Heart rate variability before the onset of ventricular tachycardia: differences between slow and fast arrhythmias

Item Type:	Article
Title:	Heart rate variability before the onset of ventricular tachycardia: differences between slow and fast arrhythmias
Creators Name:	Meyerfeldt, U. and Wessel, N. and Schuett, H. and Selbig, D. and Schumann, A. and Voss, A. and Kurths, J. and Ziehmann, C. and Dietz, R. and Schirdewan, A.
Abstract:	Background: We tested whether or not heart rate variability (HRV) changes can serve as early signs of ventricular tachycardia (VT) and predict slow and fast VT in patients with an implantable cardioverter defibrillator (ICD). Methods and results: We studied the ICD stored 1000 beat-to-beat intervals before the onset of VT (131 episodes) and during a control time without VT (74 series) in 63 chronic heart failure ICD patients. Standard HRV parameters as well as two nonlinear parameters, namely ‘Polvar10’ from symbolic dynamics and the finite time growth rates ‘Fitgra9’ were calculated. Comparing the control and the VT series, no linear HRV parameter showed a significant difference. The nonlinear parameters detected a significant increase in short phases with low variability before the onset of VT (for time series with less than 10% ectopy, P<0.05). Subdividing VT into fast (cycle length ≤270 ms) and slow (>270 ms) events, we found that the onset of slow VT was characterized by a significant increase in heart rate, whereas fast VT was triggered during decreased heart rates, compared to the control series. Conclusions: Our data may permit the development of automatic ICD algorithms based on nonlinear dynamic HRV parameters to predict VT before it starts. Furthermore, they may facilitate improved prevention strategies.
Keywords:	Autonomic Nervous System, Defibrillator, Ventricular Tachycardia, Heart Rate Variability
Source:	International Journal of Cardiology
ISSN:	0167-5273
Publisher:	Elsevier
Volume:	84
Number:	2-3
Page Range:	141-151
Date:	August 2002
Official Publication:	https://doi.org/10.1016/S0167-5273(02)00139-0
PubMed:	View item in PubMed

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