title: Restrictive versus nonrestrictive physiology following repair of tetralogy of Fallot: is there a difference?
abstract: BACKGROUND
  Long-term outcome in repaired tetralogy of Fallot (TOF) is related to chronic pulmonary insufficiency (PI), right ventricular (RV) dilation, and deterioration of RV function. The aim of this study was to characterize clinical differences between restrictive and nonrestrictive RV physiology in young patients with repaired TOF.
  
  
  METHODS
  Patients were prospectively enrolled from February 2008 to August 2009. Each had a clinic visit, brain natriuretic peptide assessment, exercise test, cardiac magnetic resonance study, and echocardiographic examination with assessment of regional myocardial mechanics. Consistent antegrade diastolic pulmonary arterial flow with atrial contraction identified restrictive RV physiology.
  
  
  RESULTS
  Twenty-nine patients (median age, 12 years; range, 8-33 years; nine male patients) were studied. Twelve had restrictive RV physiology. The median time since initial TOF repair was 12 years (range, 5-27 years). Restrictive physiology appeared more prevalent after transannular patch repair and was not influenced by other demographic features. The restrictive group had more PI (46% vs 28%, P = .002), larger RV end-diastolic volumes (128 vs 98 mL/m(2), P = .046), but similar ejection fractions, brain natriuretic peptide levels, New York Heart Association classes, and exercise capacity. RV basal and mid free wall peak diastolic strain rate differed between groups, negatively correlating with exercise time and positively correlating with PI in patients with restrictive physiology.
  
  
  CONCLUSIONS
  Restrictive RV physiology correlates with a larger right ventricle and increased PI after TOF repair but does not negatively affect other markers of myocardial health. Diastolic regional RV myocardial mechanics, particularly diastolic velocity and peak diastolic strain rate, differ for postoperative TOF patients with restrictive and nonrestrictive RV physiology; longitudinal study is necessary to understand the relationship of regional myocardial mechanics and patients' clinical status.
authors.affiliation: Department of Pediatrics, Division of Cardiology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA. msamyn@chw.org
authors.forename: Margaret M
authors.initials: MM
authors.lastname: Samyn
authors.forename: Elena N
authors.initials: EN
authors.lastname: Kwon
authors.forename: Jessica S
authors.initials: JS
authors.lastname: Gorentz
authors.forename: Ke
authors.initials: K
authors.lastname: Yan
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Danduran
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Cava
authors.forename: Pippa M
authors.initials: PM
authors.lastname: Simpson
authors.forename: Peter C
authors.initials: PC
authors.lastname: Frommelt
authors.forename: James S
authors.initials: JS
authors.lastname: Tweddell
mesh_terms: D000293:Adolescent; D000328:Adult; D002313:Cardiomyopathy, Restrictive / Q000175:diagnosis* / Q000503:physiopathology; D002648:Child; D004452:Echocardiography; D005080:Exercise Test; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011183:Postoperative Complications / Q000175:diagnosis* / Q000503:physiopathology; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D013771:Tetralogy of Fallot / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome