Heart rate variability, ECG minor changes, and HRV-ECG coupling associated with an adjunctive structured breathing-meditation protocol in combat-exposed military personnel.
Combat-related stress is associated with autonomic nervous system (ANS) dysregulation-sympathetic predominance, reduced vagal tone, and decreased heart rate variability (HRV)-linked to increased cardiovascular risk. Non-pharmacological interventions targeting autonomic regulation show promise, but controlled studies in combat-exposed populations remain limited. We assessed whether adding a structured breathing-meditation protocol, the Technique of Mental Relaxation (TMR), to standard rehabilitation is associated with changes in HRV and electrocardiogram (ECG)-derived indices of autonomic regulation in Ukrainian servicemen.
A controlled, non-randomized study screened 84 male servicemen; 77 were allocated to a TMR group (n = 37; TMR plus standard treatment) or a control group (n = 40; standard treatment alone). Paired baseline and post-treatment 5-min supine recordings, obtained over a 14-day rehabilitation period, were available for 74 participants (TMR n = 35, control n = 39); a civilian reference group (n = 89) provided baseline comparison. Primary HRV outcomes were SDNN, RMSSD, the Baevsky Stress Index, and heart rate; ECG analysis added repolarization intervals, with Hedges' g.
At baseline, both military groups showed impaired autonomic regulation versus civilians (all p < 0.0001). After intervention, the TMR group improved (SDNN 23→30 ms, p < 0.001; RMSSD 12→19 ms, p < 0.001; Stress Index 422→253, p < 0.001), whereas controls deteriorated; post-treatment between-group differences were significant for all primary outcomes (p ≤ 0.008).
Heart-rate-adjusted analyses attenuated part of this difference, the Stress Index remaining most robust. Given the non-randomized design, these findings warrant caution and support randomized trials, with HRV as an objective monitoring tool.
A controlled, non-randomized study screened 84 male servicemen; 77 were allocated to a TMR group (n = 37; TMR plus standard treatment) or a control group (n = 40; standard treatment alone). Paired baseline and post-treatment 5-min supine recordings, obtained over a 14-day rehabilitation period, were available for 74 participants (TMR n = 35, control n = 39); a civilian reference group (n = 89) provided baseline comparison. Primary HRV outcomes were SDNN, RMSSD, the Baevsky Stress Index, and heart rate; ECG analysis added repolarization intervals, with Hedges' g.
At baseline, both military groups showed impaired autonomic regulation versus civilians (all p < 0.0001). After intervention, the TMR group improved (SDNN 23→30 ms, p < 0.001; RMSSD 12→19 ms, p < 0.001; Stress Index 422→253, p < 0.001), whereas controls deteriorated; post-treatment between-group differences were significant for all primary outcomes (p ≤ 0.008).
Heart-rate-adjusted analyses attenuated part of this difference, the Stress Index remaining most robust. Given the non-randomized design, these findings warrant caution and support randomized trials, with HRV as an objective monitoring tool.
Authors
Matsyshyn Matsyshyn, Kravchenko Kravchenko, Ovodiuk Ovodiuk, Zharkov Zharkov, Apykhtin Apykhtin, Romanchuk Romanchuk, Chaikovsky Chaikovsky
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