Complex Fractionated Atrial Electrogram Ablation in AF
Complex Fractionated Atrial Electrogram Ablation in AF
The concept of focal sources and centrifugal organized activation existing during atrial fibrillation (AF) is supported by animal studies identifying stable focal sources (rotors) initiating and perpetuating AF. Spectral analysis of local bipolar signals acquired during AF indicates substantial periodic elements and frequency domain analysis reveals gradients from high to low dominant frequencies (DF). Using DF mapping the hierarchical distribution of frequencies in the atria during AF may be displayed and sites with highest DF may be localized as drivers. Sanders et al. in 2005 performed real-time spectral and frequency mapping of the left atrium in AF patients and ablation at these sites was able to terminate AF in paroxysmal patients. These findings appeared to prove the concept of focal firing sources during AF identified during high DF mapping.
Fractionated electrograms have been documented to represent sites of reentry facilitating maintenance of AF. Complex fractionated atrial electrograms (CFAEs) are defined as low-voltage fractionated atrial electrograms with a cycle length <120 ms. Rapid electrical impulses emanating from rotors/drivers are conducted within the atria and fragmentation arises from interaction with functional and anatomic boundaries. These sites with CFAE appear spatially stable and ablation at these sites may also result in AF termination.
Whereas effective pulmonary vein isolation (PVI) remains the cornerstone of AF therapy, limited data on efficacy of an additional electrogram-guided ablation approach using frequency and CFAE mapping are available and their mechanisms are still controversial.
Editorial Comment
The concept of focal sources and centrifugal organized activation existing during atrial fibrillation (AF) is supported by animal studies identifying stable focal sources (rotors) initiating and perpetuating AF. Spectral analysis of local bipolar signals acquired during AF indicates substantial periodic elements and frequency domain analysis reveals gradients from high to low dominant frequencies (DF). Using DF mapping the hierarchical distribution of frequencies in the atria during AF may be displayed and sites with highest DF may be localized as drivers. Sanders et al. in 2005 performed real-time spectral and frequency mapping of the left atrium in AF patients and ablation at these sites was able to terminate AF in paroxysmal patients. These findings appeared to prove the concept of focal firing sources during AF identified during high DF mapping.
Fractionated electrograms have been documented to represent sites of reentry facilitating maintenance of AF. Complex fractionated atrial electrograms (CFAEs) are defined as low-voltage fractionated atrial electrograms with a cycle length <120 ms. Rapid electrical impulses emanating from rotors/drivers are conducted within the atria and fragmentation arises from interaction with functional and anatomic boundaries. These sites with CFAE appear spatially stable and ablation at these sites may also result in AF termination.
Whereas effective pulmonary vein isolation (PVI) remains the cornerstone of AF therapy, limited data on efficacy of an additional electrogram-guided ablation approach using frequency and CFAE mapping are available and their mechanisms are still controversial.
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