About this study

The purpose of this study is to evaluate the safety and effectiveness of a hybrid sinus node sparing ablation procedure for the treatment of symptomatic drug refractory or drug intolerant inappropriate sinus tachycardia (IST).

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  • Age ≥ 18 years and ≤ 75 years at time of enrollment consent.
  • Subject has a diagnosis of IST:
    • Documentation of mean heart rate > 90bpm with 7-day monitor within 90 days of the Index Procedure; and
    • Documentation of a resting heart rate of > 100bpm; and
    • Documentation of presence of IST for at least 6-months; and
    • Documentation of absence of other tachycardia; and
    • Documentation of absence of secondary causes such as hormonal issues or systemic illness that might contribute to increased heart rate.
  • Documentation of refractoriness (intolerance or failure) of a drug (e.g., rate control drugs such as beta-blockers/calcium channel blockers, ivabradine), and/or AADs.
  • Subject is willing and able to provide written informed consent.

Exclusion Criteria:

  • Subjects on whom cardiac surgery or single lung ventilation cannot be performed.
  • Subjects with indication for or existing ICDs/Pacemakers.
  • Presence of channelopathies.
  • Previous cardio-thoracic surgery.
  • Left Ventricular Ejection Fraction (LVEF) < 50%.
  • Body Mass Index (BMI) ≥ 35.
  • Presence of supraventricular or ventricular tachycardia.
  • Presence of Postural Orthostatic Sinus Tachycardia (POTS).
  • Presence of congenital heart disease.
  • History suggestive of secondary cause of tachycardia such as pheochromocytoma, anemia, thyrotoxicosis, chronic fever of unknown origin, COPD, long-term bronchodilators use, severe asthma or carcinoid syndrome.
  • Subjects who have had a previous catheter ablation in the right atrium for IST or other disorders:
    • Allowed catheter ablations in the right atrium:
    • One previous catheter ablation > 90 days prior to the Index Procedure for AVRT or CTI;
    • One previous catheter ablation > 180 days prior to the Index Procedure for AVNRT.
  • Life expectancy < 24 months
  • Pregnant or planning to become pregnant during trial
  • Subjects with substance abuse
  • Subjects with previous weight loss surgery
  • Subject is unwilling and/or unable to return for scheduled follow-up visits
  • Current participation in another clinical investigation of a medical device or a drug, or recent participation in such a trial that may interfere with trial results
  • Not competent to legally represent him or herself (e.g., requires a guardian or caretaker as a legal representative) and;
  • Presence of other anatomic or comorbid conditions, or other medical, social, or psychological conditions that, in the investigator's opinion, could limit the subject's ability to participate in the clinical investigation or to comply with follow-up requirements, or impact the scientific soundness of the clinical investigation result

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 8/25/23. Questions regarding updates should be directed to the study team contact.

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Ammar Killu, M.B.B.S.

Open for enrollment

Contact information:

CVRU Heart Rhythm Services Research Team

(507) 255-0774

More information


Publications are currently not available

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