New heart-zapping technique tested to improve irregular heartbeat treatment

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

Inclusion Criteria: 1. Persistent atrial fibrillation documented on a 12 lead ECG, Holter monitor or implantable cardiac device within last 2 years of enrollment 2. Persistent atrial fibrillation is defined as a sustained episode lasting \> 7 days 3. Candidate for ablation based on current atrial fibrillation guidelines 4. Continuous anticoagulation with Vitamin-K-Antagonists or a NOAC for ≥4 weeks prior to the ablation; or a transesophageal echocardiography and/or CT scan that excludes left atrial thrombus ≤48 hours before the ablation procedure 5. Age of 18 years or older on the date of informed consent 6. Signed informed consent Exclusion Criteria: 1. Previous left atrial ablation or left atrial surgery 2. Left atrial diameter \>60 mm in the parasternal long axis 3. Patients with paroxysmal atrial fibrillation 4. Patients with persistent atrial fibrillation lasting \>3 years 5. AF due to reversible causes (e.g. hyperthyroidism, cardiothoracic surgery) 6. Intracardiac thrombus 7. Pre-existing pulmonary vein stenosis or pulmonary vein stent 8. Pre-existing hemidiaphragmatic paralysis 9. Contraindication to anticoagulation or radiocontrast materials 10. Prior mitral valve surgery 11. Severe mitral regurgitation or moderate/severe mitral stenosis 12. Myocardial infarction during the 3-month period preceding the consent date 13. Ongoing triple antithrombotic/anticoagulation therapy 14. Cardiac surgery during the 3-month interval preceding the informed consent date or scheduled cardiac surgery/ transcatheter aortic valve implantation 15. Significant congenital heart defect (including atrial septal defects or pulmonary vein abnormalities but not including a patent foramen ovale) 16. NYHA class III or IV congestive heart failure 17. Left ventricular ejection fraction (LVEF) \<35% 18. Hypertrophic cardiomyopathy (wall thickness \>1.5 cm) 19. Significant chronic kidney disease (eGFR \<30 ml/min) 20. Uncontrolled hyperthyroidism 21. Cerebral ischemic event (stroke or TIA) during the 6-month interval preceding the informed consent date 22. Ongoing systemic infections 23. History of cryoglobulinemia 24. Cardiac amyloidosis 25. Pregnancy (to exclude pregnancy a blood test (HCG) is performed in women \< 50 years before inclusion) 26. Life expectancy less than one year per physician opinion 27. Currently participating in any other clinical trial, which may confound the results of this trial 28. Unwilling or unable to comply fully with the study procedures and follow-up