27,070 research outputs found

    Arrhythmic risk in elderly patients candidates to transcatheter aortic valve replacement. predicative role of repolarization temporal dispersion

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    Degenerative aortic valve stenosis (AS) is associated to ventricular arrhythmias and sudden cardiac death, as well as mental stress in speciïŹc patients. In such a context, substrate, autonomic imbalance as well as repolarization dispersion abnormalities play an undoubted role. Aim of the study was to evaluate the increase of premature ventricular contractions (PVC) and complex ventricular arrhythmias during mental stress in elderly patients candidate to the transcatheter aortic valve replacement (TAVR). In eighty-one elderly patients with AS we calculated several short-period RRand QT-derived variables at rest, during controlled breathing and during mild mental stress, the latter being represented by a mini-mental state evaluation (MMSE). All the myocardial repolarization dispersion markers worsened during mental stress (p < 0.05). Furthermore, during MMSE, low frequency component of the RR variability increased signiïŹcantly both as absolute power (LFRR) and normalized units (LFRRNU) (p < 0.05) as well as the low-high frequency ratio (LFRR/HFRR) (p < 0.05). Eventually, twenty-four (30%) and twelve (15%) patients increased signiïŹcantly PVC and, respectively, complex ventricular arrhythmias during the MMSE administration. At multivariate logistic regression analysis, the standard deviation of QTend (QTesd), obtained at rest, was predictive of increased PVC (odd ratio: 1.54, 95% CI 1.14–2.08; p = 0.005) and complex ventricular arrhythmias (odd ratio: 2.31, 95% CI 1.40–3.83; p = 0.001) during MMSE. The QTesd showed the widest sensitive-speciïŹcity area under the curve for the increase of PVC (AUC: 0.699, 95% CI: 0.576–0.822, p < 0.05) and complex ventricular arrhythmias (AUC: 0.801, 95% CI: 0.648–0.954, p < 0.05). In elderly with AS ventricular arrhythmias worsened during a simple cognitive assessment, this events being a possible further burden on the outcome of TAVR. QTesd might be useful to identify those patients with the highest risk of ventricular arrhythmias. Whether the TAVR could led to a QTesd reduction and, hence, to a reductionof thearrhythmicburdenin thissettingofpatients isworthytobe investigated

    High concordance between mental stress-induced and adenosine-induced myocardial ischemia assessed using SPECT in heart failure patients:Hemodynamic and biomarker correlates

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    Mental stress can trigger myocardial ischemia, but the prevalence of mental stress–induced ischemia in congestive heart failure (CHF) patients is unknown. We characterized mental stress–induced and adenosine-induced changes in myocardial perfusion and neurohormonal activation in CHF patients with reduced left-ventricular function using SPECT to precisely quantify segment-level myocardial perfusion. Methods: Thirty-four coronary artery disease patients (mean age ± SD, 62 ± 10 y) with CHF longer than 3 mo and ejection fraction less than 40% underwent both adenosine and mental stress myocardial perfusion SPECT on consecutive days. Mental stress consisted of anger recall (anger-provoking speech) followed by subtraction of serial sevens. The presence and extent of myocardial ischemia was quantified using the conventional 17-segment model. Results: Sixty-eight percent of patients had 1 ischemic segment or more during mental stress and 81% during adenosine. On segment-by-segment analysis, perfusion with mental stress and adenosine were highly correlated. No significant differences were found between any 2 time points for B-type natriuretic peptide, tumor necrosis factor-α, IL-1b, troponin, vascular endothelin growth factor, IL-17a, matrix metallopeptidase-9, or C-reactive protein. However, endothelin-1 and IL-6 increased, and IL-10 decreased, between the stressor and 30 min after stress. Left-ventricular end diastolic dimension was 179 ± 65 mL at rest and increased to 217 ± 71 after mental stress and 229 ± 86 after adenosine (P < 0.01 for both). Resting end systolic volume was 129 ± 60 mL at rest and increased to 158 ± 66 after mental stress (P < 0.05) and 171 ± 87 after adenosine (P < 0.07), with no significant differences between adenosine and mental stress. Ejection fraction was 30 ± 12 at baseline, 29 ± 11 with mental stress, and 28 ± 10 with adenosine (P = not significant). Conclusion: There was high concordance between ischemic perfusion defects induced by adenosine and mental stress, suggesting that mental stress is equivalent to pharmacologic stress in eliciting clinically significant myocardial perfusion defects in CHF patients. Cardiac dilatation suggests clinically important changes with both conditions. Psychosocial stressors during daily life may contribute to the ischemic burden of CHF patients with coronary artery disease. Keywords: heart failure, mental stress, ischemia, myocardial perfusion, adenosine, single-photon emission computed tomograph

    The Cultural Revolution, Stress and Cancer

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    The link between mental stress and cancer is still a belief, not a well established scientific fact. Scientists have relied largely on opinions of cancer stricken patients to establish a link between stress and cancer. Such opinion surveys tend to produce contradictory statistical inferences. Although it is difficult to conduct scientific experiments on humans similar to those on animals, human history is replete with “experiments” that have caused enormous stress on some human populations. The objective of this exercise is to draw evidence from one such massive experiment, the Cultural Revolution in China. Cancer data from Shanghai analyzed through an age-period-cohort technique show very strong evidence in support of the hypothesis that mental stress causes cancer.

