Analysis of Heart Rate Variability During Emergency Flight Simulator Missions in Fighter Pilots

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).

Study Overview

• Status: Completed
• Conditions: Heart Rate Variability; Autonomic Nervous System
• Intervention / Treatment: Device: Analysis of heart rate variability

Detailed Description

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.

• Study Type: Observational
• Enrollment (Actual): 18

Contacts and Locations

Study Locations

• Spain
  • Badajoz, Spain, 06006
    • Universidad de Extremadura

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

The selection of the sample was made in the accessible population of the Talavera la Real Air Base (Badajoz).

Description

Inclusion Criteria:

• Pilots who had the status of instructor or student assigned at the time of assessment to the ALA 23 district of the Talavera la Real Air Base of the Ministry of Defense of the Government of Spain (Badajoz).

Exclusion Criteria:

• Any uncontrolled neurological or cardiac disorder.
• Being involved in ongoing medical-legal conflicts.

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Only
• Time Perspectives: Cross-Sectional

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Instructors group; Group of flight instructors at the reactor school.	Device: Analysis of heart rate variability; 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).
Students group; Group of students at the reactor school.	Device: Analysis of heart rate variability; 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).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Root Mean Square of the Successive Differences (RMSSD)	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.	1 week
Stress Score	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.	1 week
Sympathetic/parasympathetic ratio (S/PS)	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	1 week

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Standard Deviation 1 (SD1)	It indicates the sensitivity of short-term variability in HRV non-linear spectrum. It is considered an indicator of parasympathetic activity.	1 week
Standard Deviation 2 (SD2)	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.	1 week
Min_HR	Minimum heart rate variability.	1 week
Max_HR	Maximum heart rate variability.	1 week
Mean_HR	It corresponds to the interval between two beats (R peaks on the ECG).	1 week
pNN50	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.	1 week
Low Frequency Power (LF)	Situated between 0.04 and 0.15 Hz. In long-term recordings it provides us with more information about the activity of the SNS.	1 week
High Frequency Power (HF)	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.	1 week
Low/High Frequency ratio (HF/LF)	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.	1 week

Collaborators and Investigators

• Sponsor: Universidad de Extremadura
• Investigators: Principal Investigator: Luis Espejo-Antúnez, PhD, Universidad de Extremadura

Publications and helpful links

General Publications

• 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.
• 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.
• 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.
• 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.
• 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.
• 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.

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2019
• Primary Completion (Actual): November 18, 2019
• Study Completion (Actual): March 10, 2020

Study Registration Dates

• First Submitted: July 22, 2020
• First Submitted That Met QC Criteria: July 22, 2020
• First Posted (Actual): July 27, 2020

Study Record Updates

• Last Update Posted (Actual): September 16, 2022
• Last Update Submitted That Met QC Criteria: September 14, 2022
• Last Verified: September 1, 2022

More Information

Terms related to this study

• Keywords: autonomic nervous system; heart rate variability; Emergency missions; Assesment; Military Health Services
• Additional Relevant MeSH Terms: Pathologic Processes; Disease Attributes; Emergencies
• Other Study ID Numbers: 02

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No