Predictors of high-degree conduction disturbances and pacemaker implantation after transcatheter aortic valve replacement: Prognostic role of the electrophysiological study.

BACKGROUND: Predictors of high-degree atrioventricular block (HAVB) after transcatheter aortic valve replacement (TAVR) are recognized, but the electrophysiological study's (EPS) role is still a subject to debate. The objective of our study was to determine factors associated with PPM implantation including the potential role of EPS before and/or after TAVR. METHODS AND RESULTS: Seventy four consecutive patients (pts) were included and 21 pts (28.4%) received a PPM during the immediate postoperative follow-ups (until Day 5): HAVB in 15 pts (71.4%), prophylactic implantation due to a documented increased HV interval ≥ 95-100 ms plus LBBB in 2 pts (9.5%), a high-degree HV block evidenced at the EPS plus LBBB in 3 pts (14.3%) and one additional patient was implanted for AV-block in presence of AFib (4.8%). In the multivariate model 1 including parameters before TAVR, both prosthesis diameter and PR lengthening remained significantly associated with PPM as well RBBB. In the multivariate model 2 including parameters after TAVR, only HV remained significantly associated with the risk of PPM (OR = 1.15 (1.05-1.26), p = .004). When all the significant variables in models 1 and 2 were analyzed together in model 3, only HV after TAVR remained significantly associated with an increased risk of PPM. CONCLUSIONS: In this prospective observational study, it was revealed that a Day 4-5 EPS is likely to more precisely stratify the risk of PPM implantation regarding its ability to discover asymptomatic severe infra-hisian conduction disturbances particularly in presence of LBBB. Multivariate analysis confirmed the prognostic value of HV alteration.

Longer-term effects of supervised physical activity on obstructive sleep apnea and subsequent health consequences.

Although recent trials have shown promising benefits of exercise on obstructive sleep apnea (OSA) severity, the long-term effect of these interventions remains unknown. The aim of this study was to assess the effect of a 9-month community physical activity program on OSA severity one year later in free-living conditions. OSA patients, previously included in a 9-month randomized controlled trial (EXESAS study) evaluating the effects of supervised community physical activity on OSA severity, were invited to participate in an extra one-year observational study. Twenty-eight patients completed the study. Although OSA severity did not significantly worsen over the real-life period (9 to 21 months of follow-up), reductions in apnea-hypopnea index (AHI) and oxygen desaturation index were no longer significant after 21 months of follow-up compared to baseline (baseline AHI: 22.2 ± 6.3 /h; 9 months: 16.3 ± 6.4 /h; 21 months: 18.7 ± 8.9 /h). Benefits observed at 9 months on daytime sleepiness and mental health were preserved at 21 months, whereas cardiorespiratory fitness slightly decreased. Per-protocol analysis revealed that patients who stopped exercise at 9 months had worsened OSA severity compared to those who continued exercise during the real-life period (AHI: +9.0 ± 8.8 vs. -1.3 ± 5.3 /h; p < .01). In conclusion, our study suggested that improvements in OSA severity remain transient and is dependent on long-term adherence to regular physical activity practice.

Muscle Proteomic and Transcriptomic Profiling of Healthy Aging and Metabolic Syndrome in Men.

(1) Background: Aging is associated with a progressive decline in muscle mass and function. Aging is also a primary risk factor for metabolic syndrome, which further alters muscle metabolism. However, the molecular mechanisms involved remain to be clarified. Herein we performed omic profiling to decipher in muscle which dominating processes are associated with healthy aging and metabolic syndrome in old men. (2) Methods: This study included 15 healthy young, 15 healthy old, and 9 old men with metabolic syndrome. Old men were selected from a well-characterized cohort, and each vastus lateralis biopsy was used to combine global transcriptomic and proteomic analyses. (3) Results: Over-representation analysis of differentially expressed genes (ORA) and functional class scoring of pathways (FCS) indicated that healthy aging was mainly associated with upregulations of apoptosis and immune function and downregulations of glycolysis and protein catabolism. ORA and FCS indicated that with metabolic syndrome the dominating biological processes were upregulation of proteolysis and downregulation of oxidative phosphorylation. Proteomic profiling matched 586 muscle proteins between individuals. The proteome of healthy aging revealed modifications consistent with a fast-to-slow transition and downregulation of glycolysis. These transitions were reduced with metabolic syndrome, which was more associated with alterations in NADH/NAD+ shuttle and ß-oxidation. Proteomic profiling further showed that all old muscles overexpressed protein chaperones to preserve proteostasis and myofiber integrity. There was also evidence of aging-related increases in reactive oxygen species but better detoxifications of cytotoxic aldehydes and membrane protection in healthy than in metabolic syndrome muscles. (4) Conclusions: Most candidate proteins and mRNAs identified herein constitute putative muscle biomarkers of healthy aging and metabolic syndrome in old men.

