Improved Ventricular Function after TEE-guided Cardioversion of Atrial Arrhythmias in Patients after the Fontan Operation.
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.


DESIGN
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.


CONCLUSION
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.
['Poterucha|Joseph T|JT|', 'Egbe|Alexander C|AC|', 'Johnson|Jonathan N|JN|', 'Niaz|Talha|T|', 'Wackel|Phillip L|PL|', 'Cannon|Bryan C|BC|', 'Eidem|Benjamin W|BW|', 'Cetta|Frank|F|']
D000293:Adolescent D000328:Adult D001281:Atrial Fibrillation D001282:Atrial Flutter D002648:Child D016208:Databases, Factual D018572:Disease-Free Survival D017548:Echocardiography, Transesophageal D004554:Electric Countershock D005260:Female D018729:Fontan Procedure D006330:Heart Defects, Congenital 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 D013997:Time Factors D016896:Treatment Outcome D016277:Ventricular Function, Left D016278:Ventricular Function, Right D055815:Young Adult
Cardioversion Atrial Arrhythmias Fontan Adult Congenital Heart Disease Transesophageal Echocardiography