Rapid improvement in left ventricular function after sinus rhythm restoration in patients with idiopathic cardiomyopathy and atrial fibrillation.

AIMS: Sinus rhythm restoration (SRR) in patients with atrial fibrillation (AF) and heart failure may improve systolic function and impact on consecutive clinical management, but time course and potential predictors of response to SRR are uncertain. METHODS AND
RESULTS: We prospectively studied 50 consecutive patients who presented in heart failure with reduced ejection fraction (EF) and concomitant AF. After exclusion of valvular and coronary artery disease patients underwent electrical cardioversion. Serial echocardiography, cardiac magnetic resonance imaging (cMRI), and 24-h electrocardiograms were performed at baseline, and on Days 3 and 40 following SRR. Baseline left ventricular EF of the study population (76% male, age 69 ± 11 years) was 30 ± 7%. Sustained SRR (≥3 days) significantly improved EF (Day 3: 43 ± 7%, n = 46; Day 40: 53 ± 9%, n = 34; P < 0.001) as quantified by echocardiography. Comparable results were obtained using cMRI (baseline: 29 ± 8%; Day 3: 42 ± 9%). Three patients showed no response to SRR (EF improvement <15%). The percentage of patients meeting current criteria for implantable cardioverter-defibrillator (ICD) implantation for primary prevention dropped from 76% (n = 38) to 11% (n = 3) on Day 40 following SRR. No specific clinical or echocardiographic factor predicting improved EF after SRR could be identified.
CONCLUSION: The majority of patients presenting with non-ischaemic, non-valvular heart failure with reduced EF and concomitant AF show a significant and rapid improvement in EF following SRR. An attempt at SRR and reassessment of the need for ICD implantation after 40 days may be warranted in all such patients. Published on behalf of the European Society of Cardiology. All rights reserved.