basic variability signals of RR, SBP and diastolic blood pressure (DBP), using an approach which allows direct comparison between bivariate and multivariate coupling measures. To this end, we compute information-theoretic measures of the strength and delay of causal interactions between RR, SBP and DBP using both bivariate and trivariate (conditioned) formulations in a group of healthy subjects in a resting state and during stress conditions induced by head-up tilt (HUT) and mental arithmetics (MA). We find that bivariate measures better quantify the overall (direct+indirect) information transferred between variables, while trivariate measures better reflect the existence and delay of directed interactions. The main physiological results are: (i) the detection during supine rest of strong interactions along the pathway RR���DBP���SBP, reflecting marked Windkessel and/or Frank-Starling effects; (ii) the finding of relatively weak baroreflex effects SBP���RR at rest; (iii) the invariance of cardiovascular interactions during MA, and the emergence of stronger and faster SBP���RR interactions, as well as of weaker RR���DBP interactions, during HUT. These findings support the importance of investigating cardiovascular interactions from a network perspective, and suggest the usefulness of directed information measures to assess physiological mechanisms and track their

  12. [Cardiovascular variables in construction workers in Santander, Colombia. Comparative profile years 2011 and 2012].

    PubMed

    Rodríguez-Amaya, R M

    2015-01-01

    The construction sector has an important workforce for the country; however it is believed that this group of workers have inadequate healthy lifestyles. The aim of this study was to compare the clinical and para-clinical cardiovascular characteristics of these workers in 2 time periods. A retrospective study and analysis was performed using the medical records of 291 construction workers. The data collected included, sociodemographic variables, work, clinical and para-clinical details related to the cardiovascular status for the years 2011 and 2012. The mean age was 40.1 years, and mean body mass index was 26. In addition, 46% of workers were overweight and 15% obese. The annual increase in mean systolic blood pressure increased from 114.4 to 121.7mmHg (P=.000), and in diastolic pressure it increased from 72.8 to 79.5mmHg (P=.000), with the BMI increasing from 26 to 26.24 (P=.0000). The cholesterol levels ranged from 204.4 to 200.3mg/dl (P=.03) and triglycerides ranged from 175.6 to 208.2mg/dl (P=.0001). An annual increase was observed in several cardiovascular risk factors in construction workers in Colombia. An intervention is required for primary prevention focused on regular and quality education in these workers in order to mitigate cardiovascular risk and the presence of subsequent disease. Copyright © 2015 SEHLELHA. Published by Elsevier Espana. All rights reserved.

  13. A MATLAB toolbox for correcting within-individual effects of respiration rate and tidal volume on respiratory sinus arrhythmia during variable breathing.

    PubMed

    Schulz, Stefan M; Ayala, Erica; Dahme, Bernhard; Ritz, Thomas

    2009-11-01

    Respiratory sinus arrhythmia (RSA) is a common estimator of vagal outflow to the heart, dependent on parasympathetic activity. During variable breathing, both respiration rate and tidal volume contribute substantially to within-individual RSA variance. A respiratory control method allows for within-individual correction of the time-domain index of RSA. rsaToolbox is a set of MATLAB programs for scoring respiration-corrected RSA using measurements of cardiac interbeat intervals, respiratory-cycle times, and tidal volumes, recorded at different paced-breathing frequencies. The within-individual regression of RSA divided by tidal volume upon total respiratory cycle time is then used to estimate the baseline vagal tone for each breath of a given total respiratory-cycle time. During a subsequent analysis, the difference between the observed RSA (divided by the tidal volume at each breath) and the RSA divided by the tidal volume that was predicted by the baseline equation serves as an estimate of changes in vagal tone. rsaToolbox includes a graphical user interface for intuitive handling. Modular implementation of the algorithm also allows for flexible integration within other analytic strategies or for batch processing.

  14. Power spectrum analysis of cardiovascular variability during passive heating in conscious rats.

    PubMed

    Moura, Anselmo Gomes; Pires, Washington; Leite, Laura Hora Rios; da Cunha, Daise Nunes Queiroz; Peçanha, Tiago; de Lima, Jorge Roberto Peurrot; Natali, Antônio José; Prímola-Gomes, Thales Nicolau

    2016-12-01

    The cardiovascular system plays a direct role in the maintenance of body temperature. Whether passive heating alters cardiovascular autonomic modulation in conscious rats is still unknown. This study investigated the effects of passive heating on systolic blood pressure variability (SBPV) and heart rate variability (HRV) in conscious rats and the involvement of the renin-angiotensin system in the passive heating effects on SBPV and HRV. Fourteen male Wistar rats were randomly assigned to the control group or the losartan treatment group. A catheter was implanted in the left carotid artery to record pulsatile arterial pressure (PAP), and a telemetry sensor was implanted in the abdominal cavity to measure body temperature (Tbody). After recovering from surgery, the animals were subjected to a passive heating protocol (35°C; 30min) in resting conditions, during which Tbody, tail skin temperature and PAP were measured. The mean arterial pressure, systolic and diastolic blood pressure, heart rate, double product (i.e., the product of systolic blood pressure by heart rate), SBPV and HRV were calculated from the PAP. SBPV and HRV were analyzed in terms of both time and frequency domains. Increases in the thermoregulatory and cardiovascular parameters were observed during passive heating in both groups, and those increases were reflected in the higher time and frequency domains of the SBPV. However, passive heating was not effective in altering HRV. Passive heating altered SBPV but not HRV in conscious rats when they were treated with losartan.

  15. Cardiovascular variability as a function of sleep-wake behaviour in narcolepsy with cataplexy.

    PubMed

    Silvani, Alessandro; Grimaldi, Daniela; Barletta, Giorgio; Bastianini, Stefano; Vandi, Stefano; Pierangeli, Giulia; Plazzi, Giuseppe; Cortelli, Pietro

    2013-04-01

    Hypocretin/orexin signalling varies among sleep-wake behaviours, impacts upon cardiovascular autonomic control and is impaired in patients with narcolepsy with cataplexy (NC). However, evidence concerning disturbed cardiovascular autonomic control in NC patients is contrasting, and limited mainly to waking behaviour. We thus investigated whether control of cardiovascular variability is altered in NC patients during wakefulness preceding sleep, light (1-2) and deep (3-4) stages of non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. Polysomnographic recordings and finger blood pressure measurements were performed on nine drug-free male NC patients and nine matched healthy control subjects during spontaneous sleep-wake behaviour in a standardized laboratory environment. Indices of autonomic function were computed based on spontaneous fluctuations of systolic blood pressure (SBP) and heart period (HP). During wakefulness before sleep, NC patients showed significant decreases in indices of vagal HP modulation, cardiac baroreflex sensitivity and amplitude of central autonomic (feed-forward) cardiac control compared with control subjects. During NREM sleep, the negative correlation between HP and subsequent SBP values was greater in NC patients than in control subjects, suggesting a greater contribution of central autonomic commands to cardiac control. Collectively, these results provide preliminary evidence that autonomic control of cardiac variability by baroreflex and central autonomic (feed-forward) mechanisms is altered in NC patients during spontaneous sleep-wake behaviour, and particularly during wakefulness before sleep. © 2012 European Sleep Research Society.

  16. Impaired heart rate variability as a marker of cardiovascular autonomic dysfunction in multiple sclerosis.

    PubMed

    Tombul, Temel; Anlar, Omer; Tuncer, Mustafa; Huseyinoglu, Nergis; Eryonucu, Beyhan

    2011-06-01

    Multiple sclerosis (MS) can cause alterations in autonomic cardiovascular functions. We aimed to investigate the correlation of disease activity and disability with heart rate variability (HRV) of cardiovascular autonomic dysfunction (CAD) demonstrated by 24-h Holter monitorization. Thirty-four patients with clinically active relapsing-remitting MS, age 33.8 +/- 7.6 years, were studied. Twenty healthy volunteers served as controls. The time domain long-term HRV parameters were recorded by a digicorder recorder calculated by ambulatory electrocardiograms. Variabilities in time domain were lower in the MS patients: SDNN (standard deviation of all R-R intervals, p = 0,019), SDANN (standard deviation of the averages of R-R intervals in all 5-minute segments of the entire recordings, p = 0,040), RMSSD (the square root of the mean of the sum of the squares of differences between adjacent R-R intervals, p = 0,026), HRVM (mean of the SDNN in all the 5-minute intervals, p = 0,029), HRVSD (standard deviation of the SDNN in all the 5-minute, p = 0,043). These results suggest that MS causes CAD manifesting as long-term HRV abnormalities. This illness seems to cause a dysfunction in parasympathetic cardiovascular tone. Depressed HRV parameters are independent from the clinicalfindings, but the illness progression partially seems to provoke a decrease in such parameters.

  17. In vitro study on work of breathing during non-invasive ventilation using a new variable flow generator.

    PubMed

    Flink, Rutger C; van Kaam, Anton H; de Jongh, Frans H

    2015-07-01

    In an attempt to reduce the work of breathing (WOB) and the risk of respiratory failure, preterm infants are increasingly treated with nasal synchronised biphasic positive airway pressure (BPAP) via the Infant Flow SiPAP system. However, the relatively high resistance of the generator limits the pressure amplitude (PA) and pressure build-up (PB) of this system. This in vitro study investigates the impact of a new generator with improved fluid mechanics on the WOB, PA and PB during BPAP. Using a low compliance lung model, WOB, PA and PB, were measured during BPAP using the old and the new Infant Flow generators. Airway resistance (tube sizes 2.5 mm, 3.0 mm and 3.5 mm), nasal interface sizes (small, medium and large) and four different ventilator settings were used to mimic different clinical conditions. Compared with the old generator, the new generator significantly reduced the WOB between 10% and 70%, depending on the measurement configuration. The maximum PA was higher when using the new (6-7 cm H2O) generator versus the old (3-4 cm H2O) generator. During the first 100 ms of inspiration, the new generator reached between 33% and 40% of the peak pressure compared with 11-20% for the old generator. This in vitro study shows that a new generator of the Infant Flow SiPAP device results in a significant reduction in WOB and an increase in PA and PB during BPAP. The results of this study need to be confirmed under variable clinical conditions in preterm infants. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  18. The Association between Neuroticism and Heart Rate Variability Is Not Fully Explained by Cardiovascular Disease and Depression.

    PubMed

    Čukić, Iva; Bates, Timothy C

    2015-01-01

    Neuroticism is associated with cardiovascular disease, autonomic reactivity, and depression. Here we address the extent to which neuroticism accounts for the excess heart disease risk associated with depression and test whether cardiac autonomic tone plays a role as mediator. Subjects were derived from a nationally representative sample (n = 1,255: mean age 54.5, SD = 11.5). Higher neuroticism was associated with reduced heart rate variability equally under rest and stress. The baseline structural equation model revealed significant paths from neuroticism to heart rate variability, cardiovascular disease and depression, and between depression and cardiovascular disease, controlling for age, sex, height, weight, and BMI. Dropping both the neuroticism to heart rate variability, and neuroticism to heart disease paths significantly reduced the model fit (p < .001 in each case). We conclude that neuroticism has independent associations with both autonomic reactivity and cardiovascular disease, over and above its associations with depression and other related variables.

  19. The Association between Neuroticism and Heart Rate Variability Is Not Fully Explained by Cardiovascular Disease and Depression

    PubMed Central

    Čukić, Iva; Bates, Timothy C.

    2015-01-01

    Neuroticism is associated with cardiovascular disease, autonomic reactivity, and depression. Here we address the extent to which neuroticism accounts for the excess heart disease risk associated with depression and test whether cardiac autonomic tone plays a role as mediator. Subjects were derived from a nationally representative sample (n = 1,255: mean age 54.5, SD = 11.5). Higher neuroticism was associated with reduced heart rate variability equally under rest and stress. The baseline structural equation model revealed significant paths from neuroticism to heart rate variability, cardiovascular disease and depression, and between depression and cardiovascular disease, controlling for age, sex, height, weight, and BMI. Dropping both the neuroticism to heart rate variability, and neuroticism to heart disease paths significantly reduced the model fit (p < .001 in each case). We conclude that neuroticism has independent associations with both autonomic reactivity and cardiovascular disease, over and above its associations with depression and other related variables. PMID:25951236

  20. Breathing difficulty

    MedlinePlus

    ... pulmonary disease (COPD), such as chronic bronchitis or emphysema Other lung disease Pneumonia Pulmonary hypertension Problems with ... of breath; Breathlessness; Difficulty breathing; Dyspnea Images Lungs Emphysema References Kraft M. Approach to the patient with ...

  1. Breathing Problems

    MedlinePlus

    ... getting enough air. Sometimes you can have mild breathing problems because of a stuffy nose or intense ... panic attacks Allergies If you often have trouble breathing, it is important to find out the cause.

  2. Cardiovascular variability in major depressive disorder and effects of imipramine or mirtazapine (Org 3770).

    PubMed

    Tulen, J H; Bruijn, J A; de Man, K J; Pepplinkhuizen, L; van den Meiracker, A H; Man in 't Veld, A J

    1996-04-01

    Spectral analysis of fluctuations in heart rate (HR) and blood pressure (BP) was applied to assess sympathetic and parasympathetic cardiovascular control mechanisms in patients with unipolar affective disorder before and after treatment with imipramine (IMI) or mirtazapine (MIR). In a double-blind randomized study, 10 patients received treatment with IMI and 10 patients received treatment with MIR. Cardiovascular parameters were studied before and after 4 weeks of treatment: HR and BP (Finapres) were recorded continuously during supine rest (SR) and orthostatic challenge (OC; 60-degrees head-up tilting). During SR and OC, power spectra were calculated for HR and systolic BP. Spectral density was assessed for three frequency bands: low (0.02-0.06 Hz), mid (0.07-0.14 Hz), and high (0.15-0.50 Hz). Before treatment, the depressed patients (N = 20) differed from age-matched controls (N = 20) only in their response to OC: the depressed patients showed more suppression of HR variability (both mid- and high-frequency band fluctuations), indicating stronger vagal inhibition, and a reduced increase of BP variability (mid-frequency band fluctuations), indicating reduced sympathetic activation. After 4 weeks of treatment, patients treated with either antidepressant drug showed significant changes of HR (increase) and HR variability (decrease) during SR and OC; the suppression of mid- and high-frequency fluctuations of HR was larger for IMI than for MIR. The increase in HR and decrease in HR variability may be attributed to the anticholinergic properties of IMI (strong) and MIR (weak), resulting in cardiac vagal inhibition. Whereas MIR had no effect on BP or BP variability, IMI specifically reduced mid-frequency band fluctuations of BP as the result of a suppression of central sympathetic activity. Our data confirm and extend previous observations on the presence of autonomic dysfunctions in unmedicated depressed patients: spectral analysis of HR and BP fluctuations suggested

  3. Continuous assessment of hemodynamic control by complex demodulation of cardiovascular variability.

    PubMed

    Hayano, J; Taylor, J A; Yamada, A; Mukai, S; Hori, R; Asakawa, T; Yokoyama, K; Watanabe, Y; Takata, K; Fujinami, T

    1993-04-01

    Usefulness of complex demodulation (CDM) in assessing the frequency components of cardiovascular variability was assessed and, subsequently, this technique was utilized to determine the time-dependent responses of the low-frequency (LF) and high-frequency (HF) amplitudes of heart rate and blood pressure variabilities during postural tilt. CDM provides the time-dependent changes in amplitude of a particular frequency component on a continuous basis. Analysis of simulated data showed that CDM has sufficient frequency resolution to separately measure LF and HF amplitudes with a time resolution < 15 s and that CDM is robust to alterations in the frequency of the components. Analysis of actual data during postural tilt test in 23 young healthy subjects demonstrated that the HF amplitude of heart rate, an index of cardiac parasympathetic tone, rapidly decayed with head-up tilt (P < 0.01) and increased quickly showing an overshoot with tilt back to the supine position (P < 0.01). The LF amplitude of blood pressure, an index of vasomotor sympathetic activity, showed marked rhythmic fluctuation at an interval of 48-100 s during head-up tilt (P < 0.01), synchronizing with similar fluctuation in the LF amplitude of heart rate (P < 0.01). These results suggest that CDM can be used to provide a continuous assessment of cardiovascular variability components and that the dynamic responses of autonomic circulatory control to upright posture result in a phasic modulation of LF amplitude.

  4. Application of cardiovascular models in comparative physiology and blood pressure variability.

    PubMed

    Avolio, Alberto P; Xu, Ke; Butlin, Mark

    2013-01-01

    The usefulness of cardiovascular models is determined by their intended function with respect to elucidating underlying hemodynamic concepts and to enable simulations that will assist in understanding the effects of specific parameters. Models can take different forms, including mock circulatory constructs with physical components, mathematical representations of parameter space relations employing constitutive equations, or closed form representations of electrical circuit analogs described in the time or frequency domain. This investigation describes the use of cardiovascular models based on electrical analogs of mechanical hydrodynamic systems to elucidate two different physiologic concepts: (i) the use of distributed vascular impedance to investigate comparative physiology of optimal design and features related to body size across a broad range of animal species; (ii) use of lumped parameter models to assess the role of arterial stiffness in blood pressure variability. The impedance model shows that an allometric relationship between body weight and aortic effective length can be determined by using the frequency of minimum input impedance and aortic pulse wave velocity. This concept provides a background for optimal matching of body size and hemodynamic load on the heart. The lumped parameter model indicates that arterial stiffness, simulated by the total arterial compliance term, has a significant impact on variability of arterial pressure when changes are due to dynamic alterations of peripheral resistance. In addition, the known pressure dependency of arterial stiffness results in a curvilinear relationship between blood pressure variability and mean pressure. This has implications in hypertensive treatment where there are marked changes in arterial stiffness, as occurs with aging.

  5. Slow Breathing and Hypoxic Challenge: Cardiorespiratory Consequences and Their Central Neural Substrates

    PubMed Central

    Critchley, Hugo D.; Nicotra, Alessia; Chiesa, Patrizia A.; Nagai, Yoko; Gray, Marcus A.; Minati, Ludovico; Bernardi, Luciano

    2015-01-01

    Controlled slow breathing (at 6/min, a rate frequently adopted during yoga practice) can benefit cardiovascular function, including responses to hypoxia. We tested the neural substrates of cardiorespiratory control in humans during volitional controlled breathing and hypoxic challenge using functional magnetic resonance imaging (fMRI). Twenty healthy volunteers were scanned during paced (slow and normal rate) breathing and during spontaneous breathing of normoxic and hypoxic (13% inspired O2) air. Cardiovascular and respiratory measures were acquired concurrently, including beat-to-beat blood pressure from a subset of participants (N = 7). Slow breathing was associated with increased tidal ventilatory volume. Induced hypoxia raised heart rate and suppressed heart rate variability. Within the brain, slow breathing activated dorsal pons, periaqueductal grey matter, cerebellum, hypothalamus, thalamus and lateral and anterior insular cortices. Blocks of hypoxia activated mid pons, bilateral amygdalae, anterior insular and occipitotemporal cortices. Interaction between slow breathing and hypoxia was expressed in ventral striatal and frontal polar activity. Across conditions, within brainstem, dorsal medullary and pontine activity correlated with tidal volume and inversely with heart rate. Activity in rostroventral medulla correlated with beat-to-beat blood pressure and heart rate variability. Widespread insula and striatal activity tracked decreases in heart rate, while subregions of insular cortex correlated with momentary increases in tidal volume. Our findings define slow breathing effects on central and cardiovascular responses to hypoxic challenge. They highlight the recruitment of discrete brainstem nuclei to cardiorespiratory control, and the engagement of corticostriatal circuitry in support of physiological responses that accompany breathing regulation during hypoxic challenge. PMID:25973923

  6. Slow breathing and hypoxic challenge: cardiorespiratory consequences and their central neural substrates.

    PubMed

    Critchley, Hugo D; Nicotra, Alessia; Chiesa, Patrizia A; Nagai, Yoko; Gray, Marcus A; Minati, Ludovico; Bernardi, Luciano

    2015-01-01

    Controlled slow breathing (at 6/min, a rate frequently adopted during yoga practice) can benefit cardiovascular function, including responses to hypoxia. We tested the neural substrates of cardiorespiratory control in humans during volitional controlled breathing and hypoxic challenge using functional magnetic resonance imaging (fMRI). Twenty healthy volunteers were scanned during paced (slow and normal rate) breathing and during spontaneous breathing of normoxic and hypoxic (13% inspired O2) air. Cardiovascular and respiratory measures were acquired concurrently, including beat-to-beat blood pressure from a subset of participants (N = 7). Slow breathing was associated with increased tidal ventilatory volume. Induced hypoxia raised heart rate and suppressed heart rate variability. Within the brain, slow breathing activated dorsal pons, periaqueductal grey matter, cerebellum, hypothalamus, thalamus and lateral and anterior insular cortices. Blocks of hypoxia activated mid pons, bilateral amygdalae, anterior insular and occipitotemporal cortices. Interaction between slow breathing and hypoxia was expressed in ventral striatal and frontal polar activity. Across conditions, within brainstem, dorsal medullary and pontine activity correlated with tidal volume and inversely with heart rate. Activity in rostroventral medulla correlated with beat-to-beat blood pressure and heart rate variability. Widespread insula and striatal activity tracked decreases in heart rate, while subregions of insular cortex correlated with momentary increases in tidal volume. Our findings define slow breathing effects on central and cardiovascular responses to hypoxic challenge. They highlight the recruitment of discrete brainstem nuclei to cardiorespiratory control, and the engagement of corticostriatal circuitry in support of physiological responses that accompany breathing regulation during hypoxic challenge.

  7. Selected anthropometric variables and aerobic fitness as predictors of cardiovascular disease risk in children

    PubMed Central

    Szmuchrowski, LA; Prado, LS; Couto, BP; Machado, JCQ; Damasceno, VO; Lamounier, JA

    2014-01-01

    The aim of this study was to assess the suitability of body mass index, waist circumference, waist-to-height ratio and aerobic fitness as predictors of cardiovascular risk factor clustering in children. A cross-sectional study was conducted with 290 school boys and girls from 6 to 10 years old, randomly selected. Blood was collected after a 12-hour fasting period. Blood pressure, waist circumference (WC), height and weight were evaluated according to international standards. Aerobic fitness (AF) was assessed by the 20-metre shuttle-run test. Clustering was considered when three of these factors were present: high systolic or diastolic blood pressure, high low-density lipoprotein (LDL) cholesterol, high triglycerides, high plasma glucose, high insulin concentrations and low high-density lipoprotein (HDL) cholesterol. A ROC curve identified the cut-off points of body mass index (BMI), WC, waist-to-height ratio (WHtR) and AF as predictors of risk factor clustering. BMI, WC and WHR resulted in significant areas under the ROC curves, which was not observed for AF. The anthropometric variables were good predictors of cardiovascular risk factor clustering in both sexes, whereas aerobic fitness should not be used to identify cardiovascular risk factor clustering in these children. PMID:26424930

  8. The Applicability of Nonlinear Systems Dynamics Chaos Measures to Cardiovascular Physiology Variables

    NASA Technical Reports Server (NTRS)

    Hooker, John C.

    1991-01-01

    Three measures of nonlinear chaos (fractal dimension, Approximate Entropy (ApEn), and Lyapunov exponents) were studied as potential measures of cardiovascular condition. It is suggested that these measures have potential in the assessment of cardiovascular condition in environments of normal cardiovascular stress (normal gravity on the Earth surface), cardiovascular deconditioning (microgravity of space), and increased cardiovascular stress (lower body negative pressure (LBNP) treatments).

  9. Lamaze Breathing

    PubMed Central

    Lothian, Judith A.

    2011-01-01

    Lamaze breathing historically is considered the hallmark of Lamaze preparation for childbirth. This column discusses breathing in the larger context of contemporary Lamaze. Controlled breathing enhances relaxation and decreases perception of pain. It is one of many comfort strategies taught in Lamaze classes. In restricted birthing environments, breathing may be the only nonpharmacological comfort strategy available to women. Conscious breathing and relaxation, especially in combination with a wide variety of comfort strategies, can help women avoid unnecessary medical intervention and have a safe, healthy birth. PMID:22379360

  10. Fasting-induced reductions in cardiovascular and metabolic variables occur sooner in obese vs. lean mice

    PubMed Central

    Tanner, Jason M.; Kearns, Devin T.; Kim, Bum Jun; Sloan, Crystal; Jia, Zhanjun; Yang, Tianxin; Abel, E. Dale; Symons, J. David

    2012-01-01

    It is not uncommon for laboratory animals to be fasted prior to experimentation. Fasting evokes marked reductions in heart rate (HR), blood pressure (BP), heat production, and oxygen consumption (VO2) in rodents. Mice with diet-induced obesity exhibit elevated HR and BP, and lower VO2 and heat production in the fed condition vs. their lean counterparts. It is unknown whether body composition alters the tempo of response to fasting. We tested the hypothesis that cardiovascular and metabolic responses to fasting are delayed in obese vs. lean male C57BL/6J mice. In the fed condition mice that consumed high-fat (HF, 45% fat) chow for 98±5 days had elevated (p<0.05) body fat percentage (DEXA), serum leptin (ELISA), HR and BP (72 h biotelemetry), and lower (p<0.05) heat production and VO2 (72 h metabolic chamber) vs. animals that consumed standard chow (CON, 10% fat; n=16 per group). HR, BP, VO2, heat production, and serum leptin decreased (all p<0.05) in response to a 16 h fast (1600 h to 0800 h) in both groups. Although the overall fold changes in cardiovascular and metabolic parameters were similar in magnitude among animals, fasting-induced reductions in cardiovascular and metabolic variables occurred ~ 4 h and ~ 7 h earlier (p<0.05), respectively, in HF vs. CON mice. These findings indicate that while metabolic and cardiovascular stress evoked by a 16 h fast at 22°C is not different between HF and CON mice, fasting-induced responses occur sooner in obese animals. PMID:21127345

  11. Reporting of sex as a variable in cardiovascular studies using cultured cells.

    PubMed

    Taylor, K Efua; Vallejo-Giraldo, Catalina; Schaible, Niccole S; Zakeri, Rosita; Miller, Virginia M

    2011-11-07

    Chromosomal complement, including that provided by the sex chromosomes, influences expression of proteins and molecular signaling in every cell. However, less than 50% of the scientific studies published in 2009 using experimental animals reported sex as a biological variable. Because every cell has a sex, we conducted a literature review to determine the extent to which sex is reported as a variable in cardiovascular studies on cultured cells. Articles from 10 cardiovascular journals with high impact factors (Circulation, J Am Coll Cardiol, Eur Heart J, Circ Res, Arterioscler Thromb Vasc Biol, Cardiovasc Res, J Mol Cell Cardiol, Am J Physiol Heart Circ Physiol, J Heart Lung Transplant and J Cardiovasc Pharmacol) and published in 2010 were searched using terms 'cultured' and 'cells' in any order to determine if the sex of those cells was reported. Studies using established cell lines were excluded. Using two separate search strategies, we found that only 25 of 90 articles (28%) and 20 of 101 articles (19.8%) reported the sex of cells. Of those reporting the sex of cells, most (68.9%; n = 31) used only male cells and none used exclusively female cells. In studies reporting the sex of cells of cardiovascular origin, 40% used vascular smooth-muscle cells, and 30% used stem/progenitor cells. In studies using cells of human origin, 35% did not report the sex of those cells. None of the studies using neonatal cardiac myocytes reported the sex of those cells. The complement of sex chromosomes in cells studied in culture has the potential to affect expression of proteins and 'mechanistic' signaling pathways. Therefore, consistent with scientific excellence, editorial policies should require reporting sex of cells used in in vitro experiments.

  12. Factors influencing breath ammonia determination.

    PubMed

    Solga, Steven F; Mudalel, Matthew; Spacek, Lisa A; Lewicki, Rafal; Tittel, Frank; Loccioni, Claudio; Russo, Adolfo; Risby, Terence H

    2013-09-01

    Amongst volatile compounds (VCs) present in exhaled breath, ammonia has held great promise and yet it has confounded researchers due to its inherent reactivity. Herein we have evaluated various factors in both breath instrumentation and the breath collection process in an effort to reduce variability. We found that the temperature of breath sampler and breath sensor, mouth rinse pH, and mode of breathing to be important factors. The influence of the rinses is heavily dependent upon the pH of the rinse. The basic rinse (pH 8.0) caused a mean increase of the ammonia concentration by 410 ± 221 ppb. The neutral rinse (pH 7.0), slightly acidic rinse (pH 5.8), and acidic rinse (pH 2.5) caused a mean decrease of the ammonia concentration by 498 ± 355 ppb, 527 ± 198 ppb, and 596 ± 385 ppb, respectively. Mode of breathing (mouth-open versus mouth-closed) demonstrated itself to have a large impact on the rate of recovery of breath ammonia after a water rinse. Within 30 min, breath ammonia returned to 98 ± 16% that of the baseline with mouth open breathing, while mouth closed breathing allowed breath ammonia to return to 53 ± 14% of baseline. These results contribute to a growing body of literature that will improve reproducibly in ammonia and other VCs.

  13. Physiological variability in volatile organic compounds (VOCs) in exhaled breath and released from faeces due to nutrition and somatic growth in a standardized caprine animal model.

    PubMed

    Fischer, Sina; Trefz, Phillip; Bergmann, Andreas; Steffens, Markus; Ziller, Mario; Miekisch, Wolfram; Schubert, Jochen S; Köhler, Heike; Reinhold, Petra

    2015-05-14

    Physiological effects may change volatile organic compound (VOC) concentrations and may therefore act as confounding factors in the definition of VOCs as disease biomarkers. To evaluate the extent of physiological background variability, this study assessed the effects of feed composition and somatic growth on VOC patterns in a standardized large animal model. Fifteen clinically healthy goats were followed during their first year of life. VOCs present in the headspace over faeces, exhaled breath and ambient air inside the stable were repeatedly assessed in parallel with the concentrations of glucose, protein, and albumin in venous blood. VOCs were collected and analysed using solid-phase or needle-trap microextraction and gas chromatograpy together with mass spectroscopy. The concentrations of VOCs in exhaled breath and above faeces varied significantly with increasing age of the animals. The largest variations in volatiles detected in the headspace over faeces occurred with the change from milk feeding to plant-based diet. VOCs above faeces and in exhaled breath correlated significantly with blood components. Among VOCs exhaled, the strongest correlations were found between exhaled nonanal concentrations and blood concentrations of glucose and albumin. Results stress the importance of a profound knowledge of the physiological backgrounds of VOC composition before defining reliable and accurate marker sets for diagnostic purposes.

  14. Identification of Patients with Sleep Disordered Breathing: Comparing the Four-Variable Screening Tool, STOP, STOP-Bang, and Epworth Sleepiness Scales

    PubMed Central

    Silva, Graciela E.; Vana, Kimberly D.; Goodwin, James L.; Sherrill, Duane L.; Quan, Stuart F.

    2011-01-01

    Study Objective: The Epworth Sleepiness Scale (ESS) has been used to detect patients with potential sleep disordered breathing (SDB). Recently, a 4-Variable screening tool was proposed to identify patients with SDB, in addition to the STOP and STOP-Bang questionnaires. This study evaluated the abilities of the 4-Variable screening tool, STOP, STOP-Bang, and ESS questionnaires in identifying subjects at risk for SDB. Methods: A total of 4,770 participants who completed polysomnograms in the baseline evaluation of the Sleep Heart Health Study (SHHS) were included. Subjects with RDIs ≥ 15 and ≥ 30 were considered to have moderate-to-severe or severe SDB, respectively. Variables were constructed to approximate those in the questionnaires. The risk of SDB was calculated by the 4-Variable screening tool according to Takegami et al. The STOP and STOP-Bang questionnaires were evaluated including variables for snoring, tiredness/sleepiness, observed apnea, blood pressure, body mass index, age, neck circumference, and gender. Sleepiness was evaluated using the ESS questionnaire and scores were dichotomized into < 11 and ≥ 11. Results: The STOP-Bang questionnaire had higher sensitivity to predict moderate-to-severe (87.0%) and severe (70.4%) SDB, while the 4-Variable screening tool had higher specificity to predict moderate-to-severe and severe SDB (93.2% for both). Conclusions: In community populations such as the SHHS, high specificities may be more useful in excluding low-risk patients, while avoiding false positives. However, sleep clinicians may prefer to use screening tools with high sensitivities, like the STOP-Bang, in order to avoid missing cases that may lead to adverse health consequences and increased healthcare costs. Citation: Silva GE; Vana KD; Goodwin JL; Sherrill DL; Quan SF. Identification of patients with sleep disordered breathing: comparing the Four-Variable screening tool, STOP, STOP-Bang, and Epworth Sleepiness Scales. J Clin Sleep Med 2011

  15. Chest associated to motor physiotherapy improves cardiovascular variables in newborns with respiratory distress syndrome

    PubMed Central

    2011-01-01

    Background We aimed to evaluate the effects of chest and motor physiotherapy treatment on hemodynamic variables in preterm newborns with respiratory distress syndrome. Methods We evaluated heart rate (HR), respiratory rate (RR), systolic (SAP), mean (MAP) and diastolic arterial pressure (DAP), temperature and oxygen saturation (SO2%) in 44 newborns with respiratory distress syndrome. We compared all variables between before physiotherapy treatment vs. after the last physiotherapy treatment. Newborns were treated during 11 days. Variables were measured 2 minutes before and 5 minutes after each physiotherapy treatment. We applied paired Student t test to compare variables between the two periods. Results HR (148.5 ± 8.5 bpm vs. 137.1 ± 6.8 bpm - p < 0.001), SAP (72.3 ± 11.3 mmHg vs. 63.6 ± 6.7 mmHg - p = 0.001) and MAP (57.5 ± 12 mmHg vs. 47.7 ± 5.8 mmHg - p = 0.001) were significantly reduced after 11 days of physiotherapy treatment compared to before the first session. There were no significant changes regarding RR, temperature, DAP and SO2%. Conclusions Chest and motor physiotherapy improved cardiovascular parameters in respiratory distress syndrome newborns. PMID:22029840

  16. Sleep-Disordered Breathing in Chronic SCI: A Randomized Controlled Trial of Treatment Impact on Cognition, Quality of Life, and Cardiovascular Disease

    DTIC Science & Technology

    2015-10-01

    AWARD NUMBER: W81XWH-13-1-0479 TITLE: Sleep -Disordered Breathing in Chronic SCI: A Randomized Controlled Trial of Treatment Impact on...October 2015 2. REPORT TYPE Annual Report 3. DATES COVERED 30 Sep 2014 - 29 Sep 2015 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Sleep -Disordered...randomized controlled trial, we will objectively measure sleep disordered breathing (SDB) in chronic SCI patients using portable sleep studies, and

  17. Sleep Disordered Breathing in Chronic SCI: A Randomized Controlled Trial of Treatment Impact on Cognition, Quality of Life, and Cardiovascular Disease

    DTIC Science & Technology

    2015-11-30

    AWARD NUMBER: W81XWH-13-1-0479 TITLE: Sleep -Disordered Breathing in Chronic SCI: A Randomized Controlled Trial of Treatment Impact on...October 2015 2. REPORT TYPE Annual Report 3. DATES COVERED 30 Sep 2014 - 29 Sep 2015 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Sleep -Disordered...randomized controlled trial, we will objectively measure sleep disordered breathing (SDB) in chronic SCI patients using portable sleep studies, and

  18. Measuring myokines with cardiovascular functions: pre-analytical variables affecting the analytical output.

    PubMed

    Lombardi, Giovanni; Sansoni, Veronica; Banfi, Giuseppe

    2017-08-01

    In the last few years, a growing number of molecules have been associated to an endocrine function of the skeletal muscle. Circulating myokine levels, in turn, have been associated with several pathophysiological conditions including the cardiovascular ones. However, data from different studies are often not completely comparable or even discordant. This would be due, at least in part, to the whole set of situations related to the preparation of the patient prior to blood sampling, blood sampling procedure, processing and/or store. This entire process constitutes the pre-analytical phase. The importance of the pre-analytical phase is often not considered. However, in routine diagnostics, the 70% of the errors are in this phase. Moreover, errors during the pre-analytical phase are carried over in the analytical phase and affects the final output. In research, for example, when samples are collected over a long time and by different laboratories, a standardized procedure for sample collecting and the correct procedure for sample storage are acknowledged. In this review, we discuss the pre-analytical variables potentially affecting the measurement of myokines with cardiovascular functions.

  19. Non-uniform multivariate embedding to assess the information transfer in cardiovascular and cardiorespiratory variability series.

    PubMed

    Faes, Luca; Nollo, Giandomenico; Porta, Alberto

    2012-03-01

    The complexity of the short-term cardiovascular control prompts for the introduction of multivariate (MV) nonlinear time series analysis methods to assess directional interactions reflecting the underlying regulatory mechanisms. This study introduces a new approach for the detection of nonlinear Granger causality in MV time series, based on embedding the series by a sequential, non-uniform procedure, and on estimating the information flow from one series to another by means of the corrected conditional entropy. The approach is validated on short realizations of linear stochastic and nonlinear deterministic processes, and then evaluated on heart period, systolic arterial pressure and respiration variability series measured from healthy humans in the resting supine position and in the upright position after head-up tilt.

  20. Influence of acute progressive hypoxia on cardiovascular variability in conscious spontaneously hypertensive rats

    PubMed Central

    Sugimura, Mitsutaka; Hirose, Yohsuke; Hanamoto, Hiroshi; Okada, Kenji; Boku, Aiji; Morimoto, Yoshinari; Taki, Kunitaka; Niwa, Hitoshi

    2008-01-01

    The purpose of this study is to examine the influence of acute progressive hypoxia on cardiovascular variability and striatal dopamine (DA) levels in conscious, spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). After preparation for measurement, the inspired oxygen concentration of rats was decreased to 10% within 5 min (descent stage), maintained at 10% for 10 min (fixed stage), and then elevated back to 20% over 5 min (recovery stage). The systolic blood pressure (SBP) and heart rate (HR) variability at each stage was calculated to evaluate the autonomic nervous system response using the wavelet method. Striatal DA during each stage was measured using in vivo microdialysis. We found that SHR showed a more profound hemodynamic response to progressive hypoxia as compared to WKY. Cardiac parasympathetic activity in SHR was significantly inhibited by acute progressive hypoxia during all stages, as shown by the decrease in the high frequency band of HR variability (HR-HF), along with transient increase in sympathetic activity during the early hypoxic phase. This decrease in the HR-HF continued even when SBP was elevated. Striatal DA levels showed the transient similar elevation in both groups. These findings suggest that acute progressive hypoxic stress in SHR inhibits cardiac parasympathetic activity through reduction of baroreceptor reflex sensitivity, with potentially severe deleterious effects on circulation, in particular on HR and circulatory control. Furthermore, it is thought that the influence of acute progressive hypoxia on striatal DA levels is similar in SHR and WKY. PMID:18599365

  1. Placebo cessation in binge eating disorder: effect on anthropometric, cardiovascular, and metabolic variables.

    PubMed

    Blom, Thomas J; Guerdjikova, Anna I; Mori, Nicole; Casuto, Leah S; McElroy, Susan L

    2015-01-01

    The aim of this study was to evaluate the effects of cessation of binge eating in response to placebo treatment in binge eating disorder (BED) on anthropometric, cardiovascular, and metabolic variables. We pooled participant-level data from 10 randomized, double-blind, placebo-controlled trials of medication for BED. We then compared patients who stopped binge eating with those who did not on changes in weight, body mass index (BMI), systolic and diastolic blood pressure, pulse, and fasting lipids and glucose. Of 234 participants receiving placebo, 60 (26%) attained cessation from binge eating. Patients attaining cessation showed modestly decreased diastolic blood pressure compared with patients who continued to binge eat. Weight and BMI remained stable in patients who stopped binge eating, but increased somewhat in those who continued to binge eat. Patients who stopped binge eating with placebo had greater reductions in diastolic blood pressure and gained less weight than patients who continued to binge eat. Self-report of eating pathology in BED may predict physiologic variables. Copyright © 2014 John Wiley & Sons, Ltd and Eating Disorders Association. Copyright © 2014 John Wiley & Sons, Ltd and Eating Disorders Association.

  2. Regional variability in diving physiology and behavior in a widely distributed air-breathing marine predator, the South American sea lion (Otaria byronia).

    PubMed

    Hückstädt, Luis A; Tift, Michael S; Riet-Sapriza, Federico; Franco-Trecu, Valentina; Baylis, Alastair M M; Orben, Rachael A; Arnould, John P Y; Sepulveda, Maritza; Santos-Carvallo, Macarena; Burns, Jennifer M; Costa, Daniel P

    2016-08-01

    Our understanding of how air-breathing marine predators cope with environmental variability is limited by our inadequate knowledge of their ecological and physiological parameters. Because of their wide distribution along both coasts of the sub-continent, South American sea lions (Otaria byronia) provide a valuable opportunity to study the behavioral and physiological plasticity of a marine predator in different environments. We measured the oxygen stores and diving behavior of South American sea lions throughout most of its range, allowing us to demonstrate that diving ability and behavior vary across its range. We found no significant differences in mass-specific blood volumes of sea lions among field sites and a negative relationship between mass-specific oxygen storage and size, which suggests that exposure to different habitats and geographical locations better explains oxygen storage capacities and diving capability in South American sea lions than body size alone. The largest animals in our study (individuals from Uruguay) were the shallowest and shortest duration divers, and had the lowest mass-specific total body oxygen stores, while the deepest and longest duration divers (individuals from southern Chile) had significantly larger mass-specific oxygen stores, despite being much smaller animals. Our study suggests that the physiology of air-breathing diving predators is not fixed, but that it can be adjusted, to a certain extent, depending on the ecological setting and or habitat. These adjustments can be thought of as a 'training effect': as the animal continues to push its physiological capacity through greater hypoxic exposure, its breath-holding capacity increases.

  3. Physical activity and heart rate variability in older adults: the Cardiovascular Health Study.

    PubMed

    Soares-Miranda, Luisa; Sattelmair, Jacob; Chaves, Paulo; Duncan, Glen E; Siscovick, David S; Stein, Phyllis K; Mozaffarian, Dariush

    2014-05-27

    Cardiac mortality and electrophysiological dysfunction both increase with age. Heart rate variability (HRV) provides indices of autonomic function and electrophysiology that are associated with cardiac risk. How habitual physical activity among older adults prospectively relates to HRV, including nonlinear indices of erratic sinus patterns, is not established. We hypothesized that increasing the levels of both total leisure-time activity and walking would be prospectively associated with more favorable time-domain, frequency-domain, and nonlinear HRV measures in older adults. We evaluated serial longitudinal measures of both physical activity and 24-hour Holter HRV over 5 years among 985 older US adults in the community-based Cardiovascular Health Study. After multivariable adjustment, greater total leisure-time activity, walking distance, and walking pace were each prospectively associated with specific, more favorable HRV indices, including higher 24-hour standard deviation of all normal-to-normal intervals (Ptrend=0.009, 0.02, 0.06, respectively) and ultralow-frequency power (Ptrend=0.02, 0.008, 0.16, respectively). Greater walking pace was also associated with a higher short-term fractal scaling exponent (Ptrend=0.003) and lower Poincaré ratio (Ptrend=0.02), markers of less erratic sinus patterns. Greater total leisure-time activity, and walking alone, as well, were prospectively associated with more favorable and specific indices of autonomic function in older adults, including several suggestive of more normal circadian fluctuations and less erratic sinoatrial firing. Our results suggest potential mechanisms that might contribute to lower cardiovascular mortality with habitual physical activity later in life. © 2014 American Heart Association, Inc.

  4. Cardiovascular Endurance and Heart Rate Variability in Adolescents With Type 1 or Type 2 Diabetes

    PubMed Central

    Faulkner, Melissa Spezia; Quinn, Laurie; Rimmer, James H.; Rich, Barry H.

    2006-01-01

    Background Incidence rates of both type 1 and type 2 diabetes mellitus (DM) are increasing in youth and may eventually contribute to premature heart disease in early adulthood. This investigation explored the influence of type of diabetes, gender, body mass index (BMI), metabolic control (HbA 1c ), exercise beliefs and physical activity on cardiovascular endurance (CE), and heart rate variability (HRV). Differences in exercise beliefs, physical activity, HRV, and CE in youth with type 1 versus type 2 DM were determined. Methods Adolescents with type 1 DM (n = 105) or with type 2 DM (n = 27) completed the Exercise Belief Instrument and the Physical Activity Recall. Twenty-four HRV measures were obtained via Holter monitoring and analyzed using SpaceLabs Vision Premier™ software system. The McMaster cycle test was used to measure CE (V02peak). Results Regardless of the type of DM, females and those with higher BMI, poorer metabolic control, and lower amounts of physical activity tended to have lower levels of CE. Exercise beliefs consistently predicted both frequency and time domain HRV measures. Measures of exercise beliefs, self-reported physical activity, CE (V0 2peak ), and HRV were significantly lower in adolescents with type 2 DM in comparison to those with type 1 DM. Conclusions and Recommendations Early findings of poor physical fitness, lower HRV, fewer positive beliefs about exercise, and less active lifestyles highlight the importance of developing culturally sensitive interventions for assisting youth to make lifelong changes in their physical activity routines. Females, those with poorer metabolic control, and minority youth with type 2 DM may be particularly vulnerable to later cardiovascular disease. PMID:15920000

  5. [Estimating cardiovascular age of civil flying personnel by means of heart rate and blood pressure variability analysis].

    PubMed

    Niu, Y G; Zhang, L F; Zhang, Y H; Wang, S Y; Xu, X Y; Su, J X; Yan, Y B

    2001-06-01

    Objective. To estimate the cardiovascular age of civil flying personnel by means of heart rate and blood pressure variability analysis and to evaluate its significance in aviation medicine. Method. First, heart rate variability (HRV), blood pressure variability (BPV) and spontaneous baroreflex sensitivity (BRS) were analyzed among 89 healthy civil flying personnel by using conventional AR spectral analysis and sequence method respectively. Then, principal component analysis was conducted over original and derived variables of HRV and BPV spectral and BRS data. Finally, by the use of multiple regression in which the chronological age acted as the dependent variable and the components significantly related to age were used as the regressors, the equation for estimating the cardiovascular age was established. Result. Only seven principal components can exactly reflect the same information of autonomic regulatory function which was embodied in the 17 variables of HRV and BPV spectral and BRS parameters. Among the seven principal components, the PC2orig, PC4orig and PC2deri were negatively correlated with chronological age (P<0.05), whereas the PC3orig was positively correlated with the chronological age (P<0.01). The cardiovascular age derived from the equation was significantly correlated with the chronological age of the civil flying personnel (r= 0.73, P<0.01). Conclusion. The cardiovascular age estimated by means of a multi-variate analysis of HRV, BPV and BRS can be treated as a comprehensive indicator reflecting the age dependency of autonomic regulatory function of cardiovascular system in healthy civil flying personnel, and its interpretation and significance in application are surely worthy of further and fully dedicated efforts.

  6. Decreased reaction time variability is associated with greater cardiovascular responses to acute stress

    PubMed Central

    Hamer, Mark; Steptoe, Andrew; Endrighi, Romano

    2016-01-01

    Abstract Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75‐min recovery. RT measures were generated from an ex‐Gaussian distribution that yielded three predictors: mu‐RT, sigma‐RT, and tau‐RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = −.009, SE = .005, p = .09) and diastolic (B = −.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = −.007, SE = .003, p = .03) and impaired vagal tone (B = −.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses. PMID:26894967

  7. Assessment of training-induced autonomic adaptations in athletes with spectral analysis of cardiovascular variability signals.

    PubMed

    Shin, K; Minamitani, H; Onishi, S; Yamazaki, H; Lee, M

    1995-01-01

    The purpose of this study was to assess the adaptive effects of endurance training on autonomic functions in athletes with spectral analysis of cardiovascular variability signals. Continuous ECG, arterial blood pressure (ABP), and respiratory signals were recorded from 15 athletes (VO2max > 55 ml/(kg.min)) and 15 nonathletes (VO2max < 45 ml/(kg.min)) in the sitting position during controlled respiration (tidal volume 700 ml and 15 cycles/min). The autonomic functions were assessed by the normalized low-frequency power (LF power: 0.06-0.14 Hz) and high-frequency power (HF power: the region of the respiratory frequency based on respiratory spectrum) obtained from the autospectra of the RR interval, systolic arterial pressure (SAP), and diastolic arterial pressure (DAP) variability signals. The spontaneous baroreflex sensitivity (BRS) was evaluated by the moduli, BRSLF and BRSHF, of the transfer function between the RR interval and SAP variability in LF and HF bands. The resting HR in athletes was significantly lower than that in nonathletes. In the case of RR interval spectra, the HF power was significantly higher in athletes than in nonathletes, whereas the LF power was significantly lower in athletes than in nonahtletes. These differences might reflect an alteration of sympathovagal interaction with a predominance of parasympathetic activity. However, there was no significant difference in the LF power of SAP and DAP autospectra, reflecting the sympathetic vascular control. The BRSLF and BRSHF were significantly higher in athletes as compared with nonathletes. These results indicate that endurance training induces autonomic imbalance (i.e., the enhanced vagal activities/the attenuated sympathetic tone), which may in part contribute to the resting bradycardia and an increase in the spontaneous BRS in athletes.

  8. Decreased reaction time variability is associated with greater cardiovascular responses to acute stress.

    PubMed

    Wawrzyniak, Andrew J; Hamer, Mark; Steptoe, Andrew; Endrighi, Romano

    2016-05-01

    Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75-min recovery. RT measures were generated from an ex-Gaussian distribution that yielded three predictors: mu-RT, sigma-RT, and tau-RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = -.009, SE = .005, p = .09) and diastolic (B = -.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = -.007, SE = .003, p = .03) and impaired vagal tone (B = -.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses.

  9. Cardiovascular disease risk factors and socioeconomic variables in a nation undergoing epidemiologic transition.

    PubMed

    Rasiah, Rajah; Yusoff, Khalid; Mohammadreza, Amiri; Manikam, Rishya; Tumin, Makmor; Chandrasekaran, Sankara Kumar; Khademi, Shabnam; Bakar, Najmin Abu

    2013-09-25

    Cardiovascular disease (CVD) related deaths is not only the prime cause of mortality in the world, it has also continued to increase in the low and middle income countries. Hence, this study examines the relationship between CVD risk factors and socioeconomic variables in Malaysia, which is a rapidly growing middle income nation undergoing epidemiologic transition. Using data from 11,959 adults aged 30 years and above, and living in urban and rural areas between 2007 and 2010, this study attempts to examine the prevalence of CVD risk factors, and the association between these factors, and socioeconomic and demographic variables in Malaysia. The socioeconomic and demographic, and anthropometric data was obtained with blood pressure and fasting venous blood for glucose and lipids through a community-based survey. The association between CVD risk factors, and education and income was mixed. There was a negative association between smoking and hypertension, and education and income. The association between diabetes, hypercholesterolemia and being overweight with education and income was not clear. More men than women smoked in all education and income groups. The remaining consistent results show that the relationship between smoking, and education and income was obvious and inverse among Malays, others, rural women, Western Peninsular Malaysia (WPM) and Eastern Peninsular Malaysia (EPM). Urban men showed higher prevalence of being overweight than rural men in all education and income categories. Except for those with no education more rural men smoked than urban men. Also, Malay men in all education and income categories showed the highest prevalence of smoking among the ethnic groups. The association between CVD risk factors and socioeconomic variables should be considered when formulating programmes to reduce morbidity and mortality rates in low and middle income countries. While general awareness programmes should be targeted at all, specific ones should be focused

  10. Comparison of cardiorespiratory variables in dorsally recumbent horses anesthetized with guaifenesin-ketamine-xylazine spontaneously breathing 50% or maximal oxygen concentrations.

