Relation of Various Parameters Used to Estimate Cardiac Vagal Activity and Validity of pNN50 in Anesthetized Humans

• Published in: Kosin Medical Journal (Online) Vol. 33; no. 3; pp. 369 - 379
• Main Authors: Lee, Jae Ho, Huh, In Young, Lee, Jae Min, Lee, Hyung Kwan, Han, Il Sang, Kang, Ho Jun
• Format: Journal Article
• Language: English
• Published: Kosin University College of Medicine 31.12.2018; 고신대학교 의과대학 학술지
• Subjects: general anesthesia; heart rate variability; pnn50; vagal tone; 의학일반
• ISSN: 2005-9531; 2586-7024; 2586-7024
• DOI: 10.7180/kmj.2018.33.3.369

Objectives Analysis of heart rate variability (HRV) has been used as a measure of cardiac autonomic function. According to the pNN50 statistic, the percentage of differences between successive normal RR intervals (RRI) that exceed 50 ms, has been known to reflect cardiac vagal modulation. Relatively little is known about the validity of pNN50 during general anesthesia (GA). Therefore, we evaluated the correlation of pNN50 with other variables such as HF, RMSSD, SD1 of HRV reflecting the vagal tone, and examined the validity of pNN50 in anesthetized patients. Methods: We assessed changes in RRI, pNN50, root mean square of successive differences of RRI (RMSSD), high frequency (HF) and standard deviation 1 (SD1) of Poincaré plots after GA using sevoflurane anesthesia. We also calculated the probability distributions for the family of pNNx statistics (x: 2-50 ms). Results All HRV variables were significantly decreased during GA. HF power was not correlated with pNN50 during GA (r = 0.096, P = 0.392). Less than pNN47 was shown to have a correlation with other variables. Conclusions These data suggest that pNN50 can not reflect the level of vagal tone during GA.