BACKGROUND: Atrial fibrillation seems to be a substantial contributor to otherwise not explained left ventricular systolic dysfunction. On the other hand atrial fibrillation is a frequent concomitant condition of cardiac diseases with impaired left ventricular function, e. g. ischaemic and dilated cardiomyopathy. Data on prevalence of arrhythmia-induced cardiomyopathy and predictors of recovery of left ventricular function after cardioversion are scarce.

METHODS: We retrospectively analysed 264 consecutive patients undergoing elective electrical cardioversion of atrial arrhythmia between January 1^st and December 31^st 2018. Of these patients, left ventricular ejection fraction (LVEF) and end-diastolic diameter (LVED), as well as biometric data and information on comorbidities were obtained. A LVEF of 45% or less was deemed a relevant left ventricular systolic dysfunction. Arrhythmia-induced cardiomyopathy alone or as a contributing factor among others was inferred if patients showed an improvement of LVEF of at least 5% after cardioversion. Statistical analyses were performed using MedCalc Statistical Software version 20.015 (MedCalc Software Ltd, Ostend, Belgium).

RESULTS: Echocardiographic assessment of left ventricular ejection fraction before cardioversion was available for 204 patients (34% female). 74 patients (36.3%, 21/74 female) had impaired left ventricular systolic function with a mean LVEF of 35.3% (95%CI 33.5-37.1%). Of the patients with complete follow up data 65.4% showed an improvement of LVEF of at least 5%. Patients with and without a relevant improvement of LVEF did not differ significantly regarding age (68.3+13.6yrs vs. 70.1+10.3yrs, p=0.612), sex (41.2% vs. 22.2% female, p=0.175), body mass index (30.7kg/m² vs. 29.4kg/m², p=0.562), CHA₂DS₂-VASc-Score (4.1 vs. 3.7, p=0.362), and LVED (52.8mm vs. 56.5mm, p=0.122). In a multivariate analysis only comorbid diabetes mellitus was inversely correlated with a relevant improvement of left ventricular systolic function.

CONCLUSIONS: Although we observed a trend towards younger and female patients with smaller end-diastolic left ventricular diameters being more likely to show a relevant improvement of left ventricular systolic function after elective electrical cardioversion of atrial arrhythmia, our study was presumably underpowered for these differences to reach statistical significance. Nevertheless, the relative paucity of data and the observed association of diabetes mellitus and limited recovery of left ventricular function after cardioversion warrant further studies.