<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT04487899</url>
  </required_header>
  <id_info>
    <org_study_id>02</org_study_id>
    <nct_id>NCT04487899</nct_id>
  </id_info>
  <brief_title>Analysis of Heart Rate Variability During Emergency Flight Simulator Missions in Fighter Pilots</brief_title>
  <official_title>Analysis of Heart Rate Variability During Emergency Flight Simulator Missions in Fighter Pilots</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Universidad de Extremadura</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>Universidad de Extremadura</source>
  <oversight_info>
    <is_fda_regulated_drug>No</is_fda_regulated_drug>
    <is_fda_regulated_device>No</is_fda_regulated_device>
  </oversight_info>
  <brief_summary>
    <textblock>
      The autonomous response of fighter and attack pilots who attend sessions in a flight&#xD;
      simulator will be evaluated by measuring and analyzing heart rate variability (HRV).&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      The autonomous response of fighter and attack pilots during emergency situations in a flight&#xD;
      simulator will be assessed by measuring and analysing heart rate variability (HRV). Eighteen&#xD;
      pilots with instructor or student status assigned at the time of the evaluation to the ALA 23&#xD;
      district of the Talavera la Real Air Base of the Ministry of Defence of the Spanish&#xD;
      Government (Badajoz) were studied during emergency situations in flight simulator. Subjects&#xD;
      were assigned by non-probabilistic randomisation to an instructor group (IG; 7 subjects), and&#xD;
      to a student group (AG; 11 subjects).&#xD;
&#xD;
      The recording of the parameters indicated corresponds to the emergency situations described&#xD;
      above. Data collection was made in three different moments:&#xD;
&#xD;
        1. Take-off: it starts after reading the checklist until the engine fault is resolved.&#xD;
&#xD;
        2. Flight: during manoeuvres characterised by the recovery of abnormal positions.&#xD;
&#xD;
        3. Landing: where the pilot performs the landing manoeuvre, with the loss of spatial&#xD;
           situation.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Completed</overall_status>
  <start_date type="Actual">October 1, 2019</start_date>
  <completion_date type="Actual">March 10, 2020</completion_date>
  <primary_completion_date type="Actual">November 18, 2019</primary_completion_date>
  <study_type>Observational</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <observational_model>Case-Only</observational_model>
    <time_perspective>Cross-Sectional</time_perspective>
  </study_design_info>
  <primary_outcome>
    <measure>Root Mean Square of the Successive Differences (RMSSD)</measure>
    <time_frame>1 week</time_frame>
    <description>It indicates the degree of activation of the Parasympathetic Nervous System on the cardiovascular system. It is obtained from the square root of the mean value of the sum of the squared differences of all successive RR intervals. This parameter reports the short-term variations of the RR intervals. It is directly associated with short-term variability.</description>
  </primary_outcome>
  <primary_outcome>
    <measure>Stress Score</measure>
    <time_frame>1 week</time_frame>
    <description>It is an index described by Naranjo-Orellana et al. to facilitate physiological interpretation of Poincaré plot. It is expressed as the inverse of the SD2 diameter multiplied by 1000 and is considered directly proportional to the sympathetic activity in the sinus node.</description>
  </primary_outcome>
  <primary_outcome>
    <measure>Sympathetic/parasympathetic ratio (S/PS)</measure>
    <time_frame>1 week</time_frame>
    <description>It is also described by Naranjo-Orellana et al., S/PS is expressed as the quotient of SS and SD1, and it is considered to reflect autonomic balance - that is, the relationship between sympathetic and parasympathetic activity</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Standard Deviation 1 (SD1)</measure>
    <time_frame>1 week</time_frame>
    <description>It indicates the sensitivity of short-term variability in HRV non-linear spectrum. It is considered an indicator of parasympathetic activity.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Standard Deviation 2 (SD2)</measure>
    <time_frame>1 week</time_frame>
    <description>It is a diameter from Poincaré plot which indicates the degree of longitudinal dispersion. It is thought to reflect long-term changes in RR intervals and it is considered an inverse indicator of parasympathetic activity.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Min_HR</measure>
    <time_frame>1 week</time_frame>
    <description>Minimum heart rate variability.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Max_HR</measure>
    <time_frame>1 week</time_frame>
    <description>Maximum heart rate variability.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Mean_HR</measure>
    <time_frame>1 week</time_frame>
