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1.
PLoS One ; 11(4): e0152994, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27071039

RESUMO

BACKGROUND: A high P-wave duration and dispersion (Pd) have been reported to be a prognostic factor for the occurrence of paroxysmal atrial fibrillation (PAF), a condition linked to obstructive sleep apnea (OSA). We tested the hypothesis of whether a short-term increase of P-wave duration and Pd can be induced by respiratory manoeuvres simulating OSA in healthy subjects and in patients with PAF. METHODS: 12-lead-electrocardiography (ECG) was recorded continuously in 24 healthy subjects and 33 patients with PAF, while simulating obstructive apnea (Mueller manoeuvre, MM), obstructive hypopnea (inspiration through a threshold load, ITH), central apnea (AP), and during normal breathing (BL) in randomized order. The P-wave duration and Pd was calculated by using dedicated software for ECG-analysis. RESULTS: P-wave duration and Pd significantly increased during MM and ITH compared to BL in all subjects (+13.1 ms and +13.8 ms during MM; +11.7 ms and +12.9 ms during ITH; p<0.001 for all comparisons). In MM, the increase was larger in healthy subjects when compared to patients with PAF (p<0.05). CONCLUSION: Intrathoracic pressure swings through simulated obstructive sleep apnea increase P-wave duration and Pd in healthy subjects and in patients with PAF. Our findings imply that intrathoracic pressure swings prolong the intra-atrial and inter-atrial conduction time and therefore may represent an independent trigger factor for the development for PAF.


Assuntos
Fibrilação Atrial/etiologia , Fibrilação Atrial/fisiopatologia , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/fisiopatologia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Eletrocardiografia/estatística & dados numéricos , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Pressão , Fatores de Risco , Apneia do Sono Tipo Central/fisiopatologia , Adulto Jovem
2.
Can J Anaesth ; 62(7): 762-9, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25663254

RESUMO

INTRODUCTION: Double-lumen endotracheal tubes (DLTs), which are commonly used for single-lung ventilation during surgery, are difficult to insert. In addition, they often move during surgical lung manipulation which can cause life-threatening complications. Flexible bronchoscopy is used routinely to establish and confirm proper DLT placement. The newly designed VivaSight DLT has an integrated camera, allowing continuous visualization of its position in the trachea. We hypothesized that the time to intubation using the VivaSight DLT would be faster than with a conventional DLT. METHODS: We enrolled 40 adults scheduled for thoracic surgery. Patients were randomized to conventional DLT (n = 20) or VivaSight DLT (n = 20). Time to intubation was our primary outcome. Secondary outcomes were insertion success without flexible bronchoscopy, frequency of tube displacement, ease of insertion, quality of lung collapse, postoperative complaints, and airway injuries. RESULTS: Time [mean (SD)] to successful intubation was significantly faster with the VivaSight DLT [63 (58) sec] compared with the conventional DLT [97 (84) sec; P = 0.03]. The VivaSight DLTs were correctly inserted during all attempts. When malpositioning of the VivaSight DLT occurred, it was easily remedied, even in the lateral position. The devices were comparable with respect to postoperative coughing, hoarseness, and sore throat. Airway injuries tended to be more common with the VivaSight DLT, although this study was underpowered for airway injuries. CONCLUSION: The VivaSight DLT camera allowed faster insertion and facilitated initial positioning. It also confirmed proper tube positioning intraoperatively and facilitated repositioning when necessary. This trial was registered at clinicaltrials.gov: NCT01807676.


Assuntos
Broncoscopia/métodos , Intubação Intratraqueal/métodos , Ventilação Monopulmonar/métodos , Procedimentos Cirúrgicos Torácicos/métodos , Adulto , Idoso , Desenho de Equipamento , Feminino , Humanos , Intubação Intratraqueal/instrumentação , Masculino , Pessoa de Meia-Idade , Sistema Respiratório/lesões , Procedimentos Cirúrgicos Torácicos/instrumentação , Fatores de Tempo
3.
BMC Pulm Med ; 14: 55, 2014 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-24690123

