This is a prospective, single center, non-randomized, open-label, single arm study in which we will gather data and physician input for the assessment and further development of the KODEX - EPD functions for assessing tissue pressure, tissue thickness, lesion transmurality.

This is a prospective, single center, non-randomized, open-label, single arm study in which we will gather data and physician input for the assessment and further development of the KODEX - EPD functions for assessing tissue pressure, tissue thickness, lesion transmurality. The study will include up to 30 subjects. We will enroll patients with atrial flutter and patients with atrial fibrillation who are scheduled to undergo RF ablation of the cavotricuspid isthmus (CTI). Both male and female subjects who meet all eligibility criteria and give written informed consent will be enrolled in the study. We will be assessing the feasibility of the KODEX-EPD tissue pressure (TP), tissue thickness and lesion transmurality applications.

Inclusion Criteria:

1. Subject must be aged >18 years.
2. Subject must have signed a written Informed Consent form to participate in the study, prior to any study related procedures.
3. Subject must be willing to comply with the protocol requirements.
4. A female subject is eligible if not of child bearing potential or has a negative pregnancy test within the previous 7 days.
5. Subject is deemed amenable to therapeutic ablation for atrial flutter or atrial fibrillation.

Exclusion Criteria:

1. Any planned surgical or endovascular intervention within 30 days before or after the index procedure.
2. Subject is enrolled in another drug or device study protocol that has not reached its primary endpoint.
3. Patient had experienced previous stroke (TIA or CVA).
4. Thrombi detected in the heart.
5. Known marked valvular insufficiency (moderate-severe and severe)
6. Life expectancy less than 12 months.
7. Known severe renal insufficiency (stages G4 and G5, characterized by severe reduction in GFR [15-29 ml/min/1.73 m2] and GFR [<15 ml/min/1.73 m2], respectively).
8. Subjects that according to the clinical judgment of the caring physician do not fit for the study.
9. Previous right atrial ablation procedure or cardiac ablation procedure performed within 90 days prior to enrollment.

Patients with Atrial Flutter and patients with Atrial Fibrillation scheduled to undergo RF ablation of the cavotricuspid isthmus (CTI). Both male and female subjects who meet all eligibility criteria and give written informed consent will be enrolled in the study.