Research Article Relationship of Natriuretic Peptides with Left Atrial Structure and Function within 1 Month after Electrical Cardioversion in Patients with Persistent Atrial Fibrillation Rasa Karaliute , 1,2 Justina Jureviciute, 2 Julija Jurgaityte, 2 Giedre Stanaitiene, 2 Vaida Mizariene, 2 Tomas Kazakevicius, 2 Daiva Urboniene, 3 and Ausra Kavoliuniene 2 1 Laboratory of Behavioral Medicine, Neuroscience Institute, Medical Academy, Lithuanian University of Health Sciences, Kaunas LT-50161, Lithuania 2 Department of Cardiology, Medical Academy, Lithuanian University of Health Sciences, Kaunas LT-50161, Lithuania 3 Department of Laboratory Medicine, Medical Academy, Lithuanian University of Health Sciences, Kaunas LT-50161, Lithuania Correspondence should be addressed to Rasa Karaliute; rasa.karaliute@lsmuni.lt Received 31 December 2018; Revised 17 February 2019; Accepted 20 February 2019; Published 17 March 2019 Academic Editor: Natale Daniele Brunetti Copyright © 2019 Rasa Karaliute et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Atrial fbrillation (AF) despite the absence of heart failure is related to increased levels of natriuretic peptides (NPs). NPs have not been widely investigated in relation to lef atrium (LA) function afer sinus rhythm (SR) restoration and duration of AF. Te aim of the study was to determine the changes of NPs levels and to defne their relation with LA phasic function afer electrical cardioversion (ECV). Methods. Te study included 48 persistent AF patients with restored SR afer ECV. NT-proANP and NT- proBNP were measured for all patients before the ECV. LA phasic function (reservoir, conduit, and pump phases) was assessed using echocardiographic volumetric analysis within the frst 24 hours afer ECV. Patients were repeatedly tested afer 1 month in case of SR maintenance. Results. Afer 1 month, SR was maintained in 26 (54%) patients. For those patients, NT-proBNP decreased signifcantly (p=0.0001), whereas NT-proANP tended to decrease (p=0.13). Following 1 month afer SR restoration, LA indexed volume decreased (p=0.0001) and all phases of LA function improved (p=<0.01). Patients with AF duration < 3 months had lower NT-proANP compared to patients with AF duration from 6 to 12 months (p = 0.005). Higher NT-proANP concentration before ECV was associated with lower LA reservoir function during the frst day afer SR restoration (R=-0.456, p=0.005), whereas higher NT- proBNP concentration afer 1 month in SR was signifcantly related to lower LA reservoir function (R=-0.429, p=0.047). Conclusions. LA indexed volume, all phases of LA function, and NT-proBNP levels improved signifcantly following 1 month of SR restoration. Preliminary results suggest that higher baseline NT-proANP levels and higher NT-proBNP for patients with maintained SR for 1 month are related to lower LA reservoir function. Te longer duration of persistent AF is associated with higher NT-proANP concentration. 1. Introduction Atrial fbrillation (AF) is the most common arrhythmia afecting approximately 1% of the adult population in Europe [1]. AF is associated with 10–30% of all ischemic strokes and predicts worse neurological outcomes [2]. Lef atrial (LA) size as a predictor of ischemic stroke was an object of studies for a long time but the exact relation has not been defned previously according to controversial results [3]. Te concept of atrial cardiomyopathy as a progressive fbrotic atrial disease has been evolved in the recent years and this concept supports the perspective for AF to be a marker of increased stroke risk [4]. Investigations of LA functional reverse afer sinus rhythm (SR) restoration become more important because LA dysfunction is known to be present despite normal LA size and SR [5]. LA also functions as a neurohumoral organ contributing to cardiovascular homeostasis by storing atrial natriuretic peptide (ANP) and small amounts of B-type natriuretic peptide (BNP) in the granules of atrial myocytes [6]. Te natriuretic peptide (NP) system response is closely associated with myocardial tension and is known to be one of the criteria Hindawi BioMed Research International Volume 2019, Article ID 7636195, 7 pages https://doi.org/10.1155/2019/7636195