Abstract 1037: Significant Autonomic Fluctuations before Sudden-Onset Episodes of Paroxysmal Atrial Fibrillation
Beside bradycardia-, tachycardia- and ectopy-related initiation of paroxysmal atrial fibrillation (pAF), those episodes without preceding rate or rhythm changes (i.e. sudden onset (SO) episodes) are particulary interesting for the investigation of autonomic fluctuations before spontaneous onset of pAF. We hypothesized that there are significant alterations of beat-to-beat RR-interval fluctuations before SO-pAF and tested this assumption in a large patient population using parameters of non-linear heart-rate dynamics.
Methods: From a total of 20.546 consecutive Holter-recordings, 715 episodes of pAF were identified in 350 patients. Detrended fluctuation analysis (DFA), approximate entropy (APEn), and parameters of heart rate variability (HRV) were analysed in 5-minute-segments before SO-pAF, and during AF-free day-and nighttime.
Results: A dominant portion of pAF onsets were SO-episodes (n=276; 39%), 299 (41%) ectopy-related, and 140 (20%) heart rate related. Time domain HRV (SDNNi, SDANN, rMSSD, TI) significantly increased before pAF-onset. The low frequency component (LF), the LF/HF-ratio, the Poincaré-SD2, and DFA also increased before pAF-onset, whereas APEn significantly decreased.
Conclusions: In this first study providing detailed analysis of heart-rate dynamics preceding SO-pAF-episodes, we were able to demonstrate that there are significant pertubations of autonomic modulation preceding SO-pAF. These transient abnormal changes of cardiac autonomic nervous control may predispose to the development of pAF.