title: Myocardial ECV Fraction Assessed by CMR Is Associated With Type of Hemodynamic Load and Arrhythmia in Repaired Tetralogy of Fallot.
abstract: OBJECTIVE
  The aim of this study was to investigate the extent of diffuse myocardial fibrosis by measuring left (LV) and right ventricular (RV) extracellular volume fraction (ECV) in patients with repaired tetralogy of Fallot (rTOF) and to explore its association with ventricular remodeling, hemodynamic load, and clinical parameters.
  
  
  BACKGROUND
  Focal myocardial fibrosis is prevalent in patients with rTOF. However, little is known about the extent of diffuse myocardial fibrosis and its clinical implications in this population.
  
  
  METHODS
  We measured ECV by pre- and post-gadolinium T1 measurements using a 1.5-T scanner in 84 patients with rTOF (median age 23.3 years). LV ECV was determined by averaging values from 6 short-axis mid-ventricular segments, and RV ECV was calculated by averaging values from the anterior-inferior and the diaphragmatic RV wall segments.
  
  
  RESULTS
  LV ECV above the upper limit of normal (>28%) was observed in 11 patients and for RV ECV (>41%) in 9 patients. LV ECV correlated positively with RV ECV (r = 0.54; p < 0.001). Greater RV ECV was associated with female gender, lower RV mass-to-volume ratio, lower RV outflow tract pressure gradient, and having volume overload as the predominant hemodynamic burden (all p < 0.001). Similar associations were observed with LV ECV. In multivariable analysis, increased LV ECV was independently associated with arrhythmia, adjusting for age and RV mass index (odds ratio: 5.69; p = 0.031).
  
  
  CONCLUSIONS
  In this cohort, LV and RV ECV values were positively correlated, indicating an adverse ventricular-ventricular interaction at the tissue level. Increased ECV was associated with RV volume overload and arrhythmia. These findings may lead to future studies exploring the role of ECV in improving risk stratification and guiding therapeutic interventions.
authors.affiliation: Department of Cardiology, Boston Children's Hospital, and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts.
authors.forename: Chun-An
authors.initials: CA
authors.lastname: Chen
authors.affiliation: Department of Cardiology, Boston Children's Hospital, and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Dusenbery
authors.affiliation: Department of Cardiology, Boston Children's Hospital, and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts.
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Valente
authors.affiliation: Department of Cardiology, Boston Children's Hospital, and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Powell
authors.affiliation: Department of Cardiology, Boston Children's Hospital, and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts. Electronic address: tal.geva@cardio.chboston.org.
authors.forename: Tal
authors.initials: T
authors.lastname: Geva
mesh_terms: D000293:Adolescent; D000328:Adult; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D016009:Chi-Square Distribution; D003287:Contrast Media; D005260:Female; D005355:Fibrosis; D019786:Gadolinium DTPA; D006801:Humans; D016015:Logistic Models; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D015999:Multivariate Analysis; D009206:Myocardium / Q000473:pathology*; D015588:Observer Variation; D016017:Odds Ratio; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012307:Risk Factors; D013318:Stroke Volume; D013771:Tetralogy of Fallot / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right; D020257:Ventricular Remodeling; D055815:Young Adult
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: cardiac magnetic resonance imaging; congenital heart disease; diffuse fibrosis; extracellular volume fraction; tetralogy of Fallot