Sex differences in healthy human heart rate variability: A meta-analysis.

The Canadian Emergency Department Triage and Acuity Scale (CTAS) has been widely adopted in emergency departments (EDs) across Canada and abroad since its initial publication in 1999. CTAS continues to be revised and updated on a continuing basis. In 2001, a paediatric version of the CTAS implementation guidelines was developed and published. With the ongoing improvements in computer technology, the increasing demands for clinical and administrative data and the wider application of information technology in EDs, the Canadian Emergency Department Information Systems (CEDIS) committee published a standardized presenting complaint list in 2003. In 2004, a revision of the adult CTAS guidelines that incorporated the CEDIS complaint list and introduced the concept of modifiers to assist nurses in the assignment of the appropriate acuity level was published. Modifiers were divided into 2 types: first order and second order. First order modifiers are defined as modifiers that are broadly applicable to a wide number of different complaints. These include vital sign modifiers (e.g., respiratory distress, hemodynamic stability, level of consciousness and fever), pain severity (e.g., central v. peripheral and acute v. chronic) and mechanism of injury. Second order modifiers are specific to a limited number of complaints. One example of a second order modifier is low blood sugar (BS) (e.g., “BS < 3 mmol/L and/or symptomatic” is a modifier for 3 complaints, including altered level of consciousness, confusion and hypoglycemia; while “BS < 3 mmol/L and asymptomatic” modifies only 1 complaint: hypoglycemia). A CTAS revisions supplement that displayed the entire CEDIS complaint list and the relevant first and second order modifiers was published (in portable document format [PDF] and Microsoft Excel format). A more sophisticated Excel application, Complaint Oriented Triage (COT) was designed (by B.U. and M.B.) in 2007. COT, along with all CTAS publications and supplementary documents, is accessible online at www.caep.ca/template .asp?id=B795164082374289BBD9C1C2BF4B8D32. In December 2006, a new combined adult and paediatric CTAS educational package was made available to certified instructors and their students. The package is maintained on a password-protected website. Research regarding CTAS continues to be published. Studies looking at reliability and validity of CTAS using computerized decision support systems have been generally

/pdf/revisions-to-the-canadian-emergency-department-triage-and-1ne5534vqh.pdf

Revisions to the Canadian Emergency Department Triage and Acuity Scale (CTAS) adult guidelines.

A high sympathetic and/or a low cardiovagal activity in patients with major depression (MD) may contribute to the higher cardiac morbidity and mortality of MD patients. Standardized tests of heart rate variability (HRV) allow a quantitative estimation of autonomic nervous system function. However, previous studies on the relationship between HRV and MD have revealed conflicting results. Our study compared time and frequency domain HRV indices (5-min resting study, deep breathing test, Valsalva test) between 32 patients with MD (DSM-III-R) and 64 non-depressed controls. The severity of depressive symptoms was assessed by the Hamilton Depression Scale (HAM-D); patients were divided into subgroups with moderate (M-HAM-D or=25). After controlling for age, gender and smoking, S-HAM-D patients showed a higher heart rate and a significantly lower modulation of cardiovagal activity compared to controls. Although some of the HRV indices of the M-HAM-D group did not differ significantly from controls, they were in the expected direction. There was a significantly negative correlation between the HAM-D scores and the vagal HRV indices, suggesting a direct association between the severity of depressive symptoms and the modulation of cardiovagal activity. Clinical consequences arising from these findings and possible implications for treatment are discussed.

/pdf/relationship-between-major-depression-and-heart-rate-2f41egtbzc.pdf

Relationship between major depression and heart rate variability. Clinical consequences and implications for antidepressive treatment.

In the recent years, short-term heart rate variability (HRV) describing complex variations of beat-to-beat interval series that are mainly controlled by the autonomic nervous system (ANS) has been increasingly analyzed to assess the ANS activity in different diseases and under various conditions. In contrast to long-term HRV analysis, short-term investigations (<30 min) provide a test result almost immediately. Thus, short-term HRV analysis is suitable for ambulatory care, patient monitoring and all those applications where the result is urgently needed. In a previous study, we could show significant variations of 5-min HRV indices according to age in almost all domains (linear and nonlinear) in 1906 healthy subjects from the KORA S4 cohort. Based on the same group of subjects, general gender-related influences on HRV indices are to be determined in this study. Short-term 5-min HRV indices from linear time and frequency domain and from nonlinear methods (compression entropy, detrended fluctuation analysis, traditional and segmented Poincare plot analysis, irreversibility analysis, symbolic dynamics, correlation and mutual information analysis) were determined from 782 females and 1124 males. First, we examined the gender differences in two age clusters (25–49 years and 50–74 years). Secondly, we investigated the gender-specific development of HRV indices in five age decade categories, namely for ages 25–34, 35–44, 45–54, 55–64 and 65–74 years. In this study, significant modifications of the indices according to gender could be obtained, especially in the frequency domain and correlation analyses. Furthermore, there were significant modifications according to age in nearly all of the domains. The gender differences disappeared within the last two age decades and the age dependencies disappeared in the last decade. To summarize gender and age influences need to be considered when performing HRV studies even if these influences only partly differ.

https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0118308&type=printable

Short-term heart rate variability--influence of gender and age in healthy subjects.

Occupational or recreational exercise reduces mortality from cardiovascular disease. The potential mechanisms for this reduction may include changes in blood pressure (BP) and autonomic control of ...

https://www.physiology.org/doi/pdf/10.1152/japplphysiol.00482.2003

Dose-response relationship of the cardiovascular adaptation to endurance training in healthy adults: how much training for what benefit?

The authors undertook this study to determine the effects of age, gender, and heart rate (HR) on the results of cardiac autonomic function tests for measuring heart rate variability (HRV) in a large sample of healthy subjects (n = 309). Conventional tests (deep breathing, maximum/minimum 30:15 ratio), and a standardized 5-minute resting study, including spectral analysis of HR, were used. The main findings included (1) the indices of all tests, except for the ratio of the low- (LF) to high-frequency (HF) spectral power (LF/HF ratio) and HR itself, are inversely related to age in both sexes; (2) the 5-minute spectral bands (except for the LF/HF ratio), the variation coefficient, expiratory-inspiratory ratio during deep breathing, and the maximum/minimum 30:15 ratio are independent of HR; (3) women up to the age of 55 years have a higher resting HR compared with men; (4) young and middle-aged women show a significantly lower LF power and LF/HF ratio compared with age-matched men, whereas no significant gender differences are observed in the absolute HF power. The authors computed age- and gender-dependent normal values for each of the HRV indices studied here and discuss the clinical consequences arising from gender differences in HRV.

Frank Akila

Papers

Standardized tests of heart rate variability: normal ranges obtained from 309 healthy humans, and effects of age, gender, and heart rate.