Heart drug after ablation: did it prevent AFib return?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: Patients must meet the following criteria to be enrolled in the trial. * Male or female patients aged over 18 years of age. * Patients with paroxysmal or persistent atrial fibrillation who are undergoing ablation of atrial fibrillation, regardless of whether they were receiving an anti-arrhythmic drug (AADs) before enrollment or not. Exclusion Criteria: Patients will be excluded from enrollment if any of the following criteria are present. * Any health-related gadolinium/MRI contraindications (e.g. allergy to gadolinium, pacemakers, Implantable Cardioverter Defibrillators \[ICD's\], other devices/implants contraindicated for use of MRI, etc.). * Patients weighing \>300 Ibs. (MRI quality decreases as BMI increases). * Patients with contraindications to dronedarone. (Including patients with decompensated heart failure or class NYHA IV (New York Heart Association Class IV), second or third-degree atrioventricular (AV) block or sick-sinus syndrome \[except when used in conjunction with a functioning pacemaker\]), concomitant use of strong cytochrome P450, family 3, subfamily A (CYP-3A) inhibitors or other Class I or III AADs, drug or herbal products that prolongs the QT interval and may induce Torsades de Pointes. * Liver or lung toxicity related to the previous use of amiodarone, severe hepatic impairment including any stage of cirrhosis and acute liver failure, bradycardia \<50bpm, QTc Bazett interval \>500ms or PR interval \>280ms, or hypersensitivity to the active substance or to any of its excipients. * Acute or chronic severe renal disease with a low glomerular filtration rate (GFR), \<30 mL per minute per 1.73m2 will be excluded from the trial. * Patients with a history of prior left atrial ablation or valvular cardiac surgery (myocardial scarring/fibrosis from prior surgeries may confound data). * Pre-menopausal (last menstruation \<1 year prior to screening) who: 1. are pregnant or breast-feeding or plan to become pregnant during the study period or, 2. are not surgically sterile or, 3. are of childbearing potential and not practising two acceptable methods of birth control or, 4. do not plan to continue practising two acceptable methods of birth control throughout the trial (highly effective methods of birth control are defined as those, used alone, or in combination, that result in a low failure rate i.e. less than 1% per year when used consistently and correctly). * Patients who do not have access to the Internet/e-mail. * Patients without daily access to a smart phone-compatible with ECG Check device application and ability to upload ECG tracings for the entire follow-up period. * Patients unable or unwilling to return to the clinic for follow up CMR scans. * Patients with cognitive impairments who are unable to give informed consent.