Opposite trend after interim analysis

The study is aimed at testing the hypothesis whether atrial fibrillary rate (AFR), as a measure of atrial electrical remodeling assessed from surface ECG, is predictive of sinus rhythm maintenance after electrical cardioversion.

Earlier studies performed in a retrospective fashion suggested that high AFR exceeding 350-360 fibrillations per minute is an independent predictor of AF relapse after cardioversion, particularly in patients with duration of AF episode not exceeding 30 days, however this hypothesis has not been tested in a prospective study.

CASAF is an observational study that will enroll patients with short duration (< 30 days) AF admitted for electrical cardioversion. Admission ECG will be extracted in a digital format and processed off-line for estimation of AFR. AF relapse will be assessed during 6-weeks long follow-up period during which ECG control will be scheduled at week 1 and 6.

Inclusion Criteria:

• Recurrent AF verified by at least one ECG recording prior to the index admission
• Known onset of symptoms within 30 days from index admission.
• Sinus rhythm ECG within 30 days prior to the index admission If onset of symptoms is unknown.
• If duration of the present AF episode >48 hours then thromboembolic risk should be minimized by either verifying that the patient is adequately anticoagulated according to the hospital routine or TEE performed to verify the lack of contraindications for electrical cardioversion.
• Echocardiography at any time since first onset of AF to verify the lack of significant valvular disease.
• Age older than 18 years.

Exclusion Criteria:

• AF due to reversible cause or significant valvular heart disease
• Treatment with class I or III antiarrhythmic drugs within five half-lives of their elimination period. No amiodarone treatment within six months before admission
• Prior ablation of AF
• Unability to verify onset of symptoms within 30 days prior to the index admission

Patients with recent onset persistent atrial fibrillation admitted for cardioversion