    Effect of beta-blockade on low heart rate-related ischemia during mental stress

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    To explore the effect of beta-adrenergic blockade on low heart rate-related (mental stress) ischemia, 19 patients with coronary artery disease were randomized into a double-blind crossover trial of metoprolol, 100 mg twice daily, and underwent serial mental stress/bicycle exercise studies. Mental stress-induced wall motion abnormalities occurred at a lower heart rate than exercise-induced wall motion abnormalities during placebo administration (81 ± 16 vs. 123 ± 20 beats/min, p < 0.05). Metoprolol reduced the mean magnitude of exercise-induced wall motion abnormalities (2.8 ± 2.0 vs. 1.6 ± 2.4, p = 0.003); improvement was related to the magnitude of hemodynamic beta-blockade effect. Metoprolol did not significantly reduce the mean magnitude of mental stress-induced wall motion abnormalities (3.0 ± 2.2 vs. 2.6 ± 2.2), although individual responses predominantly either improved (50%) or worsened (29%).Unlike exercise, the magnitude of hemodynamic beta-blockade did not predict mental stress response and metoprolol did not block mental stress-induced blood pressure elevations. Patients with abolition of exercise-induced ischemia were more likely to have reduction of mental stress-induced ischemia. Patients whose ischemia worsened with metoprolol during mental stress had more easily inducible ischemia, as assessed by exercise-induced placebo wall motion abnormality, chest pain and prior myocardial infarction. Beta-blockade was associated with a lowering of ischemia-related hemodynamic thresholds compared with placebo.These results suggest that beta-blockade has a variable effect on low heart rate-related ischemia that may be due to a lack of effect on mental stress-induced blood pressure elevation in patients with easily induced ischemia or to effects on coronary vasomotor tone, or both

    Impaired hemodynamic response to mental stress in subjects with prehypertension is improved after a single bout of maximal dynamic exercise

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    INTRODUCTION: High blood pressure during mental stress in subjects with prehypertension is associated with blunted vasodilation in skeletal muscles, which might be improved by an acute bout of exercise. OBJECTIVE: To investigate the hemodynamic responses to mental stress before and after a bout of exercise in subjects with prehypertension. METHOD: Eighteen subjects with prehypertension and 16 with normotension underwent a mental stress test before and after a maximal cardiopulmonary exercise test on a treadmill. Blood pressure was measured by auscultation, and forearm blood flow was measured by venous occlusion plethysmography; from these measurements, the vascular conductance was calculated. RESULTS: Subjects with prehypertension had a higher mean blood pressure during mental stress (prehypertension 112±2 vs. normotension 101±3 mm Hg, p<0.05), and their vascular conductance did not increase (baseline 0.025±0.004 vs. mental stress 0.022±0.003 a.u., p.0.05). After the exercise bout, the mean blood pressure during mental stress was lower in subjects with prehypertension (before exercise 112±2 vs. after exercise 107±2 mm Hg, p<0.05), and vascular conductance increased (baseline 0.011±0.001 vs. mental stress 0.024±0.004 a.u., p<0.05). CONCLUSION: Subjects with prehypertension had elevated blood pressure and a blunted vasodilator response during mental stress, but their blood pressure was attenuated and their vasodilator response was normalized after a single bout of maximal dynamic exercise

    Attenuated Sympathetic Baroreflex Sensitivity Evoked by Acute Mental Stress but not Prolonged Sleep Restriction in Healthy Adults

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    Sleep restriction and psychological stress have both been found to increase the risk of hypertension. To understand how these factors affect blood pressure, the sympathetic baroreflex sensitivity (sBRS) was measured throughout 1) 10 minutes of mental stress and 2) after a period of consecutive sleep restriction. A randomized cross-over study design was used to evaluate these effects in14 healthy, young adults. Continuous muscle sympathetic nerve activity was measured along with continuous realtime blood pressure and heart rate to evaluates RS. Mental stress included 5 minutes of a mental arithmetic task followed by a Stroop color-word test, while sleep restriction testing involved 4 hours of sleep per night for 14 or 19 days with a4-night acclimation period. Acute mental stress appeared to reduce baroreflex function compared to baseline, especially during the initial 5 minutes of mental stress testing. However, sBRS did not show any significant action between restricted sleep conditions and mental stress. This shows that sBRS is attenuated early during mental stress but returns to baseline quickly in young, healthy adults