    PubMed

    Karrasch, Nicole M; Hubbell, John A E; Aarnes, Turi K; Bednarski, Richard M; Lerche, Phillip

    2015-04-01

    This study compared cardiorespiratory variables in dorsally recumbent horses anesthetized with guaifenesin-ketamine-xylazine and spontaneously breathing 50% or maximal (> 90%) oxygen (O2) concentrations. Twelve healthy mares were randomly assigned to breathe 50% or maximal O2 concentrations. Horses were sedated with xylazine, induced to recumbency with ketamine-diazepam, and anesthesia was maintained with guaifenesin-ketamine-xylazine to effect. Heart rate, arterial blood pressures, respiratory rate, lithium dilution cardiac output (CO), inspired and expired O2 and carbon dioxide partial pressures, and tidal volume were measured. Arterial and mixed-venous blood samples were collected prior to sedation (baseline), during 30 minutes of anesthesia, 10 minutes after disconnection from O2, and 30 minutes after standing. Shunt fraction, O2 delivery, and alveolar-arterial O2 partial pressures difference [P(A-a)O2] were calculated. Recovery times were recorded. There were no significant differences between groups in cardiorespiratory parameters or in P(A-a)O2 at baseline or 30 minutes after standing. Oxygen partial pressure difference in the 50% group was significantly less than in the maximal O2 group during anesthesia.

  11. Influence of Deep Breathing on Heart Rate Variability in Parkinson’s Disease: Co-relation with Severity of Disease and Non-Motor Symptom Scale Score

    PubMed Central

    Jagtap, Gayatri J; Chakor, Rahul T

    2014-01-01

    Context: Dysautonomia and non-motor symptoms (NMS) in Parkinson’s disease (PD) are frequent, disabling and reduce quality of life of patient. Aims and Objective: There is a paucity of studies on autonomic dysfunction in PD in Indian population. The study aimed to evaluate autonomic dysfunction in PD patients and co-relate the findings with severity of PD and Non-Motor Symptoms Scale (NMSS) score. Materials and Methods: We evaluated autonomic function in 30 diagnosed patients of PD (age 55-70 years) and 30 healthy age-matched controls by 3 min deep breathing test (DBT). NMSS was used to identify non-motor symptoms and Hoehn and Yahr (HY) Scale to grade severity of PD. The DBT findings were co-related with severity of PD (HY staging) and NMSS score. Results: DBT was found to be abnormal in 40% while it was on borderline in 33.3% of PD patients. There was a statistically significant difference (p<0.01) between patients and control group for the DBT. NMS were reported across all the stages of PD but with variable frequency and severity for individual symptom. A negative co-relation was found between results of deep breathing test and clinical severity of disease and NMSS score. Conclusion: Abnormalities of autonomic function and NMS were integral and present across all the stages of PD patients. Early recognition and treatment of these may decrease morbidity and improve quality of life of PD patients. PMID:25177554

  12. Comparison of cardiorespiratory variables in dorsally recumbent horses anesthetized with guaifenesin-ketamine-xylazine spontaneously breathing 50% or maximal oxygen concentrations

    PubMed Central

    Karrasch, Nicole M.; Hubbell, John A.E.; Aarnes, Turi K.; Bednarski, Richard M.; Lerche, Phillip

    2015-01-01

    This study compared cardiorespiratory variables in dorsally recumbent horses anesthetized with guaifenesin-ketamine-xylazine and spontaneously breathing 50% or maximal (> 90%) oxygen (O2) concentrations. Twelve healthy mares were randomly assigned to breathe 50% or maximal O2 concentrations. Horses were sedated with xylazine, induced to recumbency with ketamine-diazepam, and anesthesia was maintained with guaifenesin-ketamine-xylazine to effect. Heart rate, arterial blood pressures, respiratory rate, lithium dilution cardiac output (CO), inspired and expired O2 and carbon dioxide partial pressures, and tidal volume were measured. Arterial and mixed-venous blood samples were collected prior to sedation (baseline), during 30 minutes of anesthesia, 10 minutes after disconnection from O2, and 30 minutes after standing. Shunt fraction, O2 delivery, and alveolar-arterial O2 partial pressures difference [P(A-a)O2] were calculated. Recovery times were recorded. There were no significant differences between groups in cardiorespiratory parameters or in P(A-a)O2 at baseline or 30 minutes after standing. Oxygen partial pressure difference in the 50% group was significantly less than in the maximal O2 group during anesthesia. PMID:25829559

  13. Sleep-disordered breathing in chronic heart failure is highly variable when measured remotely using a novel non-contact biomotion sensor.

    PubMed

    McDonald, Kenneth; O'Hanlon, Rory; Savage, Henry Oluwasefunmi; Khushaba, Rami N; Colefax, Michael; Farrugia, Steven; Javed, Faizan; Schindhelm, Klaus; Wilcox, Ian; Cowie, Martin R

    2017-03-21

    We used a remotely monitored non-contact biosensor (SleepMinder™) to measure breathing during sleep (SDB) in a prospective study of 91 patients with stable class II to IV heart failure (HF). The device algorithm measures a surrogate of the traditional apnoea/hypopnoea index (AHI) measured in polysomnographic sleep studies. Data was transmitted daily to a central monitoring centre and analysed in consecutive 2-week blocks. A total of 37 465 nights over 3-24 months was analysed. An AHI of >15/h was considered clinically significant. Short- and long-term (total study) patterns of SDB presence and severity were compared. Long-term analysis (total study) showed that significant sleep-disordered breathing was common: paroxysmal in many (38%) and persistent (18%) in others. Short-term analysis showed that the severity of sleep apnoea was highly variable with 48% fluctuating between mild and moderate/severe during the study. In contrast to standard sleep studies a non-contact biosensor combined with remote monitoring can detect short- and long-term trends in SDB in clinically stable HF patients, which may be an index of HF status over time and is potentially a therapeutic target.

  14. Bad Breath

    MedlinePlus

    ... and soda poor dental hygiene (say: HI-jeen), meaning not brushing and flossing regularly smoking and other tobacco use Poor oral hygiene leads to bad breath because when food particles are left in your mouth, they can rot ...

  15. Bad Breath

    MedlinePlus

    ... for lunch. But certain strong-smelling foods like onions and garlic can cause bad breath. So can ... leave behind strong smells, like cabbage, garlic, raw onions, and coffee. If you’re trying to lose ...

  16. Breath odor

    MedlinePlus

    ... drain their stomach. The breath may have an ammonia-like odor (also described as urine-like or " ... Is there a specific odor (such as fish, ammonia, fruit, feces, or alcohol)? Have you recently eaten ...

  17. Visit-to-visit SBP variability and cardiovascular disease in a multiethnic primary care setting: 10-year retrospective cohort study.

    PubMed

    Chia, Yook Chin; Ching, Siew Mooi; Lim, Hooi Min

    2017-05-01

    The current study aims to determine the relationship of long-term visit-to-visit variability of SBP to cardiovascular disease (CVD) in a multiethnic primary care setting. This is a retrospective study of a cohort of 807 hypertensive patients over a period of 10 years. Three-monthly clinic blood pressure readings were used to derive blood pressure variability (BPV), and CVD events were captured from patient records. Mean age at baseline was 57.2 ± 9.8 years with 63.3% being women. The BPV and mean SBP over 10 years were 14.7 ± 3.5 and 142 ± 8 mmHg, respectively. Prevalence of cardiovascular event was 13%. In multivariate logistic regression analysis, BPV was the predictor of CVD events, whereas the mean SBP was not independently associated with cardiovascular events in this population. Those with lower SBP and lower BPV had fewer cardiovascular events than those with the same low mean SBP but higher BPV (10.5 versus 12.8%). Similarly those with higher mean SBP but lower BPV also had fewer cardiovascular events than those with the same high mean and higher BPV (11.6 versus 16.7%). Other variables like being men, diabetes and Indian compared with Chinese are more likely to be associated with cardiovascular events. BPV is associated with an increase in CVD events even in those who have achieved lower mean SBP. Thus, we should prioritize not only control of SBP levels but also BPV to reduce CVD events further.

  18. Speech Breathing in Children and Adolescents.

    ERIC Educational Resources Information Center

    Hoit, Jeannette D.; And Others

    1990-01-01

    A study of 80 children, aged 7, 10, 13, and 16, found that gender was not an important variable in speech breathing, but age was. The youngest group exhibited such things as larger lung, rib cage, and abdominal volume initiations and terminations for breath groups and fewer syllables per breath group. (Author/JDD)

  19. CXCL5 polymorphisms are associated with variable blood pressure in cardiovascular disease-free adults

    PubMed Central

    2012-01-01

    Objective Leukocyte count has been associated with blood pressure, hypertension, and hypertensive complications. We hypothesized that polymorphisms in the CXCL5 gene, which encodes the neutrophilic chemokine ENA-78, are associated with blood pressure in cardiovascular disease (CVD)-free adults and that these polymorphisms are functional. Methods and results A total of 192 community-dwelling participants without CVD or risk equivalents were enrolled. Two CXCL5 polymorphisms (−156 G > C (rs352046) and 398 G > A (rs425535)) were tested for associations with blood pressure. Allele-specific mRNA expression in leukocytes was also measured to determine whether heterozygosity was associated with allelic expression imbalance. In −156 C variant carriers, systolic blood pressure (SBP) was 7 mmHg higher than in −156 G/G wild-type homozygotes (131 ± 17 vs. 124 ± 14 mmHg; P = 0.008). Similarly, diastolic blood pressure (DBP) was 4 mmHg higher in −156 C variant carriers (78 ± 11 vs. 74 ± 11 mmHg; P = 0.013). In multivariate analysis of SBP, age, sex, body mass index, and the −156 G > C polymorphism were identified as significant variables. Age, sex, and the −156 G > C SNP were further associated with DBP, along with white blood cells. Allelic expression imbalance and significantly higher circulating ENA-78 concentrations were noted for variant carriers. Conclusion CXCL5 gene polymorphisms are functional and associated with variable blood pressure in CVD-free individuals. The role of CXCL5 as a hypertension- and CVD-susceptibility gene should be further explored. PMID:23245743

  20. CXCL5 polymorphisms are associated with variable blood pressure in cardiovascular disease-free adults.

    PubMed

    Beitelshees, Amber L; Aquilante, Christina L; Allayee, Hooman; Langaee, Taimour Y; Welder, Gregory J; Schofield, Richard S; Zineh, Issam

    2012-08-02

    Leukocyte count has been associated with blood pressure, hypertension, and hypertensive complications. We hypothesized that polymorphisms in the CXCL5 gene, which encodes the neutrophilic chemokine ENA-78, are associated with blood pressure in cardiovascular disease (CVD)-free adults and that these polymorphisms are functional. A total of 192 community-dwelling participants without CVD or risk equivalents were enrolled. Two CXCL5 polymorphisms (-156 G > C (rs352046) and 398 G > A (rs425535)) were tested for associations with blood pressure. Allele-specific mRNA expression in leukocytes was also measured to determine whether heterozygosity was associated with allelic expression imbalance. In -156 C variant carriers, systolic blood pressure (SBP) was 7 mmHg higher than in -156 G/G wild-type homozygotes (131 ± 17 vs. 124 ± 14 mmHg; P = 0.008). Similarly, diastolic blood pressure (DBP) was 4 mmHg higher in -156 C variant carriers (78 ± 11 vs. 74 ± 11 mmHg; P = 0.013). In multivariate analysis of SBP, age, sex, body mass index, and the -156 G > C polymorphism were identified as significant variables. Age, sex, and the -156 G > C SNP were further associated with DBP, along with white blood cells. Allelic expression imbalance and significantly higher circulating ENA-78 concentrations were noted for variant carriers. CXCL5 gene polymorphisms are functional and associated with variable blood pressure in CVD-free individuals. The role of CXCL5 as a hypertension- and CVD-susceptibility gene should be further explored.

  1. Night-to-Night Variability in Sleep Disordered Breathing and the Utility of Esophageal Pressure Monitoring in Suspected Obstructive Sleep Apnea

    PubMed Central

    Skiba, Virginia; Goldstein, Cathy; Schotland, Helena

    2015-01-01

    Study Objective: Esophageal manometry (Pes) is the gold standard to detect repetitive episodes of increased respiratory effort followed by arousal (RERAs). Because RERAs are not included in the apnea-hypopnea index (AHI), we often refer patients with symptoms of sleep disordered breathing (SDB) and AHI < 5 for a second polysomnogram (PSG) with Pes. Often, the second PSG will demonstrate AHI > 5, confirming a diagnosis of OSA. We speculate that in most cases of suspected SDB, Pes does not add further diagnostic data and that night-to-night variability in OSA severity results in a first false-negative study. Methods: We conducted a retrospective review of PSGs between 2008 and 2012 in adults with initial PSG negative for OSA followed by a second study (with or without Pes) within 6 mo. Results: Of 125 studies that met inclusion criteria, a second study was completed with Pes in 105 subjects. SDB was diagnosed in 73 subjects (68.5%) completing a second PSG with Pes: 49 (46.7%) received a diagnosis based on AHI, and 24 (22.8%) received a diagnosis based on Pes (p = 0.003). There were no statistically significant differences in the mean AHI change between the two PSGs in subjects who completed the second study with or without Pes. Conclusions: In patients with symptoms of SDB and initial PSG with AHI < 5, the majority met criteria for OSA on second PSG by AHI without additional information added by Pes. Because Pes is not widely available and is somewhat invasive, a repeat study without Pes may be sufficient to diagnose SDB. Citation: Skiba V, Goldstein C, Schotland H. Night-to-night variability in sleep disordered breathing and the utility of esophageal pressure monitoring in suspected obstructive sleep apnea. J Clin Sleep Med 2015;11(6):597–602. PMID:25700868

  2. How to breathe when you are short of breath

    MedlinePlus

    Pursed lip breathing; COPD - pursed lip breathing; Emphysema - pursed lip breathing; Chronic bronchitis - pursed lip breathing; Pulmonary fibrosis - pursed lip breathing; Interstitial lung disease - pursed lip breathing; Hypoxia - pursed lip breathing; ...

  3. Cardiovascular disease risk factors and socioeconomic variables in a nation undergoing epidemiologic transition

    PubMed Central

    2013-01-01

    Background Cardiovascular disease (CVD) related deaths is not only the prime cause of mortality in the world, it has also continued to increase in the low and middle income countries. Hence, this study examines the relationship between CVD risk factors and socioeconomic variables in Malaysia, which is a rapidly growing middle income nation undergoing epidemiologic transition. Methods Using data from 11,959 adults aged 30 years and above, and living in urban and rural areas between 2007 and 2010, this study attempts to examine the prevalence of CVD risk factors, and the association between these factors, and socioeconomic and demographic variables in Malaysia. The socioeconomic and demographic, and anthropometric data was obtained with blood pressure and fasting venous blood for glucose and lipids through a community-based survey. Results The association between CVD risk factors, and education and income was mixed. There was a negative association between smoking and hypertension, and education and income. The association between diabetes, hypercholesterolemia and being overweight with education and income was not clear. More men than women smoked in all education and income groups. The remaining consistent results show that the relationship between smoking, and education and income was obvious and inverse among Malays, others, rural women, Western Peninsular Malaysia (WPM) and Eastern Peninsular Malaysia (EPM). Urban men showed higher prevalence of being overweight than rural men in all education and income categories. Except for those with no education more rural men smoked than urban men. Also, Malay men in all education and income categories showed the highest prevalence of smoking among the ethnic groups. Conclusions The association between CVD risk factors and socioeconomic variables should be considered when formulating programmes to reduce morbidity and mortality rates in low and middle income countries. While general awareness programmes should be targeted

  4. Parasympathetic Stimuli on Bronchial and Cardiovascular Systems in Humans.

    PubMed

    Zannin, Emanuela; Pellegrino, Riccardo; Di Toro, Alessandro; Antonelli, Andrea; Dellacà, Raffaele L; Bernardi, Luciano

    2015-01-01

    It is not known whether parasympathetic outflow simultaneously acts on bronchial tone and cardiovascular system waxing and waning both systems in parallel, or, alternatively, whether the regulation is more dependent on local factors and therefore independent on each system. The aim of this study was to evaluate the simultaneous effect of different kinds of stimulations, all associated with parasympathetic activation, on bronchomotor tone and cardiovascular autonomic regulation. Respiratory system resistance (Rrs, forced oscillation technique) and cardio-vascular activity (heart rate, oxygen saturation, tissue oxygenation index, blood pressure) were assessed in 13 volunteers at baseline and during a series of parasympathetic stimuli: O2 inhalation, stimulation of the carotid sinus baroreceptors by neck suction, slow breathing, and inhalation of methacholine. Pure cholinergic stimuli, like O2 inhalation and baroreceptors stimulation, caused an increase in Rrs and a reduction in heart rate and blood pressure. Slow breathing led to bradycardia and hypotension, without significant changes in Rrs. However slow breathing was associated with deep inhalations, and Rrs evaluated at the baseline lung volumes was significantly increased, suggesting that the large tidal volumes reversed the airways narrowing effect of parasympathetic activation. Finally inhaled methacholine caused marked airway narrowing, while the cardiovascular variables were unaffected, presumably because of the sympathetic activity triggered in response to hypoxemia. All parasympathetic stimuli affected bronchial tone and moderately affected also the cardiovascular system. However the response differed depending on the nature of the stimulus. Slow breathing was associated with large tidal volumes that reversed the airways narrowing effect of parasympathetic activation.

  5. Heart rate variability and arrhythmic patterns of 24-hour Holter electrocardiography among Nigerians with cardiovascular diseases.

    PubMed

    Adebayo, Rasaaq Ayodele; Ikwu, Amanze Nkemjika; Balogun, Michael Olabode; Akintomide, Anthony Olubunmi; Ajayi, Olufemi Eyitayo; Adeyeye, Victor Oladeji; Mene-Afejuku, Tuoyo Omasan; Bamikole, Olaniyi James; Ogunyemi, Suraj Adefabi; Ajibare, Adeola Olubunmi; Oketona, Omolola Abiodun

    2015-01-01

    Facilities for Holter electrocardiography (ECG) monitoring in many Nigerian hospitals are limited. There are few published works in Nigeria on the use of 24-hour Holter ECG in cardiac arrhythmic evaluation of patients with cardiovascular diseases. To study the clinical indications, arrhythmic pattern, and heart rate variability (HRV) among subjects referred for 24-hour Holter ECG at our Cardiac Care Unit. Three-hundred and ten patients (134 males and 176 females) were studied consecutively over a 48-month period using Schiller type (MT-101) Holter ECG machine. Out of the 310 patients reviewed, 134 were males (43.2%) and 176 were females (56.8%). The commonest indication for Holter ECG was palpitation followed by syncope in 71 (23%) and 49 (15.8%) of subjects, respectively. Premature ventricular complex and premature atrial complex were the commonest types of arrhythmia in 51.5% and 15% subjects, respectively. Ventricular arrhythmia was more prevalent in dilated cardiomyopathy patients (85.7%). The HRV of subjects with palpitation, stroke, and diabetes mellitus with autonomic neuropathy, using standard deviation of normal to normal intervals average (milliseconds), were 107.32±49.61, 79.15±49.15, and 66.50±15.54, respectively. The HRV, using standard deviation of averages of normal to normal intervals average (milliseconds), of patients with palpitation, stroke, and diabetes mellitus with autonomic neuropathy were 77.39±62.34, 57.82±37.05, and 55.50±12.71, respectively. Palpitation and syncope were the commonest indications for Holter ECG among our subjects. The commonest arrhythmic patterns were premature ventricular complex and premature atrial complex, with ventricular arrhythmia being more prevalent in dilated cardiomyopathy. There was a reduction in HRV in patients with stroke and diabetic autonomic neuropathy.

  6. Utility of overnight pulse oximetry and heart rate variability analysis to screen for sleep-disordered breathing in chronic heart failure.

    PubMed

    Ward, Neil R; Cowie, Martin R; Rosen, Stuart D; Roldao, Vitor; De Villa, Manuel; McDonagh, Theresa A; Simonds, Anita; Morrell, Mary J

    2012-11-01

    Sleep-disordered breathing (SDB) is under diagnosed in chronic heart failure (CHF). Screening with simple monitors may increase detection of SDB in a cardiology setting. This study aimed to evaluate the accuracy of heart rate variability analysis and overnight pulse oximetry for diagnosis of SDB in patients with CHF. 180 patients with CHF underwent simultaneous polysomnography, ambulatory electrocardiography and wrist-worn overnight pulse oximetry. SDB was defined as an apnoea-hypopnoea index ≥15/h. To identify SDB from the screening tests, the per cent very low frequency increment (%VLFI) component of heart rate variability was measured with a pre-specified cutoff ≥2.23%, and the 3% oxygen desaturation index was measured with a pre-specified cutoff >7.5 desaturations/h. 173 patients with CHF had adequate sleep study data; SDB occurred in 77 (45%) patients. Heart rate variability was measurable in 78 (45%) patients with area under the %VLFI receiver operating characteristic curve of 0.50. At the ≥2.23% cutoff, %VLFI sensitivity was 58% and specificity was 48%. The 3% oxygen desaturation index was measurable in 171 (99%) patients with area under the curve of 0.92. At the pre-specified cutoff of >7.5 desaturations/h, the 3% oxygen desaturation index had a sensitivity of 97%, specificity of 32%, negative likelihood ratio of 0.08 and positive likelihood ratio of 1.42. Diagnostic accuracy was increased using a cutoff of 12.5 desaturations/h, with sensitivity of 93% and specificity of 73%. The high sensitivity and low negative likelihood ratio of the 3% oxygen desaturation index indicates that pulse oximetry would be of use as a simple screening test to rule out SDB in patients with CHF in a cardiology setting. The %VLFI component of heart rate variability is not suitable for detection of SDB in CHF.

  7. Effect of cervical traction on cardiovascular and selected ECG variables of cervical spondylosis patients using various weights.

    PubMed

    Akinbo, S R A; Noronha, C C; Oke, D A; Okanlawon, A O; Danesi, M A

    2006-06-01

    There is currently no consensus among the clinicians regarding the tractive force to be employed during cervical traction (CT) that will correlate precisely with the percentage body weight of the patient and reduce the side effects associated with CT therapy. This study therefore aimed to investigate the response of cervical spondylosis (CS) patients to different CT weights and to establish the effect of CT on the cardiovascular system of patients with cervical spondylosis (CS). Sixty out of 78 subjects participated in the study. They were randomly assigned into three experimental groups A, B and C. Their systolic and diastolic blood pressures (SBP and DBP) and heart rates (HR) were measured. Rate pressure product (RPP) was calculated using standard equation18 and ECG recorded using the KENZ, 201 machine. Subjects' cardiovascular and ECG responses were monitored in a supine resting position (baseline) and under three experimental conditions using the subjects' 7.5% kg total body weights (TBW), 10% kg TBW and 15% TBW at different time intervals (5, 10 and 15 minutes respectively). Compared with the baseline values, there was a drop in SBP, DBP and RPP for all subjects in the three groups. The SBP, DBP and RPP alteration were not significant for the 7.5% TBW CT, but significant (p <0.05) for the 10% and 15% TBW tractions. The HR and ECG variables revealed no significant difference in all the groups, these results signified that the cardiac muscles were not adversely affected by any of the traction weights during application. Twenty subjects had side-effects including 5 subjects that terminated the treatment due to pain during the CT application. Cardiovascular alterations do occur during the application of cervical traction weights resulting in untoward patient's reactions. Efforts should be made to monitor the cardiovascular variables during and immediately after CT especially in "high risk" patients, that is, elderly patients and patients with unstable

  8. Association of heart rate variability and inflammatory response in patients with cardiovascular diseases: current strengths and limitations

    PubMed Central

    Papaioannou, Vasilios; Pneumatikos, Ioannis; Maglaveras, Nikos

    2013-01-01

    Many experimental and clinical studies have confirmed a continuous cross-talk between both sympathetic and parasympathetic branches of autonomic nervous system and inflammatory response, in different clinical scenarios. In cardiovascular diseases, inflammation has been proven to play a pivotal role in disease progression, pathogenesis and resolution. A few clinical studies have assessed the possible inter-relation between neuro-autonomic output, estimated with heart rate variability analysis, which is the variability of R-R in the electrocardiogram, and different inflammatory biomarkers, in patients suffering from stable or unstable coronary artery disease (CAD) and heart failure. Moreover, different indices derived from heart rate signals' processing, have been proven to correlate strongly with severity of heart disease and predict final outcome. In this review article we will summarize major findings from different investigators, evaluating neuro-immunological interactions through heart rate variability analysis, in different groups of cardiovascular patients. We suggest that markers originating from variability analysis of heart rate signals seem to be related to inflammatory biomarkers. However, a lot of open questions remain to be addressed, regarding the existence of a true association between heart rate variability and autonomic nervous system output or its adoption for risk stratification and therapeutic monitoring at the bedside. Finally, potential therapeutic implications will be discussed, leading to autonomic balance restoration in relation with inflammatory control. PMID:23847549

  9. Collection of breath for hydrogen estimation.

    PubMed

    Gardiner, A J; Tarlow, M J; Sutherland, I T; Sammons, H G

    1981-02-01

    The breath hydrogen test is used in gastroenterological investigation, particularly for sugar malabsorption, transit time, and the investigation of small-bowel bacterial overgrowth. Several methods of collecting breath from infants and children for hydrogen assay have been described. Four such techniques (postnasal catheter, nasal prong, Rahn-Otis end-tidal sampler, and modification of a party toy--the 'Wiggins's blowout') were compared with breath collection using the Haldane-Priestley tube. Multiple sampling of breath from 3 adults was performed after initial lactulose loads to increase breath hydrogen excretion. The variability between the different assay techniques was less than the inherent variability of repeated breath hydrogen assays using the same technique. Each technique is therefore adequate for breath hydrogen collection; we recommend the Rahn-Otis end-tidal sampler in young infants and children, and the Haldane-Priestley tube in older children, since these were most acceptable to the children and their parents.

  10. Day-to-day fasting glycaemic variability in DEVOTE: associations with severe hypoglycaemia and cardiovascular outcomes (DEVOTE 2).

    PubMed

    Zinman, Bernard; Marso, Steven P; Poulter, Neil R; Emerson, Scott S; Pieber, Thomas R; Pratley, Richard E; Lange, Martin; Brown-Frandsen, Kirstine; Moses, Alan; Ocampo Francisco, Ann Marie; Barner Lekdorf, Jesper; Kvist, Kajsa; Buse, John B

    2017-09-15

    The Trial Comparing Cardiovascular Safety of Insulin Degludec vs Insulin Glargine in Patients with Type 2 Diabetes at High Risk of Cardiovascular Events (DEVOTE) was a double-blind, randomised, event-driven, treat-to-target prospective trial comparing the cardiovascular safety of insulin degludec with that of insulin glargine U100 (100 units/ml) in patients with type 2 diabetes at high risk of cardiovascular events. This paper reports a secondary analysis investigating associations of day-to-day fasting glycaemic variability (pre-breakfast self-measured blood glucose [SMBG]) with severe hypoglycaemia and cardiovascular outcomes. In DEVOTE, patients with type 2 diabetes were randomised to receive insulin degludec or insulin glargine U100 once daily. The primary outcome was the first occurrence of an adjudicated major adverse cardiovascular event (MACE). Adjudicated severe hypoglycaemia was the pre-specified secondary outcome. In this article, day-to-day fasting glycaemic variability was based on the standard deviation of the pre-breakfast SMBG measurements. The variability measure was calculated as follows. Each month, only the three pre-breakfast SMBG measurements recorded before contact with the site were used to determine a day-to-day fasting glycaemic variability measure for each patient. For each patient, the variance of the three log-transformed pre-breakfast SMBG measurements each month was determined. The standard deviation was determined as the square root of the mean of these monthly variances and was defined as day-to-day fasting glycaemic variability. The associations between day-to-day fasting glycaemic variability and severe hypoglycaemia, MACE and all-cause mortality were analysed for the pooled trial population with Cox proportional hazards models. Several sensitivity analyses were conducted, including adjustments for baseline characteristics and most recent HbA1c. Day-to-day fasting glycaemic variability was significantly associated with severe

  11. Impact of an outpatient cardiac rehabilitation program on clinical and analytical variables in cardiovascular disease.

    PubMed

    Roca-Rodríguez, M M; García-Almeida, J M; Ruiz-Nava, J; Alcaide-Torres, J; Saracho-Domínguez, H; Rioja-Vázquez, R; García-Fernández, C; Gómez-González, A; Montiel-Trujillo, A; Tinahones-Madueño, F J

    2014-01-01

    The aim of the study was to determine the effect of lifestyle changes in patients participating in a cardiac rehabilitation program. Patients with cardiovascular disease (N = 59) were enrolled in cardiac rehabilitation, which included nutritional and exercise interventions. All patients completed the program, but only 44 attended the reassessment after 12 months because of work reasons or lack of time or interest. Ergometry before and after cardiac rehabilitation showed significant differences in exercise tolerance time (5.2 ± 1.8 minutes vs 7.1 ± 2.1 minutes; P< .001), metabolic equivalents (6.5 ± 1.8 vs 8.8 ± 2.2; P< .001), and the Börg rating of perceived exertion scale (12 ± 1.8 points vs 13.7 ± 1.6 points; P= .005). At the end of the intervention program, significant improvements were seen in body weight (82.6 ± 15.2 kg vs 80.8 ± 14.3 kg; P< .001), waist circumference (100.3 ± 12.4 cm vs 98.0 ± 11.0 cm; P= .002), and levels of fasting glucose (126.5 ± 44.6 mmol/L vs 109.6 ± 24.8 mmol/L; P< .001), low-density lipoprotein cholesterol (2.7 ± 0.9 mmol/L vs 2.5 ± 0.8 mmol/L; P= .033), and C-reactive protein (5.1 ± 8.7 μg/mL vs 4.1 ± 2.6 μg/mL; P= .008), as well as in adherence to a healthy diet as estimated by the Trichopoulou questionnaire score (7.9 ± 2.3 vs 10.6 ± 1.5; P< .001). Twelve months later, however, many of these benefits had either remained stable or worsened. Cardiac rehabilitation is an appropriate program for the improvement of clinical and analytical variables, such as functional capacity, carbohydrate and lipid metabolism, anthropometric measures, and diet. However, 12 months later, many of these benefits either remained stable or worsened.

  12. VISIT-TO-VISIT VARIABILITY OF BLOOD PRESSURE AND DEATH, ESRD AND CARDIOVASCULAR EVENTS IN PATIENTS WITH CHRONIC KIDNEY DISEASE

    PubMed Central

    CHANG, Tara I.; TABADA, Grace H.; YANG, Jingrong; TAN, Thida X.; GO, Alan S.

    2016-01-01

    OBJECTIVES Visit-to-visit variability of blood pressure is an important independent risk factor for premature death and cardiovascular events, but relatively little is known about this phenomenon in patients with chronic kidney disease not yet on dialysis. METHODS We conducted a retrospective study in a community-based cohort of 114,900 adults with chronic kidney disease stages 3–4 (estimated glomerular filtration rate 15–59 mL/min per 1.73 m2). We hypothesized that visit-to-visit variability of blood pressure would be independently associated with higher risks of death, incident treated end-stage renal disease, and cardiovascular events. We defined systolic visit-to-visit variability of blood pressure using three metrics: (1) coefficient of variation (2) standard deviation of the mean systolic blood pressure, and (3) average real variability. RESULTS The highest versus the lowest quintile of the coefficient of variation was associated with higher adjusted rates of death (hazard ratio 1.22; 95% confidence interval 1.11–1.34) and hemorrhagic stroke (hazard ratio 1.91, confidence interval 1.36–2.68). Visit-to-visit variability of blood pressure was inconsistently associated with heart failure, and was not significantly associated with acute coronary syndrome and ischemic stroke. Results were similar when using the other two visit-to-visit variability of blood pressure. Visit-to-visit variability of blood pressure had inconsistent associations with end-stage renal disease, perhaps due to the relatively low incidences of this outcome. CONCLUSIONS Higher visit-to-visit variability of blood pressure is independently associated with higher rates of death and hemorrhagic stroke in patients with moderate to advanced chronic kidney disease not yet on dialysis. PMID:26599220

  13. Relationship between cardiovascular health score and year-to-year blood pressure variability in China: a prospective cohort study

    PubMed Central

    An, Shasha; Bao, Minghui; Wang, Yang; Li, Zhifang; Zhang, Wenyan; Chen, Shuohua; Li, Junjuan; Yang, Xinchun; Wu, Shouling; Cai, Jun

    2015-01-01

    Objectives On the basis of cardiovascular health factors and behaviours, the American Heart Association proposed the Cardiovascular Health Score (CHS). It has been widely used to estimate the cardiovascular health status of individuals. The aim of this study was to investigate the relationship between CHS and year-to-year blood pressure variability (BPV). Design Prospective cohort study. Settings We stratified participants into two groups by gender: first group, female group; second group, male group. The relationship between CHS and year-to-year blood pressure variability were analysed. Participants A total of 41 613 individuals met the inclusion criteria (no history of stroke, transient ischaemic attack, myocardial infarction, malignant tumour or atrial fibrillation) and had complete blood pressure data. Results The coefficient of the variation of systolic blood pressure (SCV) was 8.33% in the total population and 8.68% and 8.22% in female and male groups, respectively (p<0.05). Multivariable linear regression analysis revealed that higher CHS was inversely associated with increasing year-to-year BPV, which persisted after adjusting for baseline systolic blood pressure and other risk factors. Each SD increase in CHS could lead to a 0.016SD decrease in SCV (p<0.05). Conclusions In summary, CHS was inversely related to year-to-year BPV, which suggested that a healthy lifestyle may contribute to better blood pressure management. PMID:26503389

  14. Association between RR interval and high-frequency heart rate variability acquired during short-term, resting recordings with free and paced breathing.

    PubMed

    Sandercock, Gavin; Gladwell, Valerie; Dawson, Samantha; Nunan, David; Brodie, David; Beneke, Ralph

    2008-07-01

    High-frequency (HF) oscillations in RR interval from 0.15-0.40 Hz are widely accepted as a measure of cardiac vagal outflow but the HF/RR relationship appears complex, particularly with longer RR intervals. The aim of this study was to evaluate the HF/RR interval relationship during free and paced breathing. HF power and mean RR interval length were recorded in 150 men and 120 women (mean age 34.5 +/- 11.4) during 5 min of supine rest with either free or paced (12 cycles min(-1)) breathing. Linear and quadratic models were used to assess the relationship between RR interval and the natural logarithm of HF power (lnHF). The RR interval length at which there was no further increase in lnHF was determined as the deflection point. ANCOVA was used to determine differences in the linear regression slopes for lnHF/RR with paced or free breathing. With free breathing (n = 131), the adjusted R(2) was similar between linear (15.3%) and quadratic (17.5%) fits and saturation of lnHF occurred within the recorded RR interval range (1326 ms). With paced breathing (n = 139), adjusted R(2) values were again similar between linear (22.4%) and quadratic (23.2%) fits. The deflection point was outside the range of recorded RR intervals at 1458 ms. ANCOVA showed a significant difference in the slope of the lnHF/RR regression lines between free and paced breathing. The lnHF/RR relationship is weaker when derived from between-subject recordings than from repeated within-subject samples. lnHF/RR showed evidence of saturation at approximately 45 bpm with free breathing. With paced breathing, a deflection in lnHF was found outside the recorded RR interval range ( approximately 41 bpm). Paced breathing creates a stronger lnHF/RR relationship. The slope of the lnHF/RR regression line with paced breathing is significantly different from that observed with free breathing. It appears that lnHF is a valid index of vagal outflow, except in subjects with very low heart rates. Paced breathing data

  15. Blood Pressure Variability and Cardiovascular Risk in the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER)

    PubMed Central

    Poortvliet, Rosalinde K. E.; Ford, Ian; Lloyd, Suzanne M.; Sattar, Naveed; Mooijaart, Simon P.; de Craen, Anton J. M.; Westendorp, Rudi G. J.; Jukema, J. Wouter; Packard, Christopher J.; Gussekloo, Jacobijn; de Ruijter, Wouter; Stott, David J.

    2012-01-01

    Variability in blood pressure predicts cardiovascular disease in young- and middle-aged subjects, but relevant data for older individuals are sparse. We analysed data from the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) study of 5804 participants aged 70–82 years with a history of, or risk factors for cardiovascular disease. Visit-to-visit variability in blood pressure (standard deviation) was determined using a minimum of five measurements over 1 year; an inception cohort of 4819 subjects had subsequent in-trial 3 years follow-up; longer-term follow-up (mean 7.1 years) was available for 1808 subjects. Higher systolic blood pressure variability independently predicted long-term follow-up vascular and total mortality (hazard ratio per 5 mmHg increase in standard deviation of systolic blood pressure = 1.2, 95% confidence interval 1.1–1.4; hazard ratio 1.1, 95% confidence interval 1.1–1.2, respectively). Variability in diastolic blood pressure associated with increased risk for coronary events (hazard ratio 1.5, 95% confidence interval 1.2–1.8 for each 5 mmHg increase), heart failure hospitalisation (hazard ratio 1.4, 95% confidence interval 1.1–1.8) and vascular (hazard ratio 1.4, 95% confidence interval 1.1–1.7) and total mortality (hazard ratio 1.3, 95% confidence interval 1.1–1.5), all in long-term follow-up. Pulse pressure variability was associated with increased stroke risk (hazard ratio 1.2, 95% confidence interval 1.0–1.4 for each 5 mmHg increase), vascular mortality (hazard ratio 1.2, 95% confidence interval 1.0–1.3) and total mortality (hazard ratio 1.1, 95% confidence interval 1.0–1.2), all in long-term follow-up. All associations were independent of respective mean blood pressure levels, age, gender, in-trial treatment group (pravastatin or placebo) and prior vascular disease and cardiovascular disease risk factors. Our observations suggest variability in diastolic blood pressure is more strongly associated

  16. Modeling of autonomic control in sleep-disordered breathing.

    PubMed

    Khoo, Michael C K

    2008-03-01

    There is ample evidence to support the notion that chronic exposure to repetitive episodes of interrupted breathing during sleep can lead to systemic hypertension, heart failure, myocardial infarction and stroke. Recent studies have suggested that abnormal autonomic control may be the common factor linking sleep-disordered breathing (SDB) to these cardiovascular diseases. We have developed a closed-loop minimal model that enables the delineation of the major physiological mechanisms responsible for changes in autonomic system function in SDB, and also forms the basis for a noninvasive technique that enables the early detection of cardiovascular control abnormalities. The model is "minimal" in the sense that all its parameters can be estimated through analysis of the data measured noninvasively from a single experimental procedure. Parameter estimation is enhanced by broadening the frequency content of the subject's ventilatory pattern, either through voluntary control of breathing or involuntary control using ventilator assistance. Although the original form of the model is linear and time-invariant, extensions of the model include the incorporation of nonlinear dynamics in the autonomic control of heart rate, and allowing the transfer functions of the model components to assume time-varying characteristics. The various versions of the model have been applied to different populations of subjects with SDB under different conditions (e.g. supine wakefulness, orthostatic stress, sleep). Our cumulative findings suggest that the minimal model approach provides a more sensitive means of detecting abnormalities in autonomic cardiovascular control in SDB, compared to univariate analysis of heart rate variability or blood pressure variability.

  17. Cardiovascular Response Identification Based on Nonlinear Support Vector Regression

    NASA Astrophysics Data System (ADS)

    Wang, Lu; Su, Steven W.; Chan, Gregory S. H.; Celler, Branko G.; Cheng, Teddy M.; Savkin, Andrey V.

    This study experimentally investigates the relationships between central cardiovascular variables and oxygen uptake based on nonlinear analysis and modeling. Ten healthy subjects were studied using cycle-ergometry exercise tests with constant workloads ranging from 25 Watt to 125 Watt. Breath by breath gas exchange, heart rate, cardiac output, stroke volume and blood pressure were measured at each stage. The modeling results proved that the nonlinear modeling method (Support Vector Regression) outperforms traditional regression method (reducing Estimation Error between 59% and 80%, reducing Testing Error between 53% and 72%) and is the ideal approach in the modeling of physiological data, especially with small training data set.

  18. Developmental change and intraindividual variability: relating cognitive aging to cognitive plasticity, cardiovascular lability, and emotional diversity.

    PubMed

    Ram, Nilam; Gerstorf, Denis; Lindenberger, Ulman; Smith, Jacqui

    2011-06-01

    Repeated assessments obtained over years can be used to measure individuals' developmental change, whereas repeated assessments obtained over a few weeks can be used to measure individuals' dynamic characteristics. Using data from a burst of measurement embedded in the Berlin Aging Study (BASE; Baltes & Mayer, 1999), we illustrate and examine how long-term changes in cognitive ability are related to short-term changes in cognitive performance, cardiovascular function, and emotional experience. Our findings suggest that "better" cognitive aging over approximately 13 years was associated with greater cognitive plasticity, less cardiovascular lability, and less emotional diversity over approximately 2 weeks at age 90 years. The study highlights the potential benefits of multi-time scale longitudinal designs for the study of individual function and development.

  19. Developmental Change and Intraindividual Variability: Relating Cognitive Aging to Cognitive Plasticity, Cardiovascular Lability, and Emotional Diversity

    PubMed Central

    Ram, Nilam; Gerstorf, Denis; Lindenberger, Ulman; Smith, Jacqui

    2010-01-01

    Repeated assessments obtained over years can be used to measure individuals’ developmental change, whereas repeated assessments obtained over a few weeks can be used to measure individuals’ dynamic characteristics. Using data from a burst of measurement embedded in the Berlin Aging Study (BASE: Baltes & Mayer, 1999), we illustrate and examine how long-term changes in cognitive ability are related to short-term changes in cognitive performance, cardiovascular function, and emotional experience. Our findings suggest that “better” cognitive aging over approximately13 years was associated with greater cognitive plasticity, less cardiovascular lability, and less emotional diversity over approximately 2 weeks at age 90 years. The study highlights the potential benefits of multi-time scale longitudinal designs for the study of individual function and development. PMID:21443355

  20. Feasibility of free-breathing, GRAPPA-based, real-time cardiac cine assessment of left-ventricular function in cardiovascular patients at 3T.

    PubMed

    Zhu, Xiaomei; Schwab, Felix; Marcus, Roy; Hetterich, Holger; Theisen, Daniel; Kramer, Harald; Notohamiprodjo, Mike; Schlett, Christopher L; Nikolaou, Konstantin; Reiser, Maximilian F; Bamberg, Fabian

    2015-05-01

    To determine the feasibility of free-breathing, GRAPPA-based, real-time (RT) cine 3T cardiac magnetic resonance imaging (MRI) with high acceleration factors for the assessment of left-ventricular function in a cohort of patients as compared to conventional segmented cine imaging. In this prospective cohort study, subjects with various cardiac conditions underwent MRI involving two RT cine sequences (high resolution and low resolution) and standard segmented cine imaging. Standard qualitative and quantitative parameters of left-ventricular function were quantified. Among 25 subjects, 24 were included in the analysis (mean age: 50.5±21 years, 67% male, 25% with cardiomyopathy). RT cine derived quantitative parameters of volumes and left ventricular mass were strongly correlated with segmented cine imaging (intraclass correlation coefficient [ICC]: >0.72 for both RT cines) but correlation for peak ejection and filling rates were moderate to poor for both RT cines (ICC<0.40). Similarly, RT cines significantly underestimated peak ejection and filling rates (>103.2±178 ml/s). Among patient-related factors, heart rate was strongly predictive for deviation of measurements (p<0.05). RT cine MRI at 3T is feasible for qualitative and quantitative assessment of left ventricular function for low and high-resolution sequences but results in significant underestimation of systolic function, peak ejection and filling rates. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  1. Kidney motion during free breathing and breath hold for MR-guided radiotherapy

    NASA Astrophysics Data System (ADS)

    Stam, Mette K.; van Vulpen, Marco; Barendrecht, Maurits M.; Zonnenberg, Bernard A.; Intven, Martijn; Crijns, Sjoerd P. M.; Lagendijk, Jan J. W.; Raaymakers, Bas W.

    2013-04-01

    Current treatments for renal cell carcinoma have a high complication rate due to the invasiveness of the treatment. With the MRI-linac it may be possible to treat renal tumours non-invasively with high-precision radiotherapy. This is expected to reduce complications. To deliver a static dose distribution, radiation gating will be used. In this study the reproducibility and efficiency of free breathing gating and a breath hold treatment of the kidney was investigated. For 15 patients with a renal lesion the kidney motion during 2 min of free breathing and 10 consecutive expiration breath holds was studied with 2D cine MRI. The variability in kidney expiration position and treatment efficiency for gating windows of 1 to 20 mm was measured for both breathing patterns. Additionally the time trend in free breathing and the variation in expiration breath hold kidney position with baseline shift correction was determined. In 80% of the patients the variation in expiration position during free breathing is smaller than 2 mm. No clinically relevant time trends were detected. The variation in expiration breath hold is for all patients larger than the free breathing expiration variation. Gating on free breathing is, for gating windows of 1 to 5 mm more efficient than breath hold without baseline correction. When applying a baseline correction to the breath hold it increases the treatment efficiency. The kidney position is more reproducible in expiration free breathing than non-guided expiration breath hold. For small gating windows it is also more time efficient. Since free breathing also seems more comfortable for the patients it is the preferred breathing pattern for MRI-Linac treatments of the kidney.

  2. Rapid shallow breathing

    MedlinePlus

    Tachypnea; Breathing - rapid and shallow; Fast shallow breathing; Respiratory rate - rapid and shallow ... Shallow, rapid breathing has many possible medical causes, including: Asthma Blood clot in an artery in the lung Choking ...

  3. Breathing and Relaxation

    MedlinePlus

    ... Home Health Insights Stress & Relaxation Breathing and Relaxation Breathing and Relaxation Make an Appointment Ask a Question ... level is often dependent on his or her breathing pattern. Therefore, people with chronic lung conditions may ...

  4. Deep breathing after surgery

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000440.htm Deep breathing after surgery To use the sharing features on ... way to do so is by doing deep breathing exercises. Deep breathing keeps your lungs well-inflated ...

  5. Relationship between cardiovascular health score and year-to-year blood pressure variability in China: a prospective cohort study.

    PubMed

    An, Shasha; Bao, Minghui; Wang, Yang; Li, Zhifang; Zhang, Wenyan; Chen, Shuohua; Li, Junjuan; Yang, Xinchun; Wu, Shouling; Cai, Jun

    2015-10-26

    On the basis of cardiovascular health factors and behaviours, the American Heart Association proposed the Cardiovascular Health Score (CHS). It has been widely used to estimate the cardiovascular health status of individuals. The aim of this study was to investigate the relationship between CHS and year-to-year blood pressure variability (BPV). Prospective cohort study. We stratified participants into two groups by gender: first group, female group; second group, male group. The relationship between CHS and year-to-year blood pressure variability were analysed. A total of 41,613 individuals met the inclusion criteria (no history of stroke, transient ischaemic attack, myocardial infarction, malignant tumour or atrial fibrillation) and had complete blood pressure data. The coefficient of the variation of systolic blood pressure (SCV) was 8.33% in the total population and 8.68% and 8.22% in female and male groups, respectively (p<0.05). Multivariable linear regression analysis revealed that higher CHS was inversely associated with increasing year-to-year BPV, which persisted after adjusting for baseline systolic blood pressure and other risk factors. Each SD increase in CHS could lead to a 0.016SD decrease in SCV (p<0.05). In summary, CHS was inversely related to year-to-year BPV, which suggested that a healthy lifestyle may contribute to better blood pressure management. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  6. Can arterial wave augmentation in young adults help account for variability of cardiovascular risk in different British ethnic groups?

    PubMed Central

    Faconti, Luca; Silva, Maria J.; Molaodi, Oarabile R.; Enayat, Zinat E.; Cassidy, Aidan; Karamanos, Alexis; Nanino, Elisa; Read, Ursula M.; Dall, Philippa; Stansfield, Ben; Harding, Seeromanie; Cruickshank, Kennedy J.

    2016-01-01

    Objective: Traditional cardiovascular risk factors do not fully account for ethnic differences in cardiovascular disease. We tested if arterial function indices, particularly augmentation index (AIx), and their determinants from childhood could underlie such ethnic variability among young British adults in the ‘DASH’ longitudinal study. Methods: DASH, at http://dash.sphsu.mrc.ac.uk/, includes representative samples of six main British ethnic groups. Pulse wave velocity (PWV) and AIx were recorded using the Arteriograph device at ages 21–23 years in a subsample (n = 666); psychosocial, anthropometric, and blood pressure (BP) measures were collected then and in two previous surveys at ages 11–13 years and 14–16 years. For n = 334, physical activity was measured over 5 days (ActivPal). Results: Unadjusted values and regression models for PWVs were similar or lower in ethnic minority than in White UK young adults, whereas AIx was higher – Caribbean (14.9, 95% confidence interval 12.3–17.0%), West African (15.3, 12.9–17.7%), Indian (15.1, 13.0–17.2%), and Pakistani/Bangladeshi (15.7, 13.7–17.7%), compared with White UK (11.9, 10.2–13.6%). In multivariate models, adjusted for sex, central SBP, height, and heart rate, Indian and Pakistani/Bangladeshi young adults had higher AIx (β = 3.35, 4.20, respectively, P < 0.01) than White UK with a similar trend for West Africans and Caribbeans but not statistically significant. Unlike PWV, physical activity, psychosocial or deprivation measures were not associated with AIx, with borderline associations from brachial BP but no other childhood variables. Conclusion: Early adult AIx, but not arterial stiffness, may be a useful tool for testing components of excess cardiovascular risk in some ethnic minority groups. PMID:27490950

  7. The association between phenomena on the Sun, geomagnetic activity, meteorological variables, and cardiovascular characteristic of patients with myocardial infarction

    NASA Astrophysics Data System (ADS)

    Vencloviene, Jone; Babarskiene, Ruta; Slapikas, Rimvydas; Sakalyte, Gintare

    2013-09-01

    It has been found that solar and geomagnetic activity affects the cardiovascular system. Some evidence has been reported on the increase in the rate of myocardial infarction, stroke and myocardial infarction related deaths during geomagnetic storms. We investigated the association between cardiovascular characteristics of patients, admitted for myocardial infarction with ST elevation (STEMI), and geomagnetic activity (GMA), solar proton events (SPE), solar flares, and meteorological variables during admission. The data of 1,979 patients hospitalized at the Hospital of Lithuanian University of Health Sciences (Kaunas) were analyzed. We evaluated the association between environmental variables and patient's characteristics by multivariate logistic regression, controlling patient's gender and age. Two days after geomagnetic storms the risk of STEMI was over 1.5 times increased in patients who had a medical history of myocardial infarction, stable angina, renal or pulmonary diseases. The dose-response association between GMA level and STEMI risk for patients with renal diseases in history was observed. Two days after SPE the risk of STEMI in patients with stable angina in anamnesis was increased over 1.5 times, adjusting by GMA level. The SPE were associated with an increase of risk for patients with renal diseases in history. This study confirms the strongest effect of phenomena in the Sun in high risk patients.

