Cavo-Tricuspid Isthmus Block Durability After Pulsed Electric Field Ablation

Inclusion Criteria: * patients with paroxysmal AF undergoing PVI by PEF energy with documented typical atrial flutter or patients with persistent AF in whom catheter ablation of CTI is planned as a part of a complex procedure * Age ≥ 18 years at the time of study enrollment * Signed informed consent Exclusion Criteria: * \- LA diameter \> 65 mm (measured in the parasternal long-axis view) * History of CTI ablation in the past * History of cardiac valve surgery * Significant valvular defect * Age below 18 years * Pregnancy, breastfeeding * Any disease with a life expectancy \<1 year * Uncorrected congenital heart disease or valvular obstruction * Active myocarditis * Untreated hypothyroidism or hyperthyroidism * Recipient of any major organ transplant (e.g., lung, liver, heart) * HIV positivity with a survival expectancy of less than five years due to HIV * Chronic dialysis treatment * Unwillingness to participate.