Abstract—Heart rate variability in Holter electrocardiogram (ECG) that incidentally recorded the onset process of heatstroke during golf play was analyzed in comparison to control ECGs in the same subject and in a healthy control group. During playing golf normally, the amplitude of high-frequency (HF) component, known as an index of cardiac parasympathetic function, was suppressed (4.3 ± 2.2 ms). Whereas, 135 min before the onset of syncope, spiky HF bursts (amplitude ~10 ms and width <60 s) appeared repeatedly at an interval of 10-15 min and the burst amplitude increased to 20-30 ms from 51 min before to the onset of syncope. No such phenomenon was observed in control ECGs even during walking exercise. Although spiky HF burst was observed 30% of subjects in control group, none of them showed repetitive burst during short period <15 min. Repetitive spiky HF burst may be a prodromal sign for predicting heatstroke from heartbeat information.
Index Terms—Heatstroke, syncope, heart rate variability, autonomic nervous system, hot environment, golf, Holter electrocardiogram, complex demodulation.
E. Yuda is with the Department of Electrical Engineering, Tohoku University Graduate School of Engineering, Sendai 980-8759, Japan (e-mail: firstname.lastname@example.org).
R. Iino is with Belling Co., Ltd. Kashiwa City 277-0822, Chiba, Japan Y. Yoshida is with the Nagoya City University Graduate School of Design and Architecture, Nagoya 464-0083, Japan (e-mail: email@example.com).
J. Hayano is with the Department of Medical Education, Nagoya City University Graduate School of Medical Sciences, Nagoya 467-8602, Japan (e-mail: firstname.lastname@example.org).
Cite: Emi Yuda, Rui Iino, Yutaka Yoshida, and Junichiro Hayano, "Spiky Burst of High Frequency Heart Rate Variability: A Prodromal Sign of Syncope Accompanying Heatstroke," International Journal of Environmental Science and Development vol. 10, no. 8, pp. 241-245, 2019.Copyright © 2019 by the authors. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).