    Feedback Control of Human Stress with Music Modulation

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    Mental stress has known detrimental effects on human health, however few algorithmic methods of reducing mental stress have been widely explored. While the act of listening to music has been shown to have beneficial effects for stress reduction, and furthermore, audio players have been designed to selectively choose music and other inputs with the intent of stress reduction, limited work has been conducted for real-time stress reduction with feedback control using physiological input signals such as heart rate or Heart Rate Variability (HRV). This thesis proposes a feedback controller that uses HRV signals from wearable sensors to perform real-time (< 1 second) modulations to music through tempo changes with the goal to regulate and reduce stress levels. A standardized, stress inducing test based on the popular Stroop test is also introduced, which has been shown to induce acute stress in subjects and can be used as a testing benchmark for controller design. Ultimately, a controller is presented that when used is not only able to maintain stress levels during stress-inducing inputs to a human but even provides de-stressing effects beyond baseline performance.No embargoAcademic Major: Electrical and Computer Engineerin

    Acute mental stress assessment via short term HRV analysis in healthy adults : a systematic review with meta-analysis

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    Mental stress reduces performances, on the work place and in daily life, and is one of the first causes of cognitive dysfunctions, cardiovascular disorders and depression. This study systematically reviewed existing literature investigating, in healthy subjects, the associations between acute mental stress and short term Heart Rate Variability (HRV) measures in time, frequency and non-linear domain. The goal of this study was to provide reliable information about the trends and the pivot values of HRV measures during mental stress. A systematic review and meta-analysis of the evidence was conducted, performing an exhaustive research of electronic repositories and linear researching references of papers responding to the inclusion criteria. After removing duplicates and not pertinent papers, journal papers describing well-designed studies that analyzed rigorously HRV were included if analyzed the same population of healthy subjects at rest and during mental stress. 12 papers were shortlisted, enrolling overall 758 volunteers and investigating 22 different HRV measures, 9 of which reported by at least 2 studies and therefore meta-analyzed in this review. Four measures in time and non-linear domains, associated with a normal degree of HRV variations resulted significantly depressed during stress. The power of HRV fluctuations at high frequencies was significantly depressed during stress, while the ratio between low and high frequency resulted significantly increased, suggesting a sympathetic activation and a parasympathetic withdrawal during acute mental stress. Finally, among the 15 non-linear measures extracted, only 2 were reported by at least 2 studies, therefore pooled, and only one resulted significantly depressed, suggesting a reduced chaotic behaviour during mental stress. HRV resulted significantly depressed during mental stress, showing a reduced variability and less chaotic behaviour. The pooled frequency domain measures demonstrated a significant autonomic balance shift during acute mental stress towards the sympathetic activation and the parasympathetic withdrawal. Pivot values for the pooled mean differences of HRV measures are provided. Further studies investigating HRV non-linear measures during mental stress are still required. However, the method proposed to transform and then meta-analyze the HRV measures can be applied to other fields where HRV proved to be clinically significant

    Life events and acute cardiovascular reactions to mental stress: a cohort study

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    Objective: This study addressed the issue of whether frequent exposure to life events is associated with aggravation or blunting of cardiovascular reactions to acute mental stress. Methods: In a substantial cohort of 585 healthy young adults, systolic and diastolic blood pressure and pulse rate were recorded at rest and in response to a mental arithmetic stress task. Participants indicated, from a list of 50 events, those they had experienced in the last year. Results: There was an overall association between life events and blunted cardiovascular reactivity that was driven by variations in the frequency of exposure to desirable events. The total number of events and the number of personal events were negatively associated with systolic blood pressure and pulse rate reactions to acute stress, whereas the number of work-related events was negatively associated with diastolic blood pressure and pulse rate reactivity. The negative association between total events and systolic blood pressure reactivity was stronger for women than men, whereas men exposed to frequent undesirable events showed enhanced diastolic blood pressure reactivity. The blunting of pulse rate reactivity associated with frequent personal life events was evident particularly for those who had a relatively large number of close friends. Conclusions: The nature and extent of the association between life events exposure and stress reactivity in young adults depends on the valence of the events together with the sex of the individual and their social network size

    The Influence of Windows on Surgeons\u27 Stress

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    Surgeons endure a significant amount of mental stress while operating in complex and intense surgical environments. In the United States, most operating rooms are windowless spaces that rely on artificial lighting and mechanical ventilation. Surgeons spend much of their day in these surgical environments with little access to exterior views or daylight. There is a growing body of occupational health research that supports the therapeutic benefits of views and daylight in various non-surgical work environments. It is reasonable to consider that windows in operating rooms may mitigate surgeon mental stress and consequently improve surgeon occupational health. This study used a quasi-experimental strategy with an equivalent time samples study design to understand how window access may influence surgeon mental stress in a real operating room setting. Measures of surgeon mental stress from pairs of observed surgical procedures were compared with and without the window treatment. Surgeon mental stress was assessed with a combination of physiological and subjective measures to include momentary stress questionnaires, high-frequency component of heart rate intervals, salivary cortisol, and general stress surveys. Observational measures of surgeon task lighting levels and surgeon gaze direction were considered in the analysis. The study outcomes provide a better understanding of how window access may influence surgeon mental stress in the operating room. Furthermore, this study showed how clinical research methods might be adapted to investigate features of the built environment
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