RHythmia mAPping and Signal acquisitiOn for Data analYsis (RHAPSODY)

Inclusion Criteria:

1. Age 18 or above, or above legal age and willing and capable of giving informedconsent specific to national law

2. Scheduled for standard of care catheter-based endocardial mapping for atrial orventricular tachyarrhythmias using a commercial Rhythmia Mapping System.

Exclusion Criteria:

1. Prothrombotic or bleeding tendency due to coagulopathy or blood dyscrasia

2. Inability to tolerate heparin therapy (e.g. heparin induced thrombocytopenia,allergy, etc.)

3. Prosthetic or stenotic valves in the chamber where the intended mapping will occur,or in the path of the catheter access route

4. Active systemic infection or sepsis

5. Hemodynamic instability or shock at baseline precluding ablation in the assessmentof the investigator.

6. Presence of intracardiac thrombus, tumor, or other abnormality which precludescatheter introduction

7. Women who are pregnant or lactating

8. Cardiac surgery within the past 90 days

9. Acute myocardial infarction within 3 months

10. Stable/unstable angina or ongoing myocardial ischemia

11. Subjects with an active heart failure decompensation

12. Long QT Syndrome, Brugada Syndrome, or Torsade de Pointes

13. Congenital heart disease with or without corrective surgery that would complicate amapping procedure

14. Subjects having untreatable allergy to contrast media

15. Vascular pathology or tortuosity precluding standard vascular access techniques

16. Subjects who are currently enrolled in another investigational study or registrythat would directly interfere with the current study, except when the patient isparticipating in a mandatory governmental registry, or a purely observationalregistry with no associated treatments. Each instance should be brought to theattention of the sponsor to determine eligibility.