Analysis of Heart Rate Variability Five Minutes Before the Onset of Paroxysmal Atrial Fibrillation

Abstract

We observed abrupt changes in sympathovagal balance in the last 5 minutes preceding an episode of atrial fibrillation. This can be related to a double behavior in the neurogenic drive: in Type A episodes there is an increase of the LF spectrum, LF:HF ratio, and a decrease of the HF spectrum consistent with an increase of neurogenic sympathetic drive; in Type B episodes there is a reduction of the LF spectrum, LF/HF ratio, and an increase of HF spectrum consistent with an enhancement of the neurogenic parasympathetic drive. In some patients, we found that the two mechanisms operate during different hours of the day and that sometimes there is an increase of sympathetic tone, and in the same instances an increase of parasympathetic tone. Heart-rate variability measures fluctuation in autonomic inputs to the heart rather than the mean level of autonomic impulse; autonomic imbalance is probably more important than the vagal or sympathetic drive alone.

ACC/AHA/ESC 2006 Guidelines for the Management of Patients With Atrial Fibrillation

“…Vagal predominance in the minutes preceding the onset of AF has been observed in some patients with structurally normal hearts, while in others there is a shift toward sympathetic predominance. 283,284 Although Coumel 285 recognized that certain patients could be characterized in terms of a vagal or adrenergic form of AF, these cases likely represent the extremes of either influence. In general, vagally mediated AF occurs at night or after meals, while adrenergically induced AF typically occurs during the daytime in patients with organic heart disease.…”

Central Sleep-disordered Breathing Predicts Incident Atrial Fibrillation in Older Men

“…An underlying increase in central and peripheral chemoresponsiveness may contribute to augmented sympathetic activity and autonomic imbalance, which are predisposing factors for AF (37)(38)(39). It is possible that CSA is a marker of augmented respiratory chemoreflexes and autonomic nervous system dysfunction rather than the primary impetus for AF development.…”

ACC/AHA/ESC 2006 Guidelines for the Management of Patients With Atrial Fibrillation—Executive Summary

“…Vagal predominance has been observed in the minutes preceding the onset of AF in some patients with structurally normal hearts, while in others there is a shift toward sympathetic predominance. 108,109 Although certain patients can be characterized in terms of a vagal or an adrenergic form of AF, these cases likely represent the extremes of either influence. 110 In general, vagally mediated AF occurs at night or after meals, while adrenergically induced AF typically occurs during the daytime.…”