  8. The association between phenomena on the sun, geomagnetic activity, meteorological variables, and cardiovascular characteristic of patients with myocardial infarction.

    PubMed

    Vencloviene, Jone; Babarskiene, Ruta; Slapikas, Rimvydas; Sakalyte, Gintare

    2013-09-01

    It has been found that solar and geomagnetic activity affects the cardiovascular system. Some evidence has been reported on the increase in the rate of myocardial infarction, stroke and myocardial infarction related deaths during geomagnetic storms. We investigated the association between cardiovascular characteristics of patients, admitted for myocardial infarction with ST elevation (STEMI), and geomagnetic activity (GMA), solar proton events (SPE), solar flares, and meteorological variables during admission. The data of 1,979 patients hospitalized at the Hospital of Lithuanian University of Health Sciences (Kaunas) were analyzed. We evaluated the association between environmental variables and patient's characteristics by multivariate logistic regression, controlling patient's gender and age. Two days after geomagnetic storms the risk of STEMI was over 1.5 times increased in patients who had a medical history of myocardial infarction, stable angina, renal or pulmonary diseases. The dose-response association between GMA level and STEMI risk for patients with renal diseases in history was observed. Two days after SPE the risk of STEMI in patients with stable angina in anamnesis was increased over 1.5 times, adjusting by GMA level. The SPE were associated with an increase of risk for patients with renal diseases in history. This study confirms the strongest effect of phenomena in the Sun in high risk patients.

  9. Affective brain areas and sleep disordered breathing

    PubMed Central

    Harper, Ronald M.; Kumar, Rajesh; Macey, Paul M.; Woo, Mary A.; Ogren, Jennifer A.

    2014-01-01

    The neural damage accompanying the hypoxia, reduced perfusion, and other consequences of sleep-disordered breathing found in obstructive sleep apnea, heart failure (HF), and congenital central hypoventilation syndrome (CCHS), appears in areas that serve multiple functions, including emotional drives to breathe, and involve systems that serve affective, cardiovascular, and breathing roles. The damage, assessed with structural magnetic resonance imaging (MRI) procedures, shows tissue loss or water content and diffusion changes indicative of injury, and impaired axonal integrity between structures; damage is preferentially unilateral. Functional MRI responses in affected areas also are time- or amplitude- distorted to ventilatory or autonomic challenges. Among the structures injured are the insular, cingulate, and ventral medial prefrontal cortices, as well as cerebellar deep nuclei and cortex, anterior hypothalamus, raphé, ventrolateral medulla, basal ganglia and, in CCHS, the locus coeruleus. Raphé and locus coeruleus injury may modify serotonergic and adrenergic modulation of upper airway and arousal characteristics. Since both axons and gray matter show injury, the consequences to function, especially to autonomic, cognitive, and mood regulation, are major. Several affected rostral sites, including the insular and cingulate cortices and hippocampus, mediate aspects of dyspnea, especially in CCHS, while others, including the anterior cingulate and thalamus, participate in initiation of inspiration after central breathing pauses, and the medullary injury can impair baroreflex and breathing control. The ancillary injury associated with sleep-disordered breathing to central structures can elicit multiple other distortions in cardiovascular, cognitive, and emotional functions in addition to effects on breathing regulation. PMID:24746053

  10. Cardiovascular manifestations of anabolic steroids in association with demographic variables in body building athletes.

    PubMed

    Gheshlaghi, Farzad; Piri-Ardakani, Mohammad-Reza; Masoumi, Gholam Reza; Behjati, Mohaddaseh; Paydar, Parva

    2015-02-01

    The most common drug abuse among athletes is anabolic steroids which lead to the development of cardiovascular diseases and sudden death. Thus, the aim of this study was to evaluate cardiovascular outcomes of anabolic consumption in body building athletes. Totally, 267 male athletes at the range of 20-45 years old with the regular consumption of anabolic steroids for >2 months with at least once weekly. High-density lipoprotein (HDL), low-density lipoprotein (LDL), triglyceride (TG), and hematocrit (Hct) levels were measured after 10 h of fasting. Data analysis was performed using K2, t-test, ANOVA and correlation coefficient through SPSS 17. There was a nonsignificant difference between groups regarding HDL, TG, and total cholesterol. There was a significant decrease in the total and categorized LDL and Hct levels in consumers of anabolic steroid versus nonusers (P = 0.01 and P = 0.041, respectively). Results showed a significant increase in systolic and diastolic blood pressure (SBP and DBP) in anabolic steroid users which associates with duration of abuse (P = 0.02 and P = 0.03, respectively). No significant electrocardiography changes were found within the follow-up period. Increase in SBP or DBP is a common complication of these drugs which can lead serious vascular disorders. The lower LDL cholesterol level might be due to the higher amounts of lipid consumption in these athletes.

  11. Cardiovascular manifestations of anabolic steroids in association with demographic variables in body building athletes

    PubMed Central

    Gheshlaghi, Farzad; Piri-Ardakani, Mohammad-Reza; Masoumi, Gholam Reza; Behjati, Mohaddaseh; Paydar, Parva

    2015-01-01

    Background: The most common drug abuse among athletes is anabolic steroids which lead to the development of cardiovascular diseases and sudden death. Thus, the aim of this study was to evaluate cardiovascular outcomes of anabolic consumption in body building athletes. Materials and Methods: Totally, 267 male athletes at the range of 20-45 years old with the regular consumption of anabolic steroids for >2 months with at least once weekly. High-density lipoprotein (HDL), low-density lipoprotein (LDL), triglyceride (TG), and hematocrit (Hct) levels were measured after 10 h of fasting. Data analysis was performed using K2, t-test, ANOVA and correlation coefficient through SPSS 17. Results: There was a nonsignificant difference between groups regarding HDL, TG, and total cholesterol. There was a significant decrease in the total and categorized LDL and Hct levels in consumers of anabolic steroid versus nonusers (P = 0.01 and P = 0.041, respectively). Results showed a significant increase in systolic and diastolic blood pressure (SBP and DBP) in anabolic steroid users which associates with duration of abuse (P = 0.02 and P = 0.03, respectively). No significant electrocardiography changes were found within the follow-up period. Conclusion: Increase in SBP or DBP is a common complication of these drugs which can lead serious vascular disorders. The lower LDL cholesterol level might be due to the higher amounts of lipid consumption in these athletes. PMID:25983770

  12. Decomposing the transfer entropy to quantify lag-specific Granger causality in cardiovascular variability.

    PubMed

    Faes, Luca; Nollo, Giandomenico

    2013-01-01

    We present a modification of the well known transfer entropy (TE) which makes it able to detect, besides the direction and strength of the information transfer between coupled processes, its exact timing. The approach follows a decomposition strategy which identifies--according to a lag-specific formulation of the concept of Granger causality--the set of time delays carrying significant information, and then assigns to each of these delays an amount of information transfer such that the total contribution yields the overall TE. We propose also a procedure for the practical estimation from time series data of the relevant delays and lag-specific TE in both bivariate and multivariate settings. The proposed approach is tested in simulations and in real cardiovascular time series, showing the feasibility of lag-specific TE estimation, the ability to reflect expected mechanisms of cardiovascular regulation, and the necessity of using the multivariate TE to properly assess time-lagged information transfer in the presence of multiple interacting systems.

  13. Prediction of space sickness in astronauts from preflight fluid, electrolyte, and cardiovascular variables and Weightless Environmental Training Facility (WETF) training

    NASA Technical Reports Server (NTRS)

    Simanonok, K.; Mosely, E.; Charles, J.

    1992-01-01

    Nine preflight variables related to fluid, electrolyte, and cardiovascular status from 64 first-time Shuttle crewmembers were differentially weighted by discrimination analysis to predict the incidence and severity of each crewmember's space sickness as rated by NASA flight surgeons. The nine variables are serum uric acid, red cell count, environmental temperature at the launch site, serum phosphate, urine osmolality, serum thyroxine, sitting systolic blood pressure, calculated blood volume, and serum chloride. Using two methods of cross-validation on the original samples (jackknife and a stratefied random subsample), these variables enable the prediction of space sickness incidence (NONE or SICK) with 80 percent sickness and space severity (NONE, MILD, MODERATE, of SEVERE) with 59 percent success by one method of cross-validation and 67 percent by another method. Addition of a tenth variable, hours spent in the Weightlessness Environment Training Facility (WETF) did not improve the prediction of space sickness incidences but did improve the prediction of space sickness severity to 66 percent success by the first method of cross-validation of original samples and to 71 percent by the second method. Results to date suggest the presence of predisposing physiologic factors to space sickness that implicate fluid shift etiology. The data also suggest that prior exposure to fluid shift during WETF training may produce some circulatory pre-adaption to fluid shifts in weightlessness that results in a reduction of space sickness severity.

  14. Fasting Glucose and the Risk of Depressive Symptoms: Instrumental-Variable Regression in the Cardiovascular Risk in Young Finns Study.

    PubMed

    Wesołowska, Karolina; Elovainio, Marko; Hintsa, Taina; Jokela, Markus; Pulkki-Råback, Laura; Pitkänen, Niina; Lipsanen, Jari; Tukiainen, Janne; Lyytikäinen, Leo-Pekka; Lehtimäki, Terho; Juonala, Markus; Raitakari, Olli; Keltikangas-Järvinen, Liisa

    2017-08-04

    Type 2 diabetes (T2D) has been associated with depressive symptoms, but the causal direction of this association and the underlying mechanisms, such as increased glucose levels, remain unclear. We used instrumental-variable regression with a genetic instrument (Mendelian randomization) to examine a causal role of increased glucose concentrations in the development of depressive symptoms. Data were from the population-based Cardiovascular Risk in Young Finns Study (n = 1217). Depressive symptoms were assessed in 2012 using a modified Beck Depression Inventory (BDI-I). Fasting glucose was measured concurrently with depressive symptoms. A genetic risk score for fasting glucose (with 35 single nucleotide polymorphisms) was used as an instrumental variable for glucose. Glucose was not associated with depressive symptoms in the standard linear regression (B = -0.04, 95% CI [-0.12, 0.04], p = .34), but the instrumental-variable regression showed an inverse association between glucose and depressive symptoms (B = -0.43, 95% CI [-0.79, -0.07], p = .020). The difference between the estimates of standard linear regression and instrumental-variable regression was significant (p = .026) CONCLUSION: Our results suggest that the association between T2D and depressive symptoms is unlikely to be caused by increased glucose concentrations. It seems possible that T2D might be linked to depressive symptoms due to low glucose levels.

  15. Cardiovascular Variability Analysis and Baroreflex Estimation in Patients with Type 2 Diabetes in Absence of Any Manifest Neuropathy

    PubMed Central

    de Moura-Tonello, Sílvia Cristina Garcia; Porta, Alberto; Marchi, Andrea; de Almeida Fagundes, Alessandra; Francisco, Cristina de Oliveira; Rehder-Santos, Patrícia; Milan-Mattos, Juliana Cristina; Simões, Rodrigo Polaquini; Gois, Mariana de Oliveira; Catai, Aparecida Maria

    2016-01-01

    Introduction Indexes derived from spontaneous heart period (HP) and systolic arterial pressure (SAP) fluctuations can detect autonomic dysfunction in individuals with type 2 diabetes mellitus (DM) associated to cardiovascular autonomic neuropathy (CAN) or other neuropathies. It is unknown whether HP and SAP variability indexes are sensitive enough to detect the autonomic dysfunction in DM patients without CAN and other neuropathies. Methods We evaluated 68 males aged between 40 and 65 years. The group was composed by DM type 2 DM with no manifest neuropathy (n = 34) and healthy (H) subjects (n = 34). The protocol consisted of 15 minutes of recording of HP and SAP variabilities at rest in supine position (REST) and after active standing (STAND). The HP power in the high frequency band (HF, from 0.15 to 0.5 Hz), the SAP power in the low frequency band (LF, from 0.04 to 0.15 Hz) and BRS estimated via spectral approach and sequence method were computed. Results The HF power of HP was lower in DM patients than in H subjects, while the two groups exhibited comparable HF power of HP during STAND. The LF power of SAP was similar in DM and H groups at REST and increased during STAND in both groups. BRSs estimated in the HF band and via baroreflex sequence method were lower in DM than in H and they decreased further during STAND in both populations. Conclusion Results suggest that vagal control of heart rate and cardiac baroreflex control was impaired in type 2 DM, while sympathetic control directed to vessels, sympathetic and baroreflex response to STAND were preserved. Cardiovascular variability indexes are sensitive enough to typify the early, peculiar signs of autonomic dysfunction in type-2 DM patients well before CAN becomes manifest. PMID:26987126

  16. Effect of meal content on heart rate variability and cardiovascular reactivity to mental stress

    PubMed Central

    Sauder, Katherine A.; Johnston, Elyse R.; Skulas-Ray, Ann C.; Campbell, Tavis S.; West, Sheila G.

    2012-01-01

    Little is known about transient effects of foods and nutrients on reactivity to mental stress. In a randomized crossover study of healthy adults (n = 20), we measured heart rate variability (respiratory sinus arrhythmia), blood pressure, and other hemodynamic variables after three test meals varying in type and amount of fat. Measurements were collected at rest and during speech and cold pressor tasks. There were significant post-meal changes in resting diastolic blood pressure (−4%), cardiac output (+18%), total peripheral resistance (−17%), and interleukin-6 (−27%). Heart rate variability and hemodynamic reactivity to stress was not affected by meal content. We recommend that future studies control for time since last meal and continue to examine effects of meal content on heart rate variability. PMID:22236402

  17. Cross-spectral coherence between geomagnetic disturbance and human cardiovascular variables at non-societal frequencies.

    PubMed

    Watanabe, Y; Hillman, D C; Otsuka, K; Bingham, C; Breus, T K; Cornélissen, G; Halberg, F

    1994-01-01

    A 35-year-old cardiologist monitored himself with an automatic ABPM-630 (Colin Electronics) monitor, mostly at 15-minute intervals around-the-clock for three years with a few interruptions. In this subject with a family history of high blood pressure and stroke, a cross-spectral analysis revealed a statistically significant coherence at 27.7 days between systolic and diastolic blood pressure and heart rate vs. the geomagnetic disturbance index, Kp. A lesser peak in coherence was found for systolic blood pressure with Kp at a trial period of 4.16 days (P = 0.046). These results suggest that changes in geomagnetism may influence the human circulation, at least in the presence of familial cardiovascular disease risk, and they may do so at frequencies that have no precise human-made cyclic worldwide match.

  18. P-glycoprotein: a focus on characterizing variability in cardiovascular pharmacotherapeutics.

    PubMed

    Al-Khazaali, Ali; Arora, Rohit

    2014-01-01

    According to the report of Agency for Healthcare Research and Quality in 2008, drug-related adverse outcomes exceed 2.7 million events per year. Therefore, it is requisite to understand the etiologies of those unpleasant outcomes. Polypharmacy especially in the elderly is considered one of the major sources of drug-related side effects. The drug-related membrane transporters play an indispensable role in the pharmacokinetics, safety, and efficacy of the drugs. P-glycoprotein, also known as P-gp, is considered one of the core drug transporters in vivo. Since its discovery in 1976, P-gp gained a tremendous attention of researchers and clinicians. The core objective of this review is to highlight the clinical correlation between the P-gp and a number of cardiovascular drugs and to address the drug-drug interaction in case of using those cardiovascular drugs with P-gp-related drugs whether substrates, inhibitors, or inducers. Bearing in mind that P-gp is found in liver and intestine, as well as cytochrome P450, a strong association between the 2 systems is expected. Yet, plenty of the drugs that can behave as substrates to P-gp can act as substrates to CYP450 too. Consequently, probable drug-drug interaction can occur between drugs that work on both systems. In other words, whenever these classes of medications prescribed together cautious monitoring of drug's level and eventually dose adjustment might be necessary to avoid drug-drug interactions, failure of therapy, or drug toxicity; especially with the use of drugs that possess narrow therapeutic index like digoxin.

  19. Algorithms for the inference of causality in dynamic processes: Application to cardiovascular and cerebrovascular variability.

    PubMed

    Faes, Luca; Porta, Alberto; Nollo, Giandomenico

    2015-08-01

    This study faces the problem of causal inference in multivariate dynamic processes, with specific regard to the detection of instantaneous and time-lagged directed interactions. We point out the limitations of the traditional Granger causality analysis, showing that it leads to false detection of causality when instantaneous and time-lagged effects coexist in the process structure. Then, we propose an improved algorithm for causal inference that combines the Granger framework with the approach proposed by Pearl for the study of causality among multiple random variables. This new approach is compared with the traditional one in theoretical and simulated examples of interacting processes, showing its ability to retrieve the correct structure of instantaneous and time-lagged interactions. These approaches for causal inference are then tested on the physiological variability series of heart period, arterial pressure and cerebral blood flow variability obtained in subjects with postural-related syncope during a tilt-test protocol.

  20. Maximal-radius multiscale entropy of cardiovascular variability: a promising biomarker of pathological mood states in bipolar disorders.

    PubMed

    Valenza, Gaetano; Nardelli, Mimma; Bertschy, Gilles; Lanatà, Antonio; Barbieri, Riccardo; Scilingo, Enzo Pasquale

    2014-01-01

    Complexity measures from Multiscale Entropy (MSE) analysis of cardiovascular variability may provide potential biomarkers of pathological mental states such as major depression. To this extent, in this study we investigate whether complexity of Heart Rate Variability (HRV) is also affected in mental disorders such as bipolar disorders (BD). As part of the European project PSYCHE, eight BD patients experiencing multiple pathological mood states among depression, hypomania, and euthymia (i.e., good affective balance) underwent long-term night recordings through a comfortable sensing t-shirt with integrated fabric electrodes and sensors. Standard radius, i.e., 20% of the HRV standard deviation, and a maximal-radius choice for the sample entropy estimation were compared along with a further multiscale Renyi Entropy analysis. We found that, despite the inter-subject variability, the maximal-radius MSE analysis is able to discern the considered pathological mental states of BD. As the current clinical practice in diagnosing BD is only based on verbal interviews and scores from specific questionnaires, these findings provide evidence on the possibility of using heartbeat complexity as the basis of novel clinical biomarkers of mental disorders.

  1. Direct and indirect quantification of mitral regurgitation with cardiovascular magnetic resonance, and the effect of heart rate variability.

    PubMed

    Myerson, Saul G; Francis, Jane M; Neubauer, Stefan

    2010-09-01

    Quantifying mitral regurgitation with cardiovascular magnetic resonance (CMR) involves indirect calculation, which increases the potential for error. We examined a direct quantification method using velocity mapping across the mitral valve, which may be less susceptible to error, and also examined the effect of heart rate variability on both techniques. Fifty-five patients underwent mitral regurgitation quantification with CMR by the direct method and two indirect methods-the standard method subtracting aortic flow (assessed by velocity mapping) from left ventricular stroke volume (assessed by cine imaging) and the 'volumetric' method using the difference between left and right ventricular stroke volumes. The methods were compared using Bland-Altman analyses. Patients with low heart rate variability (beat-to-beat variability <30 bpm; n = 44) showed good agreement between direct and indirect methods (95% confidence limits for the difference between measurements +/-16.7 ml/11.8% regurgitant fraction for the standard method; +/-21.7 ml/15.4% for the volumetric method), with no significant offset (mean difference +2.8 ml/+1.9% for standard and +3.1 ml/+2.3% for volumetric methods). Patients with high heart rate variability (>30 bpm; n = 11) showed poor agreement between techniques (95% limits +/-80.3 ml/56.0%) and significant offset (mean difference +31.7 ml/+19.5%). Direct quantification of mitral regurgitation with CMR compares well with indirect methods for patients with low heart rate variability, involves fewer calculations and is quick. All CMR measurements that use velocity mapping may be inaccurate, however, in patients with highly irregular rhythms and should be avoided in these patients.

  2. Oscillatory patterns in sympathetic neural discharge and cardiovascular variables during orthostatic stimulus

    NASA Technical Reports Server (NTRS)

    Furlan, R.; Porta, A.; Costa, F.; Tank, J.; Baker, L.; Schiavi, R.; Robertson, D.; Malliani, A.; Mosqueda-Garcia, R.

    2000-01-01

    BACKGROUND: We tested the hypothesis that a common oscillatory pattern might characterize the rhythmic discharge of muscle sympathetic nerve activity (MSNA) and the spontaneous variability of heart rate and systolic arterial pressure (SAP) during a physiological increase of sympathetic activity induced by the head-up tilt maneuver. METHODS AND RESULTS: Ten healthy subjects underwent continuous recordings of ECG, intra-arterial pressure, respiratory activity, central venous pressure, and MSNA, both in the recumbent position and during 75 degrees head-up tilt. Venous samplings for catecholamine assessment were obtained at rest and during the fifth minute of tilt. Spectrum and cross-spectrum analyses of R-R interval, SAP, and MSNA variabilities and of respiratory activity provided the low (LF, 0.1 Hz) and high frequency (HF, 0.27 Hz) rhythmic components of each signal and assessed their linear relationships. Compared with the recumbent position, tilt reduced central venous pressure, but blood pressure was unchanged. Heart rate, MSNA, and plasma epinephrine and norepinephrine levels increased, suggesting a marked enhancement of overall sympathetic activity. During tilt, LF(MSNA) increased compared with the level in the supine position; this mirrored similar changes observed in the LF components of R-R interval and SAP variabilities. The increase of LF(MSNA) was proportional to the amount of the sympathetic discharge. The coupling between LF components of MSNA and R-R interval and SAP variabilities was enhanced during tilt compared with rest. CONCLUSIONS: During the sympathetic activation induced by tilt, a similar oscillatory pattern based on an increased LF rhythmicity characterized the spontaneous variability of neural sympathetic discharge, R-R interval, and arterial pressure.

  3. Oscillatory patterns in sympathetic neural discharge and cardiovascular variables during orthostatic stimulus

    NASA Technical Reports Server (NTRS)

    Furlan, R.; Porta, A.; Costa, F.; Tank, J.; Baker, L.; Schiavi, R.; Robertson, D.; Malliani, A.; Mosqueda-Garcia, R.

    2000-01-01

    BACKGROUND: We tested the hypothesis that a common oscillatory pattern might characterize the rhythmic discharge of muscle sympathetic nerve activity (MSNA) and the spontaneous variability of heart rate and systolic arterial pressure (SAP) during a physiological increase of sympathetic activity induced by the head-up tilt maneuver. METHODS AND RESULTS: Ten healthy subjects underwent continuous recordings of ECG, intra-arterial pressure, respiratory activity, central venous pressure, and MSNA, both in the recumbent position and during 75 degrees head-up tilt. Venous samplings for catecholamine assessment were obtained at rest and during the fifth minute of tilt. Spectrum and cross-spectrum analyses of R-R interval, SAP, and MSNA variabilities and of respiratory activity provided the low (LF, 0.1 Hz) and high frequency (HF, 0.27 Hz) rhythmic components of each signal and assessed their linear relationships. Compared with the recumbent position, tilt reduced central venous pressure, but blood pressure was unchanged. Heart rate, MSNA, and plasma epinephrine and norepinephrine levels increased, suggesting a marked enhancement of overall sympathetic activity. During tilt, LF(MSNA) increased compared with the level in the supine position; this mirrored similar changes observed in the LF components of R-R interval and SAP variabilities. The increase of LF(MSNA) was proportional to the amount of the sympathetic discharge. The coupling between LF components of MSNA and R-R interval and SAP variabilities was enhanced during tilt compared with rest. CONCLUSIONS: During the sympathetic activation induced by tilt, a similar oscillatory pattern based on an increased LF rhythmicity characterized the spontaneous variability of neural sympathetic discharge, R-R interval, and arterial pressure.

  4. Ecological sounds affect breath duration more than artificial sounds.

    PubMed

    Murgia, Mauro; Santoro, Ilaria; Tamburini, Giorgia; Prpic, Valter; Sors, Fabrizio; Galmonte, Alessandra; Agostini, Tiziano

    2016-01-01

    Previous research has demonstrated that auditory rhythms affect both movement and physiological functions. We hypothesized that the ecological sounds of human breathing can affect breathing more than artificial sounds of breathing, varying in tones for inspiration and expiration. To address this question, we monitored the breath duration of participants exposed to three conditions: (a) ecological sounds of breathing, (b) artificial sounds of breathing having equal temporal features as the ecological sounds, (c) no sounds (control). We found that participants' breath duration variability was reduced in the ecological sound condition, more than in the artificial sound condition. We suggest that ecological sounds captured the timing of breathing better than artificial sounds, guiding as a consequence participants' breathing. We interpreted our results according to the Theory of Event Coding, providing further support to its validity, and suggesting its possible extension in the domain of physiological functions which are both consciously and unconsciously controlled.

  5. Breathing exercises: influence on breathing patterns and thoracoabdominal motion in healthy subjects

    PubMed Central

    Vieira, Danielle S. R.; Mendes, Liliane P. S.; Elmiro, Nathália S.; Velloso, Marcelo; Britto, Raquel R.; Parreira, Verônica F.

    2014-01-01

    BACKGROUND: The mechanisms underlying breathing exercises have not been fully elucidated. OBJECTIVES: To evaluate the impact of four on breathing exercises (diaphragmatic breathing, inspiratory sighs, sustained maximal inspiration and intercostal exercise) the on breathing pattern and thoracoabdominal motion in healthy subjects. METHOD: Fifteen subjects of both sexes, aged 23±1.5 years old and with normal pulmonary function tests, participated in the study. The subjects were evaluated using the optoelectronic plethysmography system in a supine position with a trunk inclination of 45° during quiet breathing and the breathing exercises. The order of the breathing exercises was randomized. Statistical analysis was performed by the Friedman test and an ANOVA for repeated measures with one factor (breathing exercises), followed by preplanned contrasts and Bonferroni correction. A p<0.005 value was considered significant. RESULTS: All breathing exercises significantly increased the tidal volume of the chest wall (Vcw) and reduced the respiratory rate (RR) in comparison to quiet breathing. The diaphragmatic breathing exercise was responsible for the lowest Vcw, the lowest contribution of the rib cage, and the highest contribution of the abdomen. The sustained maximal inspiration exercise promoted greater reduction in RR compared to the diaphragmatic and intercostal exercises. Inspiratory sighs and intercostal exercises were responsible for the highest values of minute ventilation. Thoracoabdominal asynchrony variables increased significantly during diaphragmatic breathing. CONCLUSIONS: The results showed that the breathing exercises investigated in this study produced modifications in the breathing pattern (e.g., increase in tidal volume and decrease in RR) as well as in thoracoabdominal motion (e.g., increase in abdominal contribution during diaphragmatic breathing), among others. PMID:25590447

  6. Effects of low-dose clonidine on cardiovascular and autonomic variables in adolescents with chronic fatigue: a randomized controlled trial.

    PubMed

    Fagermoen, Even; Sulheim, Dag; Winger, Anette; Andersen, Anders M; Gjerstad, Johannes; Godang, Kristin; Rowe, Peter C; Saul, J Philip; Skovlund, Eva; Wyller, Vegard Bruun

    2015-09-10

    Chronic Fatigue Syndrome (CFS) is a common and disabling condition in adolescence with few treatment options. A central feature of CFS is orthostatic intolerance and abnormal autonomic cardiovascular control characterized by sympathetic predominance. We hypothesized that symptoms as well as the underlying pathophysiology might improve by treatment with the alpha2A-adrenoceptor agonist clonidine. A total of 176 adolescent CFS patients (12-18 years) were assessed for eligibility at a single referral center recruiting nation-wide. Patients were randomized 1:1 by a computer system and started treatment with clonidine capsules (25 μg or 50 μg twice daily, respectively, for body weight below/above 35 kg) or placebo capsules for 9 weeks. Double-blinding was provided. Data were collected from March 2010 until October 2012 as part of The Norwegian Study of Chronic Fatigue Syndrome in Adolescents: Pathophysiology and Intervention Trial (NorCAPITAL). Effect of clonidine intervention was assessed by general linear models in intention-to-treat analyses, including baseline values as covariates in the model. A total of 120 patients (clonidine group n = 60, placebo group n = 60) were enrolled and started treatment. There were 14 drop-outs (5 in the clonidine group, 9 in the placebo group) during the intervention period. At 8 weeks, the clonidine group had lower plasma norepinephrine (difference = 205 pmol/L, p = 0.05) and urine norepinephrine/creatinine ratio (difference = 3.9 nmol/mmol, p = 0.002). During supine rest, the clonidine group had higher heart rate variability in the low-frequency range (LF-HRV, absolute units) (ratio = 1.4, p = 0.007) as well as higher standard deviation of all RR-intervals (SDNN) (difference = 12.0 ms, p = 0.05); during 20° head-up tilt there were no statistical differences in any cardiovascular variable. Symptoms of orthostatic intolerance did not change during the intervention period. Low-dose clonidine reduces catecholamine levels in adolescent

  7. Effects of slow and regular breathing exercise on cardiopulmonary coupling and blood pressure.

    PubMed

    Zhang, Zhengbo; Wang, Buqing; Wu, Hao; Chai, Xiaoke; Wang, Weidong; Peng, Chung-Kang

    2017-02-01

    Investigation of the interaction between cardiovascular variables and respiration provides a quantitative and noninvasive approach to assess the autonomic control of cardiovascular function. The aim of this paper is to investigate the changes of cardiopulmonary coupling (CPC), blood pressure (BP) and pulse transit time (PTT) during a stepwise-paced breathing (SPB) procedure (spontaneous breathing followed by paced breathing at 14, 12.5, 11, 9.5, 8 and 7 breaths per minute, 3 min each) and gain insights into the characteristics of slow breathing exercises. RR interval, respiration, BP and PTT are collected during the SPB procedure (48 healthy subjects, 27 ± 6 years). CPC is assessed through investigating both the phase and amplitude dynamics between the respiration-induced components from RR interval and respiration by the approach of ensemble empirical mode decomposition. It was found that even though the phase synchronization and amplitude oscillation of CPC were both enhanced by the SPB procedure, phase coupling does not increase monotonically along with the amplitude oscillation during the whole procedure. Meanwhile, BP was reduced significantly by the SPB procedure (SBP: from 122.0 ± 13.4 to 114.2 ± 14.9 mmHg, p < 0.001, DBP: from 82.2 ± 8.6 to 77.0 ± 9.8 mmHg, p < 0.001, PTT: from 172.8 ± 20.1 to 176.8 ± 19.2 ms, p < 0.001). Our results demonstrate that the SPB procedure can reduce BP and lengthen PTT significantly. Compared with amplitude dynamics, phase dynamics is a different marker for CPC analysis in reflecting cardiorespiratory coherence during slow breathing exercise. Our study provides a methodology to practice slow breathing exercise, including the setting of target breathing rate, change of CPC and the importance of regular breathing. The applications and usability of the study results have also been discussed.

  8. Impact of Glycemic and Blood Pressure Variability on Surrogate Measures of Cardiovascular Outcomes in Type 2 Diabetic Patients

    PubMed Central

    Di Flaviani, Alessandra; Picconi, Fabiana; Di Stefano, Paola; Giordani, Ilaria; Malandrucco, Ilaria; Maggio, Paola; Palazzo, Paola; Sgreccia, Fabrizio; Peraldo, Carlo; Farina, Fabrizio; Frajese, Gaetano; Frontoni, Simona

    2011-01-01

    OBJECTIVE The effect of glycemic variability (GV) on cardiovascular risk has not been fully clarified in type 2 diabetes. We evaluated the effect of GV, blood pressure (BP), and oxidative stress on intima-media thickness (IMT), left ventricular mass index (LVMI), flow-mediated dilation (FMD), and sympathovagal balance (low frequency [LF]/high frequency [HF] ratio) in 26 type 2 diabetic patients (diabetes duration 4.41 ± 4.81 years; HbA1c 6.70 ± 1.25%) receiving diet and/or metformin treatment, with no hypotensive treatment or complications. RESEARCH DESIGN AND METHODS Continuous glucose monitoring (CGM) data were used to calculate mean amplitude of glycemic excursion (MAGE), continuous overall net glycemic action (CONGA)-2, mean blood glucose (MBG), mean postprandial glucose excursion (MPPGE), and incremental area under the curve (IAUC). Blood pressure (BP), circadian rhythm, and urinary 15-F2t-isoprostane (8-iso-prostaglandin F2α [PGF2α]) were also evaluated. Subjects were divided into dipper (D) and nondipper (ND) groups according to ΔBP. RESULTS IMT and LVMI were increased in ND versus D (0.77 ± 0.08 vs. 0.68 ± 0.13 [P = 0.04] and 67 ± 14 vs. 55 ± 11 [P = 0.03], respectively). MBG, MAGE, and IAUC were significantly associated with LF/HF ratio at night (r = 0.50, P = 0.01; r = 0.40, P = 0.04; r = 0.41, P = 0.04, respectively), MPPGE was negatively associated with FMD (r = −0.45, P = 0.02), and CONGA-2 was positively associated with LVMI (r = 0.55, P = 0.006). The Δsystolic BP was negatively associated with IMT (r = −0.43, P = 0.03) and with LVMI (r = −0.52, P = 0.01). Urinary 8-iso-PGF2α was positively associated with LVMI (r = 0.68 P < 0.001). CONCLUSIONS An impaired GV and BP variability is associated with endothelial and cardiovascular damage in short-term diabetic patients with optimal metabolic control. Oxidative stress is the only independent predictor of increased LV mass and correlates with glucose and BP variability. PMID:21610126

  9. Of larks and hearts--morningness/eveningness, heart rate variability and cardiovascular stress response at different times of day.

    PubMed

    Roeser, Karolin; Obergfell, Friederike; Meule, Adrian; Vögele, Claus; Schlarb, Angelika A; Kübler, Andrea

    2012-05-15

    Inter-individual differences in the circadian period of physical and mental functions can be described on the dimension of morningness/eveningness. Previous findings support the assumption that eveningness is related to greater impulsivity and susceptibility to stress than morningness. Heart rate variability (HRV) serves as a physiological correlate of self- and emotional regulation and has not yet been investigated in relation to chronotypes. The study explores differences in HRV and other cardiovascular measures in morning- and evening-types at rest and under stress at different times of day (8-11 a.m. or 4-7 p.m.). Students (N=471) were screened for chronotype and n=55 females (27 morning- and 28 evening-types) were recruited for testing. These participants performed a mental arithmetic task while heart rate (HR) and blood pressure (BP) were recorded. Spectral components and a time-domain measure of HRV were calculated on HR data from resting and mental stress periods. Evening-types had significantly higher HR and systolic BP, but lower HRV than morning-types both at baseline and during stress. Stress induced in the evening had a significantly stronger impact on absolute and baseline corrected physiological measures in both chronotypes. The interaction of chronotype and testing time did not reach the level of significance for any of the dependent variables. The enhanced physiological arousal in evening-types might contribute to increased vulnerability to psychological distress. Hence, previous behavioral findings are supported by the physiological data of this study.

  10. Addition of 24-Hour Heart Rate Variability Parameters to the Cardiovascular Health Study Stroke Risk Score and Prediction of Incident Stroke: The Cardiovascular Health Study.

    PubMed

    Bodapati, Rohan K; Kizer, Jorge R; Kop, Willem J; Kamel, Hooman; Stein, Phyllis K

    2017-07-21

    Heart rate variability (HRV) characterizes cardiac autonomic functioning. The association of HRV with stroke is uncertain. We examined whether 24-hour HRV added predictive value to the Cardiovascular Health Study clinical stroke risk score (CHS-SCORE), previously developed at the baseline examination. N=884 stroke-free CHS participants (age 75.3±4.6), with 24-hour Holters adequate for HRV analysis at the 1994-1995 examination, had 68 strokes over ≤8 year follow-up (median 7.3 [interquartile range 7.1-7.6] years). The value of adding HRV to the CHS-SCORE was assessed with stepwise Cox regression analysis. The CHS-SCORE predicted incident stroke (HR=1.06 per unit increment, P=0.005). Two HRV parameters, decreased coefficient of variance of NN intervals (CV%, P=0.031) and decreased power law slope (SLOPE, P=0.033) also entered the model, but these did not significantly improve the c-statistic (P=0.47). In a secondary analysis, dichotomization of CV% (LOWCV% ≤12.8%) was found to maximally stratify higher-risk participants after adjustment for CHS-SCORE. Similarly, dichotomizing SLOPE (LOWSLOPE <-1.4) maximally stratified higher-risk participants. When these HRV categories were combined (eg, HIGHCV% with HIGHSLOPE), the c-statistic for the model with the CHS-SCORE and combined HRV categories was 0.68, significantly higher than 0.61 for the CHS-SCORE alone (P=0.02). In this sample of older adults, 2 HRV parameters, CV% and power law slope, emerged as significantly associated with incident stroke when added to a validated clinical risk score. After each parameter was dichotomized based on its optimal cut point in this sample, their composite significantly improved prediction of incident stroke during ≤8-year follow-up. These findings will require validation in separate, larger cohorts. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  11. Parasympathetic Stimuli on Bronchial and Cardiovascular Systems in Humans

    PubMed Central

    Zannin, Emanuela; Pellegrino, Riccardo; Di Toro, Alessandro; Antonelli, Andrea; Dellacà, Raffaele L.; Bernardi, Luciano

    2015-01-01

    Background It is not known whether parasympathetic outflow simultaneously acts on bronchial tone and cardiovascular system waxing and waning both systems in parallel, or, alternatively, whether the regulation is more dependent on local factors and therefore independent on each system. The aim of this study was to evaluate the simultaneous effect of different kinds of stimulations, all associated with parasympathetic activation, on bronchomotor tone and cardiovascular autonomic regulation. Methods Respiratory system resistance (Rrs, forced oscillation technique) and cardio-vascular activity (heart rate, oxygen saturation, tissue oxygenation index, blood pressure) were assessed in 13 volunteers at baseline and during a series of parasympathetic stimuli: O2 inhalation, stimulation of the carotid sinus baroreceptors by neck suction, slow breathing, and inhalation of methacholine. Results Pure cholinergic stimuli, like O2 inhalation and baroreceptors stimulation, caused an increase in Rrs and a reduction in heart rate and blood pressure. Slow breathing led to bradycardia and hypotension, without significant changes in Rrs. However slow breathing was associated with deep inhalations, and Rrs evaluated at the baseline lung volumes was significantly increased, suggesting that the large tidal volumes reversed the airways narrowing effect of parasympathetic activation. Finally inhaled methacholine caused marked airway narrowing, while the cardiovascular variables were unaffected, presumably because of the sympathetic activity triggered in response to hypoxemia. Conclusions All parasympathetic stimuli affected bronchial tone and moderately affected also the cardiovascular system. However the response differed depending on the nature of the stimulus. Slow breathing was associated with large tidal volumes that reversed the airways narrowing effect of parasympathetic activation. PMID:26046774

  12. Variability in ozone-induced pulmonary injury and inflammation in healthy and cardiovascular-compromised rat models.

    PubMed

    Kodavanti, Urmila P; Ledbetter, Allen D; Thomas, Ronald F; Richards, Judy E; Ward, William O; Schladweiler, Mette C; Costa, Daniel L

    2015-01-01

    The molecular bases for variability in air pollutant-induced pulmonary injury due to underlying cardiovascular (CVD) and/or metabolic diseases are unknown. We hypothesized that healthy and genetic CVD-prone rat models will exhibit exacerbated response to acute ozone exposure dependent on the type and severity of disease. Healthy male 12-14-week-old Wistar Kyoto (WKY), Wistar (WS) and Sprague Dawley (SD); and CVD-compromised spontaneously hypertensive (SH), Fawn-Hooded hypertensive (FHH), stroke-prone spontaneously hypertensive (SHSP), obese spontaneously hypertensive heart failure (SHHF) and obese JCR (JCR) rats were exposed to 0.0, 0.25, 0.5, or 1.0 ppm ozone for 4 h; pulmonary injury and inflammation were analyzed immediately following (0-h) or 20-h later. Baseline bronchoalveolar lavage fluid (BALF) protein was higher in CVD strains except for FHH when compared to healthy. Ozone-induced increases in protein and inflammation were concentration-dependent within each strain but the degree of response varied from strain to strain and with time. Among healthy rats, SD were least affected. Among CVD strains, lean rats were more susceptible to protein leakage from ozone than obese rats. Ozone caused least neutrophilic inflammation in SH and SHHF while SHSP and FHH were most affected. BALF neutrophils and protein were poorly correlated when considering the entire dataset (r = 0.55). The baseline and ozone-induced increases in cytokine mRNA varied markedly between strains and did not correlate with inflammation. These data illustrate that the degree of ozone-induced lung injury/inflammation response is likely influenced by both genetic and physiological factors that govern the nature of cardiovascular compromise in CVD models.

  13. Use of beat-to-beat cardiovascular variability data to determine the validity of sham therapy as the placebo control in osteopathic manipulative medicine research.

    PubMed

    Henley, Charles E; Wilson, Thad E

    2014-11-01

    Osteopathic manipulative medicine researchers often use sham therapy as the placebo control during clinical trials. Optimally, the sham therapy should be a hands-on procedure that is perceptually indistinguishable from osteopathic manipulative treatment, does not create an effect on its own, and is not a treatment intervention. However, the sham therapy itself may often influence the outcome. The use of cardiovascular variability (eg, beat-to-beat heart rate variability) as a surrogate for the autonomic nervous system is one objective method by which to identify such an effect. By monitoring cardiovascular variability, investigators can assess autonomic nervous system activity as a response to the sham therapy and quickly determine whether or not the selected sham therapy is a true placebo control. The authors provide evidence for assessment of beat-to-beat heart rate variability as one method for assuring objectivity of sham therapy as a placebo control in osteopathic manipulative medicine research.

  14. Power spectral analysis of cardiovascular variability in patients at risk for sudden cardiac death.

    PubMed

    Malliani, A; Lombardi, F; Pagani, M; Cerutti, S

    1994-03-01

    The time series of successive heart periods present important variations around its mean value, determining the phenomenon of heart rate variability (HRV), assessed with both time and frequency domain approaches. A low standard deviation of the heart period (a time domain index of HRV) is a powerful prognostic indicator of sudden coronary death in patients recovering from acute myocardial infarction. Spectral analysis of HRV usually demonstrates two major components: indicated as LF (low frequency, approximately 0.1 Hz) and HF (high frequency, approximately 0.25 Hz). They are defined by center frequency and associated power, which is expressed in msec2 or normalized units. When assessed in normalized units, LF and HF provide quantitative indicators of neural control of the sinoatrial node. Numerous experimental and clinical studies have consistently indicated that the LF component is a marker of sympathetic modulation and HF a marker of vagal modulation; the LF/HF ratio is a synthetic index of sympathovagal balance. In the analysis of 24-hour Holter recordings of normal subjects, a circadian rhythmicity of spectral markers of sympathetic and vagal modulation is clearly present, with a sympathetic predominance during the day and a vagal predominance during the night. In patients recovering from an acute myocardial infarction, spectral analysis of HRV revealed an increased sympathetic and decreased vagal activity during early convalescence, and a return to their normal balance by 6 to 12 months. A clear increase of LF was also evident in patients studied within a few hours of the onset of symptoms related to an acute myocardial infarction, independent of its location. Similarly, LF increased during transient myocardial ischemia. An increase in markers of sympathetic activity has also been observed prior to episodes of malignant arrhythmias. Spectral analysis of HRV could help in the understanding of the role of abnormal neural mechanisms in sudden coronary death

  15. Assessment of Risk Factor for Cardiovascular Disease Using Heart Rate Variability in Postmenopausal Women: A Comparative Study between Urban and Rural Indian Women

    PubMed Central

    Narayanaswamy, Nikhil; Halahalli, Harsha; Mirajkar, Amrit M.

    2013-01-01

    Cardiovascular diseases are important causes of morbidity and mortality in postmenopausal women. A major determinant of cardiovascular health is the status of autonomic nervous system and assessment of Heart Rate Variability (HRV). Heart Rate Variability is a noninvasive and sensitive technique to evaluate cardiovascular autonomic control. Reduced HRV is an independent risk factor for the development of heart disease. This study evaluated the risk factors for cardiovascular diseases using HRV, between urban and rural Indian postmenopausal women ranging in age from 40 to 75 years. Findings of the analysis of HRV have showed that the total power which reflects overall modulation of cardiac autonomic activity (759 ± 100  versus 444 ± 65), the absolute power of high frequency which is surrogate of cardiovagal activity (247 ± 41  versus 163 ± 45), and low frequency that reflects cardiac sympathetic activity (205 ± 26  versus 127 ± 18) were significantly higher in urban women than that of their rural counterparts. Further, among the anthropometric measures, waist circumference was significantly correlated with indices of HRV. The study concludes that rural Indian women are associated with an additional risk beyond that of ageing and postmenopausal status when compared to the urban women. The higher central obesity could be the contributing factor for developing higher risk for cardiovascular disease among the rural women. PMID:23936672

  16. Breathing difficulty - lying down

    MedlinePlus

    Waking at night short of breath; Paroxysmal nocturnal dyspnea; PND; Difficulty breathing while lying down; Orthopnea ... obstructive pulmonary disease (COPD) Cor pulmonale Heart failure ... conditions that lead to it) Panic disorder Sleep apnea Snoring

  17. Shortness of Breath

    MedlinePlus

    ... Wheezing Worsening of pre-existing shortness of breath Self-care To help keep chronic shortness of breath ... JA, et al. Dyspnea. In: Rosen's Emergency Medicine: Concepts and Clinical Practice. 8th ed. Philadelphia, Pa.: Saunders ...

  18. Minimizing Shortness of Breath

    MedlinePlus

    ... postures and exposure to environmental irritants. Pursed-Lip Breathing One focus of occupational therapy is to teach ... the accessory muscles and manage respiratory symptoms. Monitor Breathing During an activity, it is important to pause ...

  19. Pursed lip breathing (image)

    MedlinePlus

    ... were going to whistle or blow out a candle. Breathe out (exhale) slowly through your lips for 4 or ... were going to whistle or blow out a candle. Breathe out (exhale) slowly through your lips for 4 or ...

  20. Determination of regional lung air volume distribution at mid-tidal breathing from computed tomography: a retrospective study of normal variability and reproducibility

    PubMed Central

    2014-01-01

    Background Determination of regional lung air volume has several clinical applications. This study investigates the use of mid-tidal breathing CT scans to provide regional lung volume data. Methods Low resolution CT scans of the thorax were obtained during tidal breathing in 11 healthy control male subjects, each on two separate occasions. A 3D map of air volume was derived, and total lung volume calculated. The regional distribution of air volume from centre to periphery of the lung was analysed using a radial transform and also using one dimensional profiles in three orthogonal directions. Results The total air volumes for the right and left lungs were 1035 +/− 280 ml and 864 +/− 315 ml, respectively (mean and SD). The corresponding fractional air volume concentrations (FAVC) were 0.680 +/− 0.044 and 0.658 +/− 0.062. All differences between the right and left lung were highly significant (p < 0.0001). The coefficients of variation of repeated measurement of right and left lung air volumes and FAVC were 6.5% and 6.9% and 2.5% and 3.6%, respectively. FAVC correlated significantly with lung space volume (r = 0.78) (p < 0.005). FAVC increased from the centre towards the periphery of the lung. Central to peripheral ratios were significantly higher for the right (0.100 +/− 0.007 SD) than the left (0.089 +/− 0.013 SD) (p < 0.0001). Conclusion A technique for measuring the distribution of air volume in the lung at mid-tidal breathing is described. Mean values and reproducibility are described for healthy male control subjects. Fractional air volume concentration is shown to increase with lung size. PMID:25063729

  1. What Causes Bad Breath?

    MedlinePlus

    ... A Week of Healthy Breakfasts Shyness What Causes Bad Breath? KidsHealth > For Teens > What Causes Bad Breath? A A A en español ¿Qué es lo que provoca el mal aliento? Bad breath, or halitosis , can be a major problem, ...

  2. Skinfold thickness is related to cardiovascular autonomic control as assessed by heart rate variability and heart rate recovery.

    PubMed

    Esco, Michael R; Williford, Henry N; Olson, Michele S

    2011-08-01

    The purpose of this study was to determine if heart rate recovery (HRR) and heart rate variability (HRV) are related to maximal aerobic fitness and selected body composition measurements. Fifty men (age = 21.9 ± 3.0 years, height = 180.8 ± 7.2 cm, weight = 80.4 ± 9.1 kg, volunteered to participate in this study. For each subject, body mass index (BMI), waist circumference (WC), and the sum of skinfolds across the chest, abdomen, and thigh regions (SUMSF) were recorded. Heart rate variability (HRV) was assessed during a 5-minute period while the subjects rested in a supine position. The following frequency domain parameters of HRV were recorded: normalized high-frequency power (HFnu), and low-frequency to high-frequency power ratio (LF:HF). To determine maximal aerobic fitness (i.e., VO2max), each subject performed a maximal graded exercise test on a treadmill. Heart rate recovery was recorded 1 (HRR1) and 2 (HRR2) minutes during a cool-down period. Mean VO2max and BMI for all the subjects were 49.5 ± 7.5 ml·kg(-1)·min(-1) and 24.7 ± 2.2 kg·m(-2), respectively. Although VO2max, WC, and SUMSF was each significantly correlated to HRR and HRV, only SUMSF had a significant independent correlation to HRR1, HRR2, HFnu, LF:HF (p < 0.01). The results of the regression procedure showed that SUMSF accounted for the greatest variance in HRR1, HRR2, HFnu, and LF:HF (p < 0.01). The results of this study suggest that cardiovascular autonomic modulation is significantly related to maximal aerobic fitness and body composition. However, SUMSF appears to have the strongest independent relationship with HRR and HRV, compared to other body composition parameters and VO2max.

  3. Permutation entropy analysis of heart rate variability for the assessment of cardiovascular autonomic neuropathy in type 1 diabetes mellitus.

    PubMed

    Carricarte Naranjo, Claudia; Sanchez-Rodriguez, Lazaro M; Brown Martínez, Marta; Estévez Báez, Mario; Machado García, Andrés

    2017-07-01

    Heart rate variability (HRV) analysis is a relevant tool for the diagnosis of cardiovascular autonomic neuropathy (CAN). To our knowledge, no previous investigation on CAN has assessed the complexity of HRV from an ordinal perspective. Therefore, the aim of this work is to explore the potential of permutation entropy (PE) analysis of HRV complexity for the assessment of CAN. For this purpose, we performed a short-term PE analysis of HRV in healthy subjects and type 1 diabetes mellitus patients, including patients with CAN. Standard HRV indicators were also calculated in the control group. A discriminant analysis was used to select the variables combination with best discriminative power between control and CAN patients groups, as well as for classifying cases. We found that for some specific temporal scales, PE indicators were significantly lower in CAN patients than those calculated for controls. In such cases, there were ordinal patterns with high probabilities of occurrence, while others were hardly found. We posit this behavior occurs due to a decrease of HRV complexity in the diseased system. Discriminant functions based on PE measures or probabilities of occurrence of ordinal patterns provided an average of 75% and 96% classification accuracy. Correlations of PE and HRV measures showed to depend only on temporal scale, regardless of pattern length. PE analysis at some specific temporal scales, seem to provide additional information to that obtained with traditional HRV methods. We concluded that PE analysis of HRV is a promising method for the assessment of CAN. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. [SLEEP DISORDERED BREATHING AND EPILEPSY: RELATIONSHIPS AND THERAPEUTIC CONSIDERATIONS].

