title: Dyssynchrony and electromechanical delay are associated with focal fibrosis in the systemic right ventricle - Insights from echocardiography.
abstract: BACKGROUND
  Systemic right ventricular (RV) dysfunction and sudden cardiac death remain problematic late after Mustard operation for transposition of the great arteries. The exact mechanism for that relationship is likely to be multifactorial including myocardial fibrosis. Doppler echocardiography gives further insights into the role of fibrosis shown by late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) in late morbidity.
  
  
  RESULTS
  Twenty-two consecutive patients, mean age 28±8years, were studied with 2D echocardiography, and also assessed by LGE CMR. The presence of LGE in 13/22 patients (59%) was related to delayed septal shortening and lengthening (P=0.002 &P=0.049), prolonged systemic RV isovolumic contraction time (P=0.024) and reduced systemic RV free wall and septal excursion (P=0.027 &P=0.005). The systemic RV total isovolumic time was prolonged but not related to extent of LGE. LGE extent was related to markers of electromechanical delay and dyssynchrony (delayed onset of RV free wall shortening and lengthening; r=0.73 &P=0.004 and r=0.62 &P=0.041, respectively, and QRS duration r=0.68, P<0.01) and was inversely related to systolic RV free wall shortening velocity (r=-0.59 &P=0.042). The presence of LGE was also related to lower exercise capacity, ≥mild tricuspid regurgitation and more arrhythmia (P=0.008, P=0.014 and P=0.040). RV free wall excursion and systolic tissue Doppler velocity were related to CMR derived RV ejection fraction (r=0.51, P=0.015, and r=0.77, P=<0.001, respectively).
  
  
  CONCLUSIONS
  Post Mustard repair, myocardial fibrosis is related to dyssynchrony, RV long axis dysfunction and tricuspid regurgitation. Echocardiographic measurements of systemic RV function can be confidently used in serial follow-up following Mustard operation.
authors.affiliation: Adult Congenital Heart Unit, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK; NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK; National Heart and Lung Institute, Imperial College, Dovehouse Street, London SW3 6LY, UK.
authors.forename: Sonya V
authors.initials: SV
authors.lastname: Babu-Narayan
authors.affiliation: Adult Congenital Heart Unit, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK; National Heart and Lung Institute, Imperial College, Dovehouse Street, London SW3 6LY, UK; Department of Biomedical and Surgical Sciences, Section of Cardiology, Universita' degli Studi di Verona, Verona, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Prati
authors.affiliation: Adult Congenital Heart Unit, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK; NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK; National Heart and Lung Institute, Imperial College, Dovehouse Street, London SW3 6LY, UK; Department of Molecular Medicine and Surgery, Section of Clinical Physiology, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Riikka
authors.initials: R
authors.lastname: Rydman
authors.affiliation: Adult Congenital Heart Unit, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK; National Heart and Lung Institute, Imperial College, Dovehouse Street, London SW3 6LY, UK.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Dimopoulos
authors.affiliation: Adult Congenital Heart Unit, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK; National Heart and Lung Institute, Imperial College, Dovehouse Street, London SW3 6LY, UK.
authors.forename: Gerhard-Paul
authors.initials: GP
authors.lastname: Diller
authors.affiliation: Adult Congenital Heart Unit, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK.
authors.forename: Anselm
authors.initials: A
authors.lastname: Uebing
authors.affiliation: National Heart and Lung Institute, Imperial College, Dovehouse Street, London SW3 6LY, UK.
authors.forename: Michael Y
authors.initials: MY
authors.lastname: Henein
authors.affiliation: NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK; National Heart and Lung Institute, Imperial College, Dovehouse Street, London SW3 6LY, UK.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Kilner
authors.affiliation: Adult Congenital Heart Unit, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK; NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK; National Heart and Lung Institute, Imperial College, Dovehouse Street, London SW3 6LY, UK.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Gatzoulis
authors.affiliation: Adult Congenital Heart Unit, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK; National Heart and Lung Institute, Imperial College, Dovehouse Street, London SW3 6LY, UK. Electronic address: w.li@rbht.uk.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
mesh_terms: D000328:Adult; D015331:Cohort Studies; D004452:Echocardiography / Q000379:methods; D004562:Electrocardiography / Q000379:methods; D005260:Female; D005355:Fibrosis / Q000000981:diagnostic imaging / Q000503:physiopathology; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D055815:Young Adult
keywords: Fibrosis; Late gadolinium enhancement; Long axis function; Systemic right ventricle; Tissue Doppler imaging; Transposition of the great arteries