title: Improved Ventricular Function after TEE-guided Cardioversion of Atrial Arrhythmias in Patients after the Fontan Operation.
abstract: OBJECTIVE
  Atrial tachyarrhythmias frequently develop after the Fontan operation. Patients with Fontan physiology rely on atrial contribution to cardiac output, and thus control of atrial arrhythmias is important. Outcomes after cardioversion in patients after Fontan have not been reported. We sought to determine if cardioversion results in improved echocardiographic parameters or clinical symptomatology; and, discern risk factors for arrhythmia recurrence.
  
  
  METHODS
  We retrospectively analyzed the Mayo Clinic echocardiographic database to capture patients after the Fontan operation who underwent transesophageal echocardiography-guided electrical cardioversion from 2000-2015. Clinical and echocardiographic data were collected and compared at baseline and follow-up.
  
  
  RESULTS
  Eight hundred ninety patients with prior Fontan operation underwent echocardiographic evaluation; 341 (38%) developed atrial arrhythmias. Thirty-six patients [20 males, median age 29 (12-51)] underwent transesophageal echocardiography-guided cardioversion of atrial arrhythmias [atrial flutter/intraatrial reentrant tachycardia (75%); atrial fibrillation (25%)]. At follow-up, improvements were noted in ejection fraction by 10% (P < .0001); atrioventricular valve regurgitation grade (39%) (P = .002); New York Heart Association (NYHA) class (61%) (P < .001); and resolution of spontaneous echo contrast in the Fontan circuit (65%) (P < .01). No embolic events occurred following cardioversion. Eighteen patients (50%) developed recurrent atrial arrhythmias at 15 (3-36) months after cardioversion. Five-year freedom from arrhythmia recurrence was 61%. Significant univariate predictors of arrhythmia recurrence were atrial flutter/intraatrial reentrant tachycardia (HR = 4.3, P = .02); NYHA ≥ II (HR = 4.1, P = .03); systemic right ventricle (HR = 5.2; P = .02); and ejection fraction ≤ 40% (HR = 2.8; P = .04). On multivariate analysis, only systemic right ventricle (HR = 3.7; P = .02) remained an independent predictor of arrhythmia recurrence.
  
  
  CONCLUSIONS
  After the Fontan operation, cardioversion of atrial arrhythmias improves ventricular function, atrioventricular valve regurgitation grade, and NYHA class. Arrhythmia recurrence was common and patients with atrial flutter/intraatrial reentrant tachycardia, systemic right ventricle, or reduced ventricular function may be at risk of arrhythmia recurrence. Further studies are required to identify additional risk factors and protective factors for arrhythmia recurrence.
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors.forename: Joseph T
authors.initials: JT
authors.lastname: Poterucha
authors.affiliation: Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, Minn, USA.
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Egbe
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA.|Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, Minn, USA.
authors.forename: Jonathan N
authors.initials: JN
authors.lastname: Johnson
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors.forename: Talha
authors.initials: T
authors.lastname: Niaz
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors.forename: Phillip L
authors.initials: PL
authors.lastname: Wackel
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors.forename: Bryan C
authors.initials: BC
authors.lastname: Cannon
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA.|Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, Minn, USA.
authors.forename: Benjamin W
authors.initials: BW
authors.lastname: Eidem
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA.|Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, Minn, USA.
authors.forename: Frank
authors.initials: F
authors.lastname: Cetta
mesh_terms: D000293:Adolescent; D000328:Adult; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D001282:Atrial Flutter / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D002648:Child; D016208:Databases, Factual; D018572:Disease-Free Survival; D017548:Echocardiography, Transesophageal; D004554:Electric Countershock / Q000009:adverse effects / Q000379:methods*; D005260:Female; D018729:Fontan Procedure / Q000009:adverse effects*; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D008910:Minnesota; D011237:Predictive Value of Tests; D020127:Recovery of Function; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D054139:Tachycardia, Reciprocating / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right; D055815:Young Adult
keywords: Adult Congenital Heart Disease; Atrial Arrhythmias; Cardioversion; Fontan; Transesophageal Echocardiography