    PubMed

    Faludi, Béla; Bóné, Beáta; Komoly, Sámuel; Janszky, József

    2015-11-30

    The importance of the sleep related breathing disorders (obstructive sleep apnea syndrome, central sleep apnea, and Cheyne-Stokes breathing) in the pathophysiology crebro- and cardiovascular disorders is well known. The relationship of sleep related breathing abnormalities and epilepsy is also important but underestimated in the daily practice. The relation is bidirectional. The breathing abnormalities in sleep may play important role in generating epileptic seizure, but the adverse effect of seizure and antiepileptic therapy (generation of apneas and hypopneas) may worsen the seizure control. The effect of new therapies (vagal nerve and deep brain stimulation) on the sleep architecture and sleep disordered breathing must be examined and discussed. Here we present a brief case of epileptic patient with deep brain stimulation therapy on sleep as well. The examination of the sleep related breathing abnormalities in epilepsy patient may help improve the effectiveness of antiepileptic therapy.

  5. Effects of nitric oxide synthesis inhibitor or fluoxetine treatment on depression-like state and cardiovascular changes induced by chronic variable stress in rats.

    PubMed

    Almeida, Jeferson; Duarte, Josiane O; Oliveira, Leandro A; Crestani, Carlos C

    2015-01-01

    Comorbidity between mood disorders and cardiovascular disease has been described extensively. However, available antidepressants can have cardiovascular side effects. Treatment with selective inhibitors of neuronal nitric oxide synthase (nNOS) induces antidepressant effects, but whether the antidepressant-like effects of these drugs are followed by cardiovascular changes has not been previously investigated. Here, we tested in male rats exposed to chronic variable stress (CVS) the hypothesis that nNOS blockers are advantageous compared with conventional antidepressants in terms of cardiovascular side effects. We compared the effects of chronic treatment with the preferential nNOS inhibitor 7-nitroindazole (7-NI) with those evoked by the conventional antidepressant fluoxetine on alterations that are considered as markers of depression (immobility in the forced swimming test, FST, decreased body weight gain and increased plasma corticosterone concentration) and cardiovascular changes caused by CVS. Rats were exposed to a 14-day CVS protocol, while being concurrently treated daily with either 7-NI (30 mg/kg) or fluoxetine (10 mg/kg). Fluoxetine and 7-NI prevented the increase in immobility in the FST induced by CVS and reduced plasma corticosterone concentration in stressed rats. Both these treatments also prevented the CVS-evoked reduction of the depressor response to vasodilator agents and baroreflex changes. Fluoxetine and 7-NI-induced cardiovascular changes independent of stress exposure, including cardiac autonomic imbalance, increased intrinsic heart rate and vascular sympathetic modulation, a reduction of the pressor response to vasoconstrictor agents, and impairment of baroreflex activity. Altogether, these findings provide evidence that fluoxetine and 7-NI have similar effects on the depression-like state induced by CVS and on cardiovascular function.

  6. Applications of breath gas analysis in medicine

    NASA Astrophysics Data System (ADS)

    Amann, Anton; Poupart, Guy; Telser, Stefan; Ledochowski, Maximilian; Schmid, Alex; Mechtcheriakov, Sergei

    2004-12-01

    Volatile organic compounds (VOCs) in exhaled breath gas provide valuable information about the subjects' physiological and pathophysiological condition. Proton-transfer-reaction mass spectrometry (PTR-MS) allows rapid and online measurements of these substances. We present results of three studies illustrating the potential of breath gas analysis by PTR-MS in various contexts: long-time online monitoring of VOCs in sleeping subjects suggests that VOC profiles are related to sleep stages. Analysis of VOC concentrations in the breath of carbohydrate malabsorbers emphasizes the role played by bacteria in the gut. Finally, we demonstrate the large intra- and intersubject concentration variability of VOCs by considering one particular mass.

  7. Episodic breathing in alligators: role of sensory feedback.

    PubMed

    Douse, M A; Mitchell, G S

    1992-01-01

    The episodic breathing pattern in many reptiles consists of two or more clustered breaths separated by variable non-ventilatory periods. This pattern is commonly postulated to result from oscillations in lung and/or blood PO2 or PCO2 via chemoreceptor feedback. We tested this hypothesis by monitoring breathing pattern in: (1) awake, undisturbed alligators and (2) sedated alligators (approx. 25 mg/kg pentobarbital, i.p.; 3 days prior to data collection). In sedated alligators, measurements were made: (1) before and after bilateral cervical vagotomy, a procedure that removes peripheral arterial chemoreceptors, CO2-sensitive intrapulmonary chemoreceptors and pulmonary stretch receptors (n = 6); and (2) during unidirectional ventilation (UDV) at high flow rates (greater than 2 L/min), thereby minimizing oscillations in lung and blood PO2 and PCO2 (n = 6). Measurements on sedated alligators were made at 30 and 20 degrees C in each of these conditions. In awake, undisturbed alligators, breathing was typically episodic with 2-7 breaths/cluster, although the pattern was easily altered (increased breaths/cluster) by even seemingly minor disturbances. In sedated alligators, episodic breathing was still evident after vagotomy, but only at increased inspired CO2; at 5% CO2 four of six alligators exhibited episodic breathing consisting of 2-3 breaths/cluster interspersed with occasional single breaths. An episodic breathing pattern was also evident during UDV; at low levels of CO2, 2-4 breaths/cluster interspersed with occasional single breaths were evident in four alligators, while two had 6-8 breaths/cluster. Increasing CO2 in the UDV gas stream generally increased the number of breaths/cluster. After vagotomy, all six alligators could manifest an episodic breathing pattern during UDV in at least one CO2 condition (greater than 2 breaths/cluster interspersed with occasional single breaths). The episodic breathing pattern was very labile, sometimes changing to single breaths

  8. Fetal Cardiac Autonomic Control during Breathing and Non-Breathing Epochs: The Effect of Maternal Exercise

    PubMed Central

    Gustafson, Kathleen M.; May, Linda E.; Yeh, Hung-wen; Million, Stephanie K.; Allen, John J. B.

    2013-01-01

    We explored whether maternal exercise during pregnancy moderates the effect of fetal breathing movements on fetal cardiac autonomic control assessed by metrics of heart rate (HR) and heart rate variability (HRV). Thirty women were assigned to Exercise or Control group (n=15/group) based on the modifiable physical activity questionnaire (MPAQ). Magnetocardiograms (MCG) were recorded using a dedicated fetal biomagnetometer. Periods of fetal breathing activity and apnea were identified using the fetal diaphragmatic magnetomyogram (dMMG) as a marker. MCG R-waves were marked. Metrics of fetal HR and HRV were compared using 1 breathing and1 apneic epoch/fetus. The main effects of group (Exercise vs. Control) and condition (Apnea vs. Breathing) and their interactions were explored. Fetal breathing resulted in significantly lower fetal HR and higher vagally-mediated HRV. Maternal exercise resulted in significantly lower fetal HR, higher total HRV and vagally-mediated HRV with no difference in frequency band ratios. Significant interactions between maternal exercise and fetal breathing were found for metrics summarizing total HRV and a parasympathetic metric. Post hoc comparison showed no group difference during fetal apnea. Fetal breathing was associated with a loss of Total HRV in the Control group and no difference in the Exercise group. Both groups show enhanced vagal function during fetal breathing; greater in the Exercise group. During in utero breathing movements, the fetus of the exercising mother has enhanced cardiac autonomic function that may give the offspring an adaptive advantage. PMID:22264436

  9. Fetal cardiac autonomic control during breathing and non-breathing epochs: the effect of maternal exercise.

    PubMed

    Gustafson, Kathleen M; May, Linda E; Yeh, Hung-wen; Million, Stephanie K; Allen, John J B

    2012-07-01

    We explored whether maternal exercise during pregnancy moderates the effect of fetal breathing movements on fetal cardiac autonomic control assessed by metrics of heart rate (HR) and heart rate variability (HRV). Thirty women were assigned to Exercise or Control group (n=15/group) based on the modifiable physical activity questionnaire (MPAQ). Magnetocardiograms (MCG) were recorded using a dedicated fetal biomagnetometer. Periods of fetal breathing activity and apnea were identified using the fetal diaphragmatic magnetomyogram (dMMG) as a marker. MCG R-waves were marked. Metrics of fetal HR and HRV were compared using 1 breathing and 1 apneic epoch/fetus. The main effects of group (Exercise vs. Control) and condition (Apnea vs. Breathing) and their interactions were explored. Fetal breathing resulted in significantly lower fetal HR and higher vagally-mediated HRV. Maternal exercise resulted in significantly lower fetal HR, higher total HRV and vagally-mediated HRV with no difference in frequency band ratios. Significant interactions between maternal exercise and fetal breathing were found for metrics summarizing total HRV and a parasympathetic metric. Post hoc comparison showed no group difference during fetal apnea. Fetal breathing was associated with a loss of Total HRV in the Control group and no difference in the Exercise group. Both groups show enhanced vagal function during fetal breathing; greater in the Exercise group. During in utero breathing movements, the fetus of the exercising mother has enhanced cardiac autonomic function that may give the offspring an adaptive advantage.

  10. Clinical Variability in Cardiovascular Disease Risk Factor Screening and Management in Adolescent and Young Adult Women with Polycystic Ovary Syndrome.

    PubMed

    Baer, Tamara E; Milliren, Carly E; Walls, Courtney; DiVasta, Amy D

    2015-10-01

    To review the clinical presentation, evaluation, and management of normal-weight (NW), overweight (OW), and obese (OB) adolescent and young adult women with polycystic ovary syndrome (PCOS) during a 2-year follow-up. Retrospective chart review. One hundred seventy-three adolescent and young adult women, aged 12-22 years, diagnosed with PCOS. Demographic, health data, and laboratory measures were abstracted from 3 clinic visits: baseline and 1- and 2-year follow-up. Subjects were classified as NW, OW, or OB. Longitudinal data were analyzed using repeated-measures analysis of variance. Body mass index, self-reported concerns, and lifestyle changes. Most patients (73%) were OW or OB. Family history of type 2 diabetes was greater in OW (38%) and OB (53%) patients compared with NW (22%) patients (P = .002). Acanthosis nigricans was identified in OW (62%) and OB (21%) patients but not in NW patients (0%; P < .001). OW and OB patients had higher fasting insulin (P < .001) and lower high-density lipoprotein cholesterol (P = .005) levels than NW patients, although screening rates were low. Body mass index Z-scores decreased in both OW and OB patients over time (0.07 unit/yr, P < .001). Most patients with PCOS were OW or OB. Substantial clinical variability existed in cardiovascular disease (CVD) screening; among those screened, OW and OB patients had greater CVD risk factors. Despite self-reported concerns about weight and diabetes risk among OW and OB patients, no clinically significant change in body mass index percentile occurred. Evidence-based interventions and recommendations for screening tests are needed to address CVD risk in adolescents and young adults with PCOS. Copyright © 2015 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

  11. Control of breathing in the echidna (Tachyglossus aculeatus) during hibernation.

    PubMed

    Nicol, Stewart; Andersen, Niels A

    2003-12-01

    Resting non-hibernating echidnas are characterised by low metabolic rates, but also have a very low respiratory frequency and a variable respiratory minute volume, often resulting in low levels of arterial O(2) and high CO(2). As the echidna lies at one physiological extreme among the hibernators, in terms of its large size and low metabolism and ventilatory requirement when not hibernating, a study of control of breathing during hibernation in echidnas should provide a useful test of the generality of various models. We used non-invasive techniques to study breathing patterns and the control of ventilation in 6 echidnas. Hibernating echidnas (T(b) range 7-10 degrees C) showed episodic breathing with bursts of breaths (average 36+/-16 breaths in 24+/-5 min) followed by a period of apnea (76+/-17 min) then a series (8+/-4) of slow breaths at 14+/-1 min intervals leading up to the next burst. Increasing CO(2) levels in the inspired air increased the number of breaths in a burst, eventually leading to continuous breathing. Inter burst breaths were controlled by O(2): hypoxia increased inter burst breaths, and decreased burst length, while hyperoxia abolished inter burst breaths and increased the apneic period. Overall, while CO(2) was a strong respiratory stimulus in hibernating echidnas, O(2) had little effect on total ventilation, but did have a strong effect on the breathing pattern.

  12. Highly variable expression of virus receptors in the human cardiovascular system. Implications for cardiotropic viral infections and gene therapy.

    PubMed

    Poller, W; Fechner, H; Noutsias, M; Tschoepe, C; Schultheiss, H-P

    2002-12-01

    analysis of the cardiovascular expression patterns of receptors for other potentially cardiotropic viruses (CMV, EBV, HIV, HHV-6, Parvo-B19, etc.) should lead to a better understanding of individual risk factors for viral heart diseases and of their highly variable clinical courses, and offer new therapeutic options.

  13. Effects of respiratory time ratio on heart rate variability and spontaneous baroreflex sensitivity.

    PubMed

    Wang, Yong-Ping; Kuo, Terry B J; Lai, Chun-Ting; Chu, Jui-Wen; Yang, Cheryl C H

    2013-12-01

    Paced breathing is a frequently performed technique for cardiovascular autonomic studies. The relative timing of inspiration and expiration during paced breathing, however, is not consistent. We, therefore, examined whether indexes of heart rate variability and spontaneous baroreflex sensitivity would be affected by the respiratory time ratio that is set. We studied 14 healthy young adults who controlled their breathing rates to either 0.1 or 0.25 Hz in the supine and sitting positions. Four different inspiratory-to-expiratory time ratios (I/E) (uncontrolled, 1:1, 1:2, and 1:3) were examined for each condition in a randomized order. The results showed spectral indexes of heart rate variability and spontaneous baroreflex sensitivity were not influenced by the I/E that was set during paced breathing under supine and sitting positions. Porta's and Guzik's indexes of heart rate asymmetry were also not different at various I/E during 0.1-Hz breathing, but had larger values at 1:1 during 0.25-Hz breathing, although significant change was found in the sitting position only. At the same time, Porta's and Guzik's indexes obtained during 0.1-Hz breathing were greater than during 0.25-Hz breathing in both positions. The authors suggest that setting the I/E during paced breathing is not necessary when measuring spectral indexes of heart rate variability and spontaneous baroreflex sensitivity under the conditions used in this study. The necessity of paced breathing for the measurement of heart rate asymmetry, however, requires further investigation.

  14. Information dynamics in cardiorespiratory analyses: application to controlled breathing.

    PubMed

    Widjaja, Devy; Faes, Luca; Montalto, Alessandro; Van Diest, Ilse; Marinazzo, Daniele; Van Huffel, Sabine

    2014-01-01

    Voluntary adjustment of the breathing pattern is widely used to deal with stress-related conditions. In this study, effects of slow and fast breathing with a low and high inspiratory to expiratory time on heart rate variability (HRV) are evaluated by means of information dynamics. Information transfer is quantified both as the traditional transfer entropy as well as the cross entropy, where the latter does not condition on the past of HRV, thereby taking the highly unidirectional relation between respiration and heart rate into account. The results show that the cross entropy is more suited to quantify cardiorespiratory information transfer as this measure increases during slow breathing, indicating the increased cardiorespiratory coupling and suggesting the shift towards vagal activation during slow breathing. Additionally we found that controlled breathing, either slow or fast, results as well in an increase in cardiorespiratory coupling, compared to spontaneous breathing, which demonstrates the beneficial effects of instructed breathing.

  15. Cardiovascular autonomic neuropathy in patients with diabetes mellitus.

    PubMed

    Lozano, T; Ena, J

    Cardiovascular autonomic neuropathy associated with diabetes mellitus is caused by an impairment of the autonomic system. The prevalence of this condition ranges from 20% to 65%, depending on the duration of the diabetes mellitus. Clinically, the autonomic function disorder is associated with resting tachycardia, exercise intolerance, orthostatic hypotension, intraoperative cardiovascular instability, silent myocardial ischemia and increased mortality. For the diagnosis, the integrity of the parasympathetic and sympathetic nervous system is assessed. Parasympathetic activity is examined by measuring heart rate variability in response to deep breathing, standing and the Valsalva manoeuvre. Sympathetic integrity is examined by measuring blood pressure in response to standing and isometric exercise. The treatment includes the metabolic control of diabetes mellitus and of the cardiovascular risk factors. Treating symptoms such as orthostatic hypotension requires special attention.

  16. Drinking influences exhaled breath condensate acidity.

    PubMed

    Kullmann, Tamás; Barta, Imre; Antus, Balázs; Horváth, Ildikó

    2008-01-01

    Exhaled breath condensate analysis is a developing method for investigating airway pathology. Impact of food and drink on breath condensate composition has not been systematically addressed. The aim of the study was to follow exhaled breath condensate pH after drinking an acidic and a neutral beverage. Breath condensate, capillary blood, and urine of 12 healthy volunteers were collected before and after drinking either 1 l of coke or 1 l of mineral water. The pH of each sample was determined with a blood gas analyzer. The mean difference between the pH of two breath condensate samples collected within 15 min before drinking was 0.13+/-0.03. Condensate pH decreased significantly from 6.29+/-0.02 to 6.24+/-0.02 (p<0.03) after drinking coke and from 6.37+/-0.03 to 6.22+/-0.04 (p<0.003) after drinking water. Drinking coke induced significant changes in blood and urine pH as well. Drinking influences exhaled breath condensate composition and may contribute to the variability of exhaled breath condensate pH.

  17. Decreased chewing activity during mouth breathing.

    PubMed

    Hsu, H-Y; Yamaguchi, K

    2012-08-01

    This study examined the effect of mouth breathing on the strength and duration of vertical effect on the posterior teeth using related functional parameters during 3 min of gum chewing in 39 nasal breathers. A CO(2) sensor was placed over the mouth to detect expiratory airflow. When no airflow was detected from the mouth throughout the recording period, the subject was considered a nasal breather and enrolled in the study. Electromyographic (EMG) activity was recorded during 3 min of gum chewing. The protocol was repeated with the nostrils occluded. The strength of the vertical effect was obtained as integrated masseter muscle EMG activity, and the duration of vertical effect was also obtained as chewing stroke count, chewing cycle variation and EMG activity duration above baseline. Baseline activity was obtained from the isotonic EMG activity during jaw movement at 1.6 Hz without making tooth contact. The duration represented the percentage of the active period above baseline relative to the 3-min chewing period. Paired t-test and repeated analysis of variance were used to compare variables between nasal and mouth breathing. The integrated EMG activity and the duration of EMG activity above baseline, chewing stroke count and chewing cycle significantly decreased during mouth breathing compared with nasal breathing (P<0.05). Chewing cycle variance during mouth breathing was significantly greater than nasal breathing (P<0.05). Mouth breathing reduces the vertical effect on the posterior teeth, which can affect the vertical position of posterior teeth negatively, leading to malocclusion.

  18. Visit-to-visit variability of blood pressure and cardiovascular outcomes in patients with stable coronary heart disease. Insights from the STABILITY trial.

    PubMed

    Vidal-Petiot, Emmanuelle; Stebbins, Amanda; Chiswell, Karen; Ardissino, Diego; Aylward, Philip E; Cannon, Christopher P; Ramos Corrales, Marco A; Held, Claes; López-Sendón, José Luis; Stewart, Ralph A H; Wallentin, Lars; White, Harvey D; Steg, Philippe Gabriel

    2017-05-27

    To study the relation between visit-to-visit variability of blood pressure (BP) and cardiovascular risk in patients with stable coronary heart disease. In 15 828 patients from the STABILITY trial (darapladib vs. placebo in patients with established coronary heart disease), BP variability was assessed by the standard deviation (SD) of systolic BP, the SD of diastolic BP, maximum BP, and minimum BP, from 5 measurements (baseline and months 1, 3, 6, and 12) during the first year after randomisation. Mean (SD) average BP during the first year of study was 131.0 (13.7) mmHg over 78.3 (8.3) mmHg. Mean (SD) of the visit-to-visit SD was 9.8 (4.8) mmHg for systolic and 6.3 (3.0) mmHg for diastolic BP. During the subsequent median follow-up of 2.6 years, 1010 patients met the primary endpoint, a composite of time to cardiovascular death, myocardial infarction, or stroke. In Cox regression models adjusted for average BP during first year of study, baseline vascular disease, treatment, renal function and cardiovascular risk factors, the primary endpoint was associated with SD of systolic BP (hazard ratio for highest vs. lowest tertile, 1.30, 95% CI 1.10-1.53, P = 0.007), and with SD of diastolic BP (hazard ratio for highest vs. lowest tertile, 1.38, 95% CI 1.18-1.62, P < 0.001). Peaks and troughs in BP were also independently associated with adverse events. In patients with stable coronary heart disease, higher visit-to-visit variabilities of both systolic and diastolic BP are strong predictors of increased risk of cardiovascular events, independently of mean BP.

  19. Effects of acepromazine and trazodone on anesthetic induction dose of propofol and cardiovascular variables in dogs undergoing general anesthesia for orthopedic surgery.

    PubMed

    Murphy, Lindsey A; Barletta, Michele; Graham, Lynelle F; Reichl, Lorna J; Duxbury, Margaret M; Quandt, Jane E

    2017-02-15

    OBJECTIVE To compare the doses of propofol required to induce general anesthesia in dogs premedicated with acepromazine maleate or trazodone hydrochloride and compare the effects of these premedicants on cardiovascular variables in dogs anesthetized for orthopedic surgery. DESIGN Prospective, randomized study. ANIMALS 30 systemically healthy client-owned dogs. PROCEDURES 15 dogs received acepromazine (0.01 to 0.03 mg/kg [0.005 to 0.014 mg/lb], IM) 30 minutes before anesthetic induction and 15 received trazodone (5 mg/kg [2.27 mg/lb] for patients > 10 kg or 7 mg/kg [3.18 mg/lb] for patients ≤ 10 kg, PO) 2 hours before induction. Both groups received morphine sulfate (1 mg/kg [0.45 mg/lb], IM) 30 minutes before induction. Anesthesia was induced with propofol (4 to 6 mg/kg [1.82 to 2.73 mg/lb], IV, to effect) and maintained with isoflurane or sevoflurane in oxygen. Bupivacaine (0.5 mg/kg [0.227 mg/lb]) and morphine (0.1 mg/kg [0.045 mg/lb]) were administered epidurally. Dogs underwent tibial plateau leveling osteotomy (n = 22) or tibial tuberosity advancement (8) and were monitored throughout anesthesia. Propofol induction doses and cardiovascular variables (heart rate and systemic, mean, and diastolic arterial blood pressures) were compared between groups. RESULTS The mean dose of propofol required for anesthetic induction and all cardiovascular variables evaluated did not differ between groups. Intraoperative hypotension developed in 6 and 5 dogs of the acepromazine and trazodone groups, respectively; bradycardia requiring intervention developed in 3 dogs/group. One dog that received trazodone had priapism 24 hours later and was treated successfully. No other adverse effects were reported. CONCLUSIONS AND CLINICAL RELEVANCE At the described dosages, cardiovascular effects of trazodone were similar to those of acepromazine in healthy dogs undergoing anesthesia for orthopedic surgery.

  20. Phase synchronization of oscillations in cardiovascular and respiratory systems in humans

    NASA Astrophysics Data System (ADS)

    Tankanag, Arina V.; Grinevich, Andrey A.; Tikhonova, Irina V.; Chaplygina, Alina V.; Chemeris, Nikolay K.

    2017-04-01

    Phase synchronization between blood flow oscillations of left and right forearm skin sites, heart rate variability (HRV) and breath rate were studied from healthy volunteers at rest. The degree of synchronization between the phases of the analyzed signals was estimated from the value of the wavelet phase coherence. High medians of values of phase wavelet coherence function were obtained for the endothelial, neurogenic, myogenic and cardiac intervals. Significant phase synchronization were demonstrated between HRV and skin blood flow oscillations in both left and right forearms in a wide frequency range from 0.04 to 0.4 Hz. Six participants exhibited low phase synchronization (< 0.5) between the breath rate and HRV, while nine participants had high phase synchronization (> 0.5). This distribution was not affected by the sex or sympathovagal status of volunteers. Participants with low phase synchronization between breath rate and HRV featured low phase synchronization (< 0.5) between breath rate and blood flow oscillations in both forearms. Contrariwise, in subjects with high phase synchronization between respiratory rhythm and HRV both low and high phase synchronization between breath rate and blood flow oscillations in both forearms was observed. The results obtained allow us to suggest that the organism possesses a mechanism mediating the synchronization of blood flow oscillations in the skin microvasculature with all other periodical processes across the cardiovascular system, in particular, with HRV and breath rate over a wide frequency range.

  1. Breathing-metabolic simulator

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G.; Hendricks, C. M.; Morison, W. B.

    1972-01-01

    Breathing-metabolic simulator was developed to be used for evaluation of life support equipment. Apparatus simulates human breathing rate and controls temperature and humidity of exhaled air as well as its chemical composition. All functions are designed to correspond to various degrees of human response.

  2. From breathing to respiration.

    PubMed

    Fitting, Jean-William

    2015-01-01

    The purpose of breathing remained an enigma for a long time. The Hippocratic school described breathing patterns but did not associate breathing with the lungs. Empedocles and Plato postulated that breathing was linked to the passage of air through pores of the skin. This was refuted by Aristotle who believed that the role of breathing was to cool the heart. In Alexandria, breakthroughs were accomplished in the anatomy and physiology of the respiratory system. Later, Galen proposed an accurate description of the respiratory muscles and the mechanics of breathing. However, his heart-lung model was hampered by the traditional view of two non-communicating vascular systems - veins and arteries. After a period of stagnation in the Middle Ages, knowledge progressed with the discovery of pulmonary circulation. The comprehension of the purpose of breathing progressed by steps thanks to Boyle and Mayow among others, and culminated with the contribution of Priestley and the discovery of oxygen by Lavoisier. Only then was breathing recognized as fulfilling the purpose of respiration, or gas exchange. A century later, a controversy emerged concerning the active or passive transfer of oxygen from alveoli to the blood. August and Marie Krogh settled the dispute, showing that passive diffusion was sufficient to meet the oxygen needs.

  3. What Controls Your Breathing?

    MedlinePlus

    ... Explore How the Lungs Work What Are... The Respiratory System What Happens When You Breathe What Controls Your Breathing Lung Diseases & Conditions Clinical Trials Links Related Topics Asthma Bronchitis COPD How the Heart Works Respiratory Failure Send a link to NHLBI to someone ...

  4. Rate of change in adiposity and its relationship to concomitant changes in cardiovascular risk variables among biracial (black-white) children and young adults: The Bogalusa Heart Study.

    PubMed

    Srinivasan, S R; Myers, L; Berenson, G S

    2001-03-01

    To assess the annual rate of change in adiposity and its relationship to concomitant changes in cardiovascular risk variables during childhood and young adulthood, serial data on black and white children (n = 3,459; initial and follow-up mean age, 8.1 and 14.4 years) and young adults (n = 1,263; initial and follow-up mean age, 22.5 and 30.9 years) enrolled in the Bogalusa Heart Study were examined. Body mass index (BMI) and sum of subscapular and triceps skinfolds were used as indicators of adiposity. In addition, measurements were made of systolic and diastolic blood pressure and fasting levels of low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, insulin, and glucose. Annualized rate of change for each variable was estimated. The rate of increase in adiposity was significantly more pronounced during childhood versus adulthood. Race difference (blacks > whites) in the rate of increase in adiposity was seen only among females. Females, black females in particular, displayed greater rate of increase in adiposity than males. In a multivariate analysis, the rate of increase in adiposity was related independently of baseline age and baseline adiposity to adverse changes in measured cardiovascular risk variables, except glucose. Many of these associations were modulated significantly by race, sex, and age group. The impact was relatively greater for blood pressure and LDL cholesterol in adults and for triglycerides in children. The changes in blood pressure, LDL cholesterol, and HDL cholesterol were greater in whites, while the rate of increase in insulin was greater in blacks. Females displayed greater changes in blood pressure, HDL cholesterol, and insulin. On the other hand, the rate of increase in triglycerides was greater in males. These results indicate that increases in adiposity regardless of initial status of body fatness alter cardiovascular risk variables towards increased risk beginning in childhood, and

  5. Comparison of respiratory function during TIVA (romifidine, ketamine, midazolam) and isoflurane anaesthesia in spontaneously breathing ponies Part I: blood gas analysis and cardiorespiratory variables.

    PubMed

    Steblaj, Barbara; Schauvliege, Stijn; Pavlidou, Kiriaki; Gasthuys, Frank; Savvas, Ioannis; Duchateau, Luc; Kowalczyk, Lidia; Kowalczk, Lidia; Moens, Yves

    2014-11-01

    To compare pulmonary function and gas exchange in ponies during maintenance of anaesthesia with isoflurane or by a total intravenous anaesthesia (TIVA) technique. Experimental, cross-over study. Six healthy ponies weighing mean 286 (range 233-388) ± SD 61 kg, age 13 (9-16) ± 3 years. The ponies were anaesthetized twice, a minimum of two weeks apart. Following sedation with romifidine [80 μg kg(-1) intravenously (IV)], anaesthesia was induced IV with midazolam (0.06 mg kg(-1)) and ketamine (2.5 mg kg(-1), then maintained either with inhaled isoflurane (Fe'Iso = 1.1 vol%) (T-ISO) or an IV infusion of romifidine (120 μg kg(-1) hour(-1)), midazolam (0.09 mg kg(-1) hour(-1) IV) and ketamine (3.3 mg kg(-1) hour(-1)) (T-TIVA). Ponies were placed in lateral recumbency. Breathing was spontaneous and Fi'O(2) 60%. After an instrumentation/stabilisation period of 30 minutes, arterial and mixed venous blood samples were taken simultaneously every 10 minutes for 60 minutes and analysed immediately. Oxygen extraction ratio (O(2)ER) and venous admixture were calculated. Tidal volume (TV), minute volume (MV), respiratory rate (f(R)), packed cell volume (PCV), arterial blood pressure and heart rate (HR) were measured and recorded. Data were analysed with mixed model anova (α = 0.05). Treatments were compared overall and at two selected time points (T30 and T60) using Bonferroni correction. Arterial and mixed venous partial pressures of O(2) and CO(2), and TV were significantly lower and MV and f(R) were higher in T-TIVA compared to T-ISO. Venous admixture did not differ between treatments. O(2) R was significantly higher in T-TIVA. Mean arterial pressure was higher and HR was lower in T-TIVA compared to T-ISO. Whilst arterial CO(2) was within an acceptable range during both protocols, the impairment of oxygenation was more pronounced with the T-TIVA evidenced by lower arterial and venous oxygen partial pressures. © 2014 Association of Veterinary Anaesthetists and the American

  6. Cardiovascular pharmacogenetics.

    PubMed

    Myburgh, Renier; Hochfeld, Warren E; Dodgen, Tyren M; Ker, James; Pepper, Michael S

    2012-03-01

    Human genetic variation in the form of single nucleotide polymorphisms as well as more complex structural variations such as insertions, deletions and copy number variants, is partially responsible for the clinical variation seen in response to pharmacotherapeutic drugs. This affects the likelihood of experiencing adverse drug reactions and also of achieving therapeutic success. In this paper, we review key studies in cardiovascular pharmacogenetics that reveal genetic variations underlying the outcomes of drug treatment in cardiovascular disease. Examples of genetic associations with drug efficacy and toxicity are described, including the roles of genetic variability in pharmacokinetics (e.g. drug metabolizing enzymes) and pharmacodynamics (e.g. drug targets). These findings have functional implications that could lead to the development of genetic tests aimed at minimizing drug toxicity and optimizing drug efficacy in cardiovascular medicine.

  7. Effect of Pre- and Postoperative Phenylbutazone and Morphine Administration on the Breathing Response to Skin Incision, Recovery Quality, Behavior, and Cardiorespiratory Variables in Horses Undergoing Fetlock Arthroscopy: A Pilot Study

    PubMed Central

    Conde Ruiz, Clara; Cruz Benedetti, Inga-Catalina; Guillebert, Isabelle; Portier, Karine Genevieve

    2015-01-01

    This prospective blinded randomized study aimed to determine whether the timing of morphine and phenylbutazone administration affects the breathing response to skin incision, recovery quality, behavior, and cardiorespiratory variables in horses undergoing fetlock arthroscopy. Ten Standardbred horses were premedicated with acepromazine (0.04 mg kg−1 IM) and romifidine (0.04 mg kg−1 IV). Anesthesia was induced with diazepam (0.05 mg kg−1) and ketamine (2.2 mg kg−1) IV at T0. Horses in group PRE (n = 5) received morphine (0.1 mg kg−1) and phenylbutazone (2.2 mg kg−1) IV after induction and an equivalent amount of saline after surgery. Horses in group POST (n = 5) received the inversed treatment. Anesthesia was maintained with isoflurane 2% in 100% oxygen. Hypotension (mean arterial pressure <60 mmHg) was treated with dobutamine. All horses breathed spontaneously. Dobutamine requirements, respiratory rate (fR), heart rate (HR), mean arterial blood pressure, end-tidal CO2, inspired (i) and expired (e) tidal and minute volume (VT and V˙E), inspiratory time (IT), and the inspiratory gas flow (VTi/IT) were measured every 5 min. Data were averaged during four 15 min periods before (P1 and P2) and after the incision (P3 and P4). Serial blood–gas analyses were also performed. Recoveries were unassisted, video recorded, and scored by three anesthetists blinded to the treatment. The postoperative behavior of the horses (25 demeanors), HR, and fR were recorded at three time points before induction (T0–24 h, T0–12 h, and T0–2 h) and six time points after recovery (TR) (TR + 2, 4, 6, 12, 24, 48 h). Data were compared between groups using a Wilcoxon test and within groups using a Friedman test or a Kruskal–Wallis signed-rank test when applicable. Tidal volumes (VTe and VTi) were higher in PRE than in POST during all the considered periods but the difference between groups was only significant during P2 (VTe in mL kg−1

  8. Sleep Disordered Breathing and Hypertension: Does Self-Reported Sleepiness Modify the Association?

    PubMed Central

    Kapur, Vishesh K.; Resnick, Helaine E.; Gottlieb, Daniel J.

    2008-01-01

    Study Objectives: Epidemiologic studies that demonstrate increased risk of hypertension in persons with sleep disordered breathing indicate that only a minority of these persons report significant subjective sleepiness. Studies also suggest that presence of self-reported sleepiness may identify a subset of persons with sleep disordered breathing who are at greatest risk of cardiovascular sequelae, including hypertension. We explore whether self-reported sleepiness modifies the relationship between sleep disordered breathing and prevalent hypertension. Design: Cross-sectional Setting: Multicenter study Participants: 6046 subjects from the Sleep Heart Health Study Measurements: Polysomnography, systolic and diastolic blood pressure, antihypertensive medication use, questionnaire determined excessive sleepiness and Epworth Sleepiness Scale, and covariates. Results: The odds of hypertension at higher apnea hypopnea index categories were larger in participants identified as sleepy based on responses to a frequency of sleepiness question or the Epworth score. For example, for those with AHI ≥30 compared to AHI <1.5, the adjusted odds ratio for hypertension was 2.83 (1.33–6.04) among those reporting sleepiness ≥5 days per month, but only 1.22 (0.89–1.68) among those reporting less frequent daytime sleepiness. In adjusted logistic regression models, there was statistical evidence for effect modification by frequency of sleepiness (P = 0.033) of the association between apnea hypopnea index and hypertension. In adjusted models that included the Epworth score as a continuous variable, the interaction term fell slightly short of statistical significance (β = 0.010, P = 0.07). Conclusion: This study finds that the association of sleep disordered breathing with hypertension is stronger in individuals who report daytime sleepiness than in those who do not. Citation: Kapur VK; Resnick HE; Gottlieb DJ. Sleep disordered breathing and hypertension: does self

  9. Breathing metabolic simulator.

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G., Jr.; Hendricks, C. M.; Morison, W. B.

    1971-01-01

    Description of a device for simulation of the human breathing and metabolic parameters required for the evaluation of respiratory diagnostic, monitoring, support and resuscitation equipment. The remotely controlled device allows wide variations in breathing rate and depth, breath velocity contour, oxygen uptake and carbon dioxide release to simulate conditions from sleep to hard work, with respiration exchange ratios ranging from hypoventilation to hyperventilation. It also reduces the cost of prolonged testing when simulation chambers with human subjects require three shifts of crews and standby physicians. Several block diagrams of the device and subsystems are given.

  10. Breathing metabolic simulator.

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G., Jr.; Hendricks, C. M.; Morison, W. B.

    1971-01-01

    Description of a device for simulation of the human breathing and metabolic parameters required for the evaluation of respiratory diagnostic, monitoring, support and resuscitation equipment. The remotely controlled device allows wide variations in breathing rate and depth, breath velocity contour, oxygen uptake and carbon dioxide release to simulate conditions from sleep to hard work, with respiration exchange ratios ranging from hypoventilation to hyperventilation. It also reduces the cost of prolonged testing when simulation chambers with human subjects require three shifts of crews and standby physicians. Several block diagrams of the device and subsystems are given.

  11. [Prevalence of mouth breathing in children from an elementary school].

    PubMed

    Felcar, Josiane Marques; Bueno, Izabele Rafael; Massan, Ana Carolina Silva; Torezan, Roberta Pereira; Cardoso, Jefferson Rosa

    2010-03-01

    The objective of this article is to identify the prevalence of mouth breathing in children from an elementary school. 496 questionnaires were answered by 1st and 4th grade children's parents or sponsors in order to identify mouth-breathing. There were questions about habits, sleeping, behavior, eating, personal care and breathing. Mann-Whitney and the Chi-square tests were used to compare the variables between mouth-breathing and nose-breathing among the groups. To measure the exposure effect of the explanatory variables on mouth breathing, the test of logistic regression was used and its magnitude was calculated through Odds Ratio. The statistical significance was set at 5%, and the rate of returned questionnaires was 84.5%. The prevalence of the mouthbreathing over this population was 56.8%. The average age was 7 years old (6-9). There was no significant statistical difference between genders, considering 49.1% male and 50.9% female. The final model of logistic regression identified the variables dribble, sleeps well (negative association) and snores as factors that predict the occurrence of the mouth-breathing. The prevalence of mouthbreathing was similar to related in the literature. The variables dribble, sleeps well (negative association) and snores may be factors that predict the occurrence of mouth-breathing.

  12. Spectral analysis of resting cardiovascular variables and responses to oscillatory LBNP before and after 6 degree head dowm bedrest

    NASA Technical Reports Server (NTRS)

    Knapp, Charles F.; Evans, J. M.; Patwardhan, A.; Levenhagen, D.; Wang, M.; Charles, John B.

    1991-01-01

    A major focus of our research program is to develop noninvasive procedures for determining changes in cardiovascular function associated with the null gravity environment. We define changes in cardiovascular function to be (1) the result of the regulatory system operating at values different from 'normal' but with an overall control system basically unchanged by the null gravity exposure, or (2) the result of operating with a control system that has significantly different regulatory characteristics after an exposure. To this end, we have used a model of weightlessness that consisted of exposing humans to 2 hrs. in the launch position, followed by 20 hrs. of 6 deg head down bedrest. Our principal objective was to use this model to measure cardiovascular responses to the 6 deg head down bedrest protocol and to develop the most sensitive 'systems identification' procedure for indicating change. A second objective, related to future experiments, is to use the procedure in combination with experiments designed to determine the degree to which a regulatory pathway has been altered and to determine the mechanisms responsible for the changes.

  13. Model-free causality analysis of cardiovascular variability detects the amelioration of autonomic control in Parkinson's disease patients undergoing mechanical stimulation.

    PubMed

    Bassani, Tito; Bari, Vlasta; Marchi, Andrea; Tassin, Stefano; Dalla Vecchia, Laura; Canesi, Margherita; Barbic, Franca; Furlan, Raffaello; Porta, Alberto

    2014-07-01

    We tested the hypothesis that causality analysis, applied to the spontaneous beat-to-beat variability of heart period (HP) and systolic arterial pressure (SAP), can identify the improvement of autonomic control linked to plantar mechanical stimulation in patients with Parkinson's disease (PD). A causality index, measuring the strength of the association from SAP to HP variability, and derived according to the Granger paradigm (i.e. SAP causes HP if the inclusion of SAP into the set of signals utilized to describe cardiovascular interactions improves the prediction of HP series), was calculated using both linear model-based (MB) and nonlinear model-free (MF) approaches. Univariate HP and SAP variability indices in time and frequency domains, and bivariate descriptors of the HP-SAP variability interactions were computed as well. We studied ten PD patients (age range: 57-78 years; Hoehn-Yahr scale: 2-3; six males, four females) without orthostatic hypotension or symptoms of orthostatic intolerance and 'on-time' according to their habitual pharmacological treatment. PD patients underwent recordings at rest in a supine position and during a head-up tilt before, and 24 h after, mechanical stimulation was applied to the plantar surface of both feet. The MF causality analysis indicated a greater involvement of baroreflex in regulating HP-SAP variability interactions after mechanical stimulation. Remarkably, MB causality and more traditional univariate or bivariate techniques could not detect changes in cardiovascular regulation after mechanical stimulation, thus stressing the importance of accounting for nonlinear dynamics in PD patients. Due to the higher statistical power of MF causality we suggest its exploitation to monitor the baroreflex control improvement in PD patients, and we encourage the clinical application of the Granger causality approach to evaluate the modification of the autonomic control in relation to the application of a pharmacological treatment, a

  14. The effect of mouth breathing on chewing efficiency.

    PubMed

    Nagaiwa, Miho; Gunjigake, Kaori; Yamaguchi, Kazunori

    2016-03-01

    To examine the effect of mouth breathing on chewing efficiency by evaluating masticatory variables. Ten adult nasal breathers with normal occlusion and no temporomandibular dysfunction were selected. Subjects were instructed to bite the chewing gum on the habitual side. While breathing through the mouth and nose, the glucide elution from the chewing gum, number of chewing strokes, duration of chewing, and electromyography (EMG) activity of the masseter muscle were evaluated as variables of masticatory efficiency. The durations required for the chewing of 30, 60, 90, 120, 180, and 250 strokes were significantly (P < .05) longer while breathing through the mouth. There was no significant difference in the glucide elution rate (%) for each chewing stroke between nose and mouth breathings. The glucide elution rates for 1- and 3-minute chewing were significantly (P < .05) lower while breathing through the mouth. However, there was no significant difference in the glucide elution rate for 5-minute chewing between nose and mouth breathings. While chewing for 1, 3, and 5 minutes, the chewing stroke and EMG activity of the masseter muscle were significantly (P < .05) lower during mouth breathing. It takes a longer amount of time to complete chewing to obtain higher masticatory efficiency when breathing through the mouth. Therefore, mouth breathing will decrease the masticatory efficiency if the duration of chewing is restricted in everyday life.

  15. Pulse pressure variation to predict fluid responsiveness in spontaneously breathing patients: tidal vs. forced inspiratory breathing.

    PubMed

    Hong, D M; Lee, J M; Seo, J H; Min, J J; Jeon, Y; Bahk, J H

    2014-07-01

    We evaluated whether pulse pressure variation can predict fluid responsiveness in spontaneously breathing patients. Fifty-nine elective thoracic surgical patients were studied before induction of general anaesthesia. After volume expansion with hydroxyethyl starch 6 ml.kg(-1) , patients were defined as responders by a ≥ 15% increase in the cardiac index. Haemodynamic variables were measured before and after volume expansion and pulse pressure variations were calculated during tidal breathing and during forced inspiratory breathing. Median (IQR [range]) pulse pressure variation during forced inspiratory breathing was significantly higher in responders (n = 29) than in non-responders (n = 30) before volume expansion (18.2 (IQR 14.7-18.2 [9.3-31.3])% vs. 10.1 (IQR 8.3-12.6 [4.8-21.1])%, respectively, p < 0.001). The receiver-operating characteristic curve revealed that pulse pressure variation during forced inspiratory breathing could predict fluid responsiveness (area under the curve 0.910, p < 0.0001). Pulse pressure variation measured during forced inspiratory breathing can be used to guide fluid management in spontaneously breathing patients.

  16. Breath holding spell

    MedlinePlus

    ... such as Riley-Day syndrome or Rett syndrome Iron deficiency anemia A family history of breath holding spells ( ... tests may be done to check for an iron deficiency. Other tests that may be done include: EKG ...

  17. Shortness of Breath

    MedlinePlus

    ... with blood clots in the legs or pelvis (deep venous thrombosis), debilitating medical conditions, immobility, or inherited ... it hard for a person to take a deep breath, which usually results in retention of carbon ...

  18. Stop, Breathe & Think app.

    PubMed

    Shaw, Natalie

    2014-07-15

    The Stop, Breathe & Think app is free, thanks to underwriting from Tools for Peace, the non-profit organisation that teaches people of all ages how to develop and apply kindness and compassion in their daily lives.

  19. Shortness-of-Breath

    MedlinePlus

    ... can lead to shortness of breath include anxiety, panic attacks, anemia and even constipation. The experience of shortness ... are used to treat patients with anxiety or panic attacks. Other commonly used drugs include bronchodilators to widen ...

  20. Breathing difficulties - first aid

    MedlinePlus

    ... Aid If someone is having breathing difficulty, call 911 or your local emergency number right away, then: ... immediately. When to Contact a Medical Professional Call 911 or your local emergency number if you or ...

  1. Breath alcohol test

    MedlinePlus

    ... of alcohol in the air you breathe out (exhale). How the Test is Performed There are many ... Bethesda, MD 20894 U.S. Department of Health and Human Services National Institutes of Health Page last updated: ...

  2. Breathing - slowed or stopped

    MedlinePlus

    ... who is not responsive is called cardiac (or cardiopulmonary) arrest. In infants and children, the most common ... brain inflammation and infection that affects vital brain functions) Gastroesophageal reflux (heartburn) Holding one's breath Meningitis (inflammation ...

  3. Minimizing Shortness of Breath

    MedlinePlus

    ... and begin to limit our daily activities. Increase Awareness Occupational therapists find that shortness of breath is ... first steps for patients is to increase their awareness and help them recognize symptoms of shortness of ...

  4. Breath-Holding Spells

    MedlinePlus

    ... cause kids to stop breathing and sometimes lose consciousness for up to a minute. In the most ... pose a choking hazard once your child regains consciousness roll your child over onto his or her ...

  5. Breathing Problems - Multiple Languages

    MedlinePlus

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Breathing Problems URL of this page: https://medlineplus.gov/languages/breathingproblems.html Other topics A-Z Expand Section ...

  6. Bad Breath - Multiple Languages

    MedlinePlus

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Bad Breath URL of this page: https://medlineplus.gov/languages/badbreath.html Other topics A-Z Expand Section ...

  7. Visit-to-Visit Blood Pressure Variability and Arterial Stiffness Independently Predict Cardiovascular Risk Category in a General Population: Results from the SEPHAR II Study.

    PubMed

    Darabont, Roxana; Tautu, Oana-Florentina; Pop, Dana; Fruntelata, Ana; Deaconu, Alexandru; Onciul, Sebastian; Salaru, Delia; Micoara, Adolf; Dorobantu, Maria

    2015-01-01

    The aim of our study was to evaluate visit-to-visit blood pressure variability (BPV) and the association of this parameter with cardiovascular risk determinants, according to the SEPHAR II survey. Following a selection based on the multi-stratified proportional sampling procedure, a total of 1975 subjects who gave informed consent were evaluated by means of a questionnaire, anthropometric, blood pressure (BP) and arterial stiffness measurements (pulse wave velocity and augmentation index), 12-lead ECG recordings, and blood and urine analysis. BPV was quantified in terms of the standard deviation (SD) of the mean systolic blood pressure (SBP) and high BPV was defined as SBP-SD above the 4th quartile. Total cardiovascular risk was assessed by the 2013 ESH/ESC risk stratification chart. Mean BP was 132.37/82.01 mmHg. Mean systolic BPV was 6.16 mmHg, with 24.62% of values above the 75th percentile (8.48 mmHg). Factors found to be associated with high systolic BPV were age, SBP, pulse pressure, total and LDL-cholesterol, triglycerides, visceral obesity, diabetes mellitus, metabolic syndrome and increased aortic stiffness. In addition, in the hypertensive group high BPV was associated with the severity of hypertension and a lack of treatment control. Both visit-to-visit systolic BPV and aortic stiffness proved to be positively and independently correlated with the risk category. Based on these parameters it was possible to predict with 72.6% accuracy the probability of finding subjects in a high and very high cardiovascular risk category. The results of our study indicate a notable prevalence of high BPV, affecting almost a quarter of the Romanian adult population. Visit-to-visit systolic BPV and arterial stiffness are strongly correlated and together might contribute to the improvement of cardiovascular risk prediction models.

  8. Heart rate variability shows different cardiovascular modulation in Parkinson's disease patients with tremor dominant subtype compared to those with akinetic rigid dominant subtype.

    PubMed

    Solla, Paolo; Cadeddu, Christian; Cannas, Antonino; Deidda, Martino; Mura, Nicola; Mercuro, Giuseppe; Marrosu, Francesco

    2015-10-01

    Parkinson's disease (PD) can present with different motor subtypes depending on the predominant symptoms (tremor or rigidity/bradykinesia). Slower disease progression and less cognitive decline are observed in tremor-dominant patients compared to those with akinetic-rigid subtype. Autonomic cardiovascular disorders have been described in parkinsonian patients, although the definite correlations with different subtypes of PD are not clear. In this context, heart rate variability (HRV) analysis represents a non-invasive and established tool in assessing cardiovascular autonomic modulation. We investigate cardiovascular autonomic modulation in PD patients with tremor dominant subtype in comparison to akinetic rigid dominant subtype subjects using HRV analysis. Twenty-eight PD patients (17 with tremor dominant subtype and 11 with akinetic rigid dominant subtype) were enrolled and compared to 17 age and sex-matched healthy controls. HRV was analyzed in time- and frequency-domains. Low-frequency (LF) values were significantly lower in the akinetic rigid dominant subtype than in the tremor dominant group [LF 41.4 ± 13.6 vs 55.5 ± 11.6 (p < 0.007)] indicating that the disease led to a more evident impairment of the baroreflex modulation of the autonomic outflow mediated by both sympathetic and parasympathetic systems in the first class of patients. These findings support the biological relevance of clinical subtypes supporting the idea of a different pathophysiological process between these subtypes. These differences also suggest that different subtypes may also result in different responses to therapy or in the possible development of cardiovascular side effects of dopaminergic drugs in these different populations.

