Correlation of atrial fibrillation cycle length and fractionation is associated with atrial fibrillation free survival

Aims: Fractionation of electrograms in atrial fibrillation (AF) is associated with structural and electrical remodeling. We hypothesized that fractionation can also be associated with the AF cycle length (AFCL). This study was aimed at calculating the mean AFCL to fractionation correlation coefficient (mAFCC) and assessing its association with AF free survival after pulmonary vein isolation (PVI).

Methods: In twenty-eight patients, 15-second electrograms during AF were recorded with a twenty-polar catheter at the left and right atrial appendages. The AFCL was determined manually and the number of activations per second was automatically calculated into a fractionation score. The correlation between AFCL and fractionation was assessed with the mAFCC.

Results: Mean age was 53 ± 8 years and 86% had paroxysmal AF. 64% of patients were AF free after a median follow-up of 5.5 years. Baseline characteristics, mean AFCL and fractionation score were not associated with AF free survival after PVI. The mAFCC assessed at the left atrial appendage predicted long-term AF free survival (area under the curve: 0.871. P=0.002), but the mAFCC recorded at the right atrial appendage did not (0.690, P=0.131).

Conclusion: The mean AFCL mAFCC recorded at the left atrial appendage was a significant predictor of long-term AF free survival. Although not a significant predictor of AF free survival, there was a significant association between mAFCC recorded at the right atrial appendage and AF free survival.