A Study of the Effect of Exercise on Cardiac Hemodynamics After Adjusting Atrial-Ventricular and Interventricular Timing Delays in Patients with a CRT (Cardiac Resynchronization Therapy) Device


About this study

The purpose of this study is to determine the resuts of adjusting atrial-ventricular (AV) and interventricular (VV) timing delays on cardiac hemodynamics at rest and during exercise for patients who have a CRT (cardiac resynchronization therapy) device. Most current attempts to optimize CRT are done under resting conditions and patients report symptoms during mild daily exercise.

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

  • Heart failure patients 
  • Either already have a CRT device (≤ 3 mo.) or are undergoing clinically indicated CRT device implantation
  • Ages 30-80 years
  • Are able to perform very light exercise without orthopedic limitations 
  • Not morbidly obese (BMI>38)

Exclusion Criteria

  • Not able to perform light exercise with orthopedic limitations (and not morbidity obese)

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

Rochester, Minn.

Mayo Clinic principal investigator

Bruce Johnson, Ph.D.

Closed for enrollment

More information


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