Objectives: This study sought to study the change in autonomic tone that precedes the initiation of paroxysmal atrial flutter.
Background: An abrupt change in the autonomic tone of the heart is an important initiating factor in the pathogenesis of ventricular tachyarrhythmias and paroxysmal atrial fibrillation. Whether the autonomic tone has a role in the initiation of paroxysmal atrial flutter has not been reported.
Methods: Holter electrocardiographic recording was used to investigate the changes in heart rate variability before the onset of paroxysmal atrial flutter.
Results: A total of 12 patients with paroxysmal atrial flutter were analyzed. An increase in the normalized value of the low frequency (LF) component and the LF/high frequency (HF) ratio and a decrease in the normalized value of the HF component began at 6 min before the onset of episodes of paroxysmal atrial flutter, which indicated that sympathovagal balance had shifted to more sympathetic predominance.
Conclusions: An increase in sympathetic modulation or vagal withdrawal, or both, may facilitate the initiation of atrial flutter.