Exercise-induced Cardioversion in Persistent Atrial Fibrillation

Atrial fibrillation (AF) is one of the most common heart rhythm disorders worldwide. The estimated prevalence of AF in Europe is approximately 2% in the general population and increases with age, reaching 16-24% in individuals aged > 85 years. AF is significantly associated with an increased risk of heart failure, ischemic stroke, cognitive impairment, vascular dementia, and death. Aside from patient suffering, AF is a large economic burden for the healthcare system, where hospitalization is the major driver, accounting for 50-70% of the annual direct costs. Management of patients with AF is multifaceted. The main components include comorbidity and risk factor management (targeting hypertension, diabetes, heart failure), avoidance of stroke and thromboembolism, and reduction of symptoms through rate and rhythm control.

AF episodes may terminate spontaneously, and if they do so within seven days, they are classified as paroxysmal AF. Persistent AF is defined as AF episodes that are not self-terminating. Rhythm control, which involves restoring and maintaining sinus rhythm, is an important part of the management of patients with atrial fibrillation, where the main reason is to reduce symptoms of AF. One alternative treatment is electrical cardioversion (EC), which involves delivering low-energy shocks to the heart in a sedated patient to restore a normal sinus rhythm. A poorly tested alternative to EC in cardioversion is to physically increase the heart rate. In a small observational study, Gates et al. included 18 patients with AF scheduled for EC. The patients underwent a treadmill exercise test, and five (27.8%) converted to sinus rhythm during exercise. None of the patients who failed to convert to sinus rhythm with exercise did so spontaneously before electrical conversion 3 hours to 7 months later. Exercise tests are considered safe when contraindications are adhered to, termination criteria are observed, and appropriately trained personnel administer the tests.

Although EC is effective, it involves hospitalization, anesthesia, and the associated costs and risks. If exercise testing proves to be effective for converting AF to sinus rhythm, it could improve arrhythmia management by offering a non-invasive, cost-effective alternative that empowers patients to manage their condition through home-based programs. This approach not only would reduce hospital dependence and healthcare costs but also enhance cardiovascular fitness and overall quality of life.

Inclusion criteria

• Adults (18-75 years) with persistent AF
• planned for EC
• with at least 3 weeks of therapeutic oral anticoagulation before intervention

Exclusion criteria

• Unable to perform a symptom limited cycle exercise test
• Ischemic heart disease
• Heart failure
• Severe valvular disease
• Unable to speak and write Swedish language
• Unable to provide written, informed consent