Causal analyses to study autonomic regulation during acute head-out water immersion, head-down tilt and supine position.

NEW FINDINGS: What is the central question of this study? Can Granger causality analysis of R-R intervals, systolic blood pressure and respiration provide evidence for the different physiological mechanisms induced during thermoneutral water immersion, 6 deg head-down tilt and supine position tests that are not accessible using traditional heart rate variability and baroreflex methods? What is the main finding and its importance? The Granger analysis demonstrated a significant difference in the causal link from R-R intervals to respiration between water immersion and head-down tilt. The underlying physiological mechanism explaining this difference could be the variation in peripheral resistances. ABSTRACT: Thermoneutral head-out water immersion (WI) and 6 deg head-down tilt (HDT) are used to simulate SCUBA diving, swimming and microgravity, because these models induce an increase in central blood volume. Standard methods to analyse autonomic regulation have demonstrated an increase in parasympathetic activity and baroreflex sensitivity during these experimental conditions. However, such methods are not adapted to quantify all closed-loop interactions involved in respiratory and cardiovascular regulation. To overcome this limitation, we used Granger causality analysis between R-R intervals (RR), systolic blood pressure (SBP) and respiration (RE) in eight young, healthy subjects, recorded during 30 min periods in the supine position, WI and HDT. For all experimental conditions, we found a bidirectional causal relationship between RE and RR and between RR and SBP, with a dominant direction from RR to SBP, and a unidirectional causality from RE to SBP. These causal relationships remained unchanged for the three experimental tests. Interestingly, there was a lower causal relationship from RR to RE during WI compared with HDT. This causal link from RR to RE could be modulated by peripheral resistances. These results highlight differences in cardiovascular regulation during WI and HDT and confirm that Granger causality might reveal physiological mechanisms not accessible with standard methods.

Autonomic cardiovascular adaptations to acute head-out water immersion, head-down tilt and supine position.

PURPOSE: Thermoneutral head-out water immersion (WI) and 6° head-down tilt (HDT) have been considered as suitable models to increase central blood volume and simulate autonomic cardiovascular adaptations to microgravity, swimming or scuba diving. However, any differences in autonomic cardiovascular adaptations are still unclear. In this study, we hypothesized that WI induces a higher activation of arterial baroreceptors and the parasympathetic system. METHODS: Ten healthy men underwent 30 min of WI, HDT, and a supine position (SP). RR intervals (RRI) and blood pressure (BP) were continuously monitored. High frequency power (HF), low frequency power (LF) and LF/HF ratio were calculated to study sympathetic and parasympathetic activities, and a spontaneous baroreflex method was used to study arterial baroreflex sensitivity (aBRS). Lung transfer of nitric oxide and carbon monoxide (TLNO/TLCO), vital capacity and alveolar volume (Vc/VA) were measured to study central blood redistribution. RESULTS: We observed (1) a similar increase in RRI and decrease in BP; (2) a similar increase in HF power during all experimental conditions, whereas LF increased after; (3) a similar rise in aBRS; (4) a similar increase in Vc/VA and decrease in TLNO/TLCO in all experimental conditions. CONCLUSIONS: These results showed a cardiac parasympathetic dominance to the same extent, underpinned by a similar arterial baroreflex activation during WI and HDT as well as control SP. Future studies may address their association with cold or hyperoxia to assess their ability to replicate autonomic cardiovascular adaptations to microgravity, swimming or scuba diving.

