title: Relation of fragmented QRS complex to right ventricular fibrosis detected by late gadolinium enhancement cardiac magnetic resonance in adults with repaired tetralogy of fallot.
abstract: Fragmented QRS (fQRS) on 12-lead electrocardiography reflects conduction delay caused by myocardial fibrosis and dysfunction. Ventricular fibrosis detected by late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) is reportedly correlated with worse clinical outcomes in adults with repaired tetralogy of Fallot (TOF). The aim of this study was to assess whether the presence of fQRS is associated with right ventricular (RV) fibrosis or dysfunction in this patient group. In 37 consecutive patients (median age 30 years, median age at repair 6.6 years), the number of leads showing fQRS, defined as the presence of >2 notches on the R/S wave in ≥2 contiguous leads, was counted. RV systolic function, dilatation, and LGE score were measured using LGE CMR. Ventricular LGE was observed mainly at the previous surgical sites: the RV outflow tract (33 of 37), ventricular septal defect patch region (15 of 37), and RV anterior wall (11 of 37). Fragmented QRS was found mostly in the right and mid precordial leads. The fQRS group (n = 20) demonstrated higher RV LGE scores (p <0.001) and lower RV ejection fractions (p = 0.02) and a trend toward larger RV end-diastolic and end-systolic volumes (p = 0.12 and p = 0.06, respectively) compared to the non-fQRS group (n = 17). The number of electrocardiographic leads showing fQRS was positively correlated with RV LGE score (r = 0.75, p <0.001). The presence of fQRS remained independently associated with the presence of supramedian RV LGE score, even after adjusting for relevant parameters. In conclusion, fQRS was closely associated with more extensive RV fibrosis and dysfunction in adults with repaired tetralogy of Fallot.
authors.affiliation: Department of Internal Medicine, Cardiovascular Imaging Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Seung-Jung
authors.initials: SJ
authors.lastname: Park
authors.forename: Young Keun
authors.initials: YK
authors.lastname: On
authors.forename: June Soo
authors.initials: JS
authors.lastname: Kim
authors.forename: Seung Woo
authors.initials: SW
authors.lastname: Park
authors.forename: Ji-Hyuk
authors.initials: JH
authors.lastname: Yang
authors.forename: Tae-Gook
authors.initials: TG
authors.lastname: Jun
authors.forename: I-Seok
authors.initials: IS
authors.lastname: Kang
authors.forename: Heung Jae
authors.initials: HJ
authors.lastname: Lee
authors.forename: Yeon Hyeon
authors.initials: YH
authors.lastname: Choe
authors.forename: June
authors.initials: J
authors.lastname: Huh
mesh_terms: D000293:Adolescent; D000328:Adult; D006348:Cardiac Surgical Procedures; D002648:Child; D003287:Contrast Media; D003937:Diagnosis, Differential; D018450:Disease Progression; D004562:Electrocardiography; D005260:Female; D005355:Fibrosis / Q000175:diagnosis / Q000209:etiology; D005500:Follow-Up Studies; D019786:Gadolinium DTPA; D006352:Heart Ventricles / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D012189:Retrospective Studies; D013771:Tetralogy of Fallot / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D013997:Time Factors; D018497:Ventricular Dysfunction, Right / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D016278:Ventricular Function, Right / Q000502:physiology*; D055815:Young Adult
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA