Electrophysiologic characteristics and catheter ablation of focal atrial tachycardia with more than one focus.

BACKGROUND

Information about the electrophysiologic characteristics and long-term outcome of catheter ablation in patients with multiple focal atrial tachycardia (AT) is limited.

OBJECTIVE

The purpose of this study was to investigate the electrophysiologic characteristics and long-term outcome of catheter ablation in patients with multiple focal AT.

METHODS

Two hundred fifty-one patients who were referred for radiofrequency catheter ablation of focal AT were included for analysis.

RESULTS

Forty-four patients who had focal AT with more than one focus were identified. Comparing focal AT with a single focus to that with more than one focus, the existence of a left atrial focus, cardiovascular comorbidity, nonparoxysmal tachycardia, shortest tachycardia cycle length, success rate of the ablation, and procedure time all differed. Multivariate logistic analysis revealed that a left atrial focus, cardiovascular comorbidity, and shortest tachycardia cycle length were independent predictors of focal AT with more than one focus. Noncontact mapping of the right atrium revealed larger low-voltage zone and longer total activation time for focal AT with more than one focus. Patients who had focal AT with more than one focus and a failed ablation had a greater number of focal ATs and mechanisms of nonparoxysmal tachycardia. Multivariate logistic analysis revealed that only the number of focal ATs predicted a failed ablation.

CONCLUSION

Focal ATs with more than one focus have different electrophysiologic characteristics. This study provides new insight into the development and atrial remodeling of focal AT with multiple foci.