Autonomic Tone Variations Before the Onset of Paroxysmal Atrial Fibrillation

Abstract

Background-Mechanisms favoring the occurrence of paroxysmal atrial fibrillation (PAF) are complex and poorly defined. This study was designed to analyze dynamic changes in autonomic tone preceding the onset of PAF in a large group of patients. Methods and Results-Holter tapes from 77 unselected consecutive patients (63 men and 14 women aged 58Ϯ12 years) with PAF were analyzed. A total of 147 episodes of sustained AF (Ͼ30 minutes) were recorded and submitted to time-domain and frequency-domain heart rate variability analyses; 6 periods were studied using repeated measures ANOVA: the 24-hour period, the hour preceding PAF, and the 20 minutes before PAF divided into four 5-minute periods. In the time-domain analyses, a linear decrease in mean RR interval from 925Ϯ16 to 906Ϯ16 ms (PϽ0.0002) was observed before the onset of PAF, together with a significant increase in the standard deviation of NN intervals from 65Ϯ4 to 70Ϯ4 ms (PϽ0.02). In the frequency-domain analyses, a significant increase in high-frequency (HF, HF-NU) components was observed before PAF (PϽ0.001 and PϽ0.0001, respectively), together with a progressive decrease in low-frequency components (LF, LF-NU) (PϽ0.0001 and PϽ0.004, respectively). The low/high frequency ratio showed a linear increase until 10 minutes before PAF, followed by a sharp decrease immediately before PAF, suggesting a primary increase in adrenergic tone followed by a marked modulation toward vagal predominance. No difference was observed in these heart rate variability changes between patients with "lone" PAF and patients with structural heart disease. Conclusions-The occurrence of PAF greatly depends on variations of the autonomic tone, with a primary increase in adrenergic tone followed by an abrupt shift toward vagal predominance.

2012 HRS/EHRA/ECAS Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation: Recommendations for Patient Selection, Procedural Techniques, Patient Management and Follow-up, Definitions, Endpoints, and Research Trial Design

“…103,105,114,116,124,355,576,577,578,579,580,581,582 Because the GP are consistently located within areas of highly fractionated atrial potentials (FAPs), also referred to as CFAEs, 103,105,114,116,124,355,576,577,578,579,580,581,582,583,584 it is useful to begin with a fractionation map of the LA and PVs during AF. The LA FAPs are usually located in four areas: (1) LAA ridge FAP area (between LAA and left PVs); (2) superior left FAP area; (3) inferoposterior FAP area; and (4) anterior right FAP area (Figure 4).…”

Longitudinal Age-Related Changes in 24-Hour Total Heart Beats and Premature Beats and Their Relationship in Healthy Elderly Subjects

“…24) Bettoni, et al suggested that changes in autonomic nervous activities were associated with the occurrence of atrial fibrillation. 25) On the other hand, Pitzalis, et al 7) and Coumel 8) reported tachycardiainduced VPC and pointed out the possibility of involvement of sympathetic activities. Moreover, Fleg, et al and Pfeifer, et al described an age-related increase in plasma norepinephrine in elderly subjects at maximum exercise and in the supine position, respectively.…”

Mechanisms of Atrial Fibrillation – Reentry, Rotors and Reality

“…76,77 Both sympathetic and parasympathetic stimuli may be involved, 76 although in humans, the extent and importance of autonomic influences vary based on patient characteristics and comorbidities. 78 Ganglionated plexi (GP) are epicardial networks of autonomic nervous tissue present near the junctions between the pulmonary veins and LA.…”