RESUMO

BACKGROUND: Altered cardiac repolarization and increased dispersion of repolarization have been identified as risk factors for sudden cardiac death (SCD). The prevalence of and the mechanisms contributing to altered cardiac repolarization are currently unknown in COPD. METHODS: In 91 COPD patients, 32 controls matched for age, cardiovascular risk and medication, and 41 healthy subjects, measures of cardiac repolarization and dispersion of repolarization (QTc interval, QT dispersion) were derived from 12-lead electrocardiography (ECG). Prevalence rates of heart rate corrected QT (QTc) >450ms and QT dispersion >60ms were determined to assess the number of subjects at risk for SCD. Univariate and multivariate analyses were used to identify possible factors contributing to altered cardiac repolarization. RESULTS: QTc was found to be prolonged in 31.9% and QT dispersion in 24.2% of the COPD patients compared to 12.5% in matched controls and 0% in healthy subjects. The QTc interval was longer in COPD patients compared to matched and healthy controls respectively (437.9 ± 29.5 vs. 420.1 ± 25.3 ms, p = 0.001 and vs. 413.4 ± 18.2 ms, p < 0.001). QT dispersion was significantly increased in COPD patients compared to healthy subjects (45.4 (34.8 , 59.5) vs. 39.7 (29.3 , 54.8) ms, p = 0.049). Only oxygen saturation was independently associated with QTc duration in multivariate analysis (ß = -0.29, p = 0.015). CONCLUSION: One third of a typical COPD population has altered cardiac repolarization and increased dispersion of repolarization, which may be related to hypoxia. Altered cardiac repolarization may expose these patients to an increased risk for malignant ventricular arrhythmias and SCD.


Assuntos
Coração/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/complicações , Adulto , Arritmias Cardíacas/epidemiologia , Arritmias Cardíacas/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Fatores de Risco
4.
Respiration ; 87(4): 301-10, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24556641

RESUMO

BACKGROUND: It has been suggested that exhaled breath contains relevant information on health status. OBJECTIVES: We hypothesized that a novel mass spectrometry (MS) technique to analyze breath in real time could be useful to differentiate breathprints from chronic obstructive pulmonary disease (COPD) patients and controls (smokers and nonsmokers). METHODS: We studied 61 participants including 25 COPD patients [Global Initiative for Obstructive Lung Disease (GOLD) stages I-IV], 25 nonsmoking controls and 11 smoking controls. We analyzed their breath by MS in real time. Raw mass spectra were then processed and statistically analyzed. RESULTS: A panel of discriminating mass-spectral features was identified for COPD (all stages; n = 25) versus healthy nonsmokers (n = 25), COPD (all stages; n = 25) versus healthy smokers (n = 11) and mild COPD (GOLD stages I/II; n = 13) versus severe COPD (GOLD stages III/IV; n = 12). A blind classification (i.e. leave-one-out cross validation) resulted in 96% sensitivity and 72.7% specificity (COPD vs. smoking controls), 88% sensitivity and 92% specificity (COPD vs. nonsmoking controls) and 92.3% sensitivity and 83.3% specificity (GOLD I/II vs. GOLD III/IV). Acetone and indole were identified as two of the discriminating exhaled molecules. CONCLUSIONS: We conclude that real-time MS may be a useful technique to analyze and characterize the metabolome of exhaled breath. The acquisition of breathprints in a rapid manner may be valuable to support COPD diagnosis and to gain insight into the disease.


Assuntos
Testes Respiratórios/métodos , Espectrometria de Massas , Doença Pulmonar Obstrutiva Crônica/metabolismo , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
5.
Heart Lung Circ ; 23(3): 280-6, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24080024

RESUMO

BACKGROUND: Chronic obstructive pulmonary disease (COPD) has been associated with increased risk for cardiovascular disease but mechanisms underlying this association are incompletely understood. The speed of beat-to-beat changes in systolic blood pressure (vSBP) was found to be pronounced in patients with elevated cardiovascular risk. Although increased vSBP may thus be a contributing mechanism to cardiovascular morbidity, no data exist on vSBP in patients with COPD. Therefore, the purpose of this study was to evaluate whether there is an association between severity of COPD and vSBP. METHODS: Resting beat-to-beat blood pressure was recorded during 5 min. vSBP was assessed by calculating the slopes of oscillatory fluctuations in SBP for different inter-beat intervals (IBI). Univariate and multivariate analyses were performed to evaluate the association between forced expiratory volume in 1 s (FEV1) and vSBP. RESULTS: This study comprised 60 patients with COPD (24 females) with a mean [SD] FEV1 of 45.4 [22.7] %predicted and 34 healthy controls. Short-term fluctuations in SBP were more pronounced in patients with COPD compared to healthy controls. There was a significant inverse correlation between FEV1 and vSBP (r=-0.41, p=0.001). Even after adjustment for covariates in multivariate analysis, FEV1 was found to be independently associated with vSBP. CONCLUSIONS: Patients with COPD are characterised by steeper blood pressure changes than healthy controls. The speed of fluctuations in SBP is associated with the severity of airflow limitation. Increased vSBP may be a mechanism underpinning the association between COPD and cardiovascular disease.


