Background: The diagnosis of atrial fibrillation (AFIB) related cardiomyopathy relies on ruling out other causes for heart failure and on recovery of left ventricular (LV) function following return to sinus rhythm (SR). The pathophysiology underlying this pathology is multifactorial and not as completely known as the factors associated with functional recovery following the restoration of SR.

Objectives: To identify clinical and echocardiographic factors associated with LV systolic function improvement following electrical cardioversion (CV) or after catheter ablation in patients with reduced ejection fraction (EF) related to AFIB and normal LV function at baseline.

Methods: The study included patients with preserved EF at baseline while in SR whose LVEF had reduced while in AFIB and improved LVEF following CV. We compared patients who had improved LVEF to normal baseline to those who did not.

Results: Eighty-six patients with AFIB had evidence of reduced LV systolic function and improved EF following return to SR. Fifty-five (64%) returned their EF to baseline. Patients with a history of ischemic heart disease (IHD), worse LV function, and larger LV size during AFIB were less likely to return to normal LV function. Multivariant analysis revealed that younger patients with slower ventricular response, a history of IHD, larger LV size, and more significant deterioration of LVEF during AFIB were less likely to recover their EF to baseline values.

Conclusions: Patients with worse LV function and larger left ventricle during AFIB are less likely to return their baseline LV function following the restoration of sinus rhythm.