title: Arrhythmias and sudden death among older children and young adults following tetralogy of Fallot repair in the current era: are previously reported risk factors still applicable?
abstract: BACKGROUND
  Young adult patients (pts) with repaired tetralogy of Fallot (TOF) remain at risk for arrhythmias (Ar) and sudden cardiac death (SCD). Based on past studies with earlier pt subsets, Ar/SCD events were associated with right ventricular (RV) systolic pressures >60 mm Hg, outflow tract gradients >20 mm Hg, and QRS duration >180 ms. However, there are limited recent studies to evaluate these risk factors in the current patient generation.
  
  
  METHODS
  Patients with TOF followed over the past 50 years were grouped by presence of any arrhythmias (group 1), absence of arrhythmias (group 2), and presence of SCD or significant ventricular arrhythmias (group 3) and correlated with current pt age, gender, age at repair, repair types, echocardiogram, cardiac magnetic resonance imaging, electrocardiogram/Holter, hemodynamics, and electrophysiology findings.
  
  
  RESULTS
  Of 109 pts, 52 were male aged 17-58 years. Of these, 59 (54%) had Ar, two of whom had SCD. These 59 pts were chronologically older at the time of analysis, with repair at an older age and wider QRS duration (78-240, mean 158 ms) when compared with those without Ar. However, there was no correlation with surgical era, surgical repair, gender, RV pressure >60 mm Hg, right ventricular outflow tract gradient >20 mm Hg, or RV end-diastolic volume on CMRI.
  
  
  CONCLUSIONS
  Ar/SCD risk continues to correlate with repair age and advancing pt age. QRS duration is longer in these patients but at a shorter interval (mean 158 ms) and less RV pressure (mean 43 mm Hg) than previously reported. In the current TOF patient generation, neither surgical era, type of repair, RV outflow gradient nor RV volume correlate with Ar/SCD. Electrophysiologic testing to verify and identify arrhythmias remains clinically effective.
authors: Section of Pediatric Cardiology, Carmen and Ann Adams Department of Pediatrics, The Children's Hospital of Michigan, Wayne State University School of Medicine, Detroit, Mich, USA.
authors: Swati
authors: S
authors: Arya
authors: Julie
authors: J
authors: Kovach
authors: Harinder
authors: H
authors: Singh
authors: Peter P
authors: PP
authors: Karpawich
mesh_terms: D000200:Action Potentials; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology; D006348:Cardiac Surgical Procedures / Q000009:adverse effects* / Q000401:mortality; D016757:Death, Sudden, Cardiac / Q000209:etiology*; D004452:Echocardiography; D015716:Electrocardiography, Ambulatory; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008824:Michigan; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013771:Tetralogy of Fallot / Q000150:complications / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
keywords: Adult Congenital Heart; Arrhythmias; Sudden Death; Tetralogy of Fallot