Effect of exercise training on heart rate variability in patients with obstructive sleep apnea: A randomized controlled trial.

While obstructive sleep apnea (OSA) increases chemoreflex, leading to an autonomic dysfunction in the long term, no studies have yet assessed the potential benefit of exercise on cardiac autonomic activity in these patients. The aim of this study was to evaluate potential improvement in cardiac autonomic function (CAF) measured through heart rate variability (HRV) after a 9-month physical activity program in patients with OSA. Seventy-four patients with moderate OSA, aged 40-80 years, were randomly assigned to an exercise group (n = 36, 3 × 1 h/wk) or a control group (n = 38) during 9 months. Linear and nonlinear HRV parameters were measured during night using a Holter ECG. After 9 months, mean R-R intervals increased in the exercise group without any changes in HRV parameters, while controls decreased global (standard deviation of normal-to-normal intervals, total power) and parasympathetic (root mean square successive difference of N-Ns, very low frequency, high frequency, and standard deviation of the instantaneous beat-to-beat variability) indices of HRV (P < 0.05 for all). Significant correlations with moderate effect size were found between changes in apnea severity and changes in R-R intervals (P < 0.05). Improvement in moderate-to-vigorous physical activity was also correlated to improvement in nocturnal oxygen parameters (P < 0.05). In conclusion, supervised community physical activity may prevent a decline in nighttime CAF observed in nontreated community-dwelling patients with moderate OSA over a 9-month period. Thus, beyond apnea-hypopnea index improvement, exercise may be cardioprotective in OSA patients through bradycardia, CAF preservation, and VO2peak increase.

Arterial stiffness alteration and obstructive sleep apnea in an elderly cohort free of cardiovascular event history: the PROOF cohort study.

INTRODUCTION: Several studies suggest in middle-aged subjects a relationship between arterial stiffness, a cardiovascular risk marker, and moderate to severe obstructive sleep apnea (OSA). No extensive data are present in older subjects. This study explores this association in a sample of healthy older subjects suffering OSA. METHODS: A total of 101 volunteers aged 75.3 ± 0.7 years were examined at the hospital sleep center. Each subject was assessed for medical history, body mass index and 24-h blood pressure measures, biological blood samples, and home polygraphy in 2002-2003 (P2) as well as in 2009-2010 (P4). Arterial stiffness was also assessed using carotid-femoral and carotid-radial pulse wave velocity (cfPWV and crPWV) during P4 examination. RESULTS: The total group consisted of 59 women and 42 men with a mean apnea-hypopnea index (AHI) of 17.8 ± 12.1 and a mean oxygen desaturation index (ODI) of 9.8 ± 8.9. No-OSA (AHI < 15) represented 50% of the sample, and severe cases (AHI > 30) 17%. No significant differences had been founded between men and women for blood pressure, cfPWV, and crPWV. Considering the severity of the AHI, no significant differences between groups were present for PWV and blood pressure values. No difference for PWV was present for subjects with and without hypertension. No correlation was found between PWV value and AHI and ODI values at P2 or between P2 and P4 visits. cfPWV was higher in patients demonstrating incident hypertension during the follow-up. CONCLUSIONS: In this sample of older subjects, PWV is not affected by AHI and ODI but was associated with incident hypertension. These results may suggest potential protective and adaptive mechanisms in older sleep apnea patients. CLINICAL TRIAL REGISTRATIONS: NCT 00759304 and NCT 00766584 .

Sleep apnoea in the asymptomatic elderly: a real issue for the brain?

