Correlation Between State-Trait-Anxiety-Inventory and Heart Rate Variability

Study Overview
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Brief Summary
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The purpose of the study is to investigate whether there is a correlation between the vegetative stress evaluated by the State-Trait-Anxiety-Inventory (STAI-Test) and the measurement of heart rate variability (HRV). A subgroup analysis will also be performed to determine whether premedication contributes to a lower STAI score and/or heart rate variability. The primary outcome will be the parameter of frequency-based analysis Low Frequency (LF) and High Frequency (HF), and the STAI score. Secondary outcomes are the parameters Low Frequency/High Frequency-ratio (LF/HF-ratio), Standard deviation of normal-to-normal (NN) intervals (SDNN), Root Mean Square of successive differences (RMSSD) and mean heart rate, age, gender, if they are smokers and if they work in shifts.

Official Title
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Correlation Between State-Trait-Anxiety-Inventory and Heart Rate Variability: An Observational Cohort and Pilot Study

Conditions
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Preoperative Vegetative Stress

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subjects between 18 and 65 years Elective surgery with a low risk of bleeding American Society of Anesthesiologists (ASA) classification 1-2 metabolic equivalent of task (MET) > 4 Exclusion Criteria: Pre-existing cardiac conditions such as heart failure, arterial hypertension, diabetes any central nervous system diseases cardiac pacemaker renal and hepatic insufficiency regional or peridural anesthesia Pregnancy, lactation Drugs that directly influence the autonomic nervous system

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| State and Trait Anxiety Inventory (STAI-score) | STAI: State-Trait-Anxiety-Inventory-Score This test consists of 40 items and assesses the current state of anxiety in relation to the current situation in which the patient is to the current situation in which the patient finds herself (State Anxiety) and the general anxiety state existing state of anxiety, which represents a part of her personality (Trait Anxiety). A score of 20-80 could be achieved, with higher scores correlating with correlated with higher anxiety levels. Accordingly, scores of 20-39, 40-59, and 60-80 would indicate low, moderate, and high anxiety. | First questionnaire is given 40 minutes before transfer to the holding area and the second questionnaire postoperative in the recovery ward directly before transfer back to ward | 
| The measurement method of heart rate variability (especially the parameter of the frequency domain Low Frequency and High Frequency | Low frequency power (LF): Power density spectrum in the frequency range from 0.04-0.15 Hz High frequency power (HF): Power density spectrum in the frequency range from 0.15 to 0.40 Hz | One measurement (3-6 hours), start of measurement together with the first STAI questionnaire (40 min before transfer to the holding area), end of measurement after the second STAI questionnaire is done. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Heart rate variability (Standard deviation of normal-to-normal (NN) intervals (SDNN) and Root Mean Square of successive differences (RMSSD) of the time domain and LF/HF-ratio from the frequency domain) as well as mean heart rate | Standard deviation of NN-intervals (SDNN): intervals in the measuring range; NN-intervals refer to the intervals between normal R-peaks in an electrocardiogram Root Mean Square of successive differences (RMSSD) Low Frequency/High Frequency-ratio (LF/HF ratio): Quotient of the spectrum in LF and the spectrum in HF, No clear assignment, Ratio or Coefficient or Ratio between LF-and HF Band power | HRV-parameters and mean heart rate were obtained in the same time frame as outcome 2. | 
| Age, gender, if they are smokers and if they work in shifts | Age: 18-65 Gender: male, female smoker: no, (never; nonsmoker > 1 year), yes (< 5/d; 6-15/d; >15/d) working in shifts: yes, no | Outcomes will be collected following the routine anaesthesia interview with the anaesthesiologist as part of the recruitment process. |