gms | German Medical Science

28. Wissenschaftlicher Kongress der Deutschen Hochdruckliga

24. bis 27.11.2004, Hannover

Symbolic dynamics for the prediction of ventricular tachyarrhythmias

Symbolische Dynamik für die Vorhersage Ventrikulärer Tachyarrhythmien

Meeting Abstract (Hypertonie 2004)

  • presenting/speaker N. Wessel - Institut für Physik, Universität Potsdam (Potsdam, D)
  • presenting/speaker A. Schirdewan - Universität Potsdam (Potsdam, D)
  • presenting/speaker R. Bauernschmitt - Deutsches Herzzentrum (München, D)
  • presenting/speaker H. Malberg - Institut für Angewandte Informatik, Forschungszentrum Karlsruhe GmbH (Karlsruhe, D)
  • presenting/speaker J. Kurths - Forschungszentrum Karlsruhe GmbH (Karlsruhe, D)

Hypertonie 2004. 28. Wissenschaftlicher Kongress der Deutschen Hochdruckliga. Hannover, 24.-27.11.2004. Düsseldorf, Köln: German Medical Science; 2005. Doc04hochP100

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Veröffentlicht: 10. August 2005

© 2005 Wessel et al.
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Implantable cardioverter-defibrillators (ICDs) are the standard therapy in patients with ventricular tachyarrhythmia (VTA) and provide a unique opportunity to analyse beat-to-beat (RR)-interval variability (HRV) before the onset of such life-threatening event. In a pilot study, published in 2000, we found that the symbolic dynamics parameter POLVAR10 was able to differentiate significantly between HRV time series before a VTA and at a control time. Therefore, the MARITA study was conducted to validate these results prospectively. In 186 patients (153 men, mean age 61.0±10.4) with an implanted ICD (Biotronik ICDs, 9000 RR-intervals capacity) 257 heart rate recordings before a VTA (from 94 patients) and 645 series during control conditions (recordings at follow-up date without VTA) were recorded. From these time series 107 VTA and 422 control recordings were in sinus rhythm, being longer than one hour and having less 10 % ectopy. For HRV analysis standard time- and frequency parameters as well as nonlinear dynamical measures were calculated. The mean RR-interval in the VTA group was significantly decreased than in controls (752.4±13.9 vs. 819.1±8.1, p<0.0001), whereas the number of ventricular premature beats (VPBs) was increased (230.5±19.7 vs. 147.7±10.5, p<0.00001). To determine the time of sympathetic activation we calculated all HRV parameter for successive 5 minutes intervals up to 90 minutes before the onset of VTA. Heart rate and ventricular ectopy rate are significantly increased already 90 minutes before VTA, suggesting a state of sympathetic excitation. The symbolic dynamics parameter POLVAR10 was the only parameter which could detect precursors of VTA. Our result suggests that the myocardium becomes susceptible to VTA by a more complex mechanism dependent on variable neurohumoral regulatory systems, rather than solely by sympathetic activation.