    <description>It corresponds to the interval between two beats (R peaks on the ECG).</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>pNN50</measure>
    <time_frame>1 week</time_frame>
    <description>Percentage of consecutive RR intervals that differ by more than 50 ms from each other. A high value of pNN50 provides valuable information about high spontaneous HR.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Low Frequency Power (LF)</measure>
    <time_frame>1 week</time_frame>
    <description>Situated between 0.04 and 0.15 Hz. In long-term recordings it provides us with more information about the activity of the SNS.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>High Frequency Power (HF)</measure>
    <time_frame>1 week</time_frame>
    <description>They are located between 0.15 and 0.4 Hz. HF is clearly related to PNS activity and has a relaxation-related effect on HR2.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Low/High Frequency ratio (HF/LF)</measure>
    <time_frame>1 week</time_frame>
    <description>From low frequency and high frequency ratio of the HRV spectral analysis result we can estimate the vagal (related to relaxation and HF) and sympathetic (related to stress and LF) influence. Thus we can estimate sympathetic-vagal balance.</description>
  </secondary_outcome>
  <number_of_groups>2</number_of_groups>
  <enrollment type="Actual">18</enrollment>
  <condition>Heart Rate Variability</condition>
  <condition>Autonomic Nervous System</condition>
  <arm_group>
    <arm_group_label>Instructors group</arm_group_label>
    <description>Group of flight instructors at the reactor school.</description>
  </arm_group>
  <arm_group>
    <arm_group_label>Students group</arm_group_label>
    <description>Group of students at the reactor school.</description>
  </arm_group>
  <intervention>
    <intervention_type>Device</intervention_type>
    <intervention_name>Analysis of heart rate variability</intervention_name>
    <description>The HR HRV interval of the heartbeat (variations in the time interval between beats) was used as a measure of autonomous modulation, and the Firstbeat Bodyguard monitor (Firstbeat Technologies, Jyväskylä, Finland) was used to record HRV data during the session with emergency situations in the flight simulator. Data was downloaded from the devices to a computer using Firstbeat Uploader software (Firstbeat Technologies), and all R-R interval series were imported into the Kubios software package (University of Eastern Finland, Kuopio, Finland). To calculate the autonomous equilibrium, the commonly used HRV method based on the Poincaré graph was used (Brennan et al., 2001; Mourot et al., 2004).</description>
    <arm_group_label>Instructors group</arm_group_label>
    <arm_group_label>Students group</arm_group_label>
  </intervention>
  <eligibility>
    <study_pop>
      <textblock>
        The selection of the sample was made in the accessible population of the Talavera la Real&#xD;
        Air Base (Badajoz).&#xD;
      </textblock>
    </study_pop>
    <sampling_method>Non-Probability Sample</sampling_method>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  Pilots who had the status of instructor or student assigned at the time of assessment&#xD;
             to the ALA 23 district of the Talavera la Real Air Base of the Ministry of Defense of&#xD;
             the Government of Spain (Badajoz).&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  Any uncontrolled neurological or cardiac disorder.&#xD;
&#xD;
          -  Being involved in ongoing medical-legal conflicts.&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>N/A</minimum_age>
    <maximum_age>N/A</maximum_age>
    <healthy_volunteers>No</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Luis Espejo-Antúnez, PhD</last_name>
    <role>Principal Investigator</role>
    <affiliation>Universidad de Extremadura</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>Universidad de Extremadura</name>
      <address>
        <city>Badajoz</city>
        <zip>06006</zip>
        <country>Spain</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>Spain</country>
  </location_countries>
  <reference>
    <citation>de la Cruz Torres B, Albornoz Cabello M, Garcia Bermejo P, Naranjo Orellana J. Autonomic responses to ultrasound-guided percutaneous needle electrolysis of the patellar tendon in healthy male footballers. Acupunct Med. 2016 Aug;34(4):275-9. doi: 10.1136/acupmed-2015-010993. Epub 2016 Jan 20.</citation>
    <PMID>26792776</PMID>
  </reference>
  <reference>
    <citation>Kitagawa Y, Kimura K, Yoshida S. Spectral analysis of heart rate variability during trigger point acupuncture. Acupunct Med. 2014 Jun;32(3):273-8. doi: 10.1136/acupmed-2013-010440. Epub 2014 Mar 7.</citation>
    <PMID>24610637</PMID>
  </reference>
  <reference>
    <citation>Mourot L, Bouhaddi M, Perrey S, Rouillon JD, Regnard J. Quantitative Poincare plot analysis of heart rate variability: effect of endurance training. Eur J Appl Physiol. 2004 Jan;91(1):79-87. doi: 10.1007/s00421-003-0917-0. Epub 2003 Sep 4.</citation>
    <PMID>12955518</PMID>
  </reference>
  <reference>
