Atrial Fibrillation Trial to Evade Recurrence: effectS of Hiit Before electrO-Cardioversion for 3-weeKs (AFTERSHOCK)

Atrial Fibrillation Trial to Evade Recurrence: effectS of Hiit Before electrO-Cardioversion for 3-weeKs

This is a study looking at the feasibility of conducting a larger definitive research trial looking at the effectiveness of high intensity interval training in individuals who are scheduled for electro-cardioversion. Usual care for these participants is to go home and continue with their typical daily routine. The investigators will test whether participating in 3-weeks of thrice-weekly high intensity interval training before electro-cardioversion can lengthen the time to recurrence of atrial fibrillation after electro-cardioversion in these individuals. Participants will be asked to come to the University of Ottawa Heart Institute for a baseline visit at which fitness (cycle ergometer), body composition (weight, height, waist circumference and percentage body fat), heart rate variability and habitual exercise levels will be measured. Participants will then be randomized to either the exercise group or the usual care group. Those randomized to the usual care group will go home for 3-weeks and continue with their typical daily routine. Those randomized to the exercise group will return to the Heart Institute three times per week for 3-weeks to participate in a high intensity interval training program prior to their electro-cardioversion. All participants will be asked to measure daily heart rate and rhythm using the AliveCor system which is compatible with their Smartphones, for up to 12-months following their electro-cardioversion. All participants will be asked to return at 3-weeks (and prior to their electro-cardioversion) to measure fitness (cycle ergometer), body composition (weight, height, waist circumference and percentage body fat), and habitual exercise levels. The entire study should last approximately 24-months. Participants will be involved for 52-weeks. The investigators are looking to recruit 20 participants total for the feasibility trial. The investigators hypothesize that recruitment rates, drop-out rates, and adherence to the intervention will support a larger definitive trial.

This is a study looking at the feasibility of conducting a larger definitive research trial looking at the effectiveness of high intensity interval training on lengthening time to recurrence of persistent atrial fibrillation in individuals who are scheduled for electro-cardioversion. Usual care for these participants is to go home and continue with their typical daily routine until their scheduled cardioversion. The investigators will test whether participating in 3-weeks of thrice-weekly high intensity interval training before electro-cardioversion can lengthen the time to recurrence of atrial fibrillation after electro-cardioversion in these individuals. Participants will be asked to come to the University of Ottawa Heart Institute for a baseline visit at which fitness (cycle ergometer), body composition (weight, height, waist circumference and percentage body fat), and habitual exercise levels will be measured. Participants will then be randomized to either the exercise group or the usual care group. Those randomized to the usual care group will go home for 3-weeks and continue with their typical daily routine. Those randomized to the exercise group will return to the Heart Institute three times per week for 3-weeks to participate in a high intensity interval training cycle ergometer program prior to their electro-cardioversion. All participants will be asked to return at 3-weeks (and prior to their electro-cardioversion) to measure fitness (cycle ergometer), body composition (weight, height, waist circumference and percentage body fat), and habitual exercise levels. Following the electro-cardioversion, all participants will be asked to measure daily heart rate and rhythm using the AliveCor system which is compatible with their Smartphones/tablets/iPads, for up to 12-months or until they return to persistent atrial fibrillation. The entire study should last approximately 24-months. Participants will be involved for a maximum of 52-weeks. The investigators are looking to recruit a total of 20 participants for the feasibility trial. The investigators hypothesize that recruitment rates, drop-out rates, and adherence to the intervention will support a larger definitive trial.

Participants in the HIIT group will receive 3-weeks of tri-weekly supervised exercise sessions at the University of Ottawa Heart Institute prior to their scheduled electro-cardioversion. The session will last 23 minutes in duration and consist of a 2-minute warm-up at 50% of peak power output (PPO), 2 x 8-minute interval training blocks of 30 seconds at 80-100% of PPO interspersed with 30-seconds of active recovery and a 1-minute cool down at 25 % of PPO. The sessions will be lead by a Registered Kinesiologist.

Participants assigned to the control group will have usual care, which involves no behavioural interventions leading up to their electro-cardioversion.

Participants in the HIIT group will receive 3-weeks of tri-weekly supervised exercise sessions at the UOHI prior to their scheduled electro-cardioversion. The session will last 23 minutes in duration and consist of a 2-minute warm-up at 50% of peak power output (PPO), 2 x 8-minute interval training blocks of 30 seconds at 80-100% of PPO interspersed with 30-seconds of active recovery and a 1-minute cool down at 25 % of PPO. The sessions will be lead by a Registered Kinesiologist.

Time to recurrence will be measured with a daily ECG recording up to 52-weeks from randomization, using the AliveCor system and Smartphone.

Participants will also be asked to complete a questionnaire related to habitual physical activity (modified Godin) at baseline and follow-up. The modified Godin asks participants to recall the last 7 days and report the number of days and the number of minutes per day they participated in mild, moderate and vigorous bouts of physical activity. These values are then multiplied together to calculate minutes/week of mild physical activity and minutes/ week of moderate-to-vigorous intensity physical activity.

Participants will complete a CPET at baseline and 3-weeks to assess fitness level using a pre-determined protocol on a cycle ergometer (Oxycon mobile, CareFusion, USA).

Inclusion Criteria: Persistent atrial fibrillation Eligible and scheduled for electro-cardioversion at UOHI Rate controlled with a resting ventricular rate of equal to or less than 100bpm Between 18-85 years of age Owns a Smartphone Physically able to participate in exercise Willing and able to provide written, informed consent Willing and able to return for follow-up visits Willing and able to provide daily ECG recordings using the AliveCor system for the duration of the study. Exclusion Criteria: Participating in routine exercise training (more than two times per week) in the past 3 months Atrial Flutter secondary to ablation Unstable angina Diagnosed with severe mitral or aortic stenosis, hypertrophic obstructive cardiomyopathy Pregnant, lactating or planning to become pregnant during the study period Diagnosed with rheumatic heart disease