Assuntos
Pressão Sanguínea , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Adulto , Idoso , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/complicações , Fatores de Risco
6.
Hypertens Res ; 36(12): 1039-44, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23784510

RESUMO

Increased blood pressure variability (BPV), even in the absence of hypertension, has been identified as an important independent cardiovascular risk factor (CVRF). However, the role of the speed of changes in systolic blood pressure (SBP; vSBP) on cardiovascular risk needs to be investigated. The objective of this study was to investigate whether subjects with a high cardiovascular risk profile have an increased degree and speed of changes in SBP compared with subjects with low or no risk. Resting beat-to-beat blood pressure (BP) was recorded for 5 min. Standard BPV measures in both time and frequency domains were conducted. The s.d. of SBP (s.d.-SBP) values was used to quantify the degree of BPV. vSBP was assessed by calculating the slopes of oscillatory fluctuations in SBP for different interbeat intervals (IBI). Subjects were allocated to one of four groups according to the number of CVRFs (0, 1, 2, ≥ 3 CVRF). Of 122 subjects, 19.7% had 0 CVRF, 27.0% had 1, 32.0% had 2 and 21.3% had ≥ 3 CVRFs. There was an increase in vSBP across the four risk groups. The vSBP in patients without CVRF was 3.12 (1.09), 1 CVRF 3.23 (1.07), 2 CVRF 4.16 (2.26) and ≥ 3 CVRF 4.22 (1.66; P = 0.015). The s.d.-SBP was not significantly different between the cardiovascular risk groups. The speed of fluctuations in SBP rather than the degree of BPV is pronounced in patients with elevated cardiovascular risk. Increased speed of BP fluctuations may thus be a contributing mechanism to cardiovascular morbidity.


Assuntos
Pressão Sanguínea/fisiologia , Adolescente , Adulto , Idoso , Algoritmos , Determinação da Pressão Arterial , Monitorização Ambulatorial da Pressão Arterial , Doenças Cardiovasculares/fisiopatologia , Feminino , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Reprodutibilidade dos Testes , Medição de Risco , Fatores de Risco , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/fisiopatologia , Adulto Jovem
7.
J Appl Physiol (1985) ; 115(5): 613-7, 2013 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-23766507

RESUMO

Preliminary evidence supports an association between obstructive sleep apnea (OSA) and thoracic aortic dilatation, although potential causative mechanisms are incompletely understood; these may include an increase in aortic wall transmural pressures, induced by obstructive apneas and hypopneas. In patients undergoing cardiac catheterization, mean blood pressure (MBP) in the thoracic aorta and esophageal pressure was simultaneously recorded by an indwelling aortic pigtail catheter and a balloon-tipped esophageal catheter in randomized order during: normal breathing, simulated obstructive hypopnea (inspiration through a threshold load), simulated obstructive apnea (Mueller maneuver), and end-expiratory central apnea. Aortic transmural pressure (aortic MBP minus esophageal pressure) was calculated. Ten patients with a median age (range) of 64 (46-75) yr were studied. Inspiration through a threshold load, Mueller maneuver, and end-expiratory central apnea was successfully performed and recorded in 10, 7, and 9 patients, respectively. The difference between aortic MBP and esophageal pressure (and thus the extra aortic dilatory force) was median (quartiles) +9.3 (5.4, 18.6) mmHg, P = 0.02 during inspiration through a threshold load, +16.3 (12.8, 19.4) mmHg, P = 0.02 during the Mueller maneuver, and +0.4 (-4.5, 4.8) mmHg, P = 0.80 during end-expiratory central apnea. Simulated obstructive apnea and hypopnea increase aortic wall dilatory transmural pressures because intra-aortic pressures fall less than esophageal pressures. Thus OSA may mechanically promote thoracic aortic dilatation and should be further investigated as a risk factor for the development or accelerated progression of thoracic aortic aneurysms.


