Changes in Left Atrial Structure and Function After Catheter Ablation and Electrical Cardioversion for Atrial Fibrillation

Abstract

trial fibrillation (AF) occurs in 0.4% of the general population, increasing to 5% in those over 65 years of age, and it is the most common arrhythmia, increasing cardiac morbidity and mortality. 1 AF is related to the structural and functional remodeling of the left atrium (LA) and ventricle (LV) because of persistent arrhythmia. 2,3 To restore sinus rhythm (SR), both electrical cardioversion (ECV) and radiofrequency (RF) catheter ablation (ABL) have proven to be effective treatment modalities for patients with AF. 4 Reverse morphological remodeling of the LA and improvement in LV diastolic and systolic functions after restoration of SR by either treatment modality have been demonstrated. 5 However, differences in the degree and the time course of functional reverse remodeling of the LA according to the each treatment modality have not been investigated. The objective of this study was to investigate the morphological and functional changes of the LA and LV in patients with sustained SR either after ABL or ECV. Circulation Journal Vol.72, December 2008 Methods Study PopulationSixty-three AF patients who had maintained SR for 3 months after either ECV (n=30, M:F 24:6, mean age 58.6± 9.3 years) or ABL (n=33, M:F 27:6, mean age 55.9±10.2 years) were included. Patients who underwent re-do ablation were excluded. Paroxysmal AF (PAF) was defined as the occurrence of 2 or more episodes of AF during the previous 12 months, typically lasting fewer than 7 days and terminating spontaneously. Persistent AF (PeAF) was defined as AF episodes lasting more than 7 days typically requiring cardioversion for restoration of SR. 6 The 29 of 30 patients had PeAF in the ECV group and 21 of 33 patients had PAF in the ABL group. All clinical information was obtained from medical records, and all patients completed a written informed consent form to participate in the study. ECVECV was performed if LA thrombi were not seen on transesophageal echocardiography. Direct current (DC) shock was delivered during sedation induced with intravenous midazolam (0.04 mg/kg) and pentothal sodium (1.5 mg/kg). One defibrillator pad with a 10-cm diameter was placed in the second intercostal space on the right side parasternally, the other was placed in a left-sided lateral position along the midaxillary line. The cardioversion procedure started with 70 J or 100 J of stored energy followed by 125 J and 150 J until the restoration of SR or failure to convert. Continuous electrocardiographic (ECG) monitoring was performed for several hours after the procedure to assess the maintenance of SR. Background The aim of this study was to assess whether the morphological and functional changes of the left atrium (LA) differ after catheter ablation (ABL) from those after electrical cardioversion (ECV) in atrial fibrillation (AF). Methods and Results AF patients who had maintained sinus rhythm for 3 months after either ECV (n=30) or ABL (n=33) were studied. Both 2-dimensional and Doppler echocardiography were performed at baseline, 1 week, 1 month, and 3 months aft...

Association Between Left Atrial Stiffness Index and Atrial Fibrillation Recurrence in Patients Undergoing Left Atrial Ablation

“…1,2 AF has a well-known association with left atrial (LA) enlargement 3 and is known to associate with LA remodeling [4][5][6] via diffuse 7 and focal fibrosis. 8,9 AF catheter ablation (CA) using pulmonary vein isolation by wide-area circumferential ablation has been used to decrease the burden of disease and improve AF-free survival.…”

Short-term amiodarone therapy after reversion of persistent atrial fibrillation reduces recurrences at 18 months

“…Disappearance of structural and functional changes generally lags behind the reversal of electrical remodeling [29,30]. However, although reversal of electrical remodeling can be rapidly achieved [28,29], the chance of AF recurrence may also depend on the underlying structural abnormalities [25].…”

Cardioversion of recent-onset atrial fibrillation and flutter in the emergency department

“…After CV, risk of thrombo-embolism due to post-CV left atrial/LAA dysfunction (so-called 'atrial stunning') persists up to 3 months [25]. Thromboembolic events have been reported in about 3% to 5% of patients who did not receive anticoagulation before CV, whereas it is only 0% to 1% by adequate anticoagulation or by exclusion of left atrium thrombus before the procedure [59,60].…”

“…After CV, risk of thrombo-embolism due to post-CV left atrial/left atrial appendage (LAA) dysfunction (so-called 'atrial stunning') persists up to 3 months [25]. Anticoagulation in pre-CV and post-CV periods is crucial and discussed more detailed later in the passage.…”