415 The Immediate Impact of Electrical Cardioversion on Right Ventricular Systolic Function in Patients With Non-Valvular Atrial Fibrillation

Abstract

Successful electrical cardioversion (ECV) for atrial fibrillation (AF) is often followed by a transient period of atrial stunning, where depressed mechanical atrial function persists despite reversion to sinus rhythm (SR). Left ventricular (LV) changes following ECV are well characterised, but knowledge of early changes to right ventricular (RV) function is lacking. We aimed to assess the immediate impact of ECV on right heart function. Patients referred for ECV with non-valvular AF between Jan 2017 to Jan 2018 were assessed. Patients without history of heart failure, normal left ventricular ejection fraction, and who successfully reverted to SR following ECV were prospectively recruited. RV metrics of systolic function including 2-dimensional RV free wall longitudinal strain (RV-FWLs) was measured offline from transthoracic echocardiogram images obtained prior to and immediately following ECV (TomTec Imaging system). Of 50 patients (64.14±11.01yrs, 60% male) assessed, 28% had a history of ischaemic heart disease and 5% had obstructive sleep apnoea. Paired T-test analysis showed a significant improvement in RV-FWLs (pre-ECV: 14.18±4.42 vs post-ECV: 21.02±6.80; p<0.01) and RV-FAC (pre-ECV: 36.77±8.85 vs post-ECV: 40.80±10.16; p=0.02) following ECV. Based on a cut-off value of ≥23% for RV-FWLs, 10% of the cohort had normal RV-FWLs pre-ECV which significantly increased to 36% post-ECV (p<0.01). A similar trend was observed with RV-FAC (cut-off value of ≤35%), although not statistical significant (pre-ECV: 60% normal RV-FAC, post-ECV: 74% normal RV-FAC; p=0.17). Improvements in RV-FWLs and RV-FAC was observed following ECV, suggesting that there are immediate improvements in RV function in this population.