The link between sleep apnoea and brain structure is unclear; although dysfunction of the hippocampus, middle temporal gyrus and brainstem/cerebellum have been observed previously. However, this link has been little explored in elderly subjects. The aim of this study was to explore the link between sleep apnoea and the brain in an elderly population.226 asymptomatic elderly subjects (age mean±sd 75.3±0.9 years, range 72.3-77.8 years) from the PROOF (Evaluation of Ageing, Autonomic Nervous System Activity and Cardiovascular Events) cohort study were explored using linear voxel-based or cortical thickness with apnoea/hypopnoea index (AHI; mean±sd 15.9±11.5 events·h-1, range 6-63.6 events·h-1) as a covariate of main interest. The brain volumes of 20 control subjects, 18 apnoeic (AHI >29 events·h-1) treated patients and 20 apnoeic untreated patients from this population were compared using voxel-based morphometry, cortical thickness or surface-based analyses.AHI was not associated with any change in local brain volume, cortical thickness or cortex surface. Control subjects, apnoeic treated and untreated patients were not different in terms of local brain volume, cortical thickness or surface.In a specific population of asymptomatic elderly healthy subjects, sleep apnoea does not seem to be associated with a change in local brain volume or in cortical thickness.

A 7-year follow-up study of obstructive sleep apnoea in healthy elderly: The PROOF cohort study.

BACKGROUND AND OBJECTIVE: Clinical and epidemiological cohort studies have shown that obstructive sleep apnoea (OSA) is a common but largely undiagnosed disorder in senior subjects, where progressive deterioration of the pathology would be expected as a consequence of the ageing processes. Our study examines the longitudinal progression of OSA over a 7-year period in a community-based sample of healthy subjects. METHODS: The sample consisted of 284 volunteers, aged >65 years (52% women, 48% men) accepting clinical and instrumental follow-up at 7 years. OSA was defined as an apnoea-hypopnoea index (AHI) of ≥15. RESULTS: Between evaluations in the total sample, AHI slightly decreased from 17.8 ± 14 to 16.7 ± 11 with a decrease affecting more the hypopnoea index (P < 0.001) and associated with significant changes (P < 0.001) in all indices of hypoxaemia. While in the non-OSA group there was a slight but significant increase of AHI, a significant AHI decrease was noted in mild-moderate patients (P < 0.01) and a significant rise of nocturnal hypoxaemia in severe OSA patients (P < 0.001). The AHI decrease was not associated with clinical, weight, metabolic and blood pressure changes between the two evaluations; the baseline AHI value being the only factor correlated to the degree of AHI decline. CONCLUSIONS: In elderlies, the severity and prevalence of OSA decrease progressively with ageing without effect of factors commonly influencing OSA severity. This trend may support the hypothesis that in healthy elderly, OSA is a phenomenon related to ageing.

Sleep-related autonomic overactivity in a general elderly population and its relationship to cardiovascular regulation.

Alteration in cardiac autonomic activity during sleep is a common feature of sleep disorders. Diurnal sympathetic overactivity is a possible consequence and could contribute to future cardiovascular complications. The aim of this study is to assess the relationship between cardiac autonomic activity during sleep and diurnal autonomic cardiovascular control. In a large cohort (n = 1011) of subjects aged 65 years old (± 0.4) free of cardiac and cerebrovascular events and of sleep-related breathing disorders, we evaluated (cross-sectional study) the prevalence of unexpected alteration in sleep-related autonomic overactivity according to the presence of a cyclical nocturnal heart rate variability [quantified using the relative power spectral density of the very low-frequency band of the heart rate increment (VLFi%) from ECG Holter monitoring]. We tested its relationship with diurnal ambulatory blood pressure and spontaneous baroreflex sensitivity (sBRS). An abnormal cardiac autonomic activity during sleep was retained in 34.4% of this population according to a VLFi% >4. Using multiple logistic regression analysis, the severity of the autonomic alteration was mainly correlated after adjustment with lower sBRS (p = 0.01; OR: 0.94; 95% CI: 0.90-0.98). Diurnal baroreflex control alteration is associated with sleep-related autonomic overactivity elderly. Such alteration may contribute to the increased incidence of cardiovascular complications in sleep disorders.

Modeling of performance and ANS activity for predicting future responses to training.