Assuntos
Aorta Torácica/fisiologia , Aorta Torácica/fisiopatologia , Pressão Sanguínea/fisiologia , Apneia Obstrutiva do Sono/fisiopatologia , Idoso , Esôfago/fisiologia , Esôfago/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Respiração , Fatores de Risco
8.
Eur Respir J ; 42(5): 1194-204, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23429917

RESUMO

Chronic obstructive pulmonary disease (COPD) is associated with increased cardiovascular mortality. Endothelial dysfunction may underpin this association. This cross-sectional study aimed to determine the impact of airflow obstruction, systemic inflammation, oxidative stress, sympathetic activation, hypoxaemia and physical activity on endothelial function in COPD. In stable COPD patients, assessments of endothelial function by flow-mediated dilatation (FMD), cardiovascular risk (Pocock score), airflow obstruction (forced expiratory volume in 1 s (FEV1)), systemic inflammation (high-sensitivity C-reactive protein and interleukin-6), oxidative stress (malondialdehyde), sympathetic activation (baroreflex sensitivity), hypoxaemia (arterial oxygen tension), hypercapnia (arterial carbon dioxide tension (PaCO2)), physical activity (steps per day) and exercise capacity (6-min walking distance) were performed. Associations between FMD and potential determinants were assessed in univariate and multivariate analyses. 106 patients (Global Initiative for Chronic Obstructive Lung Disease stage I/II 35%, stage III 25% and stage IV 40%) were included. In multivariate analysis FEV1 was positively associated with FMD, independent of other significant FMD determinants from univariate analysis (sex, smoking, combined inhaled long-acting ß-adrenergic and steroid medication, heart rate, baroreflex sensitivity and PaCO2) and adjusted for potential confounders (cardiovascular risk and age). In addition, the FMD and FEV1 association was modified by physical activity. The findings of this study demonstrate that the severity of airflow obstruction is a significant determinant of endothelial function in patients with COPD. A high level of physical activity seems to have a favourable effect on this association.


Assuntos
Doenças Cardiovasculares/fisiopatologia , Endotélio Vascular/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Corticosteroides/química , Adulto , Idoso , Barorreflexo , Gasometria , Pressão Sanguínea , Artéria Braquial/patologia , Proteína C-Reativa/metabolismo , Doenças Cardiovasculares/complicações , Estudos de Coortes , Feminino , Volume Expiratório Forçado , Frequência Cardíaca , Humanos , Hipóxia , Inflamação , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo , Oxigênio/química , Doença Pulmonar Obstrutiva Crônica/complicações , Análise de Regressão , Risco , Sistema Nervoso Simpático/fisiopatologia
9.
Eur J Appl Physiol ; 113(2): 489-96, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22806087

RESUMO

Preliminary evidence supports an association between OSA and cardiac dysrhythmias. Negative intrathoracic pressure, as occurring during OSA, may provoke cardiac dysrhythmias. Thus, we aimed to study the acute effects of simulated apnea and hypopnea on arrhythmic potential and measures of cardiac repolarization [QT(C) and T (peak) to T (end) intervals [TpTec]) in humans. In 41 healthy volunteers, ECG was continuously recorded prior, during and after simulated obstructive hypopnea (inspiration through a threshold load), simulated apnea (Mueller maneuver), end-expiratory central apnea and normal breathing in randomized order. The number of subjects with premature beats was significantly higher during inspiration through a threshold load (n = 7), and the Mueller maneuver (n = 7) compared to normal breathing (n = 0) (p = 0.008 for all comparisons), but not during end-expiratory central apnea (n = 3, p = 0.125). Inspiration through a threshold load was associated with a non-significant mean (SD) increase of the QT(C) interval [+5.4 (22.4) ms, 95 %CI -1.7 to +12.4 ms, p = 0.168] and a significant increase of the TpTcc interval [+3.7 (8.9) ms, 95 %CI +0.9 to +6.6 ms, p = 0.010]. The Mueller maneuver induced a significant increase of the QT(C) interval [+8.3 (23.4) ms, 95 %CI 0.9 to +15.6 ms, p = 0.035] and the TpTec interval (+4.2 (8.2) ms, 95 %CI +1.6 to +6.8 ms, p = 0.002). There were no significant changes of the QT(C) and TpTec intervals during central end-expiratory apnea. These data indicate that simulated obstructive apnea and hypopnea are associated with an increase of premature beats and prolongation of QT(C) and TpTec intervals. Therefore, negative intrathoracic pressure changes may be a contributory mechanism for the association between OSA and cardiac dysrhythmias.


