Abstract 13542: Electrical Delay, LA Electromechanical Delay, and LA Volume Contribute to Increased LA Stiffness in Relatively Elderly Patients With Pulmonary Vein Isolation for Atrial Fibrillation

Abstract

Background: Atrial dysfunction occurs after pulmonary vein isolation (PVI) for atrial fibrillation (AF), and some reports suggest that electrical conduction delay (ECD) via the Bachmann bundle could be a contributing factor. However, the relationship between ECD in the atria and LA function after PVI remains unclear. The LA reservoir strain (LARS) by speckle-tracking echocardiography (STE) is used to assess LA booster function, with a decrease indicating increased LA stiffness. Purpose: We aim to investigate ECD, LA electromechanical delay (LAEMD), and LA function in patients after PVI for AF. Methods: This single-center retrospective study included 74 patients (Mean age at 70.4 ± 9.1 years, 44 males, left ventricular ejection fraction (LVEF): 62.9 ± 6.8 %, LA volume index: LAVI 39.0 ± 10.8 ml/m 2 ) who were in sinus rhythm at the echocardiographic examination. ECD on the ECG was defined as the presence of biphasic P waves, which were classified into those not observed (group A; n=42), those observed only in III lead (group B; n=23), and those observed in all lower wall leads (II, III, aVF) (group C; n=9). LAEMD was defined as the time interval between the top of the R wave on the ECG and the start of the late diastolic wave (a') on the tissue doppler imaging, and the lateral (a' lateral) and septum (a' septum) time differences (a’ sep-lat time) were calculated. To evaluate the LA function, two-dimensional STE was analyzed. Results: Mean observation period was 19.2 months after PVI. Groups B and C showed significant differences in a' sep-lat time compared to group A. LARS was markedly reduced in all groups (average: 19.0 ± 6.3). LARS and LAVI showed a significant difference between groups A and C. Multivariate analysis of factors leading to LARS showed correlations with a', E/e'. Conclusion: These results suggest that in relatively elderly post-PVI AF patients with preserved LVEF, the ECD and LAEMD as well as LAVI may affect LA function long after PVI and contribute to increased LA stiffness.