Acute Responses to Exercise in Females and Males With Symptomatic Atrial Fibrillation (ACUTE-AF)

April 29, 2026 updated by: Ottawa Heart Institute Research Corporation

Feasibility of Examining Acute Responses to Exercise in Symptomatic Females and Males With Atrial Fibrillation: a Pilot Randomized Crossover Study

The main purpose of this pilot project is to measure the feasibility of conducting a randomized crossover study examining short-term changes in atrial fibrillation (AF) symptoms in symptomatic females and males with paroxysmal or persistent AF when they engage in a standard week of exercise (i.e. moderate-intensity continuous training [MICT] or high-intensity interval training [HIIT]) compared to a control week (i.e. no moderate to vigorous exercise over 7 days).

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Exercise training (e.g. 8 to 12-week exercise programs) has been shown to improve cardiorespiratory fitness and QoL, and reduce atrial fibrillation (AF) symptoms and time in AF in patients with AF. However, regular exercise participation is hindered by patient concerns regarding an increase in AF symptoms and episodes during or following an exercise session. Patients with AF also worry about potential negative consequences of increasing heart rate during exercise. This fear may be sex-specific as females report more AF symptoms at rest, experience faster heart rates during exercise and AF, and report greater symptoms of fear/anxiety than males. How exercise acutely changes AF symptoms remains to be examined.

The main purpose of this pilot project is to measure the feasibility of conducting a randomized crossover study examining short-term changes in AF symptoms in symptomatic females and males with paroxysmal or persistent AF when they engage in a standard week of exercise (i.e. moderate-intensity continuous training [MICT] or high-intensity interval training [HIIT]) compared to a control week (i.e. no moderate to vigorous exercise over 7 days). As secondary outcomes we will explore sex differences in short-term changes in AF symptoms (self reported with a questionnaire) and AF status (device measured with a wireless four-finger AliveCor KardiaMobile ECG) when symptomatic patients with AF engage in a standard week of exercise (i.e. HIIT, MICT) compared to a control week. Results from this pilot study will provide novel insight into the typical acute response to exercise in females and males with AF, and will inform appropriate approaches for the conduct of a future larger trial. This work is key to informing practitioners and patients of the typical acute exercise response in the AF population with the goal of facilitating exercise prescription and participation.

Study Type

Interventional

Enrollment (Estimated)

36

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Canada
    • Ontario
      • Ottawa, Ontario, Canada, K1Y4W7
        • Recruiting
        • University of Ottawa Heart Institute
        • Contact:
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

40 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Paroxysmal and Persistent AF
  • Rate controlled (resting ventricular rate <110 bpm)
  • Able to do a symptom limited exercise test
  • At least 40 years of age
  • Self-reports being symptomatic in the past 4 weeks
  • If female, self-reports being post-menopausal
  • Able to read and understand English or French
  • Agrees to sign informed consent

Exclusion Criteria:

  • Currently participating in routine exercise training
  • Unstable angina or uncontrolled diabetes mellitus; or established diagnosis of severe mitral or aortic stenosis, or hypertrophic obstructive cardiomyopathy with significant obstruction
  • Unable to access the Internet or a phone (iPhone and iPad require iOS version 10.0 and up, Android requires version 6.0 and up) during the study period
  • Has an automated external defibrillator, an implantable cardioverter defibrillator or other types of pacemaker
  • Unwilling or unable to complete the three conditions
  • Unable to provide written, informed consent

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Moderate Intensity Continuous Training (MICT)
Participants will do 3 sessions of moderate-intensity continous exercise training over 7 days
Behavioral: Moderate-intensity continuous training (MICT)
Participants will engage in exercise and record AF symptoms prospectively over 7 days
Experimental: High Intensity Interval Training (HIIT)
Participants will do 3 sessions of high-intensity interval training over 7 days
Behavioral: High-intensity interval training (HIIT)
Participants will engage in exercise and record AF symptoms prospectively over 7 days
No Intervention: Rest
Participants will abstain from doing moderate- to high-intensity interval training over 7 days

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Feasibility of the pilot study - Recruitment and consent rate
Time Frame: Through study completion, an average of 1.5 years
Through study completion, an average of 1.5 years
Feasibility of the pilot study - Participant fidelity
Time Frame: During the week of HIIT and MICT (2 weeks)
E.g. ability of participants to comply with the exercise prescription, number of exercise sessions attended
During the week of HIIT and MICT (2 weeks)
Feasibility of the pilot study - Study retention
Time Frame: Through study completion, an average of 1.5 years
Dropout rate of participants
Through study completion, an average of 1.5 years
Feasibility of the pilot study - Study eligibility refinement
Time Frame: Through study completion, an average of 1.5 years
Data to refine inclusion and exclusion criteria for a larger trial will be used by balancing safety, ability to complete the intervention, and generalizability (e.g. is an exclusion criterion of threshold of participation in >2 structured exercise sessions/week sufficient or restrictive?)
Through study completion, an average of 1.5 years
Feasibility of the pilot study - Adverse events
Time Frame: Through study completion, an average of 1.5 years
Side effects and adverse events during the study
Through study completion, an average of 1.5 years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
AF symptoms self-reported with a 7-day patient symptom questionnaire
Time Frame: 3 weeks (1 week of HIIT, 1 week of MICT, 1 week fo rest)

Secondary objectives will explore sex differences in short-term changes in AF symptoms when symptomatic females and males with AF engage in a standard week of exercise (MICT or HIIT), compared to a control (rest) week.

Participants will report AF symptoms prospectively during each condition. They will complete a 7-day questionnaire during MICT, a 7-day questionnaire during HIIT and a 7-day questionnaire during the rest week.
3 weeks (1 week of HIIT, 1 week of MICT, 1 week fo rest)
AF status measured daily with a KardiaMobile device
Time Frame: 3 weeks (1 week of HIIT, 1 week of MICT, 1 week fo rest)

Secondary objectives will explore sex differences in short-term changes in AF status when symptomatic females and males with AF engage in a standard week of exercise (MICT or HIIT), compared to a control week.

AF status will be measured with a Kardiamobile AliveCor wireless device. Participants will be asked to record 3 x 30-second ECGs a day (morning, afternoon, evening) during each condition (MICT, HIIT and rest). The ECG recording will allow the identification of whether the participant is in sinus rhythm or in atrial fibrillation.
3 weeks (1 week of HIIT, 1 week of MICT, 1 week fo rest)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Ottawa Heart Institute Research Corporation

Investigators

  • Principal Investigator: Jennifer Reed, PhD, Ottawa Heart Institute Research Corporation

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 8, 2022

Primary Completion (Estimated)

April 1, 2027

Study Completion (Estimated)

April 1, 2027

Study Registration Dates

First Submitted

September 13, 2021

First Submitted That Met QC Criteria

October 7, 2021

First Posted (Actual)

October 20, 2021

Study Record Updates

Last Update Posted (Actual)

May 6, 2026

Last Update Submitted That Met QC Criteria

April 29, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 20210524-01H

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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