Assuntos
Complexos Cardíacos Prematuros/etiologia , Complexos Cardíacos Prematuros/fisiopatologia , Mecânica Respiratória , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/fisiopatologia , Adulto , Feminino , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
10.
PLoS One ; 7(11): e48081, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23133612

RESUMO

BACKGROUND: Objectively measuring daily physical activity (PA) using an accelerometer is a relatively expensive and time-consuming undertaking. In routine clinical practice it would be useful to estimate PA in patients with chronic obstructive pulmonary disease (COPD) with more simple methods. OBJECTIVES: To evaluate whether PA can be estimated by simple tests commonly used in clinical practice in patients with COPD. METHODS: The average number of steps per day was measured for 7 days with a SenseWear Pro™ accelerometer and used as gold standard for PA. A physical activity level (PAL) of <1.4 was considered very inactive. Univariate and multivariate analyses were used to examine the relationship between the 6-minute walking distance (6MWD), the number of stands in the Sit-to-Stand Test (STST), hand-grip strength and the total energy expenditure as assessed by the Zutphen Physical Activity Questionnaire (TEE(ZPAQ)). ROC curve analysis was used to identify patients with an extremely inactive lifestyle (PAL<1.4). RESULTS: In 70 patients with COPD (21 females) with a mean [SD] FEV(1) of 43.0 [22.0] %predicted, PA was found to be significantly and independently associated with the 6MWD (r = 0.69, 95% CI 0.54 to 0.80, p<0.001), STST (r = 0.51, 95% CI 0.31 to 0.66, p = 0.001) and TEEZPAQ (r = 0.50, 95% CI 0.30 to 0.66, p<0.001) but not with hand-grip strength. However, ROC curve analysis demonstrated that these tests cannot be used to reliably identify patients with an extremely inactive lifestyle. CONCLUSIONS: In patients with COPD simple tests such as the 6-Minute Walk Test, the Sit-to-Stand Test and the Zutphen Physical Activity Questionnaire cannot be used to reliably predict physical inactivity.


Assuntos
Monitorização Ambulatorial/métodos , Atividade Motora , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Aceleração , Atividades Cotidianas , Idoso , Antropometria/métodos , Tolerância ao Exercício , Feminino , Volume Expiratório Forçado , Força da Mão , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Doença Pulmonar Obstrutiva Crônica/complicações , Curva ROC , Testes de Função Respiratória , Espirometria/métodos , Inquéritos e Questionários
11.
Eur Heart J ; 33(17): 2206-12, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22453648

RESUMO

AIMS: The preliminary evidence supports an association between obstructive sleep apnoea (OSA), disturbed cardiac repolarization, and consequent cardiac dysrhythmias. The aim of the current trial was to assess the effects of continuous positive airway pressure (CPAP) therapy withdrawal on the measures of cardiac repolarization in patients with OSA. METHODS AND RESULTS: Forty-one OSA patients established on CPAP treatment were randomized to either CPAP withdrawal (subtherapeutic CPAP) or continue therapeutic CPAP for 2 weeks. Polysomnography was performed, and indices of cardiac repolarization (QT(c), TpTe(c) intervals) and dispersion of repolarization (TpTe/QT ratio) were derived from 12-lead electrocardiography (ECG) at baseline and 2 weeks. Continuous positive airway pressure withdrawal led to a recurrence of OSA. Compared with therapeutic CPAP, subtherapeutic CPAP for 2 weeks was associated with a significant increase in the length of the QT(c) and TpTe(c) intervals (mean difference between groups 21.4 ms, 95% CI 11.3-1.6 ms, P < 0.001 and 14.4 ms, 95% CI 7.2-21.5 ms, P < 0.001, respectively) and in the TpTe/QT ratio (mean difference between groups 0.02, 95% CI 0.00-0.03, P = 0.020). There was a statistically significant correlation between the change in apnoea/hypopnoea index (AHI) from baseline, and both the change in the QT(c) interval and the TpTe(c) interval (r = 0.60, 95% CI 0.36-0.77, P < 0.001 and r = 0.45, 95% CI 0.17-0.67, P = 0.003, n = 41, respectively). CONCLUSION: Continuous positive airway pressure withdrawal is associated with the prolongation of the QT(c) and TpTe(c) intervals and TpTe/QT ratio, which may provide a possible mechanistic link between OSA, cardiac dysrhythmias, and thus sudden cardiac death.


Assuntos
Arritmias Cardíacas/etiologia , Pressão Positiva Contínua nas Vias Aéreas , Sistema de Condução Cardíaco/fisiologia , Apneia Obstrutiva do Sono/terapia , Arritmias Cardíacas/fisiopatologia , Morte Súbita Cardíaca/prevenção & controle , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polissonografia , Apneia Obstrutiva do Sono/fisiopatologia , Desmame do Respirador
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