PURPOSE: Our aim was to assess whether we can predict satisfactorily performance in swimming and high frequency power (HF power) of heart rate variability from the responses to previous training. We have tested predictions using the model of Banister and the variable dose-response model. METHODS: Data came from ten swimmers followed during 30 weeks of training with performance and HF power measured each week. The first 15-week training period was used to estimate the parameters of each model for both performance and HF power. Both were then predicted in response to the training done during the second 15-week training period. The bias and precision were estimated from the mean and SD of the difference between prediction and actual value expressed as a percentage of performance or HF power at the first week. RESULTS: With the variable-dose response model, the bias for performance prediction was -0.24 ± 0.06 and the precision 0.69 ± 0.24% (mean ± between-subject SD). For HF power, the bias was 0 ± 21 and the precision 22 ± 8%. When HF power was transformed into performance using a quadratic relation in each swimmer established from the first 15-week period, the bias was 0.18 ± 0.74 and the precision 0.80 ± 0.30%. No clear trend in the error was observed during the second period. CONCLUSIONS: This study showed that the modeling of training effects on performance allowed accurate performance prediction supporting its relevance to control and predict week after week the responses to future training.

Effects of gravitational acceleration on cardiovascular autonomic control in resting humans.

PURPOSE: Previous studies of cardiovascular responses in hypergravity suggest increased sympathetic regulation. The analysis of spontaneous heart rate variability (HRV) parameters and spontaneous baroreflex sensitivity (BRS) informs on the reciprocal balance of parasympathetic and sympathetic regulations at rest. This paper was aimed at determining the effects of gravitational acceleration (a g) on HRV and BRS. METHODS: Eleven healthy subjects (age 26.6 ± 6.1) were studied in a human centrifuge at four a g levels (1, 1.5, 2 and 2.5 g) during 5-min sessions at rest. We evaluated spontaneous variability of R-R interval (RR), and of systolic and diastolic blood pressure (SAP and DAP, respectively), by power spectral analysis, and BRS by the sequence method, using the BRSanalysis(®) software. RESULTS: At 2.5 g, compared to 1 g, (1) the total power (P TOT) and the powers of LF and HF components of HRV were lower, while the LF/HF ratio was higher; (2) normalized units for LF and HF did not changed significantly; (3) the P TOT, LF and HF powers of SAP were higher; (4) the P TOT and LF power of DAP were higher; and (5) BRS was decreased. CONCLUSIONS: These results do not agree with the notion of sympathetic up-regulation supported by the increase in HR and DAP (tonic indices), and of SAP and DAP LF powers (oscillatory indices). The P TOT reduction leads to speculate that only the sympathetic branch of the ANS might have been active during elevated a g exposure. The vascular response occurred in a condition of massive baroreceptive unloading.

Even a low-dose of moderate-to-vigorous physical activity reduces mortality by 22% in adults aged ≥60†years: a systematic review and meta-analysis.

BACKGROUND: The health benefits of 150 min a week of moderate-to-vigorous-intensity physical activity (MVPA) in older adults, as currently recommended, are well established, but the suggested dose in older adults is often not reached. OBJECTIVES: We aimed to determine whether a lower dose of MVPA was effective in reducing mortality, in participants older than 60 years. METHODS: The PubMed and Embase databases were searched from inception to February 2015. Only prospective cohorts were included. Risk ratios of death were established into four doses based on weekly Metabolic Equivalent of Task (MET)-minutes, defined as inactive (reference), low (1-499), medium (500-999) or high (≥1000). Data were pooled and analysed through a random effects model using comprehensive meta-analysis software. RESULTS: Of the 835 reports screened, nine cohort studies remained, totalling 122 417 participants, with a mean follow-up of 9.8±2.7 years and 18 122 reported deaths (14.8%). A low dose of MVPA resulted in a 22% reduction in mortality risk (RR=0.78 (95% CI 0.71 to 0.87) p<0.0001). MVPA beyond this threshold brought further benefits, reaching a 28% reduction in all-cause mortality in older adults who followed the current recommendations (RR=0.72 (95% CI 0.65 to 0.80) p<0.0001) and a 35% reduction beyond 1000 MET-min per week (RR=0.65 (95% CI 0.61 to 0.70) p<0.0001). CONCLUSIONS: A dose of MVPA below current recommendations reduced mortality by 22% in older adults. A further increase in physical activity dose improved these benefits in a linear fashion. Older adults should be encouraged to include even low doses of MVPA in their daily lives.

