ĐÁNH GIÁ SỰ BIẾN ĐỔI NHỊP TIM, HUYẾT ÁP TRÊN PHI CÔNG TRONG THỬ NGHIỆM BUỒNG GIẢM ÁP MÔ PHỎNG ĐỘ CAO 5000M

Abstract

Objective: To evaluate the effects of simulated hypobaric conditions (5000 m) on heart rate and blood pressure in pilots. Methods: A cross-sectional study included 75 active Vietnamese military pilots meeting inclusion criteria. Each pilot underwent measurements of continuous heart rate and blood pressure (systolic and diastolic) before, during, and after exposure in a hypobaric chamber simulating 5000 m altitude. Data were analyzed using SPSS 22.0 with repeated-measures ANOVA to assess the impact of altitude. Results: The mean age of pilots was 31.4 ± 5.9 years, BMI 22.9 ± 2.4 kg/m². Mean baseline heart rate was 80.01 ± 11.32 beats/min, which increased significantly to 91.23 ± 10.43 beats/min at 5000 m (p<0.001). The highest heart rate (93.52 ± 9.46 beats/min) occurred at 15 minutes at 5000 m, significantly higher than at ascent start or descent end (p<0.05). Mean systolic blood pressure (SBP) rose from 120.40 ± 7.48 mmHg (pre-test) to 131.68 ± 8.71 mmHg at 5000 m and returned to 122.12 ± 8.75 mmHg post-test (p<0.05). Mean diastolic blood pressure (DBP) similarly increased from 74.94 ± 7.06 to 81.49 ± 7.13 mmHg at altitude and decreased to 76.11 ± 7.96 mmHg after (p<0.05). Conclusions: Simulated altitude of 5000 m significantly elevated heart rate and blood pressure in pilots, though changes were moderate. These findings reflect good cardiovascular fitness and adaptation in these pilots.