  9. Hiccups and breathing in human fetuses.

    PubMed Central

    Pillai, M; James, D

    1990-01-01

    Serial recording in 45 low risk fetuses throughout the second and third trimesters showed that hiccups were the predominant diaphragmatic movement before 26 weeks' gestational age and that there was a significant negative correlation with gestational age. There was a pronounced reduction between 24 and 26 weeks, which was the result of a decrease in the number of episodes of hiccups rather than a change in the duration of episodes. In contrast, fetal breathing was positively correlated with gestational age, the greatest increase in breathing occurring between 26 and 32 weeks' gestation. This was the result of both an increase in the number and duration of episodes. From the time that rest-activity cycles of behaviour could be determined in recordings, both breathing and hiccups were dependent on behavioural state or cycle, occurring predominantly during active episodes. This association between quiet and active behaviour and breathing did not alter with increasing gestational age, and the variables in fetal behavioural state became increasingly closely linked. The importance of prolonged and repeated recording, and also the need to take account of other variables in fetal behaviour, before any sinister conclusions can be drawn about the absence of fetal breathing is emphasised. PMID:2241230

  10. Breath-Holding Spells

    MedlinePlus

    ... Lessons? Visit KidsHealth in the Classroom What Other Parents Are Reading Your Child's Development (Birth to 3 Years) Feeding Your 1- to 3-Month-Old Feeding Your 4- to 7-Month-Old Feeding Your 8- to 12-Month-Old Feeding Your 1- to 2-Year-Old Breath-Holding ... > For Parents > Breath-Holding Spells Print A A A What's ...

  11. Effects of Training and Detraining on Physical Fitness, Physical Activity Patterns, Cardiovascular Variables, and HRQoL after 3 Health-Promotion Interventions in Institutionalized Elders.

    PubMed

    Lobo, Alexandrina; Carvalho, Joana; Santos, Paula

    2010-01-01

    The purpose of this study is to assess the effects of different strategies of health on the levels of physical activity (PA), physical fitness (PF), cardiovascular disease (CVD) risk factors and quality of life (QoL) of the institutionalized elderly. Concurrently studies were made of the effect of detraining on these same variables. In this investigation we carried out a prospective longitudinal study with an experimental design, with 1 year plus 3 months of a detraining period. Methodology. (a) A questionnaire with socio-demographic characteristics and a QoL scale (MOS SF-36); (b) Functional Fitness Test to assess PF; (c) An MTI Actigraph to evaluate the PA; (d) Biochemical analysis of blood, blood pressure and bio-impedance. The Main Results Indicated That: (i) ST significantly improved strength and body flexibility and AT the aerobic endurance, agility/dynamic balance and lower strength and flexibility; (ii) Implications of detraining were more evident on the PA groups in the lower body flexibility, which is associated with agility/dynamic balance and lower strength in the AT group; (iii) Cardiovascular variables improved significantly especially blood pressure, cholesterol and glucose in the ST and HDL in the AT group; not having undergone significant changes with the detraining. The results of this thesis contribute positively to highlight the importance of PA in the promotion of health, prevention and reduction of CVD risk factors and the improvement of the PF and QoL.

  12. Cardiovascular risk factor and familial aggregation of blood pressure with respect to anthropometric variables in a scheduled caste population in Punjab, a North Indian state.

    PubMed

    Badaruddoza; Kumar, Raman

    2009-06-01

    Based on anthropometric data, this study aims to detect cardiovascular risk factor and familial aggregation of blood pressure in a specific community in India. A total of 1096 adult individuals, constituting 350 families in a scheduled caste community in Punjab, India, was surveyed for blood pressure, pulse rate, pulse pressure and fifteen anthropometric measurements. Estimates of correlation among blood pressure phenotypes with other significant variables and stepwise multiple regression analysis have been carried out for both offspring and parent generations. The hypothesis for common household effects was examined by likelihood ratio tests. Almost all anthropometric variables were found to be significant with blood pressure between both generations. The percent of variance for the regression (R2) was found to be higher for the offspring generation than for the parent one. The results suggest that despite of genetic effects, common household environment for many anthropometric measurements is a significant determinant of blood pressure. The data indicate a strong familial aggregation of blood pressure and anthropometric measurements should be a useful tool for screening cardiovascular risk factor with elevated blood pressure.

  13. Effects of Training and Detraining on Physical Fitness, Physical Activity Patterns, Cardiovascular Variables, and HRQoL after 3 Health-Promotion Interventions in Institutionalized Elders

    PubMed Central

    Lobo, Alexandrina; Carvalho, Joana; Santos, Paula

    2010-01-01

    The purpose of this study is to assess the effects of different strategies of health on the levels of physical activity (PA), physical fitness (PF), cardiovascular disease (CVD) risk factors and quality of life (QoL) of the institutionalized elderly. Concurrently studies were made of the effect of detraining on these same variables. In this investigation we carried out a prospective longitudinal study with an experimental design, with 1 year plus 3 months of a detraining period. Methodology. (a) A questionnaire with socio-demographic characteristics and a QoL scale (MOS SF-36); (b) Functional Fitness Test to assess PF; (c) An MTI Actigraph to evaluate the PA; (d) Biochemical analysis of blood, blood pressure and bio-impedance. The Main Results Indicated That: (i) ST significantly improved strength and body flexibility and AT the aerobic endurance, agility/dynamic balance and lower strength and flexibility; (ii) Implications of detraining were more evident on the PA groups in the lower body flexibility, which is associated with agility/dynamic balance and lower strength in the AT group; (iii) Cardiovascular variables improved significantly especially blood pressure, cholesterol and glucose in the ST and HDL in the AT group; not having undergone significant changes with the detraining. The results of this thesis contribute positively to highlight the importance of PA in the promotion of health, prevention and reduction of CVD risk factors and the improvement of the PF and QoL. PMID:22332008

  14. Inverse problems in reduced order models of cardiovascular haemodynamics: aspects of data assimilation and heart rate variability.

    PubMed

    Pant, Sanjay; Corsini, Chiara; Baker, Catriona; Hsia, Tain-Yen; Pennati, Giancarlo; Vignon-Clementel, Irene E

    2017-01-01

    Inverse problems in cardiovascular modelling have become increasingly important to assess each patient individually. These problems entail estimation of patient-specific model parameters from uncertain measurements acquired in the clinic. In recent years, the method of data assimilation, especially the unscented Kalman filter, has gained popularity to address computational efficiency and uncertainty consideration in such problems. This work highlights and presents solutions to several challenges of this method pertinent to models of cardiovascular haemodynamics. These include methods to (i) avoid ill-conditioning of the covariance matrix, (ii) handle a variety of measurement types, (iii) include a variety of prior knowledge in the method, and (iv) incorporate measurements acquired at different heart rates, a common situation in the clinic where the patient state differs according to the clinical situation. Results are presented for two patient-specific cases of congenital heart disease. To illustrate and validate data assimilation with measurements at different heart rates, the results are presented on a synthetic dataset and on a patient-specific case with heart valve regurgitation. It is shown that the new method significantly improves the agreement between model predictions and measurements. The developed methods can be readily applied to other pathophysiologies and extended to dynamical systems which exhibit different responses under different sets of known parameters or different sets of inputs (such as forcing/excitation frequencies).

  15. Sleep and sleep disordered breathing in hospitalized patients.

    PubMed

    Knauert, Melissa P; Malik, Vipin; Kamdar, Biren B

    2014-10-01

    Sleep is a fundamental physiological process necessary for recovery from acute illness. Unfortunately for hospitalized patients, sleep is often short, fragmented, and poor in quality, and may be associated with adverse outcomes including inpatient delirium. Many factors contribute to poor sleep in the hospital setting, including preexisting sleep deprivation, sleep disordered breathing, environmental noise and light, patient care activities, and medications. Sleep disordered breathing increases the risk of potentially life-threatening cardiovascular, respiratory, and metabolic consequences, and therefore should be diagnosed and treated in hospitalized patients. Mitigating the sequelae associated with poor sleep quality and sleep disordered breathing requires early identification of modifiable factors impacting a patient's sleep, including engagement of a multidisciplinary team. In this article, we review the current knowledge of sleep in hospitalized patients with a detailed focus on patients with sleep disordered breathing. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  16. [Cardiovascular pharmacogenomics].

    PubMed

    Scibona, Paula; Angriman, Federico; Simonovich, Ventura; Heller, Martina M; Belloso, Waldo H

    2014-01-01

    Cardiovascular disease remains a major cause of morbidity and mortality worldwide. Current medical practice takes into account information based on population studies and benefits observed in large populations or cohorts. However, individual patients present great differences in both toxicity and clinical efficacy that can be explained by variations in adherence, unknown drug to drug interactions and genetic variability. The latter seems to explain from 20% up to 95% of patient to patient variability. Treating patients with cardiovascular disorders faces the clinician with the challenge to include genomic analysis into daily practice. There are several examples within cardiovascular disease of treatments that can vary in toxicity or clinical usefulness based on genetic changes. One of the main factors affecting the efficacy of Clopidogrel is the phenotype associated with polymorphisms in the gene CYP 2C9. Furthermore, regarding oral anticoagulants, changes in CYP2C9 and VKORC1 play an important role in changing the clinical response to anticoagulation. When analyzing statin treatment, one of their main toxicities (myopathy) can be predicted by the SLCO1B1 polymorphism. The potential for prediction of toxicity and clinical efficacy from the use of genetic analysis warrants further studies aiming towards its inclusion in daily clinical practice.

  17. Gaseous contaminant distribution in the breathing zone.

    PubMed

    Ojima, Jun

    2012-01-01

    Conventionally, the "breathing zone" is defined as the zone within a 0.3 m (or 10 inches) radius of a worker's nose and mouth, and it has been generally assumed that a contaminant in the breathing zone is homogeneous and its concentration is equivalent to the concentration inhaled by the worker. However, several studies have mentioned that the concentration is not uniform in the breathing zone when a worker is close to the contaminant source. In order to examine the spatial variability of contaminant concentrations in a worker's breathing zone, comparative measurements of personal exposure were carried out in a laboratory. In experiment, ethanol vapor was released in front of a model worker (human subject and mockup mannequin) and the vapor concentrations were measured at two different sampling points, at the nose and at the chest, in the breathing zone. Then, the effects of the sampling location and the body temperature on the exposure were observed. The ratios of nose concentration to chest concentration for the human subject and the mannequin were 0-0.2 and 0.12, respectively. The exposure level of the mannequin was about 5.5-9.3 times higher than that of the human subject.

  18. Data interpretation in breath biomarker research: pitfalls and directions.

    PubMed

    Miekisch, Wolfram; Herbig, Jens; Schubert, Jochen K

    2012-09-01

    Most--if not all--potential diagnostic applications in breath research involve different marker concentrations rather than unique breath markers which only occur in the diseased state. Hence, data interpretation is a crucial step in breath analysis. To avoid artificial significance in breath testing every effort should be made to implement method validation, data cross-testing and statistical validation along this process. The most common data analysis related problems can be classified into three groups: confounding variables (CVs), which have a real correlation with both the diseased state and a breath marker but lead to the erroneous conclusion that disease and breath are in a causal relationship; voodoo correlations (VCs), which can be understood as statistically true correlations that arise coincidentally in the vast number of measured variables; and statistical misconceptions in the study design (SMSD). CV: Typical confounding variables are environmental and medical history, host factors such as gender, age, weight, etc and parameters that could affect the quality of breath data such as subject breathing mode, effects of breath sampling and effects of the analytical technique itself. VC: The number of measured variables quickly overwhelms the number of samples that can feasibly be taken. As a consequence, the chances of finding coincidental 'voodoo' correlations grow proportionally. VCs can typically be expected in the following scenarios: insufficient number of patients, (too) many measurement variables, the use of advanced statistical data mining methods, and non-independent data for validation. SMSD: Non-prospective, non-blinded and non-randomized trials, a priori biased study populations or group selection with unrealistically high disease prevalence typically represent misconception of study design. In this paper important data interpretation issues are discussed, common pitfalls are addressed and directions for sound data processing and interpretation

  19. Are 30 minutes of rest between two incremental shuttle walking tests enough for cardiovascular variables and perceived exertion to return to baseline values?

    PubMed Central

    Ribeiro, Laís R. G.; Mesquita, Rafael B.; Vidotto, Laís S.; Merli, Myriam F.; Carvalho, Débora R.; de Castro, Larissa A.; Probst, Vanessa S.

    2015-01-01

    Objective: To verify whether 30 minutes of rest between two incremental shuttle walking tests (ISWT) are enough for cardiovascular variables and perceived exertion to return to baseline values in healthy subjects in a broad age range. Method: The maximal exercise capacity of 334 apparently healthy subjects (age ≥18) was evaluated using the ISWT. The test was performed twice with 30 minutes of rest in between. Heart rate (HR), arterial blood pressure (ABP), dyspnea, and leg fatigue were evaluated before and after each test. Subjects were allocated to 6 groups according to their age: G1: 18-29 years; G2: 30-39 years; G3: 40-49 years; G4: 50-59 years; G5: 60-69 years and G6: ≥70 years. Results: All groups had a good performance in the ISWT (median >90% of the predicted distance). The initial HR (HRi) of the second ISWT was higher than the first ISWT in the total sample (p<0.0001), as well as in all groups (p<0.0001). No difference was observed in the behavior of ABP (systolic and diastolic) and dyspnea between the two tests, but this difference occurred for leg fatigue (greater before the second ISWT) in G1 (p<0.05). Most subjects (58%) performed better in the second test. Conclusion: 30 minutes of rest between two ISWTs are not enough for all cardiovascular variables and perceived exertion to return to baseline values. However, this period appears to be sufficient for blood pressure and performance to recover in most subjects. PMID:25789556

  20. The chromogranin A- derived N-terminal peptide vasostatin-I: In vivo effects on cardiovascular variables in the rabbit.

    PubMed

    Roatta, Silvestro; Passatore, Magda; Novello, Matteo; Colombo, Barbara; Dondossola, Eleonora; Mohammed, Mazher; Losano, Gianni; Corti, Angelo; Helle, Karen B

    2011-06-07

    This study is the first to report on vascular effect of the chromogranin A derived Vasostatin-I (CgA(1-76)) in vivo. Cardiovascular parameters were recorded in 29 rabbits with sympathetically decentralized right carotid vascular bed. The recombinant human STA CgA(1-78) (VS-1) was infused at 480 μg/kg over 25 min. Group I was kept awake while groups II-V were anesthetized with Ketamine-xylazine. VS-1 was given alone in groups I-II while in presence of either phentolamine, phentolamine plus propranolol or hexamethonium in groups III-V. Serum VS-1 peaked at 2 μg/ml (200 nM) before onset of vascular effects and declined rapidly to ~200 ng/ml within 30 min. In all groups but III and IV VS-1 induced a brief vasoconstriction, being larger in intact than in sympathetically decentralized beds. The VS-1 induced vasoconstriction was not altered by hexamethonium but was abolished by phentolamine. In presence of the α-adrenergic blocker a long lasting vasodilatation, unaffected by propranolol, was apparent on both innervated and decentralized sides. In conclusion, VS-1 induced an α-adrenoceptor-mediated vasoconstriction presumably brought about by noradrenaline release from sympathetic nerves when infused at a dose giving an initial serum concentration of ~200 nM. This initial vasoconstriction masked a persistent adrenoceptor-independent vasodilatation, consistent with previous reports from in vitro models.

  1. Music structure determines heart rate variability of singers

    PubMed Central

    Vickhoff, Björn; Malmgren, Helge; Åström, Rickard; Nyberg, Gunnar; Ekström, Seth-Reino; Engwall, Mathias; Snygg, Johan; Nilsson, Michael; Jörnsten, Rebecka

    2013-01-01

    Choir singing is known to promote wellbeing. One reason for this may be that singing demands a slower than normal respiration, which may in turn affect heart activity. Coupling of heart rate variability (HRV) to respiration is called Respiratory sinus arrhythmia (RSA). This coupling has a subjective as well as a biologically soothing effect, and it is beneficial for cardiovascular function. RSA is seen to be more marked during slow-paced breathing and at lower respiration rates (0.1 Hz and below). In this study, we investigate how singing, which is a form of guided breathing, affects HRV and RSA. The study comprises a group of healthy 18 year olds of mixed gender. The subjects are asked to; (1) hum a single tone and breathe whenever they need to; (2) sing a hymn with free, unguided breathing; and (3) sing a slow mantra and breathe solely between phrases. Heart rate (HR) is measured continuously during the study. The study design makes it possible to compare above three levels of song structure. In a separate case study, we examine five individuals performing singing tasks (1–3). We collect data with more advanced equipment, simultaneously recording HR, respiration, skin conductance and finger temperature. We show how song structure, respiration and HR are connected. Unison singing of regular song structures makes the hearts of the singers accelerate and decelerate simultaneously. Implications concerning the effect on wellbeing and health are discussed as well as the question how this inner entrainment may affect perception and behavior. PMID:23847555

  2. Coronary heart disease incidence in sleep disordered breathing: the Wisconsin Sleep Cohort Study.

    PubMed

    Hla, Khin Mae; Young, Terry; Hagen, Erika W; Stein, James H; Finn, Laurel A; Nieto, F Javier; Peppard, Paul E

    2015-05-01

    The aim of the study was to determine the association of objectively measured sleep disordered breathing (SDB) with incident coronary heart disease (CHD) or heart failure (HF) in a nonclinical population. Longitudinal analysis of a community-dwelling cohort followed up to 24 y. Sleep laboratory at the Clinical Research Unit of the University of Wisconsin Hospital and Clinics. There were 1,131 adults who completed one or more overnight polysomnography studies, were free of CHD or HF at baseline, were not treated by continuous positive airway pressure (CPAP), and followed over 24 y. None. In-laboratory overnight polysomnography was used to assess SDB, defined by the apnea-hypopnea index (AHI) using apnea and hypopnea events per hour of sleep. Incident CHD or HF was defined by new reports of myocardial infarction, coronary revascularization procedures, congestive heart failure, and cardiovascular deaths. We used baseline AHI as the predictor variable in survival analysis models predicting CHD or HF incidence adjusted for traditional confounders. The incidence of CHD or HF was 10.9/1,000 person-years. The mean time to event was 11.2 ± 5.8 y. After adjusting for age, sex, body mass index, and smoking, estimated hazard ratios (95% confidence interval) of incident CHD or HF were 1.5 (0.9-2.6) for AHI > 0-5, 1.9 (1.05-3.5) for AHI 5 ≤ 15, 1.8 (0.85-4.0) for AHI 15 ≤ 30, and 2.6 (1.1-6.1) for AHI > 30 compared to AHI = 0 (P trend = 0.02). Participants with untreated severe sleep disordered breathing (AHI > 30) were 2.6 times more likely to have an incident coronary heart disease or heart failure compared to those without sleep disordered breathing. Our findings support the postulated adverse effects of sleep disordered breathing on coronary heart disease and heart failure. © 2015 Associated Professional Sleep Societies, LLC.

  3. Breathing Like a Fish

    ERIC Educational Resources Information Center

    Katsioloudis, Petros J.

    2010-01-01

    Being able to dive and breathe underwater has been a challenge for thousands of years. In 1980, Fuji Systems of Tokyo developed a series of prototype gills for divers as a way of demonstrating just how good its membranes are. Even though gill technology has not yet reached the point where recipients can efficiently use implants to dive underwater,…

  4. Life and Breath

    ERIC Educational Resources Information Center

    Ellis, Helen D.

    1974-01-01

    This article describes a public education program combining the screening process and a follow-up program for teaching victims of emphysema and other respiratory diseases how to better their living condition through proper breathing, avoidance of air pollutants and cigarette smoking, and taking better care of themselves physically. (PD)

  5. Metabolic breath analyzer

    NASA Technical Reports Server (NTRS)

    Perry, C. L.

    1971-01-01

    Instrument measures metabolic breathing rate and dynamics of human beings in atmospheres ranging from normal air to 100 percent oxygen at ambient pressures from 14.7 to 3.0 psia. Measurements are made at rest or performing tasks up to maximum physical capacity under either zero or normal gravity.

  6. Life and Breath

    ERIC Educational Resources Information Center

    Ellis, Helen D.

    1974-01-01

    This article describes a public education program combining the screening process and a follow-up program for teaching victims of emphysema and other respiratory diseases how to better their living condition through proper breathing, avoidance of air pollutants and cigarette smoking, and taking better care of themselves physically. (PD)

  7. Breathing metabolic simulator

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G., Jr.; Hendricks, C. M.; Morison, W. B.

    1972-01-01

    A description is given of an automatic computer controlled second generation breathing metabolic simulator (BMS). The simulator is used for evaluating and testing respiratory diagnostic, monitoring, support, and resuscitation equipment. Any desired sequence of metabolic activities can be simulated on the device for up to 15 hours. The computer monitors test procedures and provides printouts of test results.

  8. The Air We Breathe

    NASA Technical Reports Server (NTRS)

    Davila, Dina

    2010-01-01

    Topics discussed include NASA mission to pioneer the future in space exploration, scientific discovery and aeronautics research; the role of Earth's atmosphere, atmospheric gases, layers of the Earth's atmosphere, ozone layer, air pollution, effects of air pollution on people, the Greenhouse Effect, and breathing on the International Space Station.

  9. Portable Breathing Assembly

    NASA Image and Video Library

    2017-06-12

    In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, Jacobs Test and Operations Support Contract, or TOSC, technicians fill portable breathing apparatuses, or PBAS. The PBAs are to be use on board the International Space Staton to provide astronauts with breathable air in the event of a fire or other emergency situation.

  10. Breathing Like a Fish

    ERIC Educational Resources Information Center

    Katsioloudis, Petros J.

    2010-01-01

    Being able to dive and breathe underwater has been a challenge for thousands of years. In 1980, Fuji Systems of Tokyo developed a series of prototype gills for divers as a way of demonstrating just how good its membranes are. Even though gill technology has not yet reached the point where recipients can efficiently use implants to dive underwater,…

  11. Medical Issues: Breathing

    MedlinePlus

    ... About Us News Facebook Twitter YouTube Learn About SMA About SMA Types of SMA Causes & Diagnosis Genetics Testing Carriers What Diagnosis Means ... Care Packages Information Packets Equipment Pool Living With SMA Medical Issues Palliative Breathing Orthopedics Nutrition Equipment Daily ...

  12. Portable Breathing Assembly

    NASA Image and Video Library

    2017-06-12

    In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, Jacobs Test and Operations Support Contract, or TOSC, technician Rod Ostgrard helps fill portable breathing apparatuses, or PBAS. The PBAs are to be use on board the International Space Staton to provide astronauts with breathable air in the event of a fire or other emergency situation.

  13. Portable Breathing Assembly

    NASA Image and Video Library

    2017-06-12

    In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, Jacobs Test and Operations Support Contract, or TOSC, technician John Thompson helps fill portable breathing apparatuses, or PBAS. The PBAs are to be use on board the International Space Staton to provide astronauts with breathable air in the event of a fire or other emergency situation.

  14. The Air We Breathe

    NASA Technical Reports Server (NTRS)

    Davila, Dina

    2010-01-01

    Topics discussed include NASA mission to pioneer the future in space exploration, scientific discovery and aeronautics research; the role of Earth's atmosphere, atmospheric gases, layers of the Earth's atmosphere, ozone layer, air pollution, effects of air pollution on people, the Greenhouse Effect, and breathing on the International Space Station.

  15. Sleep-disordered breathing in heart failure: facts and numbers.

    PubMed

    Pietrock, Charlotte; von Haehling, Stephan

    2017-08-01

    Sleep-disordered breathing has a high prevalence in the general population, but is especially prominent in patients with heart failure (HF). HF and sleep-disordered breathing share a bidirectional relationship, with sleep-disordered breathing being both cause and effect of poor cardiac functioning. The high inter-individual variability of symptom presentation can impede the clinical diagnostic process. Polysomnography is the gold-standard method of diagnosing sleep-disordered breathing. Therapy of sleep-disordered breathing should always consist of optimizing the treatment of the underlying disorder of HF. Additional therapeutic measures include continuous positive airway pressure ventilation therapy. New therapeutic options using neurostimulation are yielding promising results; however, long-term benefits still need to be confirmed. © 2017 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.

  16. Cerebrovascular and cardiovascular variability interactions investigated through conditional joint transfer entropy in subjects prone to postural syncope.

    PubMed

    Bari, Vlasta; De Maria, Beatrice; Mazzucco, Claudio Enrico; Rossato, Gianluca; Tonon, Davide; Nollo, Giandomenico; Faes, Luca; Porta, Alberto

    2017-02-28

    A model-based conditional transfer entropy approach was exploited to quantify the information transfer in cerebrovascular (CBV) and cardiovascular (CV) systems in subjects prone to develop postural syncope. Spontaneous beat-to-beat variations of mean cerebral blood flow velocity (MCBFV) derived from a transcranial Doppler device, heart period (HP) derived from surface electrocardiogram, mean arterial pressure (MAP) and systolic arterial pressure (SAP) derived from finger plethysmographic arterial pressure device were monitored at rest in supine position (REST) and during 60° head-up tilt (TILT) in 13 individuals (age mean±standard deviation: 28±9 years, min-max range: 18-44 years, 5 males) with a history of recurrent episodes of syncope (SYNC) and in 13 age- and gender-matched controls (NonSYNC). Respiration (R) obtained from a thoracic belt was acquired as well and considered as a conditioning signal in transfer entropy assessment. Synchronous sequences of 250 consecutive MCBFV, HP, MAP, SAP and R values were utilized to estimate the information genuinely transferred from MAP to MCBFV (i.e. disambiguated from R influences) and vice versa. Analogous indexes were computed from SAP to HP and vice versa. Traditional time and frequency domain analyses were carried out as well. SYNC subjects showed an increased genuine information transfer from MAP to MCBFV during TILT, while they did not exhibit the expected rise of the genuine information transfer from SAP to HP. We conclude that SYNC individuals featured an impaired cerebral autoregulation visible during TILT and were unable to activate cardiac baroreflex to cope with the postural challenge. Traditional frequency domain markers based on transfer function modulus, phase and coherence functions were less powerful or less specific in typifying the CBV and CV controls of SYNC individuals. Conditional transfer entropy approach can identify the impairment of CBV and CV controls and provide specific clues to identify

  17. Chironex fleckeri (box jellyfish) venom proteins: expansion of a cnidarian toxin family that elicits variable cytolytic and cardiovascular effects.

    PubMed

    Brinkman, Diane L; Konstantakopoulos, Nicki; McInerney, Bernie V; Mulvenna, Jason; Seymour, Jamie E; Isbister, Geoffrey K; Hodgson, Wayne C

    2014-02-21

    The box jellyfish Chironex fleckeri produces extremely potent and rapid-acting venom that is harmful to humans and lethal to prey. Here, we describe the characterization of two C. fleckeri venom proteins, CfTX-A (∼40 kDa) and CfTX-B (∼42 kDa), which were isolated from C. fleckeri venom using size exclusion chromatography and cation exchange chromatography. Full-length cDNA sequences encoding CfTX-A and -B and a third putative toxin, CfTX-Bt, were subsequently retrieved from a C. fleckeri tentacle cDNA library. Bioinformatic analyses revealed that the new toxins belong to a small family of potent cnidarian pore-forming toxins that includes two other C. fleckeri toxins, CfTX-1 and CfTX-2. Phylogenetic inferences from amino acid sequences of the toxin family grouped CfTX-A, -B, and -Bt in a separate clade from CfTX-1 and -2, suggesting that the C. fleckeri toxins have diversified structurally and functionally during evolution. Comparative bioactivity assays revealed that CfTX-1/2 (25 μg kg(-1)) caused profound effects on the cardiovascular system of anesthetized rats, whereas CfTX-A/B elicited only minor effects at the same dose. Conversely, the hemolytic activity of CfTX-A/B (HU50 = 5 ng ml(-1)) was at least 30 times greater than that of CfTX-1/2. Structural homology between the cubozoan toxins and insecticidal three-domain Cry toxins (δ-endotoxins) suggests that the toxins have a similar pore-forming mechanism of action involving α-helices of the N-terminal domain, whereas structural diversification among toxin members may modulate target specificity. Expansion of the cnidarian toxin family therefore provides new insights into the evolutionary diversification of box jellyfish toxins from a structural and functional perspective.

  18. Prevalence of cardiovascular risk factors, the association with socioeconomic variables in adolescents from low-income region.

    PubMed

    Nascimento-Ferreira, Marcus Vinicius; De Moraes, Augusto Cesar F; Carvalho, Heraclito B; Moreno, Luis A; Gomes Carneiro, André Luiz; dos Reis, Victor Manuel M; Torres-Leal, Francisco Leonardo

    2014-01-01

    Objetivos: Estimar la prevalencia de obesidad y sobrepeso, obesidad abdominal y hipertensión arterial en una muestra de adolescentes pertenecientes a una ciudad de baja renta en Brasil y su relación con el nivel socioeconómico, nivel educativo de lo responsable de la familia y tipo de escuela. Métodos: Estudio transversal con una muestra de 1014 adolescentes (54,8% chicas), con edades entre 14-19 años, estudiantes de las escuelas de la ciudad de Imperatriz (Brasil), seleccionadas por un muestreo aleatorio. Las variables dependientes evaluadas son: obesidad general y sobrepeso, obesidad abdominal, y tensión arterial alta (sistólica y/o diastólica). Las variables independientes son: nivel socioeconómico de la familia (NSO), el nivel de educación de lo responsable de la familia (NERF) y tipo de escuela. Las variables de confusión son: sexo, edad y nivel de actividad física. La prevalencia fue estimada, y la asociación entre las variables dependientes y las variables independientes se analizaron mediante razón de prevalencia (RP), con intervalo de confianza (IC) del 95%, estimado por la regresión de Poisson. Resultados: La prevalencia de la obesidad general fue de 3,8%, sobrepeso 13,1%, obesidad abdominal 22,7% y la tesión arterial alta 21,3%. Las análisis ajustadas indicaron que las chicas con NSO alto tienen mayor probabilidad de tener sobrepeso (RP=1,71 [IC95%: 1,13 a 2,87]), y chicos de las escuelas privadas tienen más probabilidad de tener obesidad (RP=1,79 [IC95%: 1.04- 3,08]) y obesidad abdominal (RP=1,64 [IC95%: 1,06 a 2,54]). Conclusión: La prevalencia de los FRC es alta en adolescentes de una región de baja renta. Los chicos de las escuelas privadas son más propensos a tener obesi dad y obesidad abdominal, y las chicas con NSO alto son más propensas a tener sobrepeso.

  19. Astronaut Preflight Cardiovascular Variables Associated with Vascular Compliance are Highly Correlated with Post-Flight Eye Outcome Measures in the Visual Impairment Intracranial Pressure (VIIP) Syndrome Following Long Duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Otto, Christian; Ploutz-Snyder, R.

    2015-01-01

    The detection of the first VIIP case occurred in 2005, and adequate eye outcome measures were available for 31 (67.4%) of the 46 long duration US crewmembers who had flown on the ISS since its first crewed mission in 2000. Therefore, this analysis is limited to a subgroup (22 males and 9 females). A "cardiovascular profile" for each astronaut was compiled by examining twelve individual parameters; eleven of these were preflight variables: systolic blood pressure, pulse pressure, body mass index, percentage body fat, LDL, HDL, triglycerides, use of anti-lipid medication, fasting serum glucose, and maximal oxygen uptake in ml/kg. Each of these variables was averaged across three preflight annual physical exams. Astronaut age prior to the long duration mission, and inflight salt intake was also included in the analysis. The group of cardiovascular variables for each crew member was compared with seven VIIP eye outcome variables collected during the immediate post-flight period: anterior-posterior axial length of the globe measured by ultrasound and optical biometry; optic nerve sheath diameter, optic nerve diameter, and optic nerve to sheath ratio- each measured by ultrasound and magnetic resonance imaging (MRI), intraocular pressure (IOP), change in manifest refraction, mean retinal nerve fiber layer (RNFL) on optical coherence tomography (OCT), and RNFL of the inferior and superior retinal quadrants. Since most of the VIIP eye outcome measures were added sequentially beginning in 2005, as knowledge of the syndrome improved, data were unavailable for 22.0% of the outcome measurements. To address the missing data, we employed multivariate multiple imputation techniques with predictive mean matching methods to accumulate 200 separate imputed datasets for analysis. We were able to impute data for the 22.0% of missing VIIP eye outcomes. We then applied Rubin's rules for collapsing the statistical results across our 200 multiply imputed data sets to assess the canonical

  20. The indoor air we breathe.

    PubMed Central

    Oliver, L C; Shackleton, B W

    1998-01-01

    Increasingly recognized as a potential public health problem since the outbreak of Legionnaire's disease in Philadelphia in 1976, polluted indoor air has been associated with health problems that include asthma, sick building syndrome, multiple chemical sensitivity, and hypersensitivity pneumonitis. Symptoms are often nonspecific and include headache, eye and throat irritation, chest tightness and shortness of breath, and fatigue. Air-borne contaminants include commonly used chemicals, vehicular exhaust, microbial organisms, fibrous glass particles, and dust. Identified causes include defective building design and construction, aging of buildings and their ventilation systems, poor climate control, inattention to building maintenance. A major contributory factor is the explosion in the use of chemicals in building construction and furnishing materials over the past four decades. Organizational issues and psychological variables often contribute to the problem and hinder its resolution. This article describes the health problems related to poor indoor air quality and offers solutions. Images p398-a p399-a PMID:9769764

  1. Breathing exercises for dysfunctional breathing/hyperventilation syndrome in children.

    PubMed

    Barker, Nicola J; Jones, Mandy; O'Connell, Neil E; Everard, Mark L

    2013-12-18

    Dysfunctional breathing is described as chronic or recurrent changes in breathing pattern causing respiratory and non-respiratory symptoms. It is an umbrella term that encompasses hyperventilation syndrome and vocal cord dysfunction. Dysfunctional breathing affects 10% of the general population. Symptoms include dyspnoea, chest tightness, sighing and chest pain which arise secondary to alterations in respiratory pattern and rate. Little is known about dysfunctional breathing in children. Preliminary data suggest 5.3% or more of children with asthma have dysfunctional breathing and that, unlike in adults, it is associated with poorer asthma control. It is not known what proportion of the general paediatric population is affected. Breathing training is recommended as a first-line treatment for adults with dysfunctional breathing (with or without asthma) but no similar recommendations are available for the management of children. As such, breathing retraining is adapted from adult regimens based on the age and ability of the child. To determine whether breathing retraining in children with dysfunctional breathing has beneficial effects as measured by quality of life indices.To determine whether there are any adverse effects of breathing retraining in young people with dysfunctional breathing. We identified trials for consideration using both electronic and manual search strategies. We searched CENTRAL, MEDLINE and EMBASE. We searched the National Research Register (NRR) Archive, Health Services Research Projects in Progress (HSRProj), Current Controlled Trials register (incorporating the metaRegister of Controlled Trials and the International Standard Randomised Controlled Trial Number (ISRCTN) to identify research in progress and unpublished research. The latest search was undertaken in October 2013. We planned to include randomised, quasi-randomised or cluster-randomised controlled trials. We excluded observational studies, case studies and studies utilising a cross

  2. Exercise performance and cardiovascular health variables in 70-year-old male soccer players compared to endurance-trained, strength-trained and untrained age-matched men.

    PubMed

    Randers, Morten Bredsgaard; Andersen, Jesper L; Petersen, Jesper; Sundstrup, Emil; Jakobsen, Markus D; Bangsbo, Jens; Saltin, Bengt; Krustrup, Peter

    2014-01-01

    The aim was to investigate performance variables and indicators of cardiovascular health profile in elderly soccer players (SP, n = 11) compared to endurance-trained (ET, n = 8), strength-trained (ST, n = 7) and untrained (UT, n = 7) age-matched men. The 33 men aged 65-85 years underwent a testing protocol including measurements of cycle performance, maximal oxygen uptake (VO2max) and body composition, and muscle fibre types and capillarisation were determined from m. vastus lateralis biopsy. In SP, time to exhaustion was longer (16.3 ± 2.0 min; P < 0.01) than in UT (+48%) and ST (+41%), but similar to ET (+1%). Fat percentage was lower (P < 0.05) in SP (-6.5% points) than UT but not ET and ST. Heart rate reserve was higher (P < 0.05) in SP (104 ± 16 bpm) than UT (+21 bpm) and ST (+24 bpm), but similar to ET (+2 bpm), whereas VO2max was not significantly different in SP (30.2 ± 4.9 ml O2 · min(-1) · kg(-1)) compared to UT (+14%) and ST (+9%), but lower (P < 0.05) than ET (-22%). The number of capillaries per fibre was higher (P < 0.05) in SP than UT (53%) and ST (42%) but similar to ET. SP had less type IIx fibres than UT (-12% points). In conclusion, the exercise performance and cardiovascular health profile are markedly better for lifelong trained SP than for age-matched UT controls. Incremental exercise capacity and muscle aerobic capacity of SP are also superior to lifelong ST athletes and comparable to endurance athletes.

  3. Breath Sound Intensity during Tidal Breathing in COPD Patients.

    PubMed

    Ishimatsu, Akiko; Nakano, Hiroshi; Nogami, Hiroko; Yoshida, Makoto; Iwanaga, Tomoaki; Hoshino, Tomoaki

    2015-01-01

    There is a discrepancy in the intensity of breath sounds in chronic obstructive pulmonary disease (COPD) patients between subjective studies, which have reported a diminished intensity, and objective studies using airflow-standardized measurements, which have not demonstrated a diminished intensity. We herein evaluated the breath sound intensity in COPD patients during tidal breathing in order to obtain clinically relevant results. The subjects included 20 stable COPD patients and 20 normal controls. Microphones were attached to six sites on the chest wall, and breath sounds at the chest wall and airflow in the mouth were measured during resting tidal and deep tidal breathing. The octave-band power values of the breath sounds were subsequently calculated. 1. During resting breathing, the intensity of breath sounds during both inspiration and expiration was significantly greater in the COPD group than in the control group; the difference was prominent at higher frequency bands (>400 Hz). In addition, the power of the high frequency bands tended to be positively correlated with the CT visual emphysema scores but not the forced expiratory volume in one second, The airflow during resting breathing did not differ between the two groups. 2. During deep breathing, the intensity of inspiratory breath sounds at the dominant frequency band (200-400 Hz) was diminished over the upper and middle lung fields in the COPD group compared to that observed in the control group, while the intensity during expiration was not. The airflow during deep breathing was lower in the COPD group than in the control group. In the present study, the breath sound intensity in the COPD patients was diminished during deep inspiration due to a reduced airflow and increased during both resting inspiration and expiration.

  4. Emergency Response Breathing Apparatus

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Aerospace Design & Development, Inc.'s (ADD's) SCAMP was developed under an SBIR contract through Kennedy Space Center. SCAMP stands for Supercritical Air Mobility Pack. The technology came from the life support fuel cell support systems used for the Apollo and Space Shuttle programs. It uses supercritical cryogenic air and is able to function in microgravity environments. SCAMP's self-contained breathing apparatus(SCBA) systems are also ground-based and can provide twice as much air than traditional SCBA's due to its high-density capacity. The SCAMP system was designed for use in launch pad emergency rescues. ADD also developed a protective suit for use with SCAMP that is smaller and lighter system than the old ones. ADD's SCAMP allows for body cooling and breathing from the supercritical cryogenic air, requiring no extra systems. The improvement over the traditional SCBA allows for a reduction of injuries, such as heat stress, and makes it easier for rescuers to save lives.

  5. Clinical Feasibility of Free-Breathing Dynamic T1-Weighted Imaging With Gadoxetic Acid-Enhanced Liver Magnetic Resonance Imaging Using a Combination of Variable Density Sampling and Compressed Sensing.

    PubMed

    Yoon, Jeong Hee; Yu, Mi Hye; Chang, Won; Park, Jin-Young; Nickel, Marcel Dominik; Son, Yohan; Kiefer, Berthold; Lee, Jeong Min

    2017-10-01

    The purpose of the study was to investigate the clinical feasibility of free-breathing dynamic T1-weighted imaging (T1WI) using Cartesian sampling, compressed sensing, and iterative reconstruction in gadoxetic acid-enhanced liver magnetic resonance imaging (MRI). This retrospective study was approved by our institutional review board, and the requirement for informed consent was waived. A total of 51 patients at high risk of breath-holding failure underwent dynamic T1WI in a free-breathing manner using volumetric interpolated breath-hold (BH) examination with compressed sensing reconstruction (CS-VIBE) and hard gating. Timing, motion artifacts, and image quality were evaluated by 4 radiologists on a 4-point scale. For patients with low image quality scores (<3) on the late arterial phase, respiratory motion-resolved (extradimension [XD]) reconstruction was additionally performed and reviewed in the same manner. In addition, in 68.6% (35/51) patients who had previously undergone liver MRI, image quality and motion artifacts on dynamic phases using CS-VIBE were compared with previous BH-T1WIs. In all patients, adequate arterial-phase timing was obtained at least once. Overall image quality of free-breathing T1WI was 3.30 ± 0.59 on precontrast and 2.68 ± 0.70, 2.93 ± 0.65, and 3.30 ± 0.49 on early arterial, late arterial, and portal venous phases, respectively. In 13 patients with lower than average image quality (<3) on the late arterial phase, motion-resolved reconstructed T1WI (XD-reconstructed CS-VIBE) significantly reduced motion artifacts (P < 0.002-0.021) and improved image quality (P < 0.0001-0.002). In comparison with previous BH-T1WI, CS-VIBE with hard gating or XD reconstruction showed less motion artifacts and better image quality on precontrast, arterial, and portal venous phases (P < 0.0001-0.013). Volumetric interpolated breath-hold examination with compressed sensing has the potential to provide consistent, motion-corrected free-breathing dynamic T

  6. [TMJ, eating and breathing].

    PubMed

    Cheynet, F

    2016-09-01

    The study of the relationship between temporomandibular joints (TMJ), mastication and ventilation and the involvement of these two functions in the genesis of primary Temporomandibular Disorders (TMD) and in some dentofacial deformities, was initiated in France, more than 30years, by Professor Raymond Gola. Once criticized the weakness of the scientific literature in this domain, the originality of the TMJ within the masticatory system is recalled with its huge adaptation potential to very different biomechanical constraints according to the age and masticatory activities during the day. But the biomechanics of the masticatory system does not stop at night and the positions of the mandible and head during sleep should be studied carefully. In case of nocturnal mouth breathing with open mouth, the predominant sleeping position (generating small but long-term strengths) may be deleterious to the condyle-disc complex, to the surrounding muscles and the occlusal relationships. Some condyle-disc displacements and asymmetric malocclusions occur in this long portion of life what sleep, especially as oral breathing leads to a lot of dysfunctions (low position of the tongue, labio-lingual dysfunctions, exacerbation of bruxism sleep…). The aim of this work was to share our multidisciplinary experience of the biomechanical consequences of the nocturnal mouth breathing on the face involving orthodontists, maxillofacial surgeons, ENT, allergists, speech therapists, physiotherapists and radiologists. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  7. Increased cardio-respiratory coupling evoked by slow deep breathing can persist in normal humans.

    PubMed

    Dick, Thomas E; Mims, Joseph R; Hsieh, Yee-Hsee; Morris, Kendall F; Wehrwein, Erica A

    2014-12-01

    Slow deep breathing (SDB) has a therapeutic effect on autonomic tone. Our previous studies suggested that coupling of the cardiovascular to the respiratory system mediates plasticity expressed in sympathetic nerve activity. We hypothesized that SDB evokes short-term plasticity of cardiorespiratory coupling (CRC). We analyzed respiratory frequency (fR), heart rate and its variability (HR&HRV), the power spectral density (PSD) of blood pressure (BP) and the ventilatory pattern before, during, and after a 20-min epoch of SDB. During SDB, CRC and the relative PSD of BP at fR increased; mean arterial pressure decreased; but HR varied; increasing (n = 3), or decreasing (n = 2) or remaining the same (n = 5). After SDB, short-term plasticity was not apparent for the group but for individuals differences existed between baseline and recovery periods. We conclude that a repeated practice, like pranayama, may strengthen CRC and evoke short-term plasticity effectively in a subset of individuals.

  8. Cardiovascular and respiratory dysfunction in chronic obstructive pulmonary disease complicated by impaired peripheral oxygenation.

    PubMed

    Chuang, Ming-Lung; Huang, Shih-Feng; Su, Chun-Hung

    2015-01-01

    Impaired peripheral oxygenation (IPO)-related variables readily achieved with cardiopulmonary exercise testing (CPET) represent cardiovascular dysfunction. These variables include peak oxygen uptake ( [Formula: see text] predicted, anaerobic threshold [Formula: see text] predicted, [Formula: see text] rate slope <8.6 mL/watt, oxygen pulse <80% predicted, and ventilatory equivalents for O2 and CO2 at nadir of >31 and >34, respectively. Some of these six variables may be normal while the others are abnormal in patients with chronic obstructive pulmonary disease (COPD). This may result in confusion when using the interpretation algorithm for diagnostic purposes. We therefore hypothesized that patients found to have abnormal values for all six variables would have worse cardiovascular function than patients with abnormal values for none or some of these variables. In this cross-sectional comparative study, 58 COPD patients attending a university teaching hospital underwent symptom-limited CPET with multiple lactate measurements. Patients with abnormal values in all six IPO-related variables were assigned to an IPO group while those who did not meet the requirements for the IPO group were assigned to a non-IPO group. Cardiovascular function was measured by two-dimensional echocardiography and [Formula: see text], and respiratory dynamics were compared between the two groups. Fourteen IPO and 43 non-IPO patients were entered into the study. Both groups were similar with regard to left ventricular ejection fraction and right ventricular morphology (P>0.05 for both). At peak exercise, both groups reached a similar heart rate level and [Formula: see text]. The IPO patients had an unfavorable dead space to tidal volume ratio, mean inspiratory tidal flow, and shallow breathing (P<0.05-P<0.001). Our IPO and non-IPO patients with COPD had similar cardiovascular performance at rest and at peak exercise, indicating that IPO variables are non-specific for cardiovascular function

  9. Breathing exercises for dysfunctional breathing/hyperventilation syndrome in adults.

    PubMed

    Jones, Mandy; Harvey, Alex; Marston, Louise; O'Connell, Neil E

    2013-05-31

    Dysfunctional breathing/hyperventilation syndrome (DB/HVS) is a respiratory disorder, psychologically or physiologically based, involving breathing too deeply and/or too rapidly (hyperventilation) or erratic breathing interspersed with breath-holding or sighing (DB). DB/HVS can result in significant patient morbidity and an array of symptoms including breathlessness, chest tightness, dizziness, tremor and paraesthesia. DB/HVS has an estimated prevalence of 9.5% in the general adult population, however, there is little consensus regarding the most effective management of this patient group. (1) To determine whether breathing exercises in patients with DB/HVS have beneficial effects as measured by quality of life indices (2) To determine whether there are any adverse effects of breathing exercises in patients with DB/HVS SEARCH METHODS: We identified trials for consideration using both electronic and manual search strategies. We searched CENTRAL, MEDLINE, EMBASE, and four other databases. The latest search was in February 2013. We planned to include randomised, quasi-randomised or cluster randomised controlled trials (RCTs) in which breathing exercises, or a combined intervention including breathing exercises as a key component, were compared with either no treatment or another therapy that did not include breathing exercises in patients with DB/HVS. Observational studies, case studies and studies utilising a cross-over design were not eligible for inclusion.We considered any type of breathing exercise for inclusion in this review, such as breathing control, diaphragmatic breathing, yoga breathing, Buteyko breathing, biofeedback-guided breathing modification, yawn/sigh suppression. Programs where exercises were either supervised or unsupervised were eligible as were relaxation techniques and acute-episode management, as long as it was clear that breathing exercises were a key component of the intervention.We excluded any intervention without breathing exercises or

  10. Clinical variability in cardiovascular disease risk factor screening and management in adolescent and young adult women with polycystic ovary syndrome

    PubMed Central

    Baer, Tamara E.; Milliren, Carly E.; Walls, Courtney; DiVasta, Amy D.

    2014-01-01

    Study Objectives To review the clinical presentation, evaluation and management of normal-weight, overweight and obese adolescent and young adult women with PCOS over 2-year follow-up. Design Retrospective chart review Participants 173 adolescent and young adult women, aged 12–22 years, diagnosed with PCOS Interventions Demographic, health data, and laboratory measures were abstracted from 3 clinic visits: baseline and 1- and 2- year follow-up. Subjects were classified as normal-weight (NW), overweight (OW) or obese (OB). Longitudinal data were analyzed using repeated measures ANOVA. Main Outcome Measures BMI, self-reported concerns, lifestyle changes. Results Most patients (73%) were OW or OB. Family history of type II diabetes was greater in OW (38%) and OB (53%) as compared to NW (22%) patients (p=0.002). Acanthosis nigricans was identified in OW (62%) and OB (21%) patients, but not NW patients (0%; p <0.001). OW and OB patients had higher fasting insulin (p<0.001) and lower HDL cholesterol (p=0.005) than NW patients, although screening rates were low. BMI Z-scores decreased in both OW and OB patients over time (0.07 units/year; p<0.001). Conclusions Most patients with PCOS were OW/OB. Substantial clinical variability existed in CVD screening; among those screened, OW and OB patients had greater CVD risk factors. Despite self-reported concerns about weight and diabetes risk among OW/OB patients, no clinically significant change in BMI percentile occurred. Evidence-based interventions and recommendations for screening tests are needed to address CVD risk in adolescents and young adults with PCOS. PMID:26081478

  11. The Global Cardiovascular Risk Transition: Associations of Four Metabolic Risk Factors with Macroeconomic Variables in 1980 and 2008

    PubMed Central

    Danaei, Goodarz; Singh, Gitanjali M; Paciorek, Christopher J; Lin, John K; Cowan, Melanie J; Finucane, Mariel M; Farzadfar, Farshad; Stevens, Gretchen A; Riley, Leanne M; Lu, Yuan; Rao, Mayuree; Ezzati, Majid

    2014-01-01

    Background It is commonly assumed that globally CVD risk factors are associated with affluence and Westernization. We investigated the associations of body mass index (BMI), fasting plasma glucose (FPG), systolic blood pressure (SBP), and serum total cholesterol (TC) with national income, Western diet, and (for BMI) urbanization in 1980 and 2008. Methods and Results Country-level risk factor estimates for 199 countries between 1980 and 2008 were from a previous systematic analysis of population-based data. We analyzed the associations between risk factors and natural logarithm of per-capita GDP [Ln(GDP)], a measure of Western diet, and (for BMI) percent population living in urban areas. In 1980, there was a positive association between national income and population mean BMI, SBP, and TC. By 2008, the slope of the association between Ln(GDP) and SBP became negative for women and zero for men. TC was associated with national income and Western diet throughout the period. In 1980, BMI rose with per-capita GDP and then flattened at about Int$7000; by 2008, the relationship resembled an inverted-U for women, peaking at middle income levels. BMI had a positive relationship with percent urban population in both 1980 and 2008. FPG had weaker associations with these country macro characteristics, but was positively associated with BMI. Conclusions The changing associations of metabolic risk factors with macroeconomic variables indicate that there will be a global pandemic of hyperglycemia and diabetes, together with high blood pressure in low income countries, unless effective lifestyle, and pharmacological interventions are implemented. PMID:23481623

  12. Coconut fragrance and cardiovascular response to laboratory stress: results of pilot testing.

    PubMed

    Mezzacappa, Elizabeth Sibolboro; Arumugam, Uma; Chen, Sylvia Yue; Stein, Traci R; Oz, Mehmet; Buckle, Jane

    2010-01-01

    There is preliminary evidence that pleasant fragrances may alter response to stressors in different settings. This pilot study examined the effect of coconut fragrance on cardiovascular response to standard laboratory stressors. While inhaling coconut fragrance (n = 17) or air (n = 15), subjects performed a Stroop color-word task and a mental arithmetic task. Heart rate (HR), heart period variability (HPV) and blood pressure were measured during the 5-minute baseline, the task, and the recovery periods. The results indicated that subjects breathing coconut fragrance had higher HR and lower HPV than those who performed tasks while breathing air. HR response to mental arithmetic seemed to be blunted in the subjects breathing coconut; however, the lack of a difference in HPV seems to indicate that the blunting may be due to decreased sympathetic response, not decreased parasympathetic withdrawal under stress. Blood pressure recovery was slightly enhanced in subjects under coconut fragrance. Thus, the results of this pilot test suggest that coconut fragrance may alter cardiovascular activity both at rest and in response to stressors. Future experimentation should attempt to replicate and extend these findings in larger samples in clinical settings.