Metabolic syndrome is associated with poor memory and executive performance in elderly community residents: the PROOF study.

OBJECTIVE: Aging is associated with a loss of cognitive performance and an increasing occurrence of cardiovascular events. Moreover, cardiovascular risk factors are linked to cognitive impairment and dementia. Whereas individual components of metabolic syndrome (Met S) have been reported to be linked to cognitive decline and dementia, there are very few studies on Met S as a whole. The present study aims to assess the relationship between Met S and its components and cognitive functioning in a cohort of elderly non-demented community residents. DESIGN: Population-based cohort study (PROOF study). Cross-sectional analysis. PARTICIPANTS: Dementia-free community-dwellers aged 65. MEASURES: The PROOF participants underwent an extensive neuropsychological battery at baseline. Summary cognitive measures including memory, attention, and executive performance were created by converting the individual test results to Z scores and computing the average scores within each domain. Each of the three cognitive scores was individually compared between groups as a function of Met S. The cognitive scores and the covariates which were significant in univariate analyses were then included in logistic regression models. RESULTS: A significant association was observed between the presence of metabolic syndrome, poor memory, and executive function even after adjusting for confounding factors (memory: odds ratio: 1.77, p = 0.008; executive functions: odds ratio: 1.91, p = 0.002). CONCLUSIONS: Our study showed that in a sample of elderly community dwellers, Met S was associated with poor memory and executive performance. These results underline the importance of detecting and managing metabolic syndrome components to prevent cognitive impairment and dementia.

Higher gait variability is associated with decreased parietal gray matter volume among healthy older adults.

The objectives of this study were to examine the association of stride time variability (STV) with gray and white matter volumes in healthy older adults, and to determine the specific location of any parenchymal loss associated with higher STV. A total of 71 participants (mean age 69.0 ± 0.8 years; 59.7 % female) were included in this study. All participants had a 1.0 Tesla 3D T1-weighted MRI of the brain to measure gray and white matter volumes. STV was measured at steady-state self-selected walking speed using an electronic footswitch system. We found an association between higher STV and lower gray matter volume in the right parietal lobe (e.g., angular gyrus, Brodmann area 39, cluster corrected pFWE = 0.035). There were no significant associations between STV and higher gray matter volume or change in white matter volume. To the best of our knowledge this study is the first to identify a significant association of higher STV with lower right parietal gray matter volume in healthy older adults.

Prediction of pulmonary restriction from forced vital capacity in elderly is similar using GLI and ERS equations.

INTRODUCTION: The prevalence of pulmonary restriction increases in the elderly and detection could be challenging due to the difficulty in measuring lung volumes in older patients. The recently published Global Lung Function Initiative (GLI) equations were found to predict better restriction in middle-aged patients compared to ERS'93 norms. However, the ability of the GLI equations to detect pulmonary restriction in older patients has not been investigated. PATIENTS AND METHODS: We extracted spirometric data in patients older than 85 years from the database of our pulmonary function testing laboratory. The population with pulmonary restriction was defined as those having a total lung capacity value (TLC) below the lower limit of normal (LLN) using ERS'93 equations. We then compared the ability of the ERS'93 and GLI equations to detect this when the forced vital capacity (FVC) was below the LLN. RESULTS: We analyzed data from 285 patients. A true restrictive defect was found in 66 patients (23%). Sensitivity to detect a reduced TLC was higher when calculated from the GLI than the ERS'93 equations, (70 vs 45%). By contrast, specificity was lower (74 vs 89%, respectively); there was no difference in the negative predictive value (89 and 84%). Using receiver operating curves, both sets of equations performed similarly to detect spirometric restriction. CONCLUSIONS: In conclusion, both sets of equations similarly predicted a pulmonary restriction in older subjects. The high negative predictive value of the GLI equations thus allows for static lung volume measurement to be avoided in older patients when the FCV exceeds the LLN whatever the predicted equation used.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Premature atrial contractions in the general population: frequency and risk factors.