    <citation>Gil-Rodas F, Pedret C, Ramos-Castro J, Capdevila-Ortís L. Variabilidad de la frecuencia cardíaca: concepto, medidas y relación con aspectos clínicos (I). Arch Med Deporte Rev Fed Esp Med Deporte Confed Iberoam Med Deporte. 2008;(123):41-8.</citation>
  </reference>
  <reference>
    <citation>Malik M. Heart rate variability: Standards of measurement, physiological interpretation, and clinical use: Task force of the European Society of Cardiology and the North American Society for Pacing and Electrophysiology. Ann Noninvasive Electrocardiol. 1996;1(2):151-81.</citation>
  </reference>
  <reference>
    <citation>Naranjo Orellana J, de la Cruz Torres B, Sarabia Cachadina E, de Hoyo M, Dominguez Cobo S. Two new indexes for the assessment of autonomic balance in elite soccer players. Int J Sports Physiol Perform. 2015 May;10(4):452-7. doi: 10.1123/ijspp.2014-0235. Epub 2014 Oct 29.</citation>
    <PMID>25364865</PMID>
  </reference>
  <verification_date>September 2022</verification_date>
  <study_first_submitted>July 22, 2020</study_first_submitted>
  <study_first_submitted_qc>July 22, 2020</study_first_submitted_qc>
  <study_first_posted type="Actual">July 27, 2020</study_first_posted>
  <last_update_submitted>September 14, 2022</last_update_submitted>
  <last_update_submitted_qc>September 14, 2022</last_update_submitted_qc>
  <last_update_posted type="Actual">September 16, 2022</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>Universidad de Extremadura</investigator_affiliation>
    <investigator_full_name>Carlos Fernández-Morales</investigator_full_name>
    <investigator_title>Principal Investigator</investigator_title>
  </responsible_party>
  <keyword>Emergency missions</keyword>
  <keyword>Assesment</keyword>
  <keyword>Military Health Services</keyword>
  <keyword>heart rate variability</keyword>
  <keyword>autonomic nervous system</keyword>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Emergencies</mesh_term>
  </condition_browse>
  <patient_data>
    <sharing_ipd>No</sharing_ipd>
  </patient_data>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT04487899
org study id: 02
nct id: NCT04487899
lead sponsor: 
is fda regulated drug: No
is fda regulated device: No
The autonomous response of fighter and attack pilots who attend sessions in a flight
      simulator will be evaluated by measuring and analyzing heart rate variability (HRV).
The autonomous response of fighter and attack pilots during emergency situations in a flight
      simulator will be assessed by measuring and analysing heart rate variability (HRV). Eighteen
      pilots with instructor or student status assigned at the time of the evaluation to the ALA 23
      district of the Talavera la Real Air Base of the Ministry of Defence of the Spanish
      Government (Badajoz) were studied during emergency situations in flight simulator. Subjects
      were assigned by non-probabilistic randomisation to an instructor group (IG; 7 subjects), and
      to a student group (AG; 11 subjects).

      The recording of the parameters indicated corresponds to the emergency situations described
      above. Data collection was made in three different moments:

        1. Take-off: it starts after reading the checklist until the engine fault is resolved.

        2. Flight: during manoeuvres characterised by the recovery of abnormal positions.

        3. Landing: where the pilot performs the landing manoeuvre, with the loss of spatial
           situation.
observational model: Case-Only
time perspective: Cross-Sectional
measure: Root Mean Square of the Successive Differences (RMSSD)
time frame: 1 week
description: It indicates the degree of activation of the Parasympathetic Nervous System on the cardiovascular system. It is obtained from the square root of the mean value of the sum of the squared differences of all successive RR intervals. This parameter reports the short-term variations of the RR intervals. It is directly associated with short-term variability.
measure: Stress Score
time frame: 1 week
description: It is an index described by Naranjo-Orellana et al. to facilitate physiological interpretation of Poincaré plot. It is expressed as the inverse of the SD2 diameter multiplied by 1000 and is considered directly proportional to the sympathetic activity in the sinus node.
measure: Sympathetic/parasympathetic ratio (S/PS)
time frame: 1 week
description: It is also described by Naranjo-Orellana et al., S/PS is expressed as the quotient of SS and SD1, and it is considered to reflect autonomic balance - that is, the relationship between sympathetic and parasympathetic activity
measure: Standard Deviation 1 (SD1)
time frame: 1 week
description: It indicates the sensitivity of short-term variability in HRV non-linear spectrum. It is considered an indicator of parasympathetic activity.
measure: Standard Deviation 2 (SD2)
time frame: 1 week
description: It is a diameter from Poincaré plot which indicates the degree of longitudinal dispersion. It is thought to reflect long-term changes in RR intervals and it is considered an inverse indicator of parasympathetic activity.