  13. Breath-by-breath measurement of particle deposition in the lung of spontaneously breathing rats.

    PubMed

    Karrasch, S; Eder, G; Bolle, I; Tsuda, A; Schulz, H

    2009-10-01

    A number of deposition models for humans, as well as experimental animals, have been described. However, no breath-by-breath deposition measurement in rats has been reported to date. The objective of this study is to determine lung deposition of micrometer-sized particles as a function of breathing parameters in the adult rat lung. A new aerosol photometry system was designed to measure deposition of nonhygroscopic, 2-mum sebacate particles in anesthetized, intubated, and spontaneously breathing 90-day-old Wistar-Kyoto rats placed in a size-adjusted body plethysmograph box. Instrumental dead space of the system was minimized down to 310 microl (i.e., approximately 20% of respiratory dead space). The system allows continuous monitoring of particle concentration in the respired volume. Breathing parameters, such as respiratory rate (f), tidal volume (Vt), as well as inspiration/expiration times, were also monitored at different levels of anesthesia. The results showed that Vt typically varied between 1.5 and 4.0 ml for regular breathing and between 4.0 and 10.0 ml for single-sigh breaths; f ranged from 40 to 200 breaths/min. Corresponding deposition values varied between 5 and 50%, depending on breath-by-breath breathing patterns. The best fit of deposition (D) was achieved by a bilinear function of Vt and f and found to be D = 11.0 - 0.09.f + 3.75.Vt. We conclude that our approach provides more realistic conditions for the measurement of deposition than conventional models using ventilated animals and allows us to analyze the correlation between breath-specific deposition and spontaneous breathing patterns.

  14. EFFECT OF BODY SIZE ON BREATHING PATTERN AND FINE PARTICLE DEPOSITION IN CHILDREN

    EPA Science Inventory

    Inter-child variability in breathing patterns may contribute to variability in fine particle, lung deposition and morbidity in children associated with those particles. Fractional deposition (DF) of fine particles (2um monodisperse, carnauba wax particles) was measured in healthy...

  15. EFFECT OF BODY SIZE ON BREATHING PATTERN AND FINE PARTICLE DEPOSITION IN CHILDREN

    EPA Science Inventory

    Inter-child variability in breathing patterns may contribute to variability in fine particle, lung deposition and morbidity in children associated with those particles. Fractional deposition (DF) of fine particles (2um monodisperse, carnauba wax particles) was measured in healthy...

  16. Probing plasmonic breathing modes optically

    SciTech Connect

    Krug, Markus K. Reisecker, Michael; Hohenau, Andreas; Ditlbacher, Harald; Trügler, Andreas; Hohenester, Ulrich; Krenn, Joachim R.

    2014-10-27

    The confinement of surface plasmon modes in flat nanoparticles gives rise to plasmonic breathing modes. With a vanishing net dipole moment, breathing modes do not radiate, i.e., they are optically dark. Having thus escaped optical detection, breathing modes were only recently revealed in silver nanodisks with electron energy loss spectroscopy in an electron microscope. We show that for disk diameters >200 nm, retardation induced by oblique optical illumination relaxes the optically dark character. This makes breathing modes and thus the full plasmonic mode spectrum accessible to optical spectroscopy. The experimental spectroscopy data are in excellent agreement with numerical simulations.

  17. Clinical estimation of mouth breathing.

    PubMed

    Fujimoto, Sachiko; Yamaguchi, Kazunori; Gunjigake, Kaori

    2009-11-01

    Breathing mode was objectively determined by monitoring airflow through the mouth, measuring nasal resistance and lip-seal function, and collecting information via questionnaire on the patient's etiology and symptoms of mouth breathing. The expiratory airflow through the mouth was detected with a carbon dioxide sensor for 30 minutes at rest. Fifteen men and 19 women volunteers (mean age, 22.4 +/- 2.5 years) were classified as nasal breathers, complete mouth breathers, or partial mouth breathers based on the mean duration of mouth breathing. Nasal resistance, lip-sealing function, and the subjective symptoms of mouth breathing ascertained by questionnaire were statistically compared by using 1-way and 2-way analysis of variance (ANOVA) and the chi-square test in the breathing groups. Nasal resistance was significantly (P <0.05) greater for the mouth breathers than for the nasal breathers, and significantly (P <0.05) greater for the partial mouth breathers than for the complete mouth breathers. There were no significant differences in the subjective responses to questions about mouth breathing among the 3 groups. Detecting airflow by carbon dioxide sensor can discriminate breathing mode. Degree of nasal resistance and subjective symptoms of mouth breathing do not accurately predict breathing mode.

  18. Effect of a 16-week Bikram yoga program on heart rate variability and associated cardiovascular disease risk factors in stressed and sedentary adults: A randomized controlled trial.

    PubMed

    Hewett, Zoe L; Pumpa, Kate L; Smith, Caroline A; Fahey, Paul P; Cheema, Birinder S

    2017-04-21

    Chronic activation of the stress-response can contribute to cardiovascular disease risk, particularly in sedentary individuals. This study investigated the effect of a Bikram yoga intervention on the high frequency power component of heart rate variability (HRV) and associated cardiovascular disease (CVD) risk factors (i.e. additional domains of HRV, hemodynamic, hematologic, anthropometric and body composition outcome measures) in stressed and sedentary adults. Eligible adults were randomized to an experimental group (n = 29) or a no treatment control group (n = 34). Experimental group participants were instructed to attend three to five supervised Bikram yoga classes per week for 16 weeks at local studios. Outcome measures were assessed at baseline (week 0) and completion (week 17). Sixty-three adults (37.2 ± 10.8 years, 79% women) were included in the intention-to-treat analysis. The experimental group attended 27 ± 18 classes. Analyses of covariance revealed no significant change in the high-frequency component of HRV (p = 0.912, partial η (2) = 0.000) or in any secondary outcome measure between groups over time. However, regression analyses revealed that higher attendance in the experimental group was associated with significant reductions in diastolic blood pressure (p = 0.039; partial η (2) = 0.154), body fat percentage (p = 0.001, partial η (2) = 0.379), fat mass (p = 0.003, partial η (2) = 0.294) and body mass index (p = 0.05, partial η (2) = 0.139). A 16-week Bikram yoga program did not increase the high frequency power component of HRV or any other CVD risk factors investigated. As revealed by post hoc analyses, low adherence likely contributed to the null effects. Future studies are required to address barriers to adherence to better elucidate the dose-response effects of Bikram yoga practice as a medium to lower stress-related CVD risk. Retrospectively registered with Australia New Zealand Clinical Trials Registry

  19. Association of Holter-Derived Heart Rate Variability Parameters With the Development of Congestive Heart Failure in the Cardiovascular Health Study.

    PubMed

    Patel, Vaiibhav N; Pierce, Brian R; Bodapati, Rohan K; Brown, David L; Ives, Diane G; Stein, Phyllis K

    2017-06-01

    This study sought to determine whether Holter-based parameters of heart rate variability (HRV) are independently associated with incident heart failure among older adults in the CHS (Cardiovascular Health Study) as evidenced by an improvement in the predictive power of the Health Aging and Body Composition Heart Failure (Health ABC) score. Abnormal HRV, a marker of autonomic dysfunction, has been associated with multiple adverse cardiovascular outcomes but not the development of congestive heart failure (CHF). Asymptomatic CHS participants with interpretable 24-h baseline Holter recordings were included (n = 1,401). HRV measures and premature ventricular contraction (PVC) counts were compared between participants with (n = 260) and without (n = 1,141) incident CHF on follow-up. Significantly different parameters between groups were added to the components of the Health ABC score, a validated CHF prediction tool, using stepwise Cox regression. The final model included components of the Health ABC score, In PVC counts (adjusted hazard ratio [aHR]: 1.12; 95% confidence interval [CI]: 1.07 to 1.19; p < 0.001) and the following HRV measures: abnormal heart rate turbulence onset (aHR: 1.52; 95% CI: 1.11 to 2.08; p = 0.009), short-term fractal scaling exponent (aHR: 0.27; 95% CI: 0.14 to 0.53; p < 0.001), in very low frequency power (aHR: 1.28; 95% CI: 1.02 to 1.60; p = 0.037), and coefficient of variance of N-N intervals (aHR: 0.94; 95% CI: 0.90 to 0.99; p = 0.009). The C-statistic for the final model was significantly improved over the Health ABC model alone (0.77 vs. 0.73; p = 0.0002). Abnormal HRV parameters were significantly and independently associated with incident CHF in asymptomatic, older adults. When combined with increased PVCs, HRV improved the predictive power of the Health ABC score. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  20. Efficient storage system for breath hydrogen.

    PubMed

    Murray, R D; Kerzner, B; MacLean, W C; McClung, H J; Gilbert, M

    1985-10-01

    Recommended materials for breath hydrogen collection (plastic syringes with twist lock closure) are only adequate for relatively brief periods because of gradual hydrogen loss and considerable variability between duplicate samples. To document the most favorable storage conditions for breath hydrogen, we compared hydrogen retention in plastic syringes using a conventional twist-in-lock closure versus a simple, inexpensive syringe closure, a Critocap. Hydrogen retention was studied at 25, 5, and -20 degrees C in two different syringe brands over 72 h of storage. An analysis of variance confirms the superiority of Critocaps over twist-in-lock closures (p less than 0.001). Reliability was maximal when samples were placed in environments less than 5 degrees C. When storage time was extended to 7 days, mean hydrogen retention was 86 +/- 6% (means +/- SD).

  1. Sleep-Disordered Breathing in Patients with Heart Failure: New Trends in Therapy

    PubMed Central

    Kazimierczak, Anna; Krzesiński, Paweł; Krzyżanowski, Krystian; Gielerak, Grzegorz

    2013-01-01

    Heart failure (HF) is a growing health problem which paradoxically results from the advances in the treatment of etiologically related diseases (especially coronary artery disease). HF is commonly accompanied by sleep-disordered breathing (SDB), which may directly exacerbate the clinical manifestations of cardiovascular disease and confers a poorer prognosis. Obstructive sleep apnoea predominates in mild forms while central sleep apnoea in more severe forms of heart failure. Identification of SDB in patients with HF is important, as its effective treatment may result in notable clinical benefits to the patients. Continuous positive airway pressure (CPAP) is the gold standard in the management of SDB. The treatments for central breathing disorders include CPAP, bilevel positive airway pressure (BPAP), and adaptive servoventilation (ASV), with the latter being the most modern method of treatment for the Cheyne-Stokes respiration and involving ventilation support with a variable synchronisation dependent on changes in airflow through the respiratory tract and on the patient's respiratory rate. ASV exerts the most favourable effect on long-term prognosis. In this paper, we review the current state of knowledge on the diagnosis and treatment of SDB with a particular emphasis on the latest methods of treatment. PMID:23984365

  2. Effects of dietary inorganic nitrate on static and dynamic breath-holding in humans.

    PubMed

    Schiffer, Tomas A; Larsen, Filip J; Lundberg, Jon O; Weitzberg, Eddie; Lindholm, Peter

    2013-01-15

    Inorganic nitrate has been shown to reduce oxygen cost during exercise. Since the nitrate-nitrite-NO pathway is facilitated during hypoxia, we investigated the effects of dietary nitrate on oxygen consumption and cardiovascular responses during apnea. These variables were measured in two randomized, double-blind, placebo-controlled, crossover protocols at rest and ergometer exercise in competitive breath-hold divers. Subjects held their breath for predetermined times along with maximum effort apneas after two separate 3-day periods with supplementation of potassium nitrate/placebo. In contrast to our hypothesis, nitrate supplementation led to lower arterial oxygen saturation (SaO(2), 77 ± 3%) compared to placebo (80 ± 2%) during static apnea, along with lower end-tidal fraction of oxygen (FETO(2)) after 4 min of apnea (nitrate 6.9 ± 0.4% vs. placebo 7.6 ± 0.4%). Maximum apnea duration was shorter after nitrate (329 ± 13 s) compared to placebo (344 ± 13 s). During cycle ergometry nitrate had no effect on SaO(2), FETO(2) or maximum apnea duration. The negative effects of inorganic nitrate during static apnea may be explained by an attenuated diving response. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Sleep-Disordered Breathing

    PubMed Central

    Markov, Dimitri; Doghramji, Karl

    2006-01-01

    Sleep disorders are becoming more prevalent. There is an overlap of symptoms related to obstructive sleep apnea syndrome (OSAS) and many psychiatric conditions. Complaints of excessive sleepiness, insomnia, cognitive dysfunction, and depressive symptoms can be related to both disease states. Obstructive sleep apnea syndrome is characterized by repetitive disruption of sleep by cessation of breathing and was first described in the 19th century by bedside observation during sleep. Physicians observed this cessation of breathing while the patient slept and postulated that these episodes were responsible for subsequent complaints of sleepiness. OSAS can coexist with major depressive disorder, exacerbate depressive symptoms, or be responsible for a large part of the symptom complex of depression. Additionally, in schizophrenia, sleep apnea may develop as a result of chronic neuroleptic treatment and its effect on gains in body weight, a major risk factor for the development of OSAS. It is important to recognize the signs and symptoms of sleep apnea, namely excessive daytime sleepiness, snoring, and witnessed apneas. Recognition of the existence of sleep apnea, prompt referral to a sleep specialist, and ultimately treatment of an underlying sleep disorder, such as OSAS, can ameliorate symptoms of psychiatric disease. PMID:20975818

  4. 42 CFR 84.81 - Compressed breathing gas and liquefied breathing gas containers; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Compressed breathing gas and liquefied breathing... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.81 Compressed breathing gas and liquefied breathing gas containers; minimum requirements. (a) Compressed breathing gas...

  5. 42 CFR 84.81 - Compressed breathing gas and liquefied breathing gas containers; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Compressed breathing gas and liquefied breathing... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.81 Compressed breathing gas and liquefied breathing gas containers; minimum requirements. (a) Compressed breathing gas...

  6. 42 CFR 84.81 - Compressed breathing gas and liquefied breathing gas containers; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Compressed breathing gas and liquefied breathing... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.81 Compressed breathing gas and liquefied breathing gas containers; minimum requirements. (a) Compressed breathing gas...

  7. Cardiovascular group

    NASA Technical Reports Server (NTRS)

    Blomqvist, Gunnar

    1989-01-01

    As a starting point, the group defined a primary goal of maintaining in flight a level of systemic oxygen transport capacity comparable to each individual's preflight upright baseline. The goal of maintaining capacity at preflight levels would seem to be a reasonable objective for several different reasons, including the maintenance of good health in general and the preservation of sufficient cardiovascular reserve capacity to meet operational demands. It is also important not to introduce confounding variables in whatever other physiological studies are being performed. A change in the level of fitness is likely to be a significant confounding variable in the study of many organ systems. The principal component of the in-flight cardiovascular exercise program should be large-muscle activity such as treadmill exercise. It is desirable that at least one session per week be monitored to assure maintenance of proper functional levels and to provide guidance for any adjustments of the exercise prescription. Appropriate measurements include evaluation of the heart-rate/workload or the heart-rate/oxygen-uptake relationship. Respiratory gas analysis is helpful by providing better opportunities to document relative workload levels from analysis of the interrelationships among VO2, VCO2, and ventilation. The committee felt that there is no clear evidence that any particular in-flight exercise regimen is protective against orthostatic hypotension during the early readaptation phase. Some group members suggested that maintenance of the lower body muscle mass and muscle tone may be helpful. There is also evidence that late in-flight interventions to reexpand blood volume to preflight levels are helpful in preventing or minimizing postflight orthostatic hypotension.

  8. A Pilot Study on the Effects of Slow Paced Breathing on Current Food Craving.

    PubMed

    Meule, Adrian; Kübler, Andrea

    2017-03-01

    Heart rate variability biofeedback (HRV-BF) involves slow paced breathing (approximately six breaths per minute), thereby maximizing low-frequent heart rate oscillations and baroreflex gain. Mounting evidence suggests that HRV-BF promotes symptom reductions in a variety of physical and mental disorders. It may also positively affect eating behavior by reducing food cravings. The aim of the current study was to investigate if slow paced breathing can be useful for attenuating momentary food craving. Female students performed paced breathing either at six breaths per minute (n = 32) or at nine breaths per minute (n = 33) while watching their favorite food on the computer screen. Current food craving decreased during a first resting period, increased during paced breathing, and decreased during a second resting period in both conditions. Although current hunger increased in both conditions during paced breathing as well, it remained elevated after the second resting period in the nine breaths condition only. Thus, breathing rate did not influence specific food craving, but slow paced breathing appeared to have a delayed influence on state hunger. Future avenues are suggested for the study of HRV-BF in the context of eating behavior.

  9. Cardiovascular modeling and diagnostics

    SciTech Connect

    Kangas, L.J.; Keller, P.E.; Hashem, S.; Kouzes, R.T.

    1995-12-31

    In this paper, a novel approach to modeling and diagnosing the cardiovascular system is introduced. A model exhibits a subset of the dynamics of the cardiovascular behavior of an individual by using a recurrent artificial neural network. Potentially, a model will be incorporated into a cardiovascular diagnostic system. This approach is unique in that each cardiovascular model is developed from physiological measurements of an individual. Any differences between the modeled variables and the variables of an individual at a given time are used for diagnosis. This approach also exploits sensor fusion to optimize the utilization of biomedical sensors. The advantage of sensor fusion has been demonstrated in applications including control and diagnostics of mechanical and chemical processes.

  10. The US Navy/Canadian DCIEM research initiative on pressure breathing physiology

    NASA Technical Reports Server (NTRS)

    Whitley, Phillip E.

    1994-01-01

    Development of improved positive pressure breathing garments for altitude and acceleration protection has occurred without collection of sufficient physiological data to understand the mechanisms of the improvement. Furthermore, modeling of the predicted response of future enhanced garments is greatly hampered by this lack of information. A joint, international effort is under way between Canada's Defense and Civil Institute for Environmental Medicine (DCIEM) and the US Navy's Naval Air Warfare Center Aircraft Division, Warminster (NAWCACDIVWAR). Using a Canadian subject pool, experiments at both the DCIEM altitude facility and the NAWCADIVWAR Dynamic Flight Simulator have been conducted to determine the cardiovascular and respiratory consequences of high levels of positive pressure breathing for altitude and positive pressure breathing for acceleration protection. Various improved pressure breathing garments were used to collect comparative physiological and performance data. New pressure breathing level and durahon capabilities have been encountered. Further studies will address further improvements in pressure suit design and correlation of altitude and acceleration data.

  11. The US Navy/Canadian DCIEM research initiative on pressure breathing physiology

    NASA Technical Reports Server (NTRS)

    Whitley, Phillip E.

    1994-01-01

    Development of improved positive pressure breathing garments for altitude and acceleration protection has occurred without collection of sufficient physiological data to understand the mechanisms of the improvement. Furthermore, modeling of the predicted response of future enhanced garments is greatly hampered by this lack of information. A joint, international effort is under way between Canada's Defense and Civil Institute for Environmental Medicine (DCIEM) and the US Navy's Naval Air Warfare Center Aircraft Division, Warminster (NAWCACDIVWAR). Using a Canadian subject pool, experiments at both the DCIEM altitude facility and the NAWCADIVWAR Dynamic Flight Simulator have been conducted to determine the cardiovascular and respiratory consequences of high levels of positive pressure breathing for altitude and positive pressure breathing for acceleration protection. Various improved pressure breathing garments were used to collect comparative physiological and performance data. New pressure breathing level and durahon capabilities have been encountered. Further studies will address further improvements in pressure suit design and correlation of altitude and acceleration data.

  12. Breath in the technoscientific imaginary

    PubMed Central

    Rose, Arthur

    2016-01-01

    Breath has a realist function in most artistic media. It serves to remind the reader, the viewer or the spectator of the exigencies of the body. In science fiction (SF) literature and films, breath is often a plot device for human encounters with otherness, either with alien peoples, who may not breathe oxygen, or environments, where there may not be oxygen to breathe. But while there is a technoscientific quality to breath in SF, especially in its attention to physiological systems, concentrating on the technoscientific threatens to occlude other, more affective aspects raised by the literature. In order to supplement the tendency to read SF as a succession of technoscientific accounts of bodily experience, this paper recalls how SF texts draw attention to the affective, non-scientific qualities of breath, both as a metonym for life and as a metaphor for anticipation. Through an engagement with diverse examples from SF literature and films, this article considers the tension between technoscientific and affective responses to breath in order to demonstrate breath's co-determinacy in SF's blending of scientific and artistic discourses. PMID:27542677

  13. BREATHE to Understand©

    ERIC Educational Resources Information Center

    Swisa, Maxine

    2015-01-01

    BREATHE is an acronym for Breathe, Reflect, Empathize, Accept, Thank, Hearten, Engage. The addition of Understand allows for a holistic approach to living a healthy and balanced life both inside and outside the classroom. This paper took form as a result of my personal, spiritual journey, as well as my teaching practice. I noticed that the…

  14. Hydrogen breath test in schoolchildren.

    PubMed

    Douwes, A C; Schaap, C; van der Klei-van Moorsel, J M

    1985-04-01

    The frequency of negative hydrogen breath tests due to colonic bacterial flora which are unable to produce hydrogen was determined after oral lactulose challenge in 98 healthy Dutch schoolchildren. There was a negative result in 9.2%. The probability of a false normal lactose breath test (1:77) was calculated from these results together with those from a separate group of children with lactose malabsorption (also determined by hydrogen breath test). A study of siblings and mothers of subjects with a negative breath test did not show familial clustering of this condition. Faecal incubation tests with various sugars showed an increase in breath hydrogen greater than 100 parts per million in those with a positive breath test while subjects with a negative breath test also had a negative faecal incubation test. The frequency of a false negative hydrogen breath test was higher than previously reported, but this does not affect the superiority of this method of testing over the conventional blood glucose determination.

  15. Clinical applications of breath testing

    PubMed Central

    Paschke, Kelly M; Mashir, Alquam

    2010-01-01

    Breath testing has the potential to benefit the medical field as a cost-effective, non-invasive diagnostic tool for diseases of the lung and beyond. With growing evidence of clinical worth, standardization of methods, and new sensor and detection technologies the stage is set for breath testing to gain considerable attention and wider application in upcoming years. PMID:21173863

  16. Breath in the technoscientific imaginary.

    PubMed

    Rose, Arthur

    2016-12-01

    Breath has a realist function in most artistic media. It serves to remind the reader, the viewer or the spectator of the exigencies of the body. In science fiction (SF) literature and films, breath is often a plot device for human encounters with otherness, either with alien peoples, who may not breathe oxygen, or environments, where there may not be oxygen to breathe. But while there is a technoscientific quality to breath in SF, especially in its attention to physiological systems, concentrating on the technoscientific threatens to occlude other, more affective aspects raised by the literature. In order to supplement the tendency to read SF as a succession of technoscientific accounts of bodily experience, this paper recalls how SF texts draw attention to the affective, non-scientific qualities of breath, both as a metonym for life and as a metaphor for anticipation. Through an engagement with diverse examples from SF literature and films, this article considers the tension between technoscientific and affective responses to breath in order to demonstrate breath's co-determinacy in SF's blending of scientific and artistic discourses. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  17. Patient's breath controls comfort devices

    NASA Technical Reports Server (NTRS)

    Schrader, M.; Carpenter, B.; Nichols, C. D.

    1972-01-01

    Patient assist system for totally disabled persons was developed which permits a person, so paralyzed as to be unable to move, to activate by breathing, a call system to summon assistance, turn the page of a book, ajust his bed, or do any one of a number of other things. System consists of patient assist control and breath actuated switch.

  18. Long-term blood pressure variability in patients with rheumatoid arthritis (RA) and its impact on cardiovascular events and all-cause mortality in RA: a population-based comparative cohort study

    PubMed Central

    Myasoedova, Elena; Crowson, Cynthia S.; Green, Abigail B.; Matteson, Eric L.; Gabriel, Sherine E.

    2014-01-01

    Objectives To examine long-term visit-to-visit blood pressure (BP) variability in rheumatoid arthritis (RA) vs non-RA subjects and to assess its impact on cardiovascular events and mortality in RA. Methods Clinic BP measures were collected in a population-based incident cohort of RA patients (1987 ACR criteria met between 1/1/1995 and 1/1/2008) and non-RA subjects. BP variability was defined as within-subject standard deviation (SD) in systolic and diastolic BP. Results Study included 442 RA patients (mean age 55.5 years, 70% females) and 424 non-RA subjects (mean age 55.7 years, 69% females). RA patients had higher visit-to-visit variability in systolic BP (13.8±4.7 mm Hg), than non-RA subjects (13.0±5.2 mm Hg, p=0.004). Systolic BP variability declined after the index date in RA (p<0.001), but not in the non-RA cohort (p=0.73), adjusting for age, sex and calendar year of RA. During the mean follow-up of 7.1 years, 33 cardiovascular events and 57 deaths occurred in RA cohort. Visit-to-visit systolic BP variability was associated with increased risk of cardiovascular events (hazard ratio [HR] per 1 mm Hg increase in BP variability 1.12, 95% confidence interval [CI] 1.01-1.25); diastolic BP variability was associated with all-cause mortality in RA (HR 1.14, 95%CI 1.03-1.27), adjusting for systolic and diastolic BP, body mass index, smoking, diabetes, dyslipidemia, use of antihypertensives. Conclusion Patients with RA had higher visit-to-visit systolic BP variability vs non-RA subjects. There was a significant decline in systolic BP variability after RA incidence. Higher visit-to-visit BP variability was associated with adverse cardiovascular outcomes and all-cause mortality in RA. PMID:24986852

  19. Predictive value of beat-to-beat QT variability index across the continuum of left ventricular dysfunction: competing risks of noncardiac or cardiovascular death and sudden or nonsudden cardiac death.

    PubMed

    Tereshchenko, Larisa G; Cygankiewicz, Iwona; McNitt, Scott; Vazquez, Rafael; Bayes-Genis, Antoni; Han, Lichy; Sur, Sanjoli; Couderc, Jean-Philippe; Berger, Ronald D; de Luna, Antoni Bayes; Zareba, Wojciech

    2012-08-01

    The goal of the present study was to determine the predictive value of beat-to-beat QT variability in heart failure patients across the continuum of left ventricular dysfunction. Beat-to-beat QT variability index (QTVI), log-transformed heart rate variance, normalized QT variance, and coherence between heart rate variability and QT variability have been measured at rest during sinus rhythm in 533 participants of the Muerte Subita en Insuficiencia Cardiaca heart failure study (mean age, 63.1±11.7; men, 70.6%; left ventricular ejection fraction >35% in 254 [48%]) and in 181 healthy participants from the Intercity Digital Electrocardiogram Alliance database. During a median of 3.7 years of follow-up, 116 patients died, 52 from sudden cardiac death (SCD). In multivariate competing risk analyses, the highest QTVI quartile was associated with cardiovascular death (subhazard ratio, 1.67 [95% CI, 1.14-2.47]; P=0.009) and, in particular, with non-SCD (subhazard ratio, 2.91 [1.69-5.01]; P<0.001). Elevated QTVI separated 97.5% of healthy individuals from subjects at risk for cardiovascular (subhazard ratio, 1.57 [1.04-2.35]; P=0.031) and non-SCD in multivariate competing risk model (subhazard ratio, 2.58 [1.13-3.78]; P=0.001). No interaction between QTVI and left ventricular ejection fraction was found. QTVI predicted neither noncardiac death (P=0.546) nor SCD (P=0.945). Decreased heart rate variability rather than increased QT variability was the reason for increased QTVI in the present study. Increased QTVI because of depressed heart rate variability predicts cardiovascular mortality and non-SCD but neither SCD nor extracardiac mortality in heart failure across the continuum of left ventricular dysfunction. Abnormally augmented QTVI separates 97.5% of healthy individuals from heart failure patients at risk.

  20. Significance of Cardiac Rehabilitation on Visit-to-Visit Variability of Blood Pressure in Patients With Cardiovascular Disease in a 12-Month Follow-Up

    PubMed Central

    Ishida, Toshihisa; Miura, Shin-ichiro; Fujimi, Kanta; Futami, Makito; Ueda, Yoko; Ueda, Takashi; Arimura, Tadaaki; Koyoshi, Rie; Shiga, Yuhei; Kitajima, Ken; Saku, Keijiro

    2017-01-01

    Background Visit-to-visit variability (VVV) in blood pressure (BP) has been shown to be a strong predictor of cardiovascular disease (CVD). However, the long-term effect of comprehensive cardiac rehabilitation (CR) with exercise training on VVV in BP has not yet been established. Therefore, we evaluated the long-term effects of CR on VVV in BP in patients with CVD. Methods Twenty-two CVD patients in a 12-month CR program who had at least six clinic visits per month to measure BP were enrolled. We determined VVV in BP expressed as the standard deviation of average BP every month for 12 months. Results The mean age was 70 ± 8 years and the body mass index was 24.4 ± 4.9 kg/m2. In addition, the percentage (%) of males, % heart failure and % ischemic heart disease were 77%, 55% and 27%, respectively. Patients who had uncontrolled BP at baseline showed a significant reduction of both systolic BP (SBP) and diastolic BP (DBP). VVV in SBP in the first month was significantly less than that in the last month, although there was no difference in VVV in DBP. Patients were divided into larger (L-) and smaller (S-) VVV in SBP groups according to the average value of VVV in SBP as a cut-off. The L-VVV in SBP group, but not the S-VVV in SBP group, showed a significant reduction of VVV in SBP. Conclusion Comprehensive CR may improve VVV in SBP in CVD patients who have larger VVV in SBP. PMID:28270895

  1. Breath of hospitality.

    PubMed

    Škof, Lenart

    2016-12-01

    In this paper we outline the possibilities of an ethic of care based on our self-affection and subjectivity in the ethical spaces between-two. In this we first refer to three Irigarayan concepts - breath, silence and listening from the third phase of her philosophy, and discuss them within the methodological framework of an ethics of intersubjectivity and interiority. Together with attentiveness, we analyse them as four categories of our ethical becoming. Furthermore, we argue that self-affection is based on our inchoate receptivity for the needs of the other(s) and is thus dialectical in its character. In this we critically confront some epistemological views of our ethical becoming. We wind up this paper with a proposal for an ethics towards two autonomous subjects, based on care and our shared ethical becoming - both as signs of our deepest hospitality towards the other.

  2. Breathing zone air sampler

    SciTech Connect

    Tobin, J.

    1989-08-22

    A sampling apparatus is presented which comprises a sampler for sampling air in the breathing zone of a wearer of the apparatus and a support for the sampler preferably in the form of a pair of eyeglasses. The sampler comprises a sampling assembly supported on the frame of the eyeglasses and including a pair of sample transport tubes which are suspended, in use, centrally of the frame so as to be disposed on opposite sides of the nose of the wearer and which each include an inlet therein that, in use, is disposed adjacent to a respective nostril of the nose of the wearer. A filter holder connected to sample transport tubes supports a removable filter for filtering out particulate material in the air sampled by the apparatus. The sample apparatus is connected to a pump for drawing air into the apparatus through the tube inlets so that the air passes through the filter.

  3. Breathing zone air sampler

    DOEpatents

    Tobin, John

    1989-01-01

    A sampling apparatus is provided which comprises a sampler for sampling air in the breathing zone of a wearer of the apparatus and a support for the sampler preferably in the form of a pair of eyeglasses. The sampler comprises a sampling assembly supported on the frame of the eyeglasses and including a pair of sample transport tubes which are suspended, in use, centrally of the frame so as to be disposed on opposite sides of the nose of the wearer and which each include an inlet therein that, in use, is disposed adjacent to a respective nostril of the nose of the wearer. A filter holder connected to sample transport tubes supports a removable filter for filtering out particulate material in the air sampled by the apparatus. The sample apparatus is connected to a pump for drawing air into the apparatus through the tube inlets so that the air passes through the filter.

  4. Energy breathing of nanoparticles

    NASA Astrophysics Data System (ADS)

    Dynich, Raman A.

    2015-06-01

    The paper considers the energy exchange process of the electromagnetic wave with a spherical metal nanoparticle. Based on the account of the temporal dependencies of electric and magnetic fields, the author presents an analytical dependence of the energy flow passing through the spherical surface. It is shown that the electromagnetic energy, localized in metal nanoparticles, is not a stationary value and periodically varies with time. A consequence of the energy nonstationarity is a nonradiating exit of the electromagnetic energy out of the nanoparticle. During the time equal to the period of wave oscillations, the electromagnetic energy is penetrating twice into the particle and quits it twice. The particle warms up because of the difference in the incoming and outgoing energies. Such "energy breathing" is presented for spherical Ag and Au nanoparticles with radii of 10 i 33 nm, respectively. Calculations were conducted for these nanoparticles embedded into the cell cytoplasm near the frequencies of their surface plasmon resonances.

  5. Impact of Real-Time Continuous Glucose Monitoring Use on Glucose Variability and Endothelial Function in Adolescents with Type 1 Diabetes: New Technology—New Possibility to Decrease Cardiovascular Risk?

    PubMed Central

    Jamiołkowska, Milena; Jamiołkowska, Izabela; Łuczyński, Włodzimierz; Tołwińska, Joanna; Bossowski, Artur; Głowińska Olszewska, Barbara

    2016-01-01

    Children with type 1 diabetes (T1DM) are the high-risk group of accelerated atherosclerosis. Real-time continuous glucose monitoring (RT-CGM) provides possibilities for the detection of glycaemic variability, newly recognized cardiovascular risk factor. The aim of the study was to assess the usefulness of RT-CGM as an educational tool to find and reduce glycaemic variability in order to improve endothelial function in T1DM adolescents. Forty patients aged 14.6 years were recruited. The study was based on one-month CGM sensors use. Parameters of glycaemic variability were analyzed during first and last sensor use, together with brachial artery flow-mediated dilatation (FMD) to assess endothelial function. In the whole group, FMD improvement was found (10.9% to 16.6%, p < 0.005), together with decrease in all studied glycaemic variability parameters. In patients with HbA1c improvement compared to the group without HbA1c improvement, we found greater increase of FMD (12% to 19%, p < 0.005 versus 8.2% to 11.3%, p = 0.080) and greater improvement of glucose variability. RT-CGM can be considered as an additional tool that offers T1DM adolescents the quick reaction to decrease glycaemic variability in short time observation. Whether such approach might influence improvement in endothelial function and reduction of the risk of future cardiovascular disease remains to be elucidated. PMID:26649320

  6. Mouth breathing, "nasal disuse," and pediatric sleep-disordered breathing.

    PubMed

    Lee, Seo-Young; Guilleminault, Christian; Chiu, Hsiao-Yean; Sullivan, Shannon S

    2015-12-01

    Adenotonsillectomy (T&A) may not completely eliminate sleep-disordered breathing (SDB), and residual SDB can result in progressive worsening of abnormal breathing during sleep. Persistence of mouth breathing post-T&As plays a role in progressive worsening through an increase of upper airway resistance during sleep with secondary impact on orofacial growth. Retrospective study on non-overweight and non-syndromic prepubertal children with SDB treated by T&A with pre- and post-surgery clinical and polysomnographic (PSG) evaluations including systematic monitoring of mouth breathing (initial cohort). All children with mouth breathing were then referred for myofunctional treatment (MFT), with clinical follow-up 6 months later and PSG 1 year post-surgery. Only a limited subgroup followed the recommendations to undergo MFT with subsequent PSG (follow-up subgroup). Sixty-four prepubertal children meeting inclusion criteria for the initial cohort were investigated. There was significant symptomatic improvement in all children post-T&A, but 26 children had residual SDB with an AHI > 1.5 events/hour and 35 children (including the previous 26) had evidence of "mouth breathing" during sleep as defined [minimum of 44 % and a maximum of 100 % of total sleep time, mean 69 ± 11 % "mouth breather" subgroup and mean 4 ± 3.9 %, range 0 and 10.3 % "non-mouth breathers"]. Eighteen children (follow-up cohort), all in the "mouth breathing" group, were investigated at 1 year follow-up with only nine having undergone 6 months of MFT. The non- MFT subjects were significantly worse than the MFT-treated cohort. MFT led to normalization of clinical and PSG findings. Assessment of mouth breathing during sleep should be systematically performed post-T&A and the persistence of mouth breathing should be treated with MFT.

  7. Sleep and Breathing … and Cancer?

    PubMed Central

    Owens, Robert L.; Gold, Kathryn A.; Gozal, David; Peppard, Paul E.; Jun, Jonathan C.; Dannenberg, Andrew J.; Lippman, Scott M.; Malhotra, Atul

    2016-01-01

    Sleep, like eating and breathing, is an essential part of the daily life cycle. Although the science is still emerging, sleep plays an important role in immune, cardiovascular, and neurocognitive function. Despite its great importance, nearly 40% of US Adults experience problems with sleep ranging from insufficient total sleep time, trouble initiating or maintaining sleep (Insomnia), Circadian Rhythm Disorders, Sleep-Related Movement Disorders, and Sleep-Related Breathing Disorders such as obstructive sleep apnea (OSA). Herein, we discuss new evidence that suggests that sleep may also impact carcinogenesis. Specifically, we review recent epidemiological data suggesting links between cancer and OSA. As OSA is a common, underdiagnosed, and undertreated condition, this has public health implications. Intriguing animal model data support a link between cancer and sleep/OSA, although mechanisms are not yet clear. Leaders in the fields of Sleep Medicine, Pulmonology and Oncology recently met to review and discuss these data, as well as to outline future directions of study. We propose a multidisciplinary, three-pronged approach to studying the associations between cancer and sleep, utilizing mutually interactive epidemiologic studies, pre-clinical models, and early-phase clinical trials. PMID:27604751

  8. Predictive Value of Beat-to-Beat QT Variability Index across the Continuum of Left Ventricular Dysfunction: Competing Risks of Non-cardiac or Cardiovascular Death, and Sudden or Non-Sudden Cardiac Death

    PubMed Central

    Tereshchenko, Larisa G.; Cygankiewicz, Iwona; McNitt, Scott; Vazquez, Rafael; Bayes-Genis, Antoni; Han, Lichy; Sur, Sanjoli; Couderc, Jean-Philippe; Berger, Ronald D.; de Luna, Antoni Bayes; Zareba, Wojciech

    2012-01-01

    Background The goal of this study was to determine the predictive value of beat-to-beat QT variability in heart failure (HF) patients across the continuum of left ventricular dysfunction. Methods and Results Beat-to-beat QT variability index (QTVI), heart rate variance (LogHRV), normalized QT variance (QTVN), and coherence between heart rate variability and QT variability have been measured at rest during sinus rhythm in 533 participants of the Muerte Subita en Insuficiencia Cardiaca (MUSIC) HF study (mean age 63.1±11.7; males 70.6%; LVEF >35% in 254 [48%]) and in 181 healthy participants from the Intercity Digital Electrocardiogram Alliance (IDEAL) database. During a median of 3.7 years of follow-up, 116 patients died, 52 from sudden cardiac death (SCD). In multivariate competing risk analyses, the highest QTVI quartile was associated with cardiovascular death [hazard ratio (HR) 1.67(95%CI 1.14-2.47), P=0.009] and in particular with non-sudden cardiac death [HR 2.91(1.69-5.01), P<0.001]. Elevated QTVI separated 97.5% of healthy individuals from subjects at risk for cardiovascular [HR 1.57(1.04-2.35), P=0.031], and non-sudden cardiac death in multivariate competing risk model [HR 2.58(1.13-3.78), P=0.001]. No interaction between QTVI and LVEF was found. QTVI predicted neither non-cardiac death (P=0.546) nor SCD (P=0.945). Decreased heart rate variability (HRV) rather than increased QT variability was the reason for increased QTVI in this study. Conclusions Increased QTVI due to depressed HRV predicts cardiovascular mortality and non-sudden cardiac death, but neither SCD nor excracardiac mortality in HF across the continuum of left ventricular dysfunction. Abnormally augmented QTVI separates 97.5% of healthy individuals from HF patients at risk. PMID:22730411

  9. Sleep-disordered breathing in acute ischemic stroke and transient ischemic attack: effects on short- and long-term outcome and efficacy of treatment with continuous positive airways pressure--rationale and design of the SAS CARE study.

    PubMed

    Cereda, Carlo W; Petrini, Liliane; Azzola, Andrea; Ciccone, Alfonso; Fischer, Urs; Gallino, Augusto; Györik, Sandor; Gugger, Matthias; Mattis, Johannes; Lavie, Lena; Limoni, Costanzo; Nobili, Lino; Manconi, Mauro; Ott, Sebastian; Pons, Marco; Bassetti, Claudio L

    2012-10-01

    Sleep-disordered breathing represents a risk factor for cardiovascular morbidity and mortality and negatively affects short-term and long-term outcome after an ischemic stroke or transient ischemic attack. The effect of continuous positive airways pressure in patients with sleep-disordered breathing and acute cerebrovascular event is poorly known. The SAS CARE 1 study assesses the effects of sleep-disordered breathing on clinical evolution, vascular functions, and markers within the first three-months after an acute cerebrovascular event. The SAS CARE 2 assesses the effect of continuous positive airways pressure on clinical evolution, cardiovascular events, and mortality as well as vascular functions and markers at 12 and 24 months after acute cerebrovascular event. SAS CARE 1 is an open, observational multicenter study in patients with acute cerebrovascular event acutely admitted in a stroke unit: a sample of 200 acute cerebrovascular event patients will be included. Vascular functions and markers (blood pressure, heart rate variability, endothelial function by peripheral arterial tonometry and specific humoral factors) will be assessed in the acute phase and at three-months follow-up. SAS CARE 2 will include a sample of patients with acute cerebrovascular event in the previous 60-90 days. After baseline assessments, the patients will be classified according to their apnea hypopnea index in four arms: non-sleep-disordered breathing patients (apnea hypopnea index <10), patients with central sleep-disordered breathing, sleepy patients with obstructive apnea hypopnea index ≥20, which will receive continuous positive airways pressure treatment, nonsleepy patients with obstructive sleep-disordered breathing (apnea hypopnea index ≥20), which will be randomized to receive continuous positive airways pressure treatment or not. The SAS CARE study will improve our understanding of the clinical sleep-disordered breathing in patients with acute cerebrovascular event and

  10. Social relations and breath odour.

    PubMed

    McKeown, L

    2003-11-01

    In this retrospective qualitative study, the researcher reviewed 55 client records of The Breath Odour Clinic. The purpose was to determine if individuals attended a clinic specialised in treating oral malodour for medical or social reasons. The study focused on the psychosocial and breath odour history. Clients had agreed to the use of information for research purposes. Society uses odour as a means to define and interact with the world. The olfactory, smelling experience is intimate, emotionally charged and connects us with the world. It follows that the smell from mouth breath odour can connect or disconnect a person from their social environment and intimate relationships. How one experiences one's own body is very personal and private but also very public. Breath odour is public as it occurs within a social and cultural context and personal as it affects one's body image and self-confidence. Body image, self-image and social relations mesh, interact and impact upon each other. Breath odour is a dynamic and interactive aspect of the self-image. In addition, breath odour may be value-coded as 'bad'. In 75% of the cases reviewed, decreased self-confidence and insecurity in social and intimate relations led clients to seek treatment at the specialised breath odour clinic. Their doctor, dental hygienist or dentist had treated medical and oral conditions but not resolved their breath odour problem. When a person perceives a constant bad breath problem, she/he uses defence techniques, and may avoid social situations and social relations. This affects a person's well-being.

  11. Classification of Asthma Based on Nonlinear Analysis of Breathing Pattern

    PubMed Central

    Raoufy, Mohammad Reza; Ghafari, Tara; Darooei, Reza; Nazari, Milad; Mahdaviani, Seyed Alireza; Eslaminejad, Ali Reza; Almasnia, Mehdi; Gharibzadeh, Shahriar; Mani, Ali R.; Hajizadeh, Sohrab

    2016-01-01

    Normal human breathing exhibits complex variability in both respiratory rhythm and volume. Analyzing such nonlinear fluctuations may provide clinically relevant information in patients with complex illnesses such as asthma. We compared the cycle-by-cycle fluctuations of inter-breath interval (IBI) and lung volume (LV) among healthy volunteers and patients with various types of asthma. Continuous respiratory datasets were collected from forty age-matched men including 10 healthy volunteers, 10 patients with controlled atopic asthma, 10 patients with uncontrolled atopic asthma, and 10 patients with uncontrolled non-atopic asthma during 60 min spontaneous breathing. Complexity of breathing pattern was quantified by calculating detrended fluctuation analysis, largest Lyapunov exponents, sample entropy, and cross-sample entropy. The IBI as well as LV fluctuations showed decreased long-range correlation, increased regularity and reduced sensitivity to initial conditions in patients with asthma, particularly in uncontrolled state. Our results also showed a strong synchronization between the IBI and LV in patients with uncontrolled asthma. Receiver operating characteristic (ROC) curve analysis showed that nonlinear analysis of breathing pattern has a diagnostic value in asthma and can be used in differentiating uncontrolled from controlled and non-atopic from atopic asthma. We suggest that complexity analysis of breathing dynamics may represent a novel physiologic marker to facilitate diagnosis and management of patients with asthma. However, future studies are needed to increase the validity of the study and to improve these novel methods for better patient management. PMID:26824900

  12. Classification of Asthma Based on Nonlinear Analysis of Breathing Pattern.

    PubMed

    Raoufy, Mohammad Reza; Ghafari, Tara; Darooei, Reza; Nazari, Milad; Mahdaviani, Seyed Alireza; Eslaminejad, Ali Reza; Almasnia, Mehdi; Gharibzadeh, Shahriar; Mani, Ali R; Hajizadeh, Sohrab

    2016-01-01

    Normal human breathing exhibits complex variability in both respiratory rhythm and volume. Analyzing such nonlinear fluctuations may provide clinically relevant information in patients with complex illnesses such as asthma. We compared the cycle-by-cycle fluctuations of inter-breath interval (IBI) and lung volume (LV) among healthy volunteers and patients with various types of asthma. Continuous respiratory datasets were collected from forty age-matched men including 10 healthy volunteers, 10 patients with controlled atopic asthma, 10 patients with uncontrolled atopic asthma, and 10 patients with uncontrolled non-atopic asthma during 60 min spontaneous breathing. Complexity of breathing pattern was quantified by calculating detrended fluctuation analysis, largest Lyapunov exponents, sample entropy, and cross-sample entropy. The IBI as well as LV fluctuations showed decreased long-range correlation, increased regularity and reduced sensitivity to initial conditions in patients with asthma, particularly in uncontrolled state. Our results also showed a strong synchronization between the IBI and LV in patients with uncontrolled asthma. Receiver operating characteristic (ROC) curve analysis showed that nonlinear analysis of breathing pattern has a diagnostic value in asthma and can be used in differentiating uncontrolled from controlled and non-atopic from atopic asthma. We suggest that complexity analysis of breathing dynamics may represent a novel physiologic marker to facilitate diagnosis and management of patients with asthma. However, future studies are needed to increase the validity of the study and to improve these novel methods for better patient management.

  13. Blood pressure regulation, autonomic control and sleep disordered breathing in children.

    PubMed

    Nisbet, Lauren C; Yiallourou, Stephanie R; Walter, Lisa M; Horne, Rosemary S C

    2014-04-01

    Sleep disordered breathing (SDB) ranges in severity from primary snoring (PS) to obstructive sleep apnoea (OSA). In adults, SDB is associated with adverse cardiovascular consequences which are mediated, in part, by autonomic dysfunction. Although SDB is common in children, fewer paediatric studies have investigated these cardiovascular effects. Initial research focused on those with OSA, indeed children with PS were occasionally utilised as the comparison control group. However, it is essential to understand the ramifications of this disorder in all its severities, as currently the milder forms of SDB are often untreated. Methodologies used to assess autonomic function in children with SDB include blood pressure (BP), BP variability, baroreflex sensitivity, heart rate variability, peripheral arterial tonometry and catecholamine assays. The aim of this review was to summarise the findings of paediatric studies to date and explore the relationship between autonomic dysfunction and SDB in children, paying particular attention to the roles of disease severity and/or age. This review found evidence of autonomic dysfunction in children with SDB during both wakefulness and sleep. BP dysregulation, elevated generalised sympathetic activity and impairment of autonomic reflexes occur in school-aged children and adolescents with SDB. The adverse effects of SDB seem somewhat less in young children, although more studies are needed. There is mounting evidence that the cardiovascular and autonomic consequences of SDB are not limited to those with OSA, but are also evident in children with PS. The severity of disease and age of onset of autonomic consequences may be important guides for the treatment of SDB.

  14. Breathing air from protein foam.

    PubMed

    Ackermann, Douglas; Jewell, David N; Stedman, Matthew L; Burapatana, Vorakan; Atukorale, Prabhani V; Pinson, Michelle L; Wardle, Alison E; Zhu, Wenyan; Tanner, Robert D

    2003-01-01

    Protein foams can be used to extinguish fires. If foams are to be used to extinguish fires where people are present, such as in high-rise buildings or ships, then a method for allowing people to breathe in a foam-filled environment is needed. It is proposed that the air, used to create the foam be used for breathing. A canister that will break incoming air-filled foam has been designed for attachment to a standard gas mask, in order to provide breathable air to a trapped person. Preliminary results for the modified mask indicate feasibility of breathing air from air-filled protein foam.

  15. Complications of acromegaly: cardiovascular, respiratory and metabolic comorbidities.

    PubMed

    Pivonello, Rosario; Auriemma, Renata S; Grasso, Ludovica F S; Pivonello, Claudia; Simeoli, Chiara; Patalano, Roberta; Galdiero, Mariano; Colao, Annamaria

    2017-02-01

    Acromegaly is associated with an enhanced mortality, with cardiovascular and respiratory complications representing not only the most frequent comorbidities but also two of the main causes of deaths, whereas a minor role is played by metabolic complications, and particularly diabetes mellitus. The most prevalent cardiovascular complications of acromegaly include a cardiomyopathy, characterized by cardiac hypertrophy and diastolic and systolic dysfunction together with arterial hypertension, cardiac rhythm disorders and valve diseases, as well as vascular endothelial dysfunction. Biochemical control of acromegaly significantly improves cardiovascular disease, albeit completely recovering to normal mainly in young patients with short disease duration. Respiratory complications, represented mainly by sleep-breathing disorders, particularly sleep apnea, and respiratory insufficiency, frequently occur at the early stage of the disease and, although their severity decreases with disease control, this improvement does not often change the indication for a specific therapy directed to improve respiratory function. Metabolic complications, including glucose and lipid disorders, are variably reported in acromegaly. Treatments of acromegaly may influence glucose metabolism, and the presence of diabetes mellitus in acromegaly may affect the choice of treatments, so that glucose homeostasis is worth being monitored during the entire course of the disease. Early diagnosis and prompt treatment of acromegaly, aimed at obtaining a strict control of hormone excess, are the best strategy to limit the development or reverse the complications and prevent the premature mortality.

