Focus issue: Atrial fibrillationClinicalPrevalence of fractionated electrograms in the coronary sinus: Comparison between patients with persistent or paroxysmal atrial fibrillation and a control population
Introduction
Nademanee et al1 were the first to demonstrate that complex fractionated atrial electrograms (CFAEs) could be targeted for successful ablation of atrial fibrillation (AF). Since that seminal observation, CFAE ablation has been incorporated into a range of ablation procedures for treatment of both paroxysmal and persistent AF, with varying success.2, 3, 4, 5, 6 The coronary sinus (CS) has been identified as a common site of fractionated electrograms, and in many centers extensive CS ablation is an integral part of the procedure for persistent AF ablation.2, 3, 4, 7 However, the significance of fractionated electrograms is unclear, and whether they represent recordings from active drivers in the AF process or are simply passive is uncertain. Simultaneous recording of signals from CS musculature and adjacent left atrium further confuses this analysis. In the current study, we compared the prevalence of fractionated CS electrograms in paroxysmal and persistent AF populations with a control supraventricular tachycardia population in whom AF was induced during electrophysiologic study. This control population had not previously experienced a clinical episode of AF.
Section snippets
Study population
Twelve patients with paroxysmal AF and 12 patients with persistent AF were compared with 12 age-matched control patients undergoing radiofrequency ablation for supraventricular tachycardia in whom AF of at least 1-minute duration was induced by rapid atrial pacing.
All patients provided written informed consent according to a study protocol approved by the Melbourne Health research and ethics committee. With the exception of amiodarone, all antiarrhythmic medications were withheld at least five
Results
The AF and control patient groups were well matched for age (Table 1).
Discussion
This study demonstrates that both paroxysmal and persistent AF patients have a higher prevalence of CFAE and shortest cycle length activation within the proximal CS compared with control patients with induced AF. However, CFAEs within the CS also were common in control patients without clinical AF (28% of electrograms). Furthermore, at distal CS sites (bipoles 1,2 and 3,4), no difference in the prevalence of fractionated electrograms was seen between the control population and the AF groups.
The
Conclusion
This study demonstrates that both paroxysmal and persistent AF patients have a higher prevalence of CFAE and short cycle length activation associated with slowed conduction within the proximal CS compared with control patients with induced AF. However, CFAEs within the CS are also common in control patients and, as these patients have no underlying atrial “substrate,” are unlikely to signify the presence of clinically important AF drivers in this setting. Our observation that fractionated
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Cited by (23)
Risk Factor Management Before and After Atrial Fibrillation Ablation
2020, Cardiac Electrophysiology ClinicsCitation Excerpt :Clinically, this presents itself as a progression from paroxysmal AF to persistent and subsequently permanent forms of AF. The progressive nature of the atrial substrate underlying this natural progression of AF has been confirmed in atrial mapping studies; persistent AF is associated with larger left atrial dimensions, lower atrial regional voltages, increased proportion of low voltage areas, and increased proportion of complex signals (fractionated electrograms) within the left atrium.50,51 It is likely that these progressive changes explain the fact that catheter ablation of persistent AF is associated with higher attrition rates and poorer long-term maintenance of sinus rhythm in comparison to paroxysmal AF.2
Pathophysiology of Paroxysmal and Persistent Atrial Fibrillation: Rotors, Foci and Fibrosis
2017, Heart Lung and CirculationCitation Excerpt :The PersAF patients are more likely to have a higher number of concomitant AF risk factors and be exposed to longer durations of atrial remodelling (Figure 1) [7]. In general, electro-anatomical mapping studies have demonstrated the following atrial electro-structural differences in PersAF patients when compared to those with PAF: larger left atrial dimensions, lower atrial voltage, slower atrial conduction velocity, greater degree of electrogram fractionation and shorter AF cycle length [8,9]. Several mapping studies have also demonstrated higher AF complexity in those with more persistent forms of the arrhythmia to include higher number and narrower activation wavefronts, slower conduction, higher number of breakthrough waves, electrical dissociation, fractionation index and higher dominant frequencies [10–13].
Frequency analysis of atrial fibrillation from the specific ECG leads V7-V9: A lower DF in lead V9 is a marker of potential atrial remodeling
2015, Journal of CardiologyCitation Excerpt :Some reports have shown that the DF values or fractionated activity in the LA is more pronounced in persistent AF than in paroxysmal AF [9,10,13], but others have shown contradictory findings [18,19]. For example, a previous paper demonstrated that there were no significant differences in the DF within the CS electrograms between paroxysmal and persistent AF patients [18]. Rather, we believe that the DF in persistent AF might be dependent on the balance of the extent of the structural and electrical remodeling of the LA.
Morphology and pathophysiology of target anatomical sites for ablation procedures in patients with atrial fibrillation. Part I: Atrial structures (atrial myocardium and coronary sinus)
2013, International Journal of CardiologyCitation Excerpt :It has been shown that CFAEs are often targets for radiofrequency ablation in the CS of patients with AF, and so CFAE ablation has been included in a series of ablation procedures for the treatment of paroxysmal and persistent AF, albeit with varying rates of success. CFAEs are associated with slowed CS conduction and show arrhythmogenesis after PV isolation in AF patients [107,121,122]. Catheter and surgical ablation of the atrial myocardium have had a significant impact on the practice of cardiology especially in the case of supraventricular arrhythmia.
Atrial remodeling in varying clinical substrates within beating human hearts: Relevance to atrial fibrillation
2012, Progress in Biophysics and Molecular Biology
Dr. Teh is the recipient of a postgraduate research scholarship from the National Heart Foundation of Australia. Dr. Lee is the recipient of a postgraduate research scholarship from the Cardiac Society of Australia and New Zealand. Drs. Teh and Lee are the recipients of a cardiovascular and lipid research grant from Pfizer. Dr. Kistler is supported by a Research Investigatorship from the Cardiac Society of Australia and New Zealand.