Stability of complex fractionated atrial electrograms: a systematic review

Abstract

Stability of CFAE. Introduction: The efficacy of complex fractionated atrial electrograms (CFAE) ablation as additional substrate modification in atrial fibrillation (AF) patients has been shown to be highly variable. Recently, the validity of sequential CFAE mapping has been challenged by concerns regarding temporal stability of CFAE. Existing studies on CFAE stability are small with very different CFAE definitions. Here, we undertook a systematic literature review to address these controversial findings. Methods and Results: A systematic search of the scientific literature was performed through to September 1, 2011. From a total of 162 manuscripts, 7 were identified to contain assessment of the temporal stability of CFAE in human AF. These studies included a total of 96 (80 persistent/16 paroxysmal AF) patients (79% male, mean 58 years old). Varying CFAE mapping techniques or definitions were utilized. CFAE stability averaged 81% between 2 high-density sequential fractionation maps over an average time interval of 19 minutes. However, CFAE stability only averaged at 75% from shorter term continuous recordings (mean 15 comparisons within 75 seconds). Although the variability in CFAE cycle length was small (12-15 ms), coefficients of variation in continuous electrical activity were high (up to 300%). The overall spatial distribution of CFAE was found to be stable. Nevertheless, sequential mapping may not capture all CFAE sites given their dynamic characteristics. Conclusion: CFAE are temporally variable in keeping with the diverse mechanisms underlying their existence. The dynamic nature of CFAE will continue to pose a challenge for electrophysiologists in search of critical sites requiring ablation to combat AF.