  16. Detection of cancer through exhaled breath: a systematic review

    PubMed Central

    Krilaviciute, Agne; Heiss, Jonathan Alexander; Leja, Marcis; Kupcinskas, Juozas; Haick, Hossam; Brenner, Hermann

    2015-01-01

    Background Timely diagnosis of cancer represents a challenging task; in particular, there is a need for reliable non-invasive screening tools that could achieve high levels of adherence at virtually no risk in population-based screening. In this review, we summarize the current evidence of exhaled breath analysis for cancer detection using standard analysis techniques and electronic nose. Methods Relevant studies were identified searching Pubmed and Web of Science databases until April 30, 2015. Information on breath test performance, such as sensitivity and specificity, was extracted together with volatile compounds that were used to discriminate cancer patients from controls. Performance of different breath analysis techniques is provided for various cancers together with information on methodological issues, such as breath sampling protocol and validation of the results. Results Overall, 73 studies were included, where two-thirds of the studies were conducted on lung cancer. Good discrimination usually required a combination of multiple biomarkers, and area under the receiver operating characteristic curve or accuracy reached levels of 0.9 or higher in multiple studies. In 25% of the reported studies, classification models were built and validated on the same datasets. Huge variability was seen in different aspects among the studies. Conclusions Analyses of exhaled breath yielded promising results, although standardization of breath collection, sample storage and data handling remain critical issues. In order to foster breath analysis implementation into practice, larger studies should be implemented in true screening settings, paying particular attention to standardization in breath collection, consideration of covariates, and validation in independent population samples. PMID:26440312

  17. Heart rate variability biofeedback increases baroreflex gain and peak expiratory flow.

    PubMed

    Lehrer, Paul M; Vaschillo, Evgeny; Vaschillo, Bronya; Lu, Shou-En; Eckberg, Dwain L; Edelberg, Robert; Shih, Weichung Joe; Lin, Yong; Kuusela, Tom A; Tahvanainen, Kari U O; Hamer, Robert M

    2003-01-01

    We evaluated heart rate variability biofeedback as a method for increasing vagal baroreflex gain and improving pulmonary function among 54 healthy adults. We compared 10 sessions of biofeedback training with an uninstructed control. Cognitive and physiological effects were measured in four of the sessions. We found acute increases in low-frequency and total spectrum heart rate variability, and in vagal baroreflex gain, correlated with slow breathing during biofeedback periods. Increased baseline baroreflex gain also occurred across sessions in the biofeedback group, independent of respiratory changes, and peak expiratory flow increased in this group, independently of cardiovascular changes. Biofeedback was accompanied by fewer adverse relaxation side effects than the control condition. Heart rate variability biofeedback had strong long-term influences on resting baroreflex gain and pulmonary function. It should be examined as a method for treating cardiovascular and pulmonary diseases. Also, this study demonstrates neuroplasticity of the baroreflex.

  18. Cardiovascular health effects following exposure of human volunteers during fire extinction exercises.

    PubMed

    Andersen, Maria Helena Guerra; Saber, Anne Thoustrup; Pedersen, Peter Bøgh; Loft, Steffen; Hansen, Åse Marie; Koponen, Ismo Kalevi; Pedersen, Julie Elbæk; Ebbehøj, Niels; Nørskov, Eva-Carina; Clausen, Per Axel; Garde, Anne Helene; Vogel, Ulla; Møller, Peter

    2017-09-06

    Firefighters have increased risk of cardiovascular disease and of sudden death from coronary heart disease on duty while suppressing fires. This study investigated the effect of firefighting activities, using appropriate personal protective equipment (PPE), on biomarkers of cardiovascular effects in young conscripts training to become firefighters. Healthy conscripts (n = 43) who participated in a rescue educational course for firefighting were enrolled in the study. The exposure period consisted of a three-day training course where the conscripts participated in various firefighting exercises in a constructed firehouse and flashover container. The subjects were instructed to extinguish fires of either wood or wood with electrical cords and mattresses. The exposure to particulate matter (PM) was assessed at various locations and personal exposure was assessed by portable PM samplers and urinary excretion of 1-hydroxypyrene. Cardiovascular measurements included microvascular function and heart rate variability (HRV). The subjects were primarily exposed to PM in bystander positions, whereas self-contained breathing apparatus effectively abolished pulmonary exposure. Firefighting training was associated with elevated urinary excretion of 1-hydroxypyrene (105%, 95% CI: 52; 157%), increased body temperature, decreased microvascular function (-18%, 95% CI: -26; -9%) and altered HRV. There was no difference in cardiovascular measurements for the two types of fires. Observations from this fire extinction training show that PM exposure mainly occurs in situations where firefighters removed the self-contained breathing apparatus. Altered cardiovascular disease endpoints after the firefighting exercise period were most likely due to complex effects from PM exposure, physical exhaustion and increased core body temperature.

  19. Measurement of breath acetone concentrations by selected ion flow tube mass spectrometry in type 2 diabetes.

    PubMed

    Storer, Malina; Dummer, Jack; Lunt, Helen; Scotter, Jenny; McCartin, Fiona; Cook, Julie; Swanney, Maureen; Kendall, Deborah; Logan, Florence; Epton, Michael

    2011-12-01

    Selected ion flow tube-mass spectrometry (SIFT-MS) can measure volatile compounds in breath on-line in real time and has the potential to provide accurate breath tests for a number of inflammatory, infectious and metabolic diseases, including diabetes. Breath concentrations of acetone in type 2 diabetic subjects undertaking a long-term dietary modification programme were studied. Acetone concentrations in the breath of 38 subjects with type 2 diabetes were determined by SIFT-MS. Anthropomorphic measurements, dietary intake and medication use were recorded. Blood was analysed for beta hydroxybutyrate (a ketone body), HbA1c (glycated haemoglobin) and glucose using point-of-care capillary (fingerprick) testing. All subjects were able to undertake breath manoeuvres suitable for analysis. Breath acetone varied between 160 and 862 ppb (median 337 ppb) and was significantly higher in men (median 480 ppb versus 296 ppb, p = 0.01). In this cross-sectional study, no association was observed between breath acetone and either dietary macronutrients or point-of-care capillary blood tests. Breath analysis by SIFT-MS offers a rapid, reproducible and easily performed measurement of acetone concentration in ambulatory patients with type 2 diabetes. The high inter-individual variability in breath acetone concentration may limit its usefulness in cross-sectional studies. Breath acetone may nevertheless be useful for monitoring metabolic changes in longitudinal metabolic studies, in a variety of clinical and research settings.

  20. Autonomous control of cardiovascular reactivity in patients with episodic and chronic forms of migraine.

    PubMed

    Mamontov, Oleg V; Babayan, Laura; Amelin, Alexander V; Giniatullin, Rashid; Kamshilin, Alexei A

    2016-01-01

    The autonomous cardiovascular control can contribute to progression of migraine. However, current data on cardiovascular reactivity in migraine, especially severe forms, are essentially contradictory. The main aim of this study was to compare the autonomous regulation of circulation in patients with episodic and chronic migraine and healthy subjects. Seventy three migraine patients (mean age 35 ± 10) including episodic migraine (51 patients, 4-14 headache days/months) and chronic migraine (22 patients, ≥15 headache days/month) along with age-match control (71 healthy voluntaries) were examined. The autonomic regulation of circulation was examined with the tilt-table test, a deep breathing and Valsalva Maneuver, handgrip test, cold-stress vasoconstriction, arterial baroreflex and blood pressure variability. The changes in heart rate induced by deep breathing, Valsalva Maneuver, and blood pressure in tilt-table test in patients with migraine did not differ from the control group. In contrast, the values of cold-stress-vasoconstriction forearm blood-flow reactivity (p <0.001), the increase in diastolic blood pressure in handgrip test (p <0.001), mean blood pressure in the late stage of the second phase of Valsalva Maneuver (p <0.001) and blood pressure variability (p <0.005) were all higher in patients with migraine than in the control group. Thus, both episodic and chronic migraine are associated with significant disturbances in autonomous control resulting in enhanced vascular reactivity whereas the cardiac regulation remains largely unchanged.

  1. Plasma coenzyme Q10 concentration, antioxidant status, and serum N-terminal pro-brain natriuretic peptide concentration in dogs with various cardiovascular diseases and the effect of cardiac treatment on measured variables.

    PubMed

    Svete, Alenka Nemec; Verk, Barbara; Seliškar, Alenka; Tomsič, Katerina; Križman, Petra Jazbec; Petrič, Aleksandra Domanjko

    2017-04-01

    OBJECTIVE To determine the plasma total antioxidant capacity, erythrocyte superoxide dismutase activity, whole blood glutathione peroxidase activity, and plasma coenzyme Q10 (CoQ10) concentration in dogs with various stages of cardiovascular diseases and in healthy dogs; assess the influence of cardiac treatment on the levels of antioxidant variables, plasma CoQ10 concentration, and serum N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration, and determine any correlation between the disease severity (NT-proBNP concentration) and antioxidant variables or CoQ10 concentration. ANIMALS 43 dogs with various types and stages of cardiovascular diseases (congenital and acquired) and 29 healthy dogs. PROCEDURES Blood samples were collected from all dogs for spectrophotometric assessment of antioxidant variables. Plasma CoQ10 concentration was determined with a high-performance liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry method. Serum NT-proBNP concentration was measured with an ELISA. RESULTS Values for antioxidant variables did not differ among groups of dogs with cardiovascular diseases, regardless of disease stage or treatment. Plasma CoQ10 concentration was significantly increased in treated dogs with congestive heart failure (CHF), compared with untreated patients. However, plasma CoQ10 concentration did not differ among heart failure classes. A significant, negative correlation between serum NT-proBNP and plasma CoQ10 concentrations was identified in treated CHF-affected dogs, suggesting that low plasma CoQ10 concentration may be associated with increased severity of CHF. CONCLUSIONS AND CLINICAL RELEVANCE The antioxidant variables evaluated were not altered in dogs with CHF, regardless of cardiac disease stage or treatment. Further investigation into the possible effects of CoQ10 supplementation in dogs with advanced stages of CHF is warranted.

  2. Caffeine and cardiovascular health.

    PubMed

    Turnbull, Duncan; Rodricks, Joseph V; Mariano, Gregory F; Chowdhury, Farah

    2017-10-01

    This report evaluates the scientific literature on caffeine with respect to potential cardiovascular outcomes, specifically relative risks of total cardiovascular disease (CVD), coronary heart disease (CHD) and acute myocardial infarction (AMI), effects on arrhythmia, heart failure, sudden cardiac arrest, stroke, blood pressure, hypertension, and other biomarkers of effect, including heart rate, cerebral blood flow, cardiac output, plasma homocysteine levels, serum cholesterol levels, electrocardiogram (EKG) parameters, heart rate variability, endothelial/platelet function and plasma/urine catecholamine levels. Caffeine intake has been associated with a range of reversible and transient physiological effects broadly and cardiovascular effects specifically. This report attempts to understand where the delineations exist in caffeine intake and corresponding cardiovascular effects among various subpopulations. The available literature suggests that cardiovascular effects experienced by caffeine consumers at levels up to 600 mg/day are in most cases mild, transient, and reversible, with no lasting adverse effect. The point at which caffeine intake may cause harm to the cardiovascular system is not readily identifiable in part because data on the effects of daily intakes greater than 600 mg is limited. However, the evidence considered within this review suggests that typical moderate caffeine intake is not associated with increased risks of total cardiovascular disease; arrhythmia; heart failure; blood pressure changes among regular coffee drinkers; or hypertension in baseline populations. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Cardiovascular autonomic responsiveness in postmenopausal women with and without hot flushes.

    PubMed

    Hautamäki, Hanna; Piirilä, Päivi; Haapalahti, Petri; Tuomikoski, Pauliina; Sovijärvi, Anssi R A; Ylikorkala, Olavi; Mikkola, Tomi S

    2011-04-01

    During menopausal transition autonomic balance is known to shift towards sympathetic dominance, but the role of vasomotor hot flushes in this phenomenon is not understood. We compared cardiovascular autonomic responsiveness between women with and without hot flushes. One hundred fifty recently postmenopausal healthy women with varying degree of hot flushes (none, mild, moderate, severe) underwent comprehensive cardiovascular autonomic nervous testing (controlled and deep breathing, active orthostatic test, Valsalva manoeuvre and handgrip test) assessing both sympathetic and parasympathetic activity. The responses of heart rate, heart rate variability and blood pressure in these tests were evaluated. Responses in heart rate showed differences between the study groups only in the Valsalva manoeuvre where the tachycardia ratio in all symptomatic women was lower (p=0.041) than in women without hot flushes. Neither change in the heart rate variability analyses nor the blood pressure responses were affected by hot flush status. However, there was a non-significantly higher maximum systolic (140 (112-182)mmHg vs. 135 (102-208)mmHg) and diastolic blood pressure (94 (72-112)mmHg vs. 90 (66-122)mmHg) following the handgrip test in women without hot flushes vs. all the symptomatic women. Menopausal hot flushes seem to be associated with a possibly increased sympathetic preponderance without an effect on parasympathetic activity in cardiovascular autonomic responses. This may imply a potentially negative impact on cardiovascular health in women experiencing hot flushes. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. Palliative care - shortness of breath

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000471.htm Palliative care - shortness of breath To use the sharing features on this page, please enable JavaScript. Palliative care is a holistic approach to care that focuses ...

  5. Liquid-Air Breathing Apparatus

    NASA Technical Reports Server (NTRS)

    Mills, Robert D.

    1990-01-01

    Compact unit supplies air longer than compressed-air unit. Emergency breathing apparatus stores air as cryogenic liquid instead of usual compressed gas. Intended for firefighting or rescue operations becoming necessary during planned potentially hazardous procedures.

  6. Visualizing Breath using Digital Holography

    NASA Astrophysics Data System (ADS)

    Hobson, P. R.; Reid, I. D.; Wilton, J. B.

    2013-02-01

    Artist Jayne Wilton and physicists Peter Hobson and Ivan Reid of Brunel University are collaborating at Brunel University on a project which aims to use a range of techniques to make visible the normally invisible dynamics of the breath and the verbal and non-verbal communication it facilitates. The breath is a source of a wide range of chemical, auditory and physical exchanges with the direct environment. Digital Holography is being investigated to enable a visually stimulating articulation of the physical trajectory of the breath as it leaves the mouth. Initial findings of this research are presented. Real time digital hologram replay allows the audience to move through holographs of breath-born particles.

  7. The airway, breathing and orthodontics.

    PubMed

    Page, David C; Mahony, Derek

    2010-01-01

    Dentists need to play a bigger role in managing airway development and craniofacial formation even though the relationship between the airway, breathing and malocclusion remains quite controversial. Certainly the airway, the mode of breathing and craniofacial formation are so interrelated during growth and development that form can follow function and function can follow form. So, it is imperative to normalize form and function as early as possible so that function is optimized for life.

  8. Early diagnosis of sleep related breathing disorders

    PubMed Central

    Maurer, Joachim T.

    2010-01-01

    Obstructive sleep apnea (OSA) being the most frequent sleep related breathing disorder results in non-restorative sleep, an increased cardiovascular morbidity and mortality as well as an elevated number of accidents. In Germany at least two million people have to be expected. If obstructive sleep apnea is diagnosed early enough then sleep may regain its restorative function, daytime performance may be improved and accident risk as well as cardiovascular risk may be normalised. This review critically evaluates anamnestic parameters, questionnaires, clinical findings and unattended recordings during sleep regarding their diagnostic accurracy in recognising OSA. There are numerous tools with insufficient results or too few data disqualifying them for screening for OSA. Promising preliminary results are published concerning neural network analysis of a high number of clinical parameters and non-linear analysis of oximetry itself or in combination with heart rate. Nasal pressure recordings can be used for risk estimation even without expertise in sleep medicine. More data is needed. Unattended portable monitoring used by qualified physicians is the gold standard procedure when screening methods for OSA are compared. It has a very high sensitivity and specificity well documented by several meta-analyses. PMID:22073090

  9. The principle of upper airway unidirectional flow facilitates breathing in humans.

    PubMed

    Jiang, Yandong; Liang, Yafen; Kacmarek, Robert M

    2008-09-01

    Upper airway unidirectional breathing, nose in and mouth out, is used by panting dogs to facilitate heat removal via water evaporation from the respiratory system. Why some humans instinctively employ the same breathing pattern during respiratory distress is still open to question. We hypothesized that 1) humans unconsciously perform unidirectional breathing because it improves breathing efficiency, 2) such an improvement is achieved by bypassing upper airway dead space, and 3) the magnitude of the improvement is inversely proportional to the tidal volume. Four breathing patterns were performed in random order in 10 healthy volunteers first with normal breathing effort, then with variable tidal volumes: mouth in and mouth out (MMB); nose in and nose out (NNB); nose in and mouth out (NMB); and mouth in and nose out (MNB). We found that unidirectional breathing bypasses anatomical dead space and improves breathing efficiency. At tidal volumes of approximately 380 ml, the functional anatomical dead space during NMB (81 +/- 31 ml) or MNB (101 +/- 20 ml) was significantly lower than that during MMB (148 +/- 15 ml) or NNB (130 +/- 13 ml) (all P < 0.001), and the breathing efficiency obtained with NMB (78 +/- 9%) or MNB (73 +/- 6%) was significantly higher than that with MMB (61 +/- 6%) or NNB (66 +/- 3%) (all P < 0.001). The improvement in breathing efficiency increased as tidal volume decreased. Unidirectional breathing results in a significant reduction in functional anatomical dead space and improvement in breathing efficiency. We suggest this may be the reason that such a breathing pattern is preferred during respiratory distress.

  10. Baroreceptor output during normal and obstructed breathing and Mueller maneuvers.

    PubMed

    Fitzgerald, R S; Robotham, J L; Anand, A

    1981-05-01

    Cardiovascular control during asthma and other forms of obstructed breathing has not been extensively investigated. Previous studies in dogs have shown that obstructed breathing or an inspiratory effort against a blocked airway (Mueller maneuver) provoke large oscillations in blood pressure. During the inspiratory phase transmural systolic pressure relative to atmosphere drops initially, but transmural systolic pressure relative to intrathoracic pressure can remain unchanged or even increase. Because the carotid baroreceptors are located in the extrathoracic circulation, whereas the aortic baroreceptors are located in the intrathoracic circulation, and each responds to local transmural arterial pressure, simultaneous baroreceptor output from these two areas was measured in the anesthetized cat during normal and obstructed breathing and during Mueller maneuvers. Both whole-nerve and single-fiber preparations showed a significantly decreased output from the carotid baroreceptors during obstructed inspiratory efforts, whereas aortic baroreceptor output decreased significantly less or not at all. Transmural systolic pressure decreased significantly less in the aorta than in the carotid regions. Further, the aortic baroreceptors were more sensitive to changes in pulse pressure than were the carotid baroreceptors. These results suggest a mechanism for stabilizing the cardiac responses to precipitous falls in blood pressure that occur in obstructed breathing.

  11. Cardiovascular Deconditioning

    NASA Technical Reports Server (NTRS)

    Charles, John B.; Fritsch-Yelle, Janice M.; Whitson, Peggy A.; Wood, Margie L.; Brown, Troy E.; Fortner, G. William

    1999-01-01

    Spaceflight causes adaptive changes in cardiovascular function that may deleteriously affect crew health and safety. Over the last three decades, symptoms of cardiovascular changes have ranged from postflight orthostatic tachycardia and decreased exercise capacity to serious cardiac rhythm disturbances during extravehicular activities (EVA). The most documented symptom of cardiovascular dysfunction, postflight orthostatic intolerance, has affected a significant percentage of U.S. Space Shuttle astronauts. Problems of cardiovascular dysfunction associated with spaceflight are a concern to NASA. This has been particularly true during Shuttle flights where the primary concern is the crew's physical health, including the pilot's ability to land the Orbiter, and the crew's ability to quickly egress and move to safety should a dangerous condition arise. The study of astronauts during Shuttle activities is inherently more difficult than most human research. Consequently, sample sizes have been small and results have lacked consistency. Before the Extended Duration Orbiter Medical Project (EDOMP), there was a lack of normative data on changes in cardiovascular parameters during and after spaceflight. The EDOMP for the first time allowed studies on a large enough number of subjects to overcome some of these problems. There were three primary goals of the Cardiovascular EDOMP studies. The first was to establish, through descriptive studies, a normative data base of cardiovascular changes attributable to spaceflight. The second goal was to determine mechanisms of cardiovascular changes resulting from spaceflight (particularly orthostatic hypotension and cardiac rhythm disturbances). The third was to evaluate possible countermeasures. The Cardiovascular EDOMP studies involved parallel descriptive, mechanistic, and countermeasure evaluations.

  12. Optimization of Air-Breathing Engine Concept

    NASA Technical Reports Server (NTRS)

    Patnaik, Surya N.; Lavelle, Thomas M.; Hopkins, Dale A.

    1996-01-01

    The design optimization of air-breathing propulsion engine concepts has been accomplished by soft-coupling the NASA Engine Performance Program (NEPP) analyzer with the NASA Lewis multidisciplinary optimization tool COMETBOARDS. Engine problems, with their associated design variables and constraints, were cast as nonlinear optimization problems with thrust as the merit function. Because of the large number of mission points in the flight envelope, the diversity of constraint types, and the overall distortion of the design space; the most reliable optimization algorithm available in COMETBOARDS, when used by itself, could not produce satisfactory, feasible, optimum solutions. However, COMETBOARDS' unique features-which include a cascade strategy, variable and constraint formulations, and scaling devised especially for difficult multidisciplinary applications-successfully optimized the performance of subsonic and supersonic engine concepts. Even when started from different design points, the combined COMETBOARDS and NEPP results converged to the same global optimum solution. This reliable and robust design tool eliminates manual intervention in the design of air-breathing propulsion engines and eases the cycle analysis procedures. It is also much easier to use than other codes, which is an added benefit. This paper describes COMETBOARDS and its cascade strategy and illustrates the capabilities of the combined design tool through the optimization of a high-bypass- turbofan wave-rotor-topped subsonic engine and a mixed-flow-turbofan supersonic engine.

  13. Standardization of exhaled breath condensate (EBC) collection using a feedback regulated breathing pattern

    EPA Science Inventory

    Collection of exhaled breath condensate (EBC) fluid by cooling of expired breath is a potentially valuable approach for the detection of biomarkers associated with disease or exposure to xenobiotics. EBC is generally collected using unregulated breathing patterns, perceived to el...

  14. Standardization of exhaled breath condensate (EBC) collection using a feedback regulated breathing pattern

    EPA Science Inventory

    Collection of exhaled breath condensate (EBC) fluid by cooling of expired breath is a potentially valuable approach for the detection of biomarkers associated with disease or exposure to xenobiotics. EBC is generally collected using unregulated breathing patterns, perceived to el...

  15. SU-E-J-62: Breath Hold for Left-Sided Breast Cancer: Visually Monitored Deep Inspiration Breath Hold Amplitude Evaluated Using Real-Time Position Management

    SciTech Connect

    Conroy, L; Quirk, S; Smith, WL; Yeung, R; Phan, T; Hudson, A

    2015-06-15

    Purpose: We used Real-Time Position Management (RPM) to evaluate breath hold amplitude and variability when gating with a visually monitored deep inspiration breath hold technique (VM-DIBH) with retrospective cine image chest wall position verification. Methods: Ten patients with left-sided breast cancer were treated using VM-DIBH. Respiratory motion was passively collected once weekly using RPM with the marker block positioned at the xiphoid process. Cine images on the tangent medial field were acquired on fractions with RPM monitoring for retrospective verification of chest wall position during breath hold. The amplitude and duration of all breath holds on which treatment beams were delivered were extracted from the RPM traces. Breath hold position coverage was evaluated for symmetric RPM gating windows from ± 1 to 5 mm centered on the average breath hold amplitude of the first measured fraction as a baseline. Results: The average (range) breath hold amplitude and duration was 18 mm (3–36 mm) and 19 s (7–34 s). The average (range) of amplitude standard deviation per patient over all breath holds was 2.7 mm (1.2–5.7 mm). With the largest allowable RPM gating window (± 5 mm), 4 of 10 VM-DIBH patients would have had ≥ 10% of their breath hold positions excluded by RPM. Cine verification of the chest wall position during the medial tangent field showed that the chest wall was greater than 5 mm from the baseline in only 1 out of 4 excluded patients. Cine images verify the chest wall/breast position only, whether this variation is acceptable in terms of heart sparing is a subject of future investigation. Conclusion: VM-DIBH allows for greater breath hold amplitude variability than using a 5 mm gating window with RPM, while maintaining chest wall positioning accuracy within 5 mm for the majority of patients.

  16. Cardiorespiratory fitness and sleep-related breathing disorders.

    PubMed

    Vanhecke, Thomas E; Franklin, Barry A; Ajluni, Steven C; Sangal, R Bart; McCullough, Peter A

    2008-06-01

    Obstructive sleep apnea and central sleep apnea are burgeoning sleep-related breathing disorders within the general population. Most of the associated comorbidities and causes of these sleep disorders are known to negatively impact cardiorespiratory fitness; however, little is known about the direct relationships between cardiorespiratory fitness, obstructive sleep apnea and central sleep apnea. This article provides a systematic analysis of existing peer reviewed, published clinical studies pertaining to the relationship between cardiorespiratory fitness and sleep-related breathing disorders in adults. A brief description of each sleep disorder, the pathophysiology, its epidemiology and its implications for cardiorespiratory fitness are provided. Finally, we discuss therapy for each disorder and its effect on the cardiovascular system.

  17. Decompression sickness risk at 6553 m breathing two gas mixtures.

    PubMed

    Connolly, Desmond M; Lee, Vivienne M; D'Oyly, Timothy J

    2010-12-01

    The risk of severe decompression sickness (DCS) increases rapidly above 6248 m (20,500 ft) and is greater when breathing higher proportions of inert gas. Contemporary aircrew may be exposed to higher cabin altitudes while breathing molecular sieve oxygen concentrator (MSOC) product gas containing variable concentrations of oxygen, nitrogen, and argon. This study assessed the risk of DCS at 6553 m (21,500 ft) breathing two simulated MSOC product gas mixtures. In a hypobaric chamber, 10 subjects each undertook 2 4-h exposures at 6553 m breathing either 75% O2:21% N2:4% Ar or 56% 02:42% N2:2% Ar. Subjects undertook regular activities simulating in-flight movements of fast jet aircrew. Venous gas emboli (VGE) "bubble" load was graded every 15 min using 2D and Doppler echocardiography by experienced operators blinded to breathing gas composition. DCS occurred in five exposures (25%), the earliest after less than 90 min at altitude. All were minor, single-site, uncomplicated limb bends that resolved with recompression. VGE occurred in 85% of exposures with some early-onset, heavy loads. Survival (Probit) analysis indicated that breathing 56% oxygen significantly decreased VGE latency relative to breathing 75% oxygen (relative potency 3.05). From 20 experimental exposures, the risk of DCS at 6553 m is estimated at 5% by 90 min and 20% at 3 h. Exploiting the negative predictive value of VGE latency as a surrogate measure of protection from DCS, at high cabin altitudes better MSOC performance (higher product gas oxygen concentrations) will protect more aircrew for longer.

  18. Models of Cheyne-Stokes respiration with cardiovascular pathologies.

    PubMed

    Dong, Fang; Langford, William F

    2008-10-01

    Cheyne-Stokes respiration (CSR) is a periodic breathing pattern, characterized by short intervals of very little or no breathing (apnea), each followed by an interval of very heavy breathing (hyperpnea). This work presents a new compartmental model of the human cardio-respiratory system, simulating the factors that determine the concentrations of carbon dioxide in the compartments of the cardiovascular system and the lungs. The parameter set on which a Hopf bifurcation gives birth to stable CSR oscillations has been determined. The model predicts that the onset of CSR oscillations may result from an increase in any of: ventilation-perfusion ratio, feedback control gain, transport delay, left heart volume, lung congestion, or cardiovascular efficiency. The model is employed to investigate the relationship between CSR and serious cardiovascular pathologies, such as congestive heart failure and encephalitis, as well as the effects of acclimatization to higher altitudes. In all cases, the model is consistent with medical observations.

  19. A module of human peripheral blood mononuclear cell transcriptional network containing primitive and differentiation markers is related to specific cardiovascular health variables.

    PubMed

    Moldovan, Leni; Anghelina, Mirela; Kantor, Taylor; Jones, Desiree; Ramadan, Enass; Xiang, Yang; Huang, Kun; Kolipaka, Arunark; Malarkey, William; Ghasemzadeh, Nima; Mohler, Peter J; Quyyumi, Arshed; Moldovan, Nicanor I

    2014-01-01

    Peripheral blood mononuclear cells (PBMCs), including rare circulating stem and progenitor cells (CSPCs), have important yet poorly understood roles in the maintenance and repair of blood vessels and perfused organs. Our hypothesis was that the identities and functions of CSPCs in cardiovascular health could be ascertained by analyzing the patterns of their co-expressed markers in unselected PBMC samples. Because gene microarrays had failed to detect many stem cell-associated genes, we performed quantitative real-time PCR to measure the expression of 45 primitive and tissue differentiation markers in PBMCs from healthy and hypertensive human subjects. We compared these expression levels to the subjects' demographic and cardiovascular risk factors, including vascular stiffness. The tested marker genes were expressed in all of samples and organized in hierarchical transcriptional network modules, constructed by a bottom-up approach. An index of gene expression in one of these modules (metagene), defined as the average standardized relative copy numbers of 15 pluripotency and cardiovascular differentiation markers, was negatively correlated (all p<0.03) with age (R2 = -0.23), vascular stiffness (R2 = -0.24), and central aortic pressure (R2 = -0.19) and positively correlated with body mass index (R2 = 0.72, in women). The co-expression of three neovascular markers was validated at the single-cell level using mRNA in situ hybridization and immunocytochemistry. The overall gene expression in this cardiovascular module was reduced by 72±22% in the patients compared with controls. However, the compactness of both modules was increased in the patients' samples, which was reflected in reduced dispersion of their nodes' degrees of connectivity, suggesting a more primitive character of the patients' CSPCs. In conclusion, our results show that the relationship between CSPCs and vascular function is encoded in modules of the PBMCs transcriptional network

  20. Longterm blood pressure variability in patients with rheumatoid arthritis and its effect on cardiovascular events and all-cause mortality in RA: a population-based comparative cohort study.

    PubMed

    Myasoedova, Elena; Crowson, Cynthia S; Green, Abigail B; Matteson, Eric L; Gabriel, Sherine E

    2014-08-01

    To examine longterm visit-to-visit blood pressure (BP) variability in patients with rheumatoid arthritis (RA) versus non-RA subjects and to assess its effect on cardiovascular (CV) events and mortality in RA. Clinic BP measures were collected in a population-based incident cohort of patients with RA (1987 American College of Rheumatology criteria met between January 1, 1995, and January 1, 2008) and non-RA subjects. BP variability was defined as within-subject SD in systolic and diastolic BP. The study included 442 patients with RA (mean age 55.5 yrs, 70% females) and 424 non-RA subjects (mean age 55.7 yrs, 69% females). Patients with RA had higher visit-to-visit variability in systolic BP (13.8 ± 4.7 mm Hg) than did non-RA subjects (13.0 ± 5.2 mm Hg, p = 0.004). Systolic BP variability declined after the index date in RA (p < 0.001) but not in the non-RA cohort (p = 0.73), adjusting for age, sex, and calendar year of RA. During the mean followup of 7.1 years, 33 CV events and 57 deaths occurred in the RA cohort. Visit-to-visit systolic BP variability was associated with increased risk of CV events (HR per 1 mm Hg increase in BP variability 1.12, 95% CI 1.01-1.25). Diastolic BP variability was associated with all-cause mortality in RA (HR 1.14, 95% CI 1.03-1.27), adjusting for systolic and diastolic BP, body mass index, smoking, diabetes, dyslipidemia, and use of antihypertensives. Patients with RA had higher visit-to-visit systolic BP variability than did non-RA subjects. There was a significant decline in systolic BP variability after RA incidence. Higher visit-to-visit BP variability was associated with adverse CV outcomes and all-cause mortality in RA.

  1. The effect of mouth breathing versus nasal breathing on dentofacial and craniofacial development in orthodontic patients.

    PubMed

    Harari, Doron; Redlich, Meir; Miri, Shalish; Hamud, Tachsin; Gross, Menachem

    2010-10-01

    To determine the effect of mouth breathing during childhood on craniofacial and dentofacial development compared to nasal breathing in malocclusion patients treated in the orthodontic clinic. Retrospective study in a tertiary medical center. Clinical variables and cephalometric parameters of 116 pediatric patients who had undergone orthodontic treatment were reviewed. The study group included 55 pediatric patients who suffered from symptoms and signs of nasal obstruction, and the control group included 61 patients who were normal nasal breathers. Mouth breathers demonstrated considerable backward and downward rotation of the mandible, increased overjet, increase in the mandible plane angle, a higher palatal plane, and narrowing of both upper and lower arches at the level of canines and first molars compared to the nasal breathers group. The prevalence of a posterior cross bite was significantly more frequent in the mouth breathers group (49%) than nose breathers (26%), (P = .006). Abnormal lip-to-tongue anterior oral seal was significantly more frequent in the mouth breathers group (56%) than in the nose breathers group (30%) (P = .05). Naso-respiratory obstruction with mouth breathing during critical growth periods in children has a higher tendency for clockwise rotation of the growing mandible, with a disproportionate increase in anterior lower vertical face height and decreased posterior facial height.

  2. Does rhinoplasty improve nasal breathing?

    PubMed

    Xavier, Rui

    2010-08-01

    Rhinoplasty is a surgical procedure that aims to improve nasal aesthetics and nasal breathing. The aesthetic improvement of the nose is usually judged subjectively by the patient and the surgeon, but the degree of improvement of nasal obstruction is difficult to assess by clinical examination only. The measurement of peak nasal inspiratory flow (PNIF) is a reliable tool that has been shown to correlate with other objective methods of assessing nasal breathing and with patients' symptoms of nasal obstruction. Twenty-three consecutive patients undergoing rhinoplasty have been evaluated by measurement of PNIF before and after surgery. All but three patients had an increase in PNIF after surgery. The mean preoperative PNIF was 86.5 L/min and the mean postoperative PNIF was 123.0 L/min ( P < 0.001). Not surprisingly, the greatest improvement in PNIF was achieved when bilateral spreader grafts were used. This study suggests that rhinoplasty does improve nasal breathing. (c) Thieme Medical Publishers

  3. The physiology and pathophysiology of human breath-hold diving.

    PubMed

    Lindholm, Peter; Lundgren, Claes E G

    2009-01-01

    This is a brief overview of physiological reactions, limitations, and pathophysiological mechanisms associated with human breath-hold diving. Breath-hold duration and ability to withstand compression at depth are the two main challenges that have been overcome to an amazing degree as evidenced by the current world records in breath-hold duration at 10:12 min and depth of 214 m. The quest for even further performance enhancements continues among competitive breath-hold divers, even if absolute physiological limits are being approached as indicated by findings of pulmonary edema and alveolar hemorrhage postdive. However, a remarkable, and so far poorly understood, variation in individual disposition for such problems exists. Mortality connected with breath-hold diving is primarily concentrated to less well-trained recreational divers and competitive spearfishermen who fall victim to hypoxia. Particularly vulnerable are probably also individuals with preexisting cardiac problems and possibly, essentially healthy divers who may have suffered severe alternobaric vertigo as a complication to inadequate pressure equilibration of the middle ears. The specific topics discussed include the diving response and its expression by the cardiovascular system, which exhibits hypertension, bradycardia, oxygen conservation, arrhythmias, and contraction of the spleen. The respiratory system is challenged by compression of the lungs with barotrauma of descent, intrapulmonary hemorrhage, edema, and the effects of glossopharyngeal insufflation and exsufflation. Various mechanisms associated with hypoxia and loss of consciousness are discussed, including hyperventilation, ascent blackout, fasting, and excessive postexercise O(2) consumption. The potential for high nitrogen pressure in the lungs to cause decompression sickness and N(2) narcosis is also illuminated.

  4. Breathing and Singing: Objective Characterization of Breathing Patterns in Classical Singers

    PubMed Central

    Salomoni, Sauro; van den Hoorn, Wolbert; Hodges, Paul

    2016-01-01

    Singing involves distinct respiratory kinematics (i.e. movements of rib cage and abdomen) to quiet breathing because of different demands on the respiratory system. Professional classical singers often advocate for the advantages of an active control of the abdomen on singing performance. This is presumed to prevent shortening of the diaphragm, elevate the rib cage, and thus promote efficient generation of subglottal pressure during phonation. However, few studies have investigated these patterns quantitatively and inter-subject variability has hindered the identification of stereotypical patterns of respiratory kinematics. Here, seven professional classical singers and four untrained individuals were assessed during quiet breathing, and when singing both a standard song and a piece of choice. Several parameters were extracted from respiratory kinematics and airflow, and principal component analysis was used to identify typical patterns of respiratory kinematics. No group differences were observed during quiet breathing. During singing, both groups adapted to rhythmical constraints with decreased time of inspiration and increased peak airflow. In contrast to untrained individuals, classical singers used greater percentage of abdominal contribution to lung volume during singing and greater asynchrony between movements of rib cage and abdomen. Classical singers substantially altered the coordination of rib cage and abdomen during singing from that used for quiet breathing. Despite variations between participants, principal component analysis revealed consistent pre-phonatory inward movements of the abdominal wall during singing. This contrasted with untrained individuals, who demonstrated synchronous respiratory movements during all tasks. The inward abdominal movements observed in classical singers elevates intra-abdominal pressure and may increase the length and the pressure-generating capacity of rib cage expiratory muscles for potential improvements in voice

  5. Breathing and Singing: Objective Characterization of Breathing Patterns in Classical Singers.

    PubMed

    Salomoni, Sauro; van den Hoorn, Wolbert; Hodges, Paul

    2016-01-01

    Singing involves distinct respiratory kinematics (i.e. movements of rib cage and abdomen) to quiet breathing because of different demands on the respiratory system. Professional classical singers often advocate for the advantages of an active control of the abdomen on singing performance. This is presumed to prevent shortening of the diaphragm, elevate the rib cage, and thus promote efficient generation of subglottal pressure during phonation. However, few studies have investigated these patterns quantitatively and inter-subject variability has hindered the identification of stereotypical patterns of respiratory kinematics. Here, seven professional classical singers and four untrained individuals were assessed during quiet breathing, and when singing both a standard song and a piece of choice. Several parameters were extracted from respiratory kinematics and airflow, and principal component analysis was used to identify typical patterns of respiratory kinematics. No group differences were observed during quiet breathing. During singing, both groups adapted to rhythmical constraints with decreased time of inspiration and increased peak airflow. In contrast to untrained individuals, classical singers used greater percentage of abdominal contribution to lung volume during singing and greater asynchrony between movements of rib cage and abdomen. Classical singers substantially altered the coordination of rib cage and abdomen during singing from that used for quiet breathing. Despite variations between participants, principal component analysis revealed consistent pre-phonatory inward movements of the abdominal wall during singing. This contrasted with untrained individuals, who demonstrated synchronous respiratory movements during all tasks. The inward abdominal movements observed in classical singers elevates intra-abdominal pressure and may increase the length and the pressure-generating capacity of rib cage expiratory muscles for potential improvements in voice

  6. Arterial hypertension in migraine: Role of familial history and cardiovascular phenotype.

    PubMed

    Babayan, Laura; Mamontov, Oleg V; Amelin, Alexander V; Bogachev, Mikhail; Kamshilin, Alexei A

    2017-03-01

    Recent studies indicate that migraine is associated with increased risk of cardiovascular diseases. However, links between autonomic cardiovascular regulation, arterial hypertension (AH) and migraine are still little explored. In this study, we evaluated autonomic regulation in migraine patients with and without hypertension. We studied 104 patients with migraine, aged 34±10 y, including 28 with and 76 without hypertension (M+AH and M-AH groups, respectively). The control group consisted of 88 healthy volunteers matched by age and sex. The autonomic regulation of circulation was examined with the tilt-table test, deep-breathing and Valsalva Maneuver, handgrip test, cold-stress induced vasoconstriction, arterial baroreflex, and blood pressure variability measurements. We found that migraine patients with concomitant hypertension demonstrated reduced arterial baroreflex, whereas other parameters of cardiac autonomic regulation were unchanged. In contrast, most indicators of vasomotor reactivity (blood pressure response to the hand-grip, Valsalva maneuver and cold vasoconstriction) were enhanced in migraine patients with no significant differences between migraine patients with and without hypertension. Patients from both M+AH and M-AH groups more commonly had a family history of cardiovascular disorders. Our data revealed increased vasomotor reactivity in migraine patients, with or without concomitant hypertension. This was associated with the family history of cardiovascular diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Aggression supersedes individual oxygen demand to drive group air-breathing in a social catfish.

    PubMed

    Killen, Shaun S; Esbaugh, Andrew J; Martins, Nicolas; Rantin, F Tadeu; McKenzie, David J

    2017-09-20

    Group-living is widespread among animals and comes with numerous costs and benefits. To date, research examining group-living has focused on trade-offs surrounding foraging, while other forms of resource acquisition have been largely overlooked. Air breathing has evolved in many fish lineages, allowing animals to obtain oxygen in hypoxic aquatic environments. Breathing air increases the threat of predation, so some species perform group air breathing, to reduce individual risk. Within species, air breathing can be influenced by metabolic rate as well as personality, but the mechanisms of group air breathing remain unexplored. It is conceivable that keystone individuals with high metabolic demand or intrinsic tendency to breathe air may drive social breathing, especially in hypoxia. We examined social air breathing in African sharptooth catfish Clarias gariepinus, to determine whether individual physiological traits and spontaneous tendency to breathe air influence the behaviour of entire groups, and whether such influences vary in relation to aquatic oxygen availability. We studied eleven groups of four catfish in a laboratory arena and recorded air-breathing behaviour, activity, and agonistic interactions at varying levels of hypoxia. Bimodal respirometry was used to estimate individual standard metabolic rate (SMR) and the tendency to utilise aerial oxygen when alone. Fish took more air breaths in groups as compared to when they were alone, regardless of water oxygen content, and displayed temporally clustered air-breathing behaviour, consistent with existing definitions of synchronous air breathing. However, groups displayed tremendous variability in surfacing behaviour. Aggression by dominant individuals within groups was the main factor influencing air breathing of the entire group. There was no association between individual SMR, or the tendency to obtain oxygen from air when in isolation, and group air breathing. For C. gariepinus, synchronous air breathing

  8. Can Breath Test Detect Stomach Cancers Earlier?

    MedlinePlus

    ... news/fullstory_163342.html Can Breath Test Detect Stomach Cancers Earlier? New technology may also spot esophageal ... 2017 (HealthDay News) -- A breath test to detect stomach and esophageal cancers shows promise, researchers say. The ...

  9. Submarines, Spacecraft, and Exhaled Breath

    EPA Science Inventory

    The International Association of Breath Research (IABR) meetings are an eclectic gathering of researchers in the medical, environmental and instrumentation fields; our focus is on human health as assessed by the measurement and interpretation of trace chemicals in human exhaled b...

  10. Breathing Problems: An Individualized Program.

    ERIC Educational Resources Information Center

    Vodola, Thomas M.

    As one of the components of the Project ACTIVE (All Children Totally Involved Exercising) Teacher Training Model Kit, the manual is designed to enable the educator to organize, conduct, and evaluate individualized-personalized physical education programs for children (prekindergarten through high school) with breathing problems. An introductory…

  11. Submarines, Spacecraft, and Exhaled Breath

    EPA Science Inventory

    The International Association of Breath Research (IABR) meetings are an eclectic gathering of researchers in the medical, environmental and instrumentation fields; our focus is on human health as assessed by the measurement and interpretation of trace chemicals in human exhaled b...

  12. Mind-body relationships in elite apnea divers during breath holding: a study of autonomic responses to acute hypoxemia

    PubMed Central

    Laurino, Marco; Menicucci, Danilo; Mastorci, Francesca; Allegrini, Paolo; Piarulli, Andrea; Scilingo, Enzo P.; Bedini, Remo; Pingitore, Alessandro; Passera, Mirko; L'Abbate, Antonio; Gemignani, Angelo

    2011-01-01

    The mental control of ventilation with all associated phenomena, from relaxation to modulation of emotions, from cardiovascular to metabolic adaptations, constitutes a psychophysiological condition characterizing voluntary breath-holding (BH). BH induces several autonomic responses, involving both autonomic cardiovascular and cutaneous pathways, whose characterization is the main aim of this study. Electrocardiogram and skin conductance (SC) recordings were collected from 14 elite divers during three conditions: free breathing (FB), normoxic phase of BH (NPBH) and hypoxic phase of BH (HPBH). Thus, we compared a set of features describing signal dynamics between the three experimental conditions: from heart rate variability (HRV) features (in time and frequency-domains and by using nonlinear methods) to rate and shape of spontaneous SC responses (SCRs). The main result of the study rises by applying a Factor Analysis to the subset of features significantly changed in the two BH phases. Indeed, the Factor Analysis allowed to uncover the structure of latent factors which modeled the autonomic response: a factor describing the autonomic balance (AB), one the information increase rate (IIR), and a latter the central nervous system driver (CNSD). The BH did not disrupt the FB factorial structure, and only few features moved among factors. Factor Analysis indicates that during BH (1) only the SC described the emotional output, (2) the sympathetic tone on heart did not change, (3) the dynamics of interbeats intervals showed an increase of long-range correlation that anticipates the HPBH, followed by a drop to a random behavior. In conclusion, data show that the autonomic control on heart rate and SC are differentially modulated during BH, which could be related to a more pronounced effect on emotional control induced by the mental training to BH. PMID:22461774

  13. 21 CFR 868.5620 - Breathing mouthpiece.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Breathing mouthpiece. 868.5620 Section 868.5620...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5620 Breathing mouthpiece. (a) Identification. A breathing mouthpiece is a rigid device that is inserted into a patient's mouth and...

  14. 21 CFR 868.5620 - Breathing mouthpiece.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breathing mouthpiece. 868.5620 Section 868.5620...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5620 Breathing mouthpiece. (a) Identification. A breathing mouthpiece is a rigid device that is inserted into a patient's mouth and...

  15. 21 CFR 868.5620 - Breathing mouthpiece.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Breathing mouthpiece. 868.5620 Section 868.5620...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5620 Breathing mouthpiece. (a) Identification. A breathing mouthpiece is a rigid device that is inserted into a patient's mouth and...

  16. 21 CFR 868.5620 - Breathing mouthpiece.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Breathing mouthpiece. 868.5620 Section 868.5620...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5620 Breathing mouthpiece. (a) Identification. A breathing mouthpiece is a rigid device that is inserted into a patient's mouth and...

  17. 21 CFR 868.5620 - Breathing mouthpiece.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Breathing mouthpiece. 868.5620 Section 868.5620...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5620 Breathing mouthpiece. (a) Identification. A breathing mouthpiece is a rigid device that is inserted into a patient's mouth and...

  18. Functional Analysis and Intervention for Breath Holding.

    ERIC Educational Resources Information Center

    Kern, Lee; And Others

    1995-01-01

    A functional analysis of breath-holding episodes in a 7-year-old girl with severe mental retardation and Cornelia-de-Lange syndrome indicated that breath holding served an operant function, primarily to gain access to attention. Use of extinction, scheduled attention, and a picture card communication system decreased breath holding. (Author/SW)

  19. Functional Analysis and Intervention for Breath Holding.

    ERIC Educational Resources Information Center

    Kern, Lee; And Others

    1995-01-01

    A functional analysis of breath-holding episodes in a 7-year-old girl with severe mental retardation and Cornelia-de-Lange syndrome indicated that breath holding served an operant function, primarily to gain access to attention. Use of extinction, scheduled attention, and a picture card communication system decreased breath holding. (Author/SW)

  20. Types, Mechanisms, and Clinical Cardiovascular Consequences

    PubMed Central

    Javaheri, Shahrokh; Barbe, Ferran; Campos-Rodriguez, Francisco; Dempsey, Jerome A.; Khayat, Rami; Javaheri, Sogol; Malhotra, Atul; Martinez-Garcia, Miguel A.; Mehra, Reena; Pack, Allan I.; Polotsky, Vsevolod Y.; Redline, Susan; Somers, Virend K.

    2017-01-01

    Sleep apnea is highly prevalent in patients with cardiovascular disease. These disordered breathing events are associated with a profile of perturbations that include intermittent hypoxia, oxidative stress, sympathetic activation, and endothelial dysfunction, all of which are critical mediators of cardiovascular disease. Evidence supports a causal association of sleep apnea with the incidence and morbidity of hypertension, coronary heart disease, arrhythmia, heart failure, and stroke. Several discoveries in the pathogenesis, along with developments in the treatment of sleep apnea, have accumulated in recent years. In this review, we discuss the mechanisms of sleep apnea, the evidence that addresses the links between sleep apnea and cardiovascular disease, and research that has addressed the effect of sleep apnea treatment on cardiovascular disease and clinical endpoints. Finally, we review the recent development in sleep apnea treatment options, with special consideration of treating patients with heart disease. Future directions for selective areas are suggested. PMID:28209226

  1. Neural Mechanisms Underlying Breathing Complexity

    PubMed Central

    Hess, Agathe; Yu, Lianchun; Klein, Isabelle; De Mazancourt, Marine; Jebrak, Gilles; Mal, Hervé; Brugière, Olivier; Fournier, Michel; Courbage, Maurice; Dauriat, Gaelle; Schouman-Clayes, Elisabeth; Clerici, Christine; Mangin, Laurence

    2013-01-01

    Breathing is maintained and controlled by a network of automatic neurons in the brainstem that generate respiratory rhythm and receive regulatory inputs. Breathing complexity therefore arises from respiratory central pattern generators modulated by peripheral and supra-spinal inputs. Very little is known on the brainstem neural substrates underlying breathing complexity in humans. We used both experimental and theoretical approaches to decipher these mechanisms in healthy humans and patients with chronic obstructive pulmonary disease (COPD). COPD is the most frequent chronic lung disease in the general population mainly due to tobacco smoke. In patients, airflow obstruction associated with hyperinflation and respiratory muscles weakness are key factors contributing to load-capacity imbalance and hence increased respiratory drive. Unexpectedly, we found that the patients breathed with a higher level of complexity during inspiration and expiration than controls. Using functional magnetic resonance imaging (fMRI), we scanned the brain of the participants to analyze the activity of two small regions involved in respiratory rhythmogenesis, the rostral ventro-lateral (VL) medulla (pre-Bötzinger complex) and the caudal VL pons (parafacial group). fMRI revealed in controls higher activity of the VL medulla suggesting active inspiration, while in patients higher activity of the VL pons suggesting active expiration. COPD patients reactivate the parafacial to sustain ventilation. These findings may be involved in the onset of respiratory failure when the neural network becomes overwhelmed by respiratory overload We show that central neural activity correlates with airflow complexity in healthy subjects and COPD patients, at rest and during inspiratory loading. We finally used a theoretical approach of respiratory rhythmogenesis that reproduces the kernel activity of neurons involved in the automatic breathing. The model reveals how a chaotic activity in neurons can

  2. Autonomic nervous system abnormalities in spinocerebellar ataxia type 2: a cardiovascular neurophysiologic study.

    PubMed

    De Joanna, G; De Rosa, A; Salvatore, E; Castaldo, I; De Luca, N; Izzo, R; Manzo, V; Filla, A; De Michele, G

    2008-12-15

    Autonomic nervous system dysfunction is part of the spinocerebellar ataxia (SCA) clinical picture, but few data are available on this topic. The present study is aimed to report a detailed investigation of autonomic nervous system in patients with molecular diagnosis of SCA type 2, one of the most frequent forms and the commonest in Italy. Nine patients with a mild to moderate form of SCA2 underwent a questionnaire about dysautonomic symptoms and a complete cardiovascular neurophysiologic evaluation of both sympathetic and parasympathetic system, comprising head-up tilt, standing, isometric hand grip, cold pressure, mental arithmetic, Valsalva manoeuvre, deep breathing, and hyperventilation tests. An echocardiographic study and Holter-ECG recording were also performed. All patients complained dysautonomic problems regarding urinary tract, cardiovascular system, or gastrointestinal dysfunction. The neurophysiologic study showed both sympathetic and parasympathetic involvement, with highly variable degree and pattern of dysautonomia. The present study results show that the autonomic dysfunction is common in SCA2 representing a significant component of the complex picture of the disease. We found a wide spectrum of cardiovascular autonomic abnormalities, without a typical pattern of dysfunction and without correlation with clinical variables.

