This prospective randomized pilot study aims to evaluate the impact of aggressive life style modification in terms of calorie-controlled diet and supervised exercise on outcome of catheter ablation in overweight and obese patients with atrial fibrillation.

Hypothesis: Weight loss and management by adoption of strict diet and exercise regimen improves the chances of freedom from recurrence following catheter ablation.

Objective: To examine the impact of a planned life-style modification program including calorie-controlled diet and supervised exercise before and after the AF ablation on quality of life (QoL) and long-term arrhythmia recurrence in overweight and obese patients with atrial fibrillation.

Endpoints:

Primary: AF recurrence following index ablation procedure It will be assessed at 3, 6 and 12 months after the procedure by event recorders, 12-lead ECG and Holter monitoring Any episode of AF/AFL/AT > 30 sec will be considered as a recurrence. Episodes that occur during the first 3 months after the procedure (blanking period) will not be considered as recurrence.

Secondary:

1. Change in QoL It will be evaluated by a validated AF specific questionnaire (AFEQT) at baseline and 6 and 12 months post-procedure
2. Change in AF symptom severity. This will be measured by AF symptom severity and burden questionnaire at baseline and 6 and 12 months post-procedure

DIET:

Participants in the intervention group will receive individual counseling sessions with an experienced dietitian, who will prepare personalized diet plan based on their comorbidities and preferences.

To accomplish weight loss, the diet menu will be planned to reduce daily food intake by ≥ 500 calories depending on their baseline body weight.

Patients enrolled in the control group will be provided advice on heart-healthy diet and active life style.

EXERCISE:

Supervised and monitored exercise will be conducted in St. David's Cardiac Rehabilitation for 3 months starting before or 7-10 days after the ablation.

After ablation, patients will continue individualized home-exercise program for 1 year.

QoL Survey:

The AF Effect on Quality of Life survey (AFEQT) questionnaire will be used at baseline and 6 and 12 months post procedure.

Symptom Severity Survey:

This will be measured by AF symptom severity and burden questionnaire at baseline and 6 and 12 months post-procedure

Inclusion Criteria:

1. Age: > 18 years
2. AF patient undergoing first catheter ablation, at least 3 months after the enrollment
3. BMI: ≥ 26-40
4. Willing to be compliant with the weight-reduction program
5. Willing to provide informed, written consent

Exclusion Criteria:

1. Chronic obstructive lung disease (COPD)
2. Participation in another weight loss program in < 3 months
3. Musculoskeletal conditions limiting exercise capacity
4. Insulin-dependent diabetes
5. Severe valvular heart disease or cardiomyopathy
6. Heavy drinking (>14 standard drinks/week for men and >7/ week for women)
7. Inability to provide informed consent

A total of 50 consecutive AF patients with BMI 26-40, will be enrolled in this pilot study and randomized to 2 groups in a 1:1 design (25 per group).