Dipole Density Mapping in Supraventricular Tachycardia

Inclusion Criteria 1. Be aged 18-75 years 2. Be scheduled for ablation of an SVT due to the arrhythmia being recurrent, poorly tolerated, and /or unable to be controlled with antiarrhythmic drugs. 3. Be able and willing to give informed consent Exclusion Criteria 1. Have any of the following: * implanted prosthetic, artificial, or repaired cardiac valves in the chamber being mapped * permanent pacemaker or ICD leads in the chamber being mapped * hypercoagulopathy or an inability to tolerate anticoagulation during the procedure * Stents in the area of the pulmonary veins (Study CL-SVT-004 ONLY) 2. MI within the prior two (2) months 3. Cardiac surgery within the prior three (3) months 4. Intracardiac thrombus 5. Clinically significant tricuspid and/or mitral valve regurgitation or stenosis 6. Cerebral ischemic event (including TIA) in the prior six (6) months 7. Pregnant or nursing 8. Currently enrolled in another clinical investigation 9. Have a contraindication for transfemoral venous access (Study CL-SVT-004 ONLY) 10. Have a contraindication for transseptal left atrial access (for patients with left atrial arrhythmias) (Study CL-SVT-004 ONLY) 11. Life expectancy of less than one (1) year (Study CL-SVT-004 ONLY) 12. Any health condition that, in the Investigator's opinion, would not allow the application of the investigational device (Study CL-AF-004 ONLY) NOTE: The additional exclusion criteria for CL-SVT-004 were not expected to alter or bias the patient selection for study enrollment. While these criteria would have been assumed by other investigators as a standard of care for safe enrollment in a clinical study, the German EC approval required the additional statements.