This study evaluates in detail efficacy and safety (including neurological safety) of hybrid ablation of stand-alone, persistent and long-standing persistent atrial fibrillation (AF). An implantable ECG monitor will be implanted to all patients for rhythm monitoring. Neurological safety will be assessed by cerebral magnetic resonance, neuropsychological examination and periprocedural transcranial Doppler measurement.

Hybrid ablation (i.e. surgical thoracoscopic ablation, followed by catheter endocardial ablation) represent a new treatment option for patients with atrial fibrillation.

60 patients will undergo a two-stage, hybrid ablation, all of them will have an ECG monitoring device implanted and will be followed for up to three years. Neurological safety of both surgical and catheter procedures will be assessed by three examinations. Magnetic resonance will be performed before surgery, 5 days after surgery and at the 180 days visit to search for (subclinical) cerebral ischemia. Complex neuropsychological examination will be performed before surgery, afer 1 month after surgery and at 180 days visit to search for changes in cognitive functions, behavioral functions etc. Transcranial Doppler will be performed during surgical and catheter ablation to detect microembolic signals.

Inclusion Criteria:

• Patients age > 18 years
• Patients with persistent/long-standing persistent AF according to the standard EHRA definition.
• Patients with symptomatic AF that is refractory to at least one antiarrhythmic medication.
• Absence of significant structural heart disease (dilated cardiomyopathy, hypertrophic cardiomyopathy, valvular heart disease, untreated coronary artery disease)
• Ability to sign an informed consent

Exclusion Criteria:

• Paroxysmal AF
• AF secondary to a reversible cause (i.e., thyreopathy, etc.)
• Indication for open-heart surgery (coronary artery bypass grafting, valve surgery, etc.)
• Severe left ventricle dysfunction that is clearly caused by some other cardiac disease (dilated cardiomyopathy, ischaemic heart disease, etc.) where the AF is clearly of secondary etiology
• Known severe pericardial and pleural adhesions (e.g., history of cardiac surgery)

patients with symptomatic, drug-resistant, stand-alone, persistent or long-standing persistent atrial fibrillation