Risk of Stroke and Silent Cerebrovascular Thromboembolism After Cardioversion of Atrial Fibrillation

Does Cardioversion of Atrial Fibrillation Increase the Risk of Stroke and Silent Cerebrovascular Thromboembolism? Comparison of the Two Cardioversion Methods

Patients with atrial fibrillation undergoing cardioversion will be randomized to undergo transesophageal echocardiography or they will receive warfarin for 3 weeks with an international normalized ratio (INR) value between 2.0-3.0. Those who do not want to use warfarin will be given an approved new oral anticoagulant agent instead of warfarin for 3 weeks.

If thrombus is detected in left atrium or in left atrial appendage, no cardioversion will be performed. Other patients in the both groups will undergo electrical cardioversion. After the procedures all the patients will be given oral anticoagulant for at least 4 Weeks. All patients will have neurological examination and diffusion magnetic resonance imaging (MRI) at baseline and at postprocedural 7th day. Clinical and subclinical cerebral thromboembolic events detected by diffusion MRI will be recorded. Any bleeding events will also be recorded.

Inclusion Criteria:

• Patients with the age of more than 18 years who are planned to undergo electrical or medical cardioversion

Exclusion Criteria:

• Urgent cardioversion
• Patients who have implanted pace-makers or other metal devices
• Claustrophobia
• Hematological disorders disabling patients to receive anticoagulant agents
• Atrial fibrillation secondary to temporary causes.
• Serious rheumatic heart valve disease
• Hyperthyroidism
• History of malignancy
• Left atrium diameter > 55 mm
• Ejection fraction < 0.25