BACKGROUND: Premature atrial contractions (PACs) are independent predictors of atrial fibrillation, stroke, and death. However, little is known about PAC frequency in the general population and its association with other cardiovascular risk factors. METHODS AND RESULTS: We performed a cross-sectional analysis among participants of the population-based Swiss cohort Study on Air Pollution and Lung Diseases in Adults (SAPALDIA). 24-hour Holter electrocardiograms to assess PAC prevalence and frequency were performed in a random sample of 1742 participants aged ≥50 years. The median (interquartile range) number of PACs per hour was 0.8 (0.4-1.8), 1.1 (0.5-2.4), 1.4 (0.7-4.6), 2.3 (0.8-6.9), and 2.6 (1.2-6.5) among participants aged 50 to 55, 55 to 60, 60 to 65, 65 to 70, and ≥70 years, respectively (P<0.0001). Only 18 (1.0%) participants did not have at least 1 PAC during Holter monitoring. In multivariable negative binomial regression models, PAC frequency was significantly associated with age (risk ratio [RR] per SD 1.80; P<0.0001), height (RR per SD 1.52; P<0.0001), prevalent cardiovascular disease (RR 2.40; P<0.0001), log-transformed N-terminal pro B-type natriuretic peptides (RR per SD 1.27; P<0.0001), physical activity ≥2 hours per day (RR 0.69; P=0.002), and high-density lipoprotein cholesterol (RR per SD 0.80; P=0.0002). Hypertension and body mass index were not significantly related to PAC frequency. CONCLUSIONS: To our knowledge, this is the first study to assess risk factors for PAC frequency in the general population aged ≥50 years. PACs are common, and their frequency is independently associated with age, height, history of cardiovascular disease, natriuretic peptide levels, physical activity, and high-density lipoprotein cholesterol. The underlying mechanisms of these relationships need to be addressed in future studies.

CVRanalysis: a free software for analyzing cardiac, vascular and respiratory interactions.

Introduction: Simultaneous beat-to-beat R-R intervals, blood pressure and respiration signals are routinely analyzed for the evaluation of autonomic cardiovascular and cardiorespiratory regulations for research or clinical purposes. The more recognized analyses are i) heart rate variability and cardiac coherence, which provides an evaluation of autonomic nervous system activity and more particularly parasympathetic and sympathetic autonomic arms; ii) blood pressure variability which is mainly linked to sympathetic modulation and myogenic vascular function; iii) baroreflex sensitivity; iv) time-frequency analyses to identify fast modifications of autonomic activity; and more recently, v) time and frequency domain Granger causality analyses were introduced for assessing bidirectional causal links between each considered signal, thus allowing the scrutiny of many physiological regulatory mechanisms. Methods: These analyses are commonly applied in various populations and conditions, including mortality and morbidity predictions, cardiac and respiratory rehabilitation, training and overtraining, diabetes, autonomic status of newborns, anesthesia, or neurophysiological studies. Results: We developed CVRanalysis, a free software to analyze cardiac, vascular and respiratory interactions, with a friendly graphical interface designed to meet laboratory requirements. The main strength of CVRanalysis resides in its wide scope of applications: recordings can arise from beat-to-beat preprocessed data (R-R, systolic, diastolic and mean blood pressure, respiration) or raw data (ECG, continuous blood pressure and respiratory waveforms). It has several tools for beat detection and correction, as well as setting of specific areas or events. In addition to the wide possibility of analyses cited above, the interface is also designed for easy study of large cohorts, including batch mode signal processing to avoid running repetitive operations. Results are displayed as figures or saved in text files that are easily employable in statistical softwares. Conclusion: CVRanalysis is freely available at this website: anslabtools.univ-st-etienne.fr. It has been developed using MATLAB® and works on Windows 64-bit operating systems. The software is a standalone application avoiding to have programming skills and to install MATLAB. The aims of this paper area are to describe the physiological, research and clinical contexts of CVRanalysis, to introduce the methodological approach of the different techniques used, and to show an overview of the software with the aid of screenshots.