This study will be a single blind prospective randomised control trial in patients undergoing ablation for the treatment of typical atrial flutter, with the aim of investigating the benefit of a new impedance-based computer software application which measures tissue contact between the ablation catheter and the inside of the heart.

The investigators hope to demonstrate that the use of this tissue contact information reduces ablation time, Xray time, and procedure time required to complete the procedure successfully. Study participants will be randomly assigned to undergo their procedure with or without this contact data displayed for the doctor performing the ablation to see. The acute procedural endpoint of ablation is successful conduction block across the cavotricuspid isthmus of the right atrium. If the outcome of this study is positive, it will have a significant beneficial impact on this procedure, reducing procedure length, patient discomfort, and potentially reducing risk for the patient, recurrent arrythmia symptoms, and the need for repeat procedures later on.

Patients in this study will be de novo cases of atrial flutter ablation, and they will be randomised to ablation using tissue contact data provided by the St. Jude medical ECI technology (active arm), or standard ablation as per physician practice, without the use of contact data to guide ablation (control arm). The endpoint measures will include RF ablation time, procedure time, time to achieving cavotricuspid isthmus block, the need for "touch up" ablation to achieve conduction block, the recurrence rate of isthmus conduction on isuprel infusion at 20 minutes post-isolation, and clinical recurrence of atrial flutter post-operatively.

Inclusion Criteria:

1. Patient is undergoing de novo cavotricuspid isthmus ablation.
2. Participant is willing and able to give informed consent for participation in the study.
3. Male or Female, aged 18 years or over

Exclusion Criteria:

(1) Previous percutaneous or open surgical procedure involving the right atrium