  3. Cardiovascular Pharmacology of Cannabinoids

    PubMed Central

    Pacher, P.; Bátkai, S.; Kunos, G.

    2008-01-01

    Cannabinoids and their synthetic and endogenous analogs affect a broad range of physiological functions, including cardiovascular variables, the most important component of their effect being profound hypotension. The mechanisms of the cardiovascular effects of cannabinoids in vivo are complex and may involve modulation of autonomic outflow in both the central and peripheral nervous systems as well as direct effects on the myocardium and vasculature. Although several lines of evidence indicate that the cardiovascular depressive effects of cannabinoids are mediated by peripherally localized CB1 receptors, recent studies provide strong support for the existence of as-yet-undefined endothelial and cardiac receptor(s) that mediate certain endocannabinoid-induced cardiovascular effects. The endogenous cannabinoid system has been recently implicated in the mechanism of hypotension associated with hemorrhagic, endotoxic, and cardiogenic shock, and advanced liver cirrhosis. Furthermore, cannabinoids have been considered as novel antihypertensive agents. A protective role of endocannabinoids in myocardial ischemia has also been documented. In this chapter, we summarize current information on the cardiovascular effects of cannabinoids and highlight the importance of these effects in a variety of pathophysiological conditions. PMID:16596789

  4. Sleep-Disordered Breathing in the National Football League

    PubMed Central

    Rice, Thomas B.; Dunn, Reginald E.; Lincoln, Andrew E.; Tucker, Andrew M.; Vogel, Robert A.; Heyer, Robert A.; Yates, Anthony P.; Wilson, Peter W. F.; Pellmen, Elliot J.; Allen, Thomas W.; Newman, Anne B.; Strollo, Patrick J.

    2010-01-01

    Study Objectives: Prior studies have suggested that the prevalence of sleep disordered breathing (SDB) among players in the National Football League (NFL) is disproportionately high. SDB can increase cardiovascular disease risk and is correlated with hypertension. NFL players have a higher prevalence of hypertension, and we sought to determine the prevalence of SDB among players the NFL and the associations of SDB with anthropometric measures and cardiovascular risk factors. Design: Cross-sectional cohort study. Setting: NFL athletic training facilities from April to July 2007. Participants: A total of 137 active veteran players from 6 NFL teams. Measurements: This evaluation of SDB among players in the NFL used a single-channel, home-based, unattended, portable, sleep apnea monitor. Multiple domains of self-reported sleep were assessed. Weight, body mass index, body fat percentage, neck circumference, waist circumference, and waist-to-hip ratio, as well as blood pressure, cholesterol, and fasting glucose concentrations were measured. Results: The mean respiratory disturbance index was 4.7 (± 12), with a median (interquartile range) of 2 (1,4). The prevalence of at least mild SDB (RDI ≥ 5) was 19% (95% confidence interval, 12.8%-26.6%). Only 4.4% (95% confidence interval, 1.6%-9.2%) of participants had respiratory disturbance index of 15 or greater. Linemen and non-linemen were not different in their prevalence or severity of SDB. No single anthropometric measure was highly associated with SDB, and SDB was not well correlated with cardiovascular risk factors. Conclusions: The prevalence of SDB in active NFL players was modest, predominately mild, and positively associated with several measures of adiposity. SDB did not account for excess cardiovascular risk factors. Citation: Rice TB; Dunn RE; Lincoln AE; Tucker AM; Vogel RA; Heyer RA; Yates AP; Wilson PWF; Pellmen EJ; Allen TW; Newman AB; Strollo PJ. Sleep-disordered breathing in the National Football League

  5. Theme and variations: amphibious air-breathing intertidal fishes.

    PubMed

    Martin, K L

    2014-03-01

    Over 70 species of intertidal fishes from 12 families breathe air while emerging from water. Amphibious intertidal fishes generally have no specialized air-breathing organ but rely on vascularized mucosae and cutaneous surfaces in air to exchange both oxygen and carbon dioxide. They differ from air-breathing freshwater fishes in morphology, physiology, ecology and behaviour. Air breathing and terrestrial activity are present to varying degrees in intertidal fish species, correlated with the tidal height of their habitat. The gradient of amphibious lifestyle includes passive remainers that stay in the intertidal zone as tides ebb, active emergers that deliberately leave water in response to poor aquatic conditions and highly mobile amphibious skipper fishes that may spend more time out of water than in it. Normal terrestrial activity is usually aerobic and metabolic rates in air and water are similar. Anaerobic metabolism may be employed during forced exercise or when exposed to aquatic hypoxia. Adaptations for amphibious life include reductions in gill surface area, increased reliance on the skin for respiration and ion exchange, high affinity of haemoglobin for oxygen and adjustments to ventilation and metabolism while in air. Intertidal fishes remain close to water and do not travel far terrestrially, and are unlikely to migrate or colonize new habitats at present, although in the past this may have happened. Many fish species spawn in the intertidal zone, including some that do not breathe air, as eggs and embryos that develop in the intertidal zone benefit from tidal air emergence. With air breathing, amphibious intertidal fishes survive in a variable habitat with minimal adjustments to existing structures. Closely related species in different microhabitats provide unique opportunities for comparative studies.

  6. Drive mechanism for production of simulated human breath

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G.; Hendricks, C. M.; Lambert, J. W.; Morison, W. B.

    1972-01-01

    Simulated breath drive mechanism was developed as subsystem to breathing metabolic simulator. Mechanism reproduces complete range of human breath rate, breath depth, and breath waveform, as well as independently controlled functional residual capacity. Mechanism was found capable of simulating various individual human breathing characteristics without any changes of parts.

  7. Respiratory difficulties and breathing disorders in achondroplasia.

    PubMed

    Afsharpaiman, S; Saburi, A; Waters, Karen A

    2013-12-01

    Respiratory difficulties and breathing disorders in achondroplasia are thought to underlie the increased risk for sudden infant death and neuropsychological deficits seen in this condition. This review evaluates literature regarding respiratory dysfunctions and their sequelae in patients with achondroplasia. The limited number of prospective studies of respiratory disease in achondroplasia means that observational studies and case series provide a large proportion of the data regarding the spectrum of respiratory diseases in achondroplasia and their treatments. Amongst clinical respiratory problems described, snoring is the commonest observed abnormality, but the reported incidence of obstructive sleep apnoea (OSA) shows wide variance (10% to 75%). Reported treatments of OSA include adenotonsillectomy, the use of CPAP, and surgical improvement of the airway, including mid-face advancement. Otolaryngologic manifestations are also common. Respiratory failure due to small thoracic volumes is reported, but uncommon. Mortality rate at all ages was 2.27 (CI: 1.7-3.0) with age-specific mortality increased at all ages. Sudden death was most common in infants and children. Cardiovascular events are the main cause of mortality in adults. Despite earlier recognition and treatment of respiratory complications of achondroplasia, increased mortality rates and other complications remain high. Future and ongoing evaluation of the prevalence and impact of respiratory disorders, particularly OSA, in achondroplasia is recommended. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  8. Monitoring breath during oral glucose tolerance tests.

    PubMed

    Ghimenti, S; Tabucchi, S; Lomonaco, T; Di Francesco, F; Fuoco, R; Onor, M; Lenzi, S; Trivella, M G

    2013-03-01

    The evolution of breath composition during oral glucose tolerance tests (OGTTs) was analysed by thermal desorption/gas chromatography/mass spectrometry in 16 subjects and correlated to blood glucose levels. The glucose tolerance tests classified five of the subjects as diabetics, eight as affected by impaired glucose tolerance and three as normoglycaemic. Acetone levels were generally higher in diabetics (average concentration values: diabetics, 300 ± 40 ppbv; impaired glucose tolerance, 350 ± 30 ppbv; normoglycaemic, 230 ± 20 ppbv) but the large inter-individual variability did not allow us to identify the three groups by this parameter alone. The exhalation of 3-hydroxy-butan-2-one and butane-2,3-dione, likely due to the metabolization of glucose by bacteria in the mouth, was also observed. Future work will involve the extension of the analyses to other volatile compounds by attempting to improve the level of discrimination between the various classes of subjects.

  9. Envelope Analysis of the Airflow Signal To Improve Polysomnographic Assessment of Sleep Disordered Breathing

    PubMed Central

    Díaz, Javier A.; Arancibia, José M.; Bassi, Alejandro; Vivaldi, Ennio A.

    2014-01-01

    Study Objectives: Given the detailed respiratory waveform signal provided by the nasal cannula in polysomnographic (PSG) studies, to quantify sleep breathing disturbances by extracting a continuous variable based on the coefficient of variation of the envelope of that signal. Design: Application of an algorithm for envelope analysis to standard nasal cannula signal from actual polysomnographic studies. Setting: PSG recordings from a sleep disorders center were analyzed by an algorithm developed on the Igor scientific data analysis software. Patients or Participants: Recordings representative of different degrees of sleep disordered breathing (SDB) severity or illustrative of the covariation between breathing and particularly relevant factors and variables. Interventions: The method calculated the coefficient of variation of the envelope for each 30-second epoch. The normalized version of that coefficient was defined as the respiratory disturbance variable (RDV). The method outcome was the all-night set of RDV values represented as a time series. Measurements and Results: RDV quantitatively reflected departure from normal sinusoidal breathing at each epoch, providing an intensity scale for disordered breathing. RDV dynamics configured itself in recognizable patterns for the airflow limitation (e.g., in UARS) and the apnea/hypopnea regimes. RDV reliably highlighted clinically meaningful associations with staging, body position, oximetry, or CPAP titration. Conclusions: Respiratory disturbance variable can assess sleep breathing disturbances as a gradual phenomenon while providing a comprehensible and detailed representation of its dynamics. It may thus improve clinical diagnosis and provide a revealing descriptive tool for mechanistic sleep disordered breathing modeling. Respiratory disturbance variable may contribute to attaining simplified screening methodologies, novel diagnostic criteria, and insightful research tools. Citation: Díaz JA; Arancibia JM; Bassi A

  10. The effects of pentobarbitone and pethidine on foetal breathing movements in sheep.

    PubMed

    Boddy, K; Dawes, G S; Fisher, R L; Pinter, S; Robinson, J S

    1976-06-01

    1 Small doses of pentobarbitone (4 mg/kg i.v.) administered to sheep in the last third of pregancy had little overt effect on the mothers. In the foetus they caused arrest of breathing movements, an alteration in the character of the electrocorticogram and cardiovascular changes which varied with gestational age. 2 In contrast, relatively large doses of pethidine (100-200 mg) admininstered to the mother had no consistent effect on normal foetal breathing movements, though they abolished the foetal response to hypercapnia. 3 The results are discussed in relation to feotal sleep state.

  11. The effects of pentobarbitone and pethidine on foetal breathing movements in sheep.

    PubMed Central

    Boddy, K; Dawes, G S; Fisher, R L; Pinter, S; Robinson, J S

    1976-01-01

    1 Small doses of pentobarbitone (4 mg/kg i.v.) administered to sheep in the last third of pregancy had little overt effect on the mothers. In the foetus they caused arrest of breathing movements, an alteration in the character of the electrocorticogram and cardiovascular changes which varied with gestational age. 2 In contrast, relatively large doses of pethidine (100-200 mg) admininstered to the mother had no consistent effect on normal foetal breathing movements, though they abolished the foetal response to hypercapnia. 3 The results are discussed in relation to feotal sleep state. PMID:7337

  12. A double-blind, placebo-controlled, randomized trial of the effects of dark chocolate and cocoa on variables associated with neuropsychological functioning and cardiovascular health: clinical findings from a sample of healthy, cognitively intact older adults.

    PubMed

    Crews, W David; Harrison, David W; Wright, James W

    2008-04-01

    In recent years, there has been increased interest in the potential health-related benefits of antioxidant- and phytochemical-rich dark chocolate and cocoa. The objective of the study was to examine the short-term (6 wk) effects of dark chocolate and cocoa on variables associated with neuropsychological functioning and cardiovascular health in healthy older adults. A double-blind, placebo-controlled, fixed-dose, parallel-group clinical trial was used. Participants (n = 101) were randomly assigned to receive a 37-g dark chocolate bar and 8 ounces (237 mL) of an artificially sweetened cocoa beverage or similar placebo products each day for 6 wk. No significant group (dark chocolate and cocoa or placebo)-by-trial (baseline, midpoint, and end-of-treatment assessments) interactions were found for the neuropsychological, hematological, or blood pressure variables examined. In contrast, the midpoint and end-of-treatment mean pulse rate assessments in the dark chocolate and cocoa group were significantly higher than those at baseline and significantly higher than the midpoint and end-of-treatment rates in the control group. Results of a follow-up questionnaire item on the treatment products that participants believed they had consumed during the trial showed that more than half of the participants in both groups correctly identified the products that they had ingested during the experiment. This investigation failed to support the predicted beneficial effects of short-term dark chocolate and cocoa consumption on any of the neuropsychological or cardiovascular health-related variables included in this research. Consumption of dark chocolate and cocoa was, however, associated with significantly higher pulse rates at 3- and 6-wk treatment assessments.

  13. Analysis of Exhaled Breath for Disease Detection

    NASA Astrophysics Data System (ADS)

    Amann, Anton; Miekisch, Wolfram; Schubert, Jochen; Buszewski, Bogusław; Ligor, Tomasz; Jezierski, Tadeusz; Pleil, Joachim; Risby, Terence

    2014-06-01

    Breath analysis is a young field of research with great clinical potential. As a result of this interest, researchers have developed new analytical techniques that permit real-time analysis of exhaled breath with breath-to-breath resolution in addition to the conventional central laboratory methods using gas chromatography-mass spectrometry. Breath tests are based on endogenously produced volatiles, metabolites of ingested precursors, metabolites produced by bacteria in the gut or the airways, or volatiles appearing after environmental exposure. The composition of exhaled breath may contain valuable information for patients presenting with asthma, renal and liver diseases, lung cancer, chronic obstructive pulmonary disease, inflammatory lung disease, or metabolic disorders. In addition, oxidative stress status may be monitored via volatile products of lipid peroxidation. Measurement of enzyme activity provides phenotypic information important in personalized medicine, whereas breath measurements provide insight into perturbations of the human exposome and can be interpreted as preclinical signals of adverse outcome pathways.

  14. Analysis of exhaled breath for disease detection.

    PubMed

    Amann, Anton; Miekisch, Wolfram; Schubert, Jochen; Buszewski, Bogusław; Ligor, Tomasz; Jezierski, Tadeusz; Pleil, Joachim; Risby, Terence

    2014-01-01

    Breath analysis is a young field of research with great clinical potential. As a result of this interest, researchers have developed new analytical techniques that permit real-time analysis of exhaled breath with breath-to-breath resolution in addition to the conventional central laboratory methods using gas chromatography-mass spectrometry. Breath tests are based on endogenously produced volatiles, metabolites of ingested precursors, metabolites produced by bacteria in the gut or the airways, or volatiles appearing after environmental exposure. The composition of exhaled breath may contain valuable information for patients presenting with asthma, renal and liver diseases, lung cancer, chronic obstructive pulmonary disease, inflammatory lung disease, or metabolic disorders. In addition, oxidative stress status may be monitored via volatile products of lipid peroxidation. Measurement of enzyme activity provides phenotypic information important in personalized medicine, whereas breath measurements provide insight into perturbations of the human exposome and can be interpreted as preclinical signals of adverse outcome pathways.

  15. Association between the rapid shallow breathing index and extubation success in patients with traumatic brain injury

    PubMed Central

    dos Reis, Helena França Correia; Almeida, Mônica Lajana Oliveira; da Silva, Mário Ferreira; Moreira, Julião Oliveira; Rocha, Mário de Seixas

    2013-01-01

    Objective To investigate the association between the rapid shallow breathing index and successful extubation in patients with traumatic brain injury. Methods This study was a prospective study conducted in patients with traumatic brain injury of both genders who underwent mechanical ventilation for at least two days and who passed a spontaneous breathing trial. The minute volume and respiratory rate were measured using a ventilometer, and the data were used to calculate the rapid shallow breathing index (respiratory rate/tidal volume). The dependent variable was the extubation outcome: reintubation after up to 48 hours (extubation failure) or not (extubation success). The independent variable was the rapid shallow breathing index measured after a successful spontaneous breathing trial. Results The sample comprised 119 individuals, including 111 (93.3%) males. The average age of the sample was 35.0±12.9 years old. The average duration of mechanical ventilation was 8.1±3.6 days. A total of 104 (87.4%) participants achieved successful extubation. No association was found between the rapid shallow breathing index and extubation success. Conclusion The rapid shallow breathing index was not associated with successful extubation in patients with traumatic brain injury. PMID:24213084

  16. Impact of breathing patterns on the quality of life of 9- to 10-year-old schoolchildren.

    PubMed

    Leal, Rossana B; Gomes, Monalisa C; Granville-Garcia, Ana F; Goes, Paulo S A; de Menezes, Valdenice A

    2016-09-01

    Mouth breathing can cause a set of changes in craniofacial growth and development, with esthetic, functional, and psychological repercussions. To determine the impact of mouth breathing on the quality of life of schoolchildren. A school-based, cross-sectional study was conducted with 1911 children ages 9 and 10 years in the city of Recife, Brazil. The children answered the Mouth Breather Quality of Life questionnaire and a questionnaire that addressed sociodemographic data and health-related aspects. Clinical examinations were performed by an examiner who had undergone a training and calibration process for the diagnosis of mouth breathing (kappa = 0.90). Descriptive statistics were conducted to characterize the sample. Statistical analysis involved the Student's t-test and the F test (analysis of variance) (alpha = 5%). The prevalence of mouth breathing was 54.81%. Children with oral breathing demonstrated a poorer quality of life in comparison with children with nasal breathing (p < 0.001). The following variables were significantly associated with a poorer quality of life among the children with mouth breathing: a younger age (p < 0.001) and the use of medication (p = 0.002). Based on the present findings, children with the mouth-breathing pattern experience a greater negative impact on quality of life in comparison with those with the nose-breathing pattern. Thus, the early diagnosis and treatment of this clinical condition are fundamental to minimizing the consequences of mouth breathing on the quality of life of schoolchildren with respiration disorders.

  17. Assessment of training effects on autonomic modulation of the cardiovascular system in mature rats using power spectral analysis of heart rate variability.

    PubMed

    Kumae, Takashi

    2012-09-01

    To clarify the effects of forced or voluntary exercise on autonomic modulation of the cardiovascular system, we monitored changes in autonomic nervous activity in a mature rat by spectral analysis of the heart rate (HR) during a 10-week training period. Male Wistar rats implanted with a radio-telemetry system were divided into three groups at 18 weeks of age: (1) Control group (n = 8); (2) Voluntary group (n = 6), which were housed separately in a cage with a running wheel; (3) Forced group (n = 6), which were exercised on a treadmill (35 m/min, 15 min/day, 5 days/week). The electrocardiogram was analyzed by the maximum entropy method into two main oscillations, low-frequency (LF) and high-frequency (HF) oscillations, respectively. LF and HF are considered to be markers of both sympathetic and parasympathetic modulations and parasympathetic modulation, respectively. Average running distances of the Voluntary group were more than twofold higher than those of the Forced group. HR levels in the Forced group were lower than those in the Control group. LF and HF levels in the Control and the Forced groups were almost the same during the experiment, and those in the Voluntary group showed a tendency to decrease. The results in the Voluntary and the Forced groups suggest that cardiovascular adjustments are not simply caused by the quantity of exercise. In the Voluntary group, both sympathetic and parasympathetic activity may decrease with a predominance of sympathetic activity. Conversely, in the Forced group, the baroreflex may be hyper-activated by the undesired treadmill running and handling stress.

  18. Austrian Moderate Altitude Study 2000 (AMAS 2000). The effects of moderate altitude (1,700 m) on cardiovascular and metabolic variables in patients with metabolic syndrome.

    PubMed

    Schobersberger, Wolfgang; Schmid, Peter; Lechleitner, Monika; von Duvillard, Serge P; Hörtnagl, Helmut; Gunga, Hanns-Christian; Klingler, Anton; Fries, Dietmar; Kirsch, Karl; Spiesberger, Reinhard; Pokan, Rochus; Hofmann, Peter; Hoppichler, Fritz; Riedmann, Gebhard; Baumgartner, Holger; Humpeler, Egon

    2003-02-01

    We investigated the changes in the cardiovascular system [resting blood pressure (BP) and heart rate (HR), measured by means of a 24-h ambulatory BP and a holter-electrocardiogram (ECG)], glycemic parameters, and lipid metabolism of subjects suffering from metabolic syndrome during a 3-week sojourn at 1,700 m in the Austrian Alps. A total of 22 male subjects with metabolic syndrome were selected. Baseline investigations were performed at Innsbruck (500 m above sea level). During the 3-week altitude stay the participants simulated a holiday with moderate sports activities. Examinations were performed on days 1, 4, 9, and 19. After returning to Innsbruck, post-altitude examinations were conducted after 7-10 days and 6-7 weeks, respectively. The 24-h ambulatory BP and holter ECG revealed a decrease in average HR, BP, and rate pressure product (RPP: systolic blood pressure x HR) after 3 weeks of altitude exposure. In some patients, an increase in premature ventricular beats was observed at the end compared to the beginning of the exposure to moderate altitude. The ECG revealed no ischemic ST-segment changes. Maximal physical capacity as measured by symptom-limited maximal cycle ergometry tests remained unchanged during the study. Six weeks after the altitude exposure the blood pressure increased again and returned to pretest levels. The Homeostasis Model Assessment index, which is a measure of insulin resistance, decreased significantly and glucose concentrations obtained after an oral glucose tolerance test were significantly lower after the stay at altitude compared to the basal values. We conclude that after a 3-week exposure to moderate altitude, patients with metabolic syndrome (1) tolerated their sojourn without any physical problems, (2) exhibited short-term favorable effects on the cardiovascular system, and (3) had significant improvements in glycemic parameters that were paralleled by a significant increase in high-density-lipoprotein-cholesterol.

  19. Self-contained breathing apparatus

    NASA Technical Reports Server (NTRS)

    Sullivan, J. L.; Giorgini, E. A.; Simmonds, M. R. (Inventor)

    1976-01-01

    A self-contained breathing apparatus with automatic redundant fluid pressure controls and a facemask mounted low pressure whistle alarm is described. The first stage of the system includes pair of pressure regulators connected in parallel with different outlet pressures, both of which reduce the pressure of the stored supply gas to pressures compatible with the second stage breathing demand regulator. A primary regulator in the first stage delivers a low output pressure to the demand regulator. In the event of a failure closed condition of the primary regulator an automatic transfer valve switches on the backup regulator. A warning that the supply pressure has been depleted is also provided by a supply pressure actuated transfer valve which transfers the output of the first stage pressure regulators from the primary to the backup regulator. The alarm is activated in either the failure closed condition or if the supply pressure is reduced to a dangerously low level.

  20. Feedback linearization for control of air breathing engines

    NASA Technical Reports Server (NTRS)

    Phillips, Stephen; Mattern, Duane

    1991-01-01

    The method of feedback linearization for control of the nonlinear nozzle and compressor components of an air breathing engine is presented. This method overcomes the need for a large number of scheduling variables and operating points to accurately model highly nonlinear plants. Feedback linearization also results in linear closed loop system performance simplifying subsequent control design. Feedback linearization is used for the nonlinear partial engine model and performance is verified through simulation.

  1. Exhaled Breath Analysis and Sleep

    PubMed Central

    Carpagnano, Giovanna E.

    2011-01-01

    It is currently estimated that the economic burden for obstructive sleep apnea syndrome (OSAS) cases not coming to medical attention is steadily increasing, thus making OSAS a major public health concern. For its increasing incidence among the common population, the interest of researchers and clinicians has been recently directed to the study of pathological mechanisms underlying sleep disorders. Current opinion is that airway inflammation and oxidative stress play a crucial role in the pathophysiology of OSAS. Recently there has been increasing interest in the investigation of lungs by non-invasive means measuring the exhaled breath volatile mediators, such as nitric oxide (NO), carbon monoxide (CO), ethane and pentane and finally the non-volatile substances in the liquid phase of exhalate, termed breath condensate. The non-invasiveness of these techniques for the study of airways affected by different respiratory disorders and among those, the OSAS, makes these ideally suited for the evaluation and serial monitoring of patients. Notwithstanding the increasing number of scientific contributions on the use of the exhaled markers in sleep disorders, at the moment, their use is not completely suitable for clinical application. An important contribution to the increase of our knowledge on exhaled markers and for their possible concrete application in clinical practice may come from future studies using proteomics, genomics and metabolomics. In this review, we focus on exhaled breath analysis giving an update on its general aspects, its application in OSAS, and finally its actual clinical applicability and areas for future direction. Citation: Carpagnano GE. Exhaled breath analysis and sleep. J Clin Sleep Med 2011;7(5):Supplement S34-S37. PMID:22003329

  2. Physiology of long pranayamic breathing: neural respiratory elements may provide a mechanism that explains how slow deep breathing shifts the autonomic nervous system.

    PubMed

    Jerath, Ravinder; Edry, John W; Barnes, Vernon A; Jerath, Vandna

    2006-01-01

    Pranayamic breathing, defined as a manipulation of breath movement, has been shown to contribute to a physiologic response characterized by the presence of decreased oxygen consumption, decreased heart rate, and decreased blood pressure, as well as increased theta wave amplitude in EEG recordings, increased parasympathetic activity accompanied by the experience of alertness and reinvigoration. The mechanism of how pranayamic breathing interacts with the nervous system affecting metabolism and autonomic functions remains to be clearly understood. It is our hypothesis that voluntary slow deep breathing functionally resets the autonomic nervous system through stretch-induced inhibitory signals and hyperpolarization currents propagated through both neural and non-neural tissue which synchronizes neural elements in the heart, lungs, limbic system and cortex. During inspiration, stretching of lung tissue produces inhibitory signals by action of slowly adapting stretch receptors (SARs) and hyperpolarization current by action of fibroblasts. Both inhibitory impulses and hyperpolarization current are known to synchronize neural elements leading to the modulation of the nervous system and decreased metabolic activity indicative of the parasympathetic state. In this paper we propose pranayama's physiologic mechanism through a cellular and systems level perspective, involving both neural and non-neural elements. This theoretical description describes a common physiological mechanism underlying pranayama and elucidate the role of the respiratory and cardiovascular system on modulating the autonomic nervous system. Along with facilitating the design of clinical breathing techniques for the treatment of autonomic nervous system and other disorders, this model will also validate pranayama as a topic requiring more research.

  3. Effects of diaphragm breathing exercise and feedback breathing exercise on pulmonary function in healthy adults.

    PubMed

    Yong, Min-Sik; Lee, Hae-Yong; Lee, Yun-Seob

    2017-01-01

    [Purpose] The present study investigated effects of diaphragm breathing exercise and feedback breathing exercise on respiratory function. [Subjects and Methods] Thirty-one subjects were randomly assigned to two groups; the feedback breathing exercise group and the maneuver-diaphragm exercise group. The feedback breathing exercise group was asked to breathe with feedback breathing device, and the maneuver-diaphragm exercise group was asked to perform diaphragm respiration. Respiratory function was evaluated when a subject sat on a chair comfortably. [Results] There was a significant difference in the functional vital capacity and slow vital capacity before and after all breathing exercises. There was a significant between-group difference in functional vital capacity. However, no between-group difference was found in slow vital capacity. [Conclusion] Diaphragm breathing exercise and feedback breathing exercise can affect respiratory function.

  4. Effects of diaphragm breathing exercise and feedback breathing exercise on pulmonary function in healthy adults

    PubMed Central

    Yong, Min-Sik; Lee, Hae-Yong; Lee, Yun-Seob

    2017-01-01

    [Purpose] The present study investigated effects of diaphragm breathing exercise and feedback breathing exercise on respiratory function. [Subjects and Methods] Thirty-one subjects were randomly assigned to two groups; the feedback breathing exercise group and the maneuver-diaphragm exercise group. The feedback breathing exercise group was asked to breathe with feedback breathing device, and the maneuver-diaphragm exercise group was asked to perform diaphragm respiration. Respiratory function was evaluated when a subject sat on a chair comfortably. [Results] There was a significant difference in the functional vital capacity and slow vital capacity before and after all breathing exercises. There was a significant between-group difference in functional vital capacity. However, no between-group difference was found in slow vital capacity. [Conclusion] Diaphragm breathing exercise and feedback breathing exercise can affect respiratory function. PMID:28210046

  5. Running and Breathing in Mammals

    NASA Astrophysics Data System (ADS)

    Bramble, Dennis M.; Carrier, David R.

    1983-01-01

    Mechanical constraints appear to require that locomotion and breathing be synchronized in running mammals. Phase locking of limb and respiratory frequency has now been recorded during treadmill running in jackrabbits and during locomotion on solid ground in dogs, horses, and humans. Quadrupedal species normally synchronize the locomotor and respiratory cycles at a constant ratio of 1:1 (strides per breath) in both the trot and gallop. Human runners differ from quadrupeds in that while running they employ several phase-locked patterns (4:1, 3:1, 2:1, 1:1, 5:2, and 3:2), although a 2:1 coupling ratio appears to be favored. Even though the evolution of bipedal gait has reduced the mechanical constraints on respiration in man, thereby permitting greater flexibility in breathing pattern, it has seemingly not eliminated the need for the synchronization of respiration and body motion during sustained running. Flying birds have independently achieved phase-locked locomotor and respiratory cycles. This hints that strict locomotor-respiratory coupling may be a vital factor in the sustained aerobic exercise of endothermic vertebrates, especially those in which the stresses of locomotion tend to deform the thoracic complex.

  6. Exhaled breath analysis and sleep.

    PubMed

    Carpagnano, Giovanna E

    2011-10-15

    It is currently estimated that the economic burden for obstructive sleep apnea syndrome (OSAS) cases not coming to medical attention is steadily increasing, thus making OSAS a major public health concern. For its increasing incidence among the common population, the interest of researchers and clinicians has been recently directed to the study of pathological mechanisms underlying sleep disorders. Current opinion is that airway inflammation and oxidative stress play a crucial role in the pathophysiology of OSAS. Recently there has been increasing interest in the investigation of lungs by non-invasive means measuring the exhaled breath volatile mediators, such as nitric oxide (NO), carbon monoxide (CO), ethane and pentane and finally the non-volatile substances in the liquid phase of exhalate, termed breath condensate. The non-invasiveness of these techniques for the study of airways affected by different respiratory disorders and among those, the OSAS, makes these ideally suited for the evaluation and serial monitoring of patients. Notwithstanding the increasing number of scientific contributions on the use of the exhaled markers in sleep disorders, at the moment, their use is not completely suitable for clinical application. An important contribution to the increase of our knowledge on exhaled markers and for their possible concrete application in clinical practice may come from future studies using proteomics, genomics and metabolomics. In this review, we focus on exhaled breath analysis giving an update on its general aspects, its application in OSAS, and finally its actual clinical applicability and areas for future direction.

  7. Air-Breathing Rocket Engines

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This photograph depicts an air-breathing rocket engine prototype in the test bay at the General Applied Science Lab facility in Ronkonkoma, New York. Air-breathing engines, known as rocket based, combined-cycle engines, get their initial take-off power from specially designed rockets, called air-augmented rockets, that boost performance about 15 percent over conventional rockets. When the vehicle's velocity reaches twice the speed of sound, the rockets are turned off and the engine relies totally on oxygen in the atmosphere to burn hydrogen fuel, as opposed to a rocket that must carry its own oxygen, thus reducing weight and flight costs. Once the vehicle has accelerated to about 10 times the speed of sound, the engine converts to a conventional rocket-powered system to propel the craft into orbit or sustain it to suborbital flight speed. NASA's Advanced Space Transportation Program at Marshall Space Flight Center, along with several industry partners and collegiate forces, is developing this technology to make space transportation affordable for everyone from business travelers to tourists. The goal is to reduce launch costs from today's price tag of $10,000 per pound to only hundreds of dollars per pound. NASA's series of hypersonic flight demonstrators currently include three air-breathing vehicles: the X-43A, X-43B and X-43C.

  8. Cardiovascular risk

    PubMed Central

    Payne, Rupert A

    2012-01-01

    Cardiovascular disease is a major, growing, worldwide problem. It is important that individuals at risk of developing cardiovascular disease can be effectively identified and appropriately stratified according to risk. This review examines what we understand by the term risk, traditional and novel risk factors, clinical scoring systems, and the use of risk for informing prescribing decisions. Many different cardiovascular risk factors have been identified. Established, traditional factors such as ageing are powerful predictors of adverse outcome, and in the case of hypertension and dyslipidaemia are the major targets for therapeutic intervention. Numerous novel biomarkers have also been described, such as inflammatory and genetic markers. These have yet to be shown to be of value in improving risk prediction, but may represent potential therapeutic targets and facilitate more targeted use of existing therapies. Risk factors have been incorporated into several cardiovascular disease prediction algorithms, such as the Framingham equation, SCORE and QRISK. These have relatively poor predictive power, and uncertainties remain with regards to aspects such as choice of equation, different risk thresholds and the roles of relative risk, lifetime risk and reversible factors in identifying and treating at-risk individuals. Nonetheless, such scores provide objective and transparent means of quantifying risk and their integration into therapeutic guidelines enables equitable and cost-effective distribution of health service resources and improves the consistency and quality of clinical decision making. PMID:22348281

  9. Cardiovascular Disease

    USDA-ARS?s Scientific Manuscript database

    Cardiovascular disease (CVD), particularly CHD (coronary heart disease) and stroke, remain the leading causes of death of women in America and most developed countries. In recent years the rate of CVD has declined in men but not in women. This is contributed to by an under-recognition of women’s C...

  10. [The significance of sympathovagal balance in the forming of respiration-dependent oscillations in cardiovascular system in human].

    PubMed

    Krasnikov, G V; Tiurina, M Ĭ; Tankanag, A V; Piskunova, G M; Cheremis, N K

    2014-01-01

    The effect of deep breathing controlled in both rate and amplitude on the heart rate variability (HRV) and respiration-dependent blood flow oscillations of forearm and finger-pad skin has been studied in 29 young healthy volunteers from 18 to 25 years old. To reveal the effect of the segments of the vegetative autonomic nervous system on the amplitudes of HRV and respiration-dependent oscillations of skin blood flow we estimated the parameters of the cardiovascular system into two groups of participants: with formally high and low sympathovagal balance values. The sympathovagal balance value was judged by the magnitude of LF/HF power ratio calculated for each participant using the spontaneous breathing rhythmogram. It was found what the participants with predominant parasympathetic tonus had statistically significant higher amplitudes of H R V and skin blood flow oscillations in the breathing rate less than 4 cycles per min than the subjects with predominant sympathetic tonus. In the forearm skin, where the density of sympathetic innervations is low comparatively to that in the finger skin, no statistically significant differences in the amplitude of respiratory skin blood flow oscillations was found between the two groups of participants.

  11. Efficacy of a self-directed behavioral health change program: weight, body composition, cardiovascular fitness, blood pressure, health risk, and psychosocial mediating variables.

    PubMed

    Clifford, P A; Tan, S Y; Gorsuch, R L

    1991-06-01

    This study assessed the efficacy of a comprehensive behavioral health program designed to promote self-initiated change in overweight healthy middle-aged adults (M = 49 years). Three treatment groups (total n = 25) differing in type of social support provided (i.e., group plus professional versus group plus peer versus group only) received 13 treatment sessions and 6 maintenance sessions scheduled over a full year. A self-directed change intervention taught several cognitive-behavioral techniques as they applied to exercise adherence, weight reduction/maintenance, and stress management. Combined treatment groups (n = 25) improved significantly more than an assessment only control group (n = 9) in weight, percentage body fat, cardiovascular fitness, exercise adherence, health-risk appraisal, chronic tension (MBHI, scale A), and systolic and diastolic blood pressure at both post-treatment and 6-month follow-up assessments. Self-motivation, group treatment attendance, and health-risk appraisal significantly related (r's = .30-.56) to several posttreatment and follow-up measures of behavioral health change. No significant differences were found among the three treatment groups on any of the outcome measures.

  12. Pharmacogenetics of cardiovascular drugs.

    PubMed

    Johnson, Julie A; Humma, Larisa M

    2002-02-01

    Pharmacogenetics is a field aimed at understanding the genetic contribution to inter-patient variability in drug efficacy and toxicity. Treatment of cardiovascular disease is, in most cases, guided by evidence from well-controlled clinical trials. Given the solid scientific basis for the treatment of most cardiovascular diseases, it is common for patients with a given disease to be treated in essentially the same manner. Thus, the clinical trials have been very informative about treating large groups of patients with a given disease, but are slightly less informative about the treatment of individual patients. Pharmacogenetics and pharmacogenomics have the potential of taking the information derived from large clinical trials and further refining it to select the drugs with the greatest likelihood for benefit, and least likelihood for harm, in individual patients, based on their genetic make-up. In this paper, the current literature on cardiovascular pharmacogenetics is emphasised, and how the use of pharmacogenetic/pharmacogenomic information may be particularly useful in the future in the treatment of cardiovascular diseases is also highlighted.

  13. TR-BREATH: Time-Reversal Breathing Rate Estimation and Detection.

    PubMed

    Chen, Chen; Han, Yi; Chen, Yan; Lai, Hung-Quoc; Zhang, Feng; Wang, Beibei; Liu, K J Ray

    2017-04-28

    In this paper, we introduce TR-BREATH, a timereversal (TR) based contact-free breathing monitoring system. It is capable of breathing detection and multi-person breathing rate estimation within a short period of time using off-the-shelf WiFi devices. The proposed system exploits the channel state information (CSI) to capture the miniature variations in the environment caused by breathing. To magnify the CSI variations, TRBREATH projects CSIs into the TR resonating strength (TRRS) feature space and analyzes the TRRS by the Root-MUSIC and affinity propagation algorithms. Extensive experiment results indoor demonstrate a perfect detection rate of breathing. With only 10 seconds of measurement, a mean accuracy of 99% can be obtained for single-person breathing rate estimation under the non-line-of-sight (NLOS) scenario. Furthermore, it achieves a mean accuracy of 98:65% in breathing rate estimation for a dozen people under the line-of-sight (LOS) scenario and a mean accuracy of 98:07% in breathing rate estimation of 9 people under the NLOS scenario, both with 63 seconds of measurement. Moreover, TR-BREATH can estimate the number of people with an error around 1. We also demonstrate that TR-BREATH is robust against packet loss and motions. With the prevailing of WiFi, TR-BREATH can be applied for in-home and real-time breathing monitoring.

  14. Why are some studies of cardiovascular markers unreliable? The role of measurement variability and what an aspiring clinician scientist can do before it is too late.

    PubMed

    Shun-Shin, Matthew; Francis, Darrel P

    2012-01-01

    Cardiology research suffers from the scourge of unreliable results, despite honest conduct. Investigators' prior belief, compromised blinding, and scope for measurement variability are a fatally synergistic combination. Can we stop these threats ruining the results? First, clinical researchers must realize that healthy clinical practice (including intelligently integrating all available information) may be catastrophic to research. Second, experienced clinicians know that variability may necessitate remeasurement to obtain a clinically correct result but must learn that doing so in research can cause surprisingly severe distortions of correlations or differences between groups. For example, a "best-of-four" approach in comparing two 50-patient groups that are in reality identical, with a variable whose intraclass correlation is 0.8, easily generates highly significant P values. Clinicians may be habituated to poorly reproducible clinical measurements and falsely reassured by their effectiveness for group mean effects in blinded randomized controlled trials. We need a more critical approach to clinical tests if we care about evaluating individual patients reliably or want our research to be reliable. Simple steps shown here, addressed during study design, will increase the reliability of research-if considered by researchers or the juniors whom they nurture. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Sleep disordered breathing in pregnancy

    PubMed Central

    2015-01-01

    Key points Sleep disordered breathing (SDB) is common and the severity increases as pregnancy progresses. Frequent snoring, older age and high pre-pregnancy body mass index (>25 kg⋅m−2) could be reliable indicators for SDB in early pregnancy. SDB screening tools, including questionnaires, used in the nonpregnant population have poor predictive ability in pregnancy. Accumulating evidence suggests that SDB during pregnancy may be associated with increased risk of adverse pregnancy outcomes, including gestational diabetes and pre-eclampsia. However, the results should be interpreted cautiously because several studies failed to adjust for potential maternal confounders and have other study limitations. There are no pregnancy-specific practice guidelines for SDB treatment. Many clinicians and practices follow recommendations for the treatment in the general population. Women with pre-existing SDB might need to be reassessed, particularly after the sixth month of pregnancy, because symptoms can worsen with nasal congestion and weight gain. Educational aims To highlight the prevalence and severity of sleep disordered breathing (SDB) in the pregnant population. To inform readers about risk factors for SDB in pregnancy. To explore the impact of SDB on adverse maternal and fetal outcomes, and biological pathways for associated adverse maternal and fetal outcomes. To introduce current management options for SDB in pregnancy, including medical and behavioural approaches. Sleep disordered breathing (SDB) is very common during pregnancy, and is most likely explained by hormonal, physiological and physical changes. Maternal obesity, one of the major risk factors for SDB, together with physiological changes in pregnancy may predispose women to develop SDB. SDB has been associated with poor maternal and fetal outcomes. Thus, early identification, diagnosis and treatment of SDB are important in pregnancy. This article reviews the pregnancy-related changes affecting the

  16. Free-breathing radial volumetric interpolated breath-hold examination vs breath-hold cartesian volumetric interpolated breath-hold examination magnetic resonance imaging of the liver at 1.5T

    PubMed Central

    Yedururi, Sireesha; Kang, HyunSeon C; Wei, Wei; Wagner-Bartak, Nicolaus A; Marcal, Leonardo P; Stafford, R Jason; Willis, Brandy J; Szklaruk, Janio

    2016-01-01

    AIM To compare breath-hold cartesian volumetric interpolated breath-hold examination (cVIBE) and free-breathing radial VIBE (rVIBE) and determine whether rVIBE could replace cVIBE in routine liver magnetic resonance imaging (MRI). METHODS In this prospective study, 15 consecutive patients scheduled for routine MRI of the abdomen underwent pre- and post-contrast breath-hold cVIBE imaging (19 s acquisition time) and free-breathing rVIBE imaging (111 s acquisition time) on a 1.5T Siemens scanner. Three radiologists with 2, 4, and 8 years post-fellowship experience in abdominal imaging evaluated all images. The radiologists were blinded to the sequence types, which were presented in a random order for each patient. For each sequence, the radiologists scored the cVIBE and rVIBE images for liver edge sharpness, hepatic vessel clarity, presence of artifacts, lesion conspicuity, fat saturation, and overall image quality using a five-point scale. RESULTS Compared to rVIBE, cVIBE yielded significantly (P < 0.001) higher scores for liver edge sharpness (mean score, 3.87 vs 3.37), hepatic-vessel clarity (3.71 vs 3.18), artifacts (3.74 vs 3.06), lesion conspicuity (3.81 vs 3.2), and overall image quality (3.91 vs 3.24). cVIBE and rVIBE did not significantly differ in quality of fat saturation (4.12 vs 4.03, P = 0.17). The inter-observer variability with respect to differences between rVIBE and cVIBE scores was close to zero compared to random error and inter-patient variation. Quality of rVIBE images was rated as acceptable for all parameters. CONCLUSION rVIBE cannot replace cVIBE in routine liver MRI. At 1.5T, free-breathing rVIBE yields acceptable, although slightly inferior image quality compared to breath-hold cVIBE. PMID:27551341

  17. Reliability of breath by breath spirometry and relative flow-time indices for pulmonary function testing in horses.

    PubMed

    Burnheim, K; Hughes, K J; Evans, D L; Raidal, S L

    2016-11-28

    Respiratory problems are common in horses, and are often diagnosed as a cause of poor athletic performance. Reliable, accurate and sensitive spirometric tests of airway function in resting horses would assist with the diagnosis of limitations to breathing and facilitate investigations of the effects of various treatments on breathing capacity. The evaluation of respiratory function in horses is challenging and suitable procedures are not widely available to equine practitioners. The determination of relative flow or flow-time measures is used in paediatric patients where compliance may limit conventional pulmonary function techniques. The aim of the current study was to characterise absolute and relative indices of respiratory function in healthy horses during eupnoea (tidal breathing) and carbon dioxide (CO2)-induced hyperpnoea (rebreathing) using a modified mask pneumotrachographic technique well suited to equine practice, and to evaluate the reliability of this technique over three consecutive days. Coefficients of variation, intra-class correlations, mean differences and 95% confidence intervals across all days of testing were established for each parameter. The technique provided absolute measures of respiratory function (respiratory rate, tidal volume, peak inspiratory and expiratory flows, time to peak flow) consistent with previous studies and there was no significant effect of day on any measure of respiratory function. Variability of measurements was decreased during hyperpnea caused by rebreathing CO2, but a number of relative flow-time variables demonstrated good agreement during eupnoeic respiration. The technique was well tolerated by horses and study findings suggest the technique is suitable for evaluation of respiratory function in horses. The use of relative flow-time variables provided reproducible (consistent) results, suggesting the technique may be of use for repeated measures studies in horses during tidal breathing or rebreathing.

  18. Breath ammonia measurement in Helicobacter pylori infection.

    PubMed

    Kearney, David J; Hubbard, Todd; Putnam, David

    2002-11-01

    Our aim was to define the utility of breath ammonia measurement in assessing Helicobacter pylori infection. Volunteers breathed into a device containing three fiberoptic NH3 sensors at baseline and after ingesting 300 mg of urea. Breath ammonia levels were compared to the [14C]urea breath test. Thirteen subjects were tested. Before urea ingestion, H. pylori-positive subjects had significantly lower breath ammonia levels than negative subjects (mean +/- SD, 0.04 ppm +/- 0.09 vs 0.49 ppm +/- 0.24, P = 0.002) and had a significantly greater increases in breath ammonia after urea ingestion (range 198-1,494% vs 6-98%). One H. pylori-positive subject underwent treatment and breath ammonia levels shifted from the pattern seen in positive subjects to that seen in negative subjects. In conclusion, breath ammonia measurement for H. Pylori-positive and negative subjects showed distinct patterns. Breath ammonia measurement may be feasible as a diagnostic test for H. pylori.

  19. [Breath-analysis tests in gastroenetrological diagnosis].

    PubMed

    Caspary, W F

    1975-12-01

    The introduction of a simple method for analysis of 14CO2 in breath allowed a more widely application of breath-tests in the diagnosis of gastroenterological diseases. During a breath-test a 14C-labelled compound is administered orally and 14CO2 is subsequently measured in breath by discontinuous samplings of 14CO2 by virtue of a trapping solution (hyamine hydroxide). Most helpful tests in gastroenterology are the 14C-glycyl-cholate breath test for detecting increased deconjugation of bile acids due to small intestinal bacterial overgrowth or bile acid malabsorption in ileal resection or Crohn's disease of the ileum, the 14C-lactose breath test in lactase deficiency, whereas the 14C-tripalmitin test seems less helpful in the diagnosis of fat malabsorption. A 14C-aminopyrine breath test may turn out to be a simple and valuable liver function test. Oral loading tests with breath analysis of H2 have shown to be helpful in the diagnosis of carbohydrate malabsorption, determination of intestinal transit time and intestinal gas production. Due to technical reasons (gas-chromatographie analysis) H2-breath analysis is still limited to research centers. Despite low radiation doses after oral administration of 14C-labelled compounds oral loading tests with H2- or 13C-analysis might be preferable in the future.

  20. [Relationship between abnormal swallowing and mouth breathing].

    PubMed

    Wang, Meng-wu; Li, Hong-fa; Wang, Qiu-rui; Xu, Hao; He, Jing-nan

    2013-12-01

    To investigate the relationship between abnormal swallowing and mouth breathing. Thirty-eight patients with abnormal swallowing and 38 patients with normal swallowing were selected. All patients presented with no airway constriction. The age range of the patients was 11-14 years old. The number of patients with mouth breathing was calculated. Statistical analysis (χ(2) test) was performed. The number of patients with mouth breathing in the abnormal swallowing group (17, 45%) was significantly higher than that in the normal swallowing group (5, 13%) (χ(2) = 9.212, P = 0.002). Abnormal swallowing was related to mouth breathing.

  1. Calculating rhythmicity of infant breathing using wavelets

    NASA Astrophysics Data System (ADS)

    Macey, Katherine E.; Page, Wyatt H.; Harper, Ronald M.; Macey, Paul M.; Ford, Rodney P. K.

    2000-12-01

    Breathing signals are one set of physiological data that may provide information regarding the mechanisms that cause SIDS. Isolated breathing pauses have been implicated in fatal events. Other features of interest include slow amplitude modulation of the breathing signal, a phenomenon whose origin is unclear, and periodic breathing. The latter describes a repetitive series of apnea, and may be considered an extreme manifestation of amplitude modulation with successive cessations of breathing. Rhythmicity is defined to assess the impact of amplitude modulation on breathing signals and describes the extent to which frequency components remain constant for the duration of the signal. The wavelet transform was used to identify sections of constant frequency components within signals. Rhythmicity can be evaluated for all the frequency components in a signal, for individual frequencies. The rhythmicity of eight breathing epochs from sleeping infants at high and low risk for SIDS was calculated. Initial results show breathing from infants at high risk for SIDS exhibits greater rhythmicity of modulating frequencies than breathing from low risk infants.

  2. The effects of sighing on the cardiovascular system

    PubMed Central

    Vaschillo, Evgeny G.; Vaschillo, Bronya; Buckman, Jennifer F.; Nguyen-Louie, Tam; Heiss, Sydney; Pandina, Robert J.; Bates, Marsha E.

    2015-01-01

    Elicitation of high-amplitude oscillations in the cardiovascular system may serve to dampen psychophysiological reactivity to emotional and cognitive loading. Prior work has used paced breathing to impose clinically valu