629 Heart Rate Variability Response to Cold Stress in Thai Brugada Syndrome Survivors: A Pilot Study

Abstract

BackgroundBrugada syndrome is considered to be one of major causes of sudden death in male residing in Northeastern part of Thailand. Mechanisms of the syndrome have not been fully understood yet. However, recent studies suggest that autonomic modulation may relate to the syndrome. Therefore, this study aims to investigate and compare the responses of autonomic function during cold stress exposure between Thai Brugada syndrome survivors and age-match healthy subjects.MethodsEight male Brugada survivors and age-match healthy subjects (age between 36 and 56 years) participated in this study. The cold pressor test (CPT) was conducted by placing left subjects' hands in 4°c water bath for 2 min. Heart rate (HR) and blood pressure (BP) were recorded throughout the experiment. R-R interval from electrocardiograph was used to analyse time and frequency domain of HRV responses.ResultsThe results showed that cold stress exposure significantly increased HR and BP in both groups (p<0.05) However, during resting period, Brugada syndrome survivors showed significantly higher high frequency component of HRV (p<0.05) than control group (mean ± SE: 45.4 ± 5.50 nu vs 30.6 ± 2.03 nu). However, other HRV parameters did not reach statistical significance.Conclusion BackgroundBrugada syndrome is considered to be one of major causes of sudden death in male residing in Northeastern part of Thailand. Mechanisms of the syndrome have not been fully understood yet. However, recent studies suggest that autonomic modulation may relate to the syndrome. Therefore, this study aims to investigate and compare the responses of autonomic function during cold stress exposure between Thai Brugada syndrome survivors and age-match healthy subjects. Brugada syndrome is considered to be one of major causes of sudden death in male residing in Northeastern part of Thailand. Mechanisms of the syndrome have not been fully understood yet. However, recent studies suggest that autonomic modulation may relate to the syndrome. Therefore, this study aims to investigate and compare the responses of autonomic function during cold stress exposure between Thai Brugada syndrome survivors and age-match healthy subjects. MethodsEight male Brugada survivors and age-match healthy subjects (age between 36 and 56 years) participated in this study. The cold pressor test (CPT) was conducted by placing left subjects' hands in 4°c water bath for 2 min. Heart rate (HR) and blood pressure (BP) were recorded throughout the experiment. R-R interval from electrocardiograph was used to analyse time and frequency domain of HRV responses. Eight male Brugada survivors and age-match healthy subjects (age between 36 and 56 years) participated in this study. The cold pressor test (CPT) was conducted by placing left subjects' hands in 4°c water bath for 2 min. Heart rate (HR) and blood pressure (BP) were recorded throughout the experiment. R-R interval from electrocardiograph was used to analyse time and frequency domain of HRV responses. ResultsThe results showed that cold stress exposure significantly increased HR and BP in both groups (p<0.05) However, during resting period, Brugada syndrome survivors showed significantly higher high frequency component of HRV (p<0.05) than control group (mean ± SE: 45.4 ± 5.50 nu vs 30.6 ± 2.03 nu). However, other HRV parameters did not reach statistical significance. The results showed that cold stress exposure significantly increased HR and BP in both groups (p<0.05) However, during resting period, Brugada syndrome survivors showed significantly higher high frequency component of HRV (p<0.05) than control group (mean ± SE: 45.4 ± 5.50 nu vs 30.6 ± 2.03 nu). However, other HRV parameters did not reach statistical significance. Conclusion