Journal of Yeungnam Medical Science

Original Articles

Parasympathetic Modulation Plays a Key Role in Initiation of Paroxysmal Atrial Fibrillation.: Won Jae Lee, Dong Gu Shin, Geu Ru Hong, Jong Sun Park, Young Jo Kim; Yeungnam Univ J Med. 2007;24(2):216-231. Published online December 31, 2007; DOI: https://doi.org/10.12701/yujm.2007.24.2.216

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Abstract PDF: BACKGROUND
An acceleration or deceleration of the heart rate (HR), which reflects autonomic effects, is observed before the onset of paroxysmal atrial fibrillation (PAF). The purpose of this study was to assess the discrepancy in the autonomic interactions before the onset of PAF for different patterns of change in the HR. MATERIALS AND METHODS: From 105 Holter tapes with the PAF recorded, 55 episodes (42 patients, 34 men, 58+/-12 years) of PAF (>5 min), preceded by a sinus rhythm for more than 1 hour, were selected and submitted to time-domain and frequency-domain HR variability analyses. Fifty-five episodes were divided into 2 groups: group A PAF (n=30) with acceleration of the HR during the last 2 minutes before the PAF and group B (n=25) with deceleration of the HR. RESULTS: A significant linear decrease in the mean R-R interval was observed in group A (924+/-30 to 835+/-28 ms, P=0.001) and an increase from 831+/-32 to 866+/-31 ms in group B PAF episodes (P=0.046). In the frequency-domain analyses, the LF/HF ratio exhibited a progressive linear increase before the PAF in group A (P=0.005). The HF normalized units (HFnu) and natural logarithm-transformed HF (lnHF) values decreased from 30.8+/-4.0 to 16.1+/-1.8 (P=0.003) and 4.49+/-0.25 to 4.07+/-0.22 (P=0.001), respectively. Contrary to the results in group A, a significant increase in the HF components (HFnu and lnHF) (from 22.6+/-3.2 to 30.2+/-4.0, P=0.005, and 4.27+/-0.27 to 4.75 0.33, P=0.001, respectively) and a resultant decrease in the LF/HF ratio were observed in group B PAF episodes. No significant changes were observed in the LF components in either PAF group. CONCLUSION: Autonomic stimuli leading to an acceleration or deceleration of the HR before the onset of AF are due to parasympathetic modulation. Parasympathetic modulation plays a key role in the initiation of PAF

Development of Data Acquisition System for Quantification of Autonomic Nervous System Activity and It's Clinic Use.: Dong Gu Shin, Jong Sun Park, Young Jo Kim, Bong Sup Shim, Sang Hak Lee, Jun Ha Lee; Yeungnam Univ J Med. 2001;18(1):39-50. Published online June 30, 2001; DOI: https://doi.org/10.12701/yujm.2001.18.1.39

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Abstract PDF: BACKGROUND
Power spectrum analysis method is a powerful noninvasive tool for quantifying autonomic nervous system activity. In this paper, we developed a data acquistion system for estimating the activity of the autonomic nervous system by the analysis of heart rate and respiratory rate variability using power spectrum analysis. MATERIALS AND METHODS: For the detection of QRS peak and measurement of respiratory rate from patient's ECG, we used low-pass filter and impedence method respectively. This system adopt an isolated power for patient's safety. In this system, two output signnals can be obtained: R-R interval(heart rate) and respiration rate time series. Experimental ranges are 30-240 BPM for ECG and 15-80 BPM for respiration. RESULTS: The system can acquire two signals accurately both in the experimental test using simulator and in real clinical setting. CONCLUSION: The system developed in this paper if efficient for the acquisition of heart rate and respiration signals. The system will play a role in research area for improving our understanding of the pathophysiologic involvement of the autonomic nervous system in various disease states.

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