measure: Min_HR
time frame: 1 week
description: Minimum heart rate variability.
measure: Max_HR
time frame: 1 week
description: Maximum heart rate variability.
measure: Mean_HR
time frame: 1 week
description: It corresponds to the interval between two beats (R peaks on the ECG).
measure: pNN50
time frame: 1 week
description: Percentage of consecutive RR intervals that differ by more than 50 ms from each other. A high value of pNN50 provides valuable information about high spontaneous HR.
measure: Low Frequency Power (LF)
time frame: 1 week
description: Situated between 0.04 and 0.15 Hz. In long-term recordings it provides us with more information about the activity of the SNS.
measure: High Frequency Power (HF)
time frame: 1 week
description: They are located between 0.15 and 0.4 Hz. HF is clearly related to PNS activity and has a relaxation-related effect on HR2.
measure: Low/High Frequency ratio (HF/LF)
time frame: 1 week
description: From low frequency and high frequency ratio of the HRV spectral analysis result we can estimate the vagal (related to relaxation and HF) and sympathetic (related to stress and LF) influence. Thus we can estimate sympathetic-vagal balance.
arm group label: Instructors group
description: Group of flight instructors at the reactor school.
arm group label: Students group
description: Group of students at the reactor school.
intervention type: Device
intervention name: Analysis of heart rate variability
description: The HR HRV interval of the heartbeat (variations in the time interval between beats) was used as a measure of autonomous modulation, and the Firstbeat Bodyguard monitor (Firstbeat Technologies, Jyväskylä, Finland) was used to record HRV data during the session with emergency situations in the flight simulator. Data was downloaded from the devices to a computer using Firstbeat Uploader software (Firstbeat Technologies), and all R-R interval series were imported into the Kubios software package (University of Eastern Finland, Kuopio, Finland). To calculate the autonomous equilibrium, the commonly used HRV method based on the Poincaré graph was used (Brennan et al., 2001; Mourot et al., 2004).
arm group label: Instructors group
arm group label: Students group
study pop: 
sampling method: Non-Probability Sample
criteria: 
gender: All
minimum age: N/A
maximum age: N/A
healthy volunteers: No
last name: Luis Espejo-Antúnez, PhD
role: Principal Investigator
affiliation: Universidad de Extremadura
facility: 
country: Spain
citation: de la Cruz Torres B, Albornoz Cabello M, Garcia Bermejo P, Naranjo Orellana J. Autonomic responses to ultrasound-guided percutaneous needle electrolysis of the patellar tendon in healthy male footballers. Acupunct Med. 2016 Aug;34(4):275-9. doi: 10.1136/acupmed-2015-010993. Epub 2016 Jan 20.
PMID: 26792776
citation: Kitagawa Y, Kimura K, Yoshida S. Spectral analysis of heart rate variability during trigger point acupuncture. Acupunct Med. 2014 Jun;32(3):273-8. doi: 10.1136/acupmed-2013-010440. Epub 2014 Mar 7.
PMID: 24610637
citation: Mourot L, Bouhaddi M, Perrey S, Rouillon JD, Regnard J. Quantitative Poincare plot analysis of heart rate variability: effect of endurance training. Eur J Appl Physiol. 2004 Jan;91(1):79-87. doi: 10.1007/s00421-003-0917-0. Epub 2003 Sep 4.
PMID: 12955518
citation: Gil-Rodas F, Pedret C, Ramos-Castro J, Capdevila-Ortís L. Variabilidad de la frecuencia cardíaca: concepto, medidas y relación con aspectos clínicos (I). Arch Med Deporte Rev Fed Esp Med Deporte Confed Iberoam Med Deporte. 2008;(123):41-8.
citation: Malik M. Heart rate variability: Standards of measurement, physiological interpretation, and clinical use: Task force of the European Society of Cardiology and the North American Society for Pacing and Electrophysiology. Ann Noninvasive Electrocardiol. 1996;1(2):151-81.
citation: Naranjo Orellana J, de la Cruz Torres B, Sarabia Cachadina E, de Hoyo M, Dominguez Cobo S. Two new indexes for the assessment of autonomic balance in elite soccer players. Int J Sports Physiol Perform. 2015 May;10(4):452-7. doi: 10.1123/ijspp.2014-0235. Epub 2014 Oct 29.
PMID: 25364865
responsible party type: Principal Investigator
investigator affiliation: Universidad de Extremadura
investigator full name: Carlos Fernández-Morales
investigator title: Principal Investigator
mesh term: Emergencies
sharing ipd: No