title: Arrhythmia and exercise intolerance in Fontan patients: current status and future burden.
abstract: BACKGROUND
  Long-term survival after the Fontan procedure shows excellent results but is associated with a persistent risk of arrhythmias and exercise intolerance. We aimed to analyze the current burden of clinically relevant arrhythmia and severe exercise intolerance in Danish Fontan patients and furthermore, to estimate the future burden from analysis of mortality and the current burden related to age.
  
  
  METHODS
  All Danish citizens with Fontan completion from 1981 to 2009 were identified (n=235). Surviving patients performed exercise test, Holter monitoring, echocardiography, pulmonary function test, and blood sampling and medical history was retrieved from medical records.
  
  
  RESULTS
  Twenty-six (11%) patients died or had heart transplantation (HTx) after a mean (± SD) post-Fontan follow-up of 8.3 ± 5.7 years. Excluding perioperative deaths (n=8), a linear probability of HTx-free survival was observed and estimated to 99.1% per year. Prevalence of clinically relevant arrhythmia and severe exercise intolerance increased significantly with age and was found in 32% and 85% of patients ≥ 20 years, respectively. Thus, from survival data and logistic regression models the future prevalence of patients, clinically relevant arrhythmia and severe exercise intolerance were estimated, revealing a considerable augmentation. Furthermore, resting and maximum cardiac index, resting stroke volume index and pulmonary diffusing capacity decreased significantly with age while diastolic and systolic ventricular function was unchanged.
  
  
  CONCLUSIONS
  The prevalence of clinically relevant arrhythmia and severe exercise intolerance increased significantly with age in Danish Fontan patients. The future Fontan burden was estimated showing an increase in the prevalence of older patients, clinically relevant arrhythmia, and severe exercise intolerance.
authors: Department of Cardiology, Rigshospitalet, Copenhagen, Denmark; Department of Pediatrics and Adolescent Medicine, Section of Pediatric Cardiology, Rigshospitalet, Copenhagen, Denmark. Electronic address: lars.idorn@rh.regionh.dk.
authors: L
authors: L
authors: Idorn
authors: K
authors: K
authors: Juul
authors: A S
authors: AS
authors: Jensen
authors: B
authors: B
authors: Hanel
authors: K G
authors: KG
authors: Nielsen
authors: H
authors: H
authors: Andersen
authors: J I
authors: JI
authors: Reimers
authors: K E
authors: KE
authors: Sørensen
authors: L
authors: L
authors: Søndergaard
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D002648:Child; D003430:Cross-Sectional Studies; D003718:Denmark / Q000453:epidemiology; D005080:Exercise Test / Q000639:trends*; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D018729:Fontan Procedure / Q000639:trends*; D005544:Forecasting; D006801:Humans; D008297:Male; D011159:Population Surveillance; D016896:Treatment Outcome; D055815:Young Adult
keywords: Arrhythmia; Exercise capacity; Fontan procedure; Prognosis