» Articles » PMID: 25810810

Catheter Ablation of Persistent Atrial Fibrillation: The Importance of Substrate Modification

Overview
Authors
Affiliations
Soon will be listed here.
Abstract

Accumulating data have shown that elimination of atrial fibrillation (AF) sources should be the goal in persistent AF ablation. Pulmonary vein isolation, linear lesions and complex fractionated atrial electrograms (CFAEs) ablation have shown limited efficacy in patients with persistent AF. A combined approach using voltage, CFAEs and dominant frequency (DF) mapping may be helpful for the identification of AF sources and subsequent focal substrate modification. The fibrillatory activity is maintained by intramural reentry centered on fibrotic patches. Voltage mapping may assist in the identification of fibrotic areas. Stable rotors display the higher DF and possibly drive AF. Furthermore, the single rotor is usually consistent with organized AF electrograms without fractionation. It is therefore quite possible that rotors are located at relatively "healthy islands" within the patchy fibrosis. This is supported by the fact that high DF sites have been negatively correlated to the amount of fibrosis. CFAEs are located in areas adjacent to high DF. In conclusion, patchy fibrotic areas displaying the maximum DF along with high organization index and the lower fractionation index are potential targets of ablation. Prospective studies are required to validate the efficacy of substrate modification in left atrial ablation outcomes.

References
1.
Luise Estner H, Hessling G, Ndrepepa G, Wu J, Reents T, Fichtner S . Electrogram-guided substrate ablation with or without pulmonary vein isolation in patients with persistent atrial fibrillation. Europace. 2008; 10(11):1281-7. DOI: 10.1093/europace/eun244. View

2.
Shivkumar K, Ellenbogen K, Hummel J, Miller J, Steinberg J . Acute termination of human atrial fibrillation by identification and catheter ablation of localized rotors and sources: first multicenter experience of focal impulse and rotor modulation (FIRM) ablation. J Cardiovasc Electrophysiol. 2012; 23(12):1277-85. PMC: 3524347. DOI: 10.1111/jce.12000. View

3.
Willems S, Klemm H, Rostock T, Brandstrup B, Ventura R, Steven D . Substrate modification combined with pulmonary vein isolation improves outcome of catheter ablation in patients with persistent atrial fibrillation: a prospective randomized comparison. Eur Heart J. 2006; 27(23):2871-8. DOI: 10.1093/eurheartj/ehl093. View

4.
Nayyar S, Wilson L, Ganesan A, Sullivan T, Kuklik P, Chapman D . High-density mapping of ventricular scar: a comparison of ventricular tachycardia (VT) supporting channels with channels that do not support VT. Circ Arrhythm Electrophysiol. 2014; 7(1):90-8. DOI: 10.1161/CIRCEP.113.000882. View

5.
Saghy L, Callans D, Garcia F, Lin D, Marchlinski F, Riley M . Is there a relationship between complex fractionated atrial electrograms recorded during atrial fibrillation and sinus rhythm fractionation?. Heart Rhythm. 2011; 9(2):181-8. DOI: 10.1016/j.hrthm.2011.09.062. View