Supplementary Material for: Right heart structure and function after electrical cardioversion for atrial fibrillation

Introduction: Atrial fibrillation (AF) adversely impacts right ventricular (RV) and right atrial (RA) structure and function. There is limited data on these changes after electrical cardioversion (ECV) and the relative contribution of heart rate. To evaluate the immediate (1-2 hours) and short-term (4-6 weeks) changes in right cardiac chamber dimensions and RV function after ECV in patients with persistent AF. Methods: RV and RA dimensions and RV function were measured in 64 patients using transthoracic echocardiography 1-2 hours before, immediately after, and 4-6 weeks after ECV. Associations between changes in right heart measures and rhythm status at follow-up were assessed using linear regression models. Results: For patients who remained in sinus rhythm 4-6 weeks after ECV (n=48), fractional area change (FAC) at baseline, immediately after ECV, and 4-6 weeks after ECV were 39(35-42)%, 42(39-46)%, 46(43-49)% (p<0.01); tricuspid annular plane systolic excursion (TAPSE) values at the same time points were 18(17-20)mm, 20(18-23)mm and, 24(22-26)mm (p<0.01), respectively. There was no significant difference in RV end systolic area and RA volume index before and after ECV. However, RV end systolic area and RA volume index decreased significantly after 4-6 weeks from 10(8-13)cm2 to 8(7-10)cm2 (p<0.01), and from 30(24-36) ml/m² to 24(20-27) ml/m² (p<0.01). Changes in FAC and TAPSE were significantly associated with sinus rhythm at follow-up (β coefficient: 9.19; 95% CI: 3.89-14.5; p<0.053 and 5.74; 95% CI: 2.81-8.66; p=0.027), this was not true for RA measures (β coefficient: 2.01; 95% CI: -6.65-10.67; p=0.64). Conclusions: Among AF patients who remained in sinus rhythm after ECV, RV function improved immediately after ECV with a further improvement at 4-6 weeks following sinus rhythm restoration.