This study will test the ability of computer algorithms to predict successful ablation therapy for atrial arrhythmias.

Patients will be recruited prospectively from among those undergoing ablation for atrial fibrillation (AF) or atrial tachycardias (AT) which may be reentrant or focal. Each patient will undergo careful data collection, including electrogram data and sites of ablation lesions. Ablation will proceed in operator-dependent fashion, and will not be modified in any way for this study. The research question is whether algorithms based on data such as electrograms and details of the ablation performed can predict which patients will have a successful case. Primary endpoints are measures of clinical success defined by (a) acute termination of atrial arrhythmia during the case; (b) long-term reduction in arrhythmia burden; (c) long-term freedom from arrhythmia. Secondary endpoints include (a) identification of sites of arrhythmia termination; (b) improved clinical status.

Inclusion Criteria:

• Patients undergoing catheter ablation for atrial arrhythmias

Exclusion Criteria:

• Inability to sign informed consent
• Expected survival < 1 year
• Extreme comorbidity, such as advanced NYHA Class III/IV heart failure, dialysis, series stroke.

Patients undergoing clinically prescribed ablation for complex atrial arrhythmias will be approached for enrollment. Most are anticipated to be atrial fibrillation or atrial tachyarrhythmias such as post-ablation flutter. Men and women over 21 years and up to 80 years of age will be included.