title: Tissue Doppler time intervals and derived indices in hypoplastic left heart syndrome.
abstract: OBJECTIVE
  To describe tissue Doppler time intervals and derived indices in hypoplastic left heart syndrome (HLHS) across surgical stages, taking account of age-related changes in the heart rate. Correlation of the myocardial performance index (MPI) and the systolic to diastolic (S:D) time ratio with other echocardiographic and magnetic resonance imaging (MRI) measures of cardiac performance.
  
  
  RESULTS
  Fifty-seven patients at different stages of HLHS palliation were studied prospectively using tissue Doppler imaging of the right ventricular free wall, with simultaneous cardiac MRI in the majority. Both isovolumic contraction time and isovolumic relaxation time were prolonged compared with the normal left and right ventricle: median (range) z-scores for the tricuspid annulus 1.9 (-1.2 to 9.3) and 1.3 (-2.0 to 5.5), respectively. When adjusted for heart rate, the ejection, systolic, and diastolic times in HLHS were not significantly different from published normal data. The MPI was increased at all surgical stages in HLHS. Neither MPI nor heart rate-specific S:D time ratio z-score correlated with MRI ejection fraction or indexed cardiac output when the confounding effect of significant tricuspid regurgitation was taken into consideration.
  
  
  CONCLUSIONS
  The prolongation in isovolumic relaxation and contraction times may be due to adaptation or reduced myocardial performance. Differences in the S:D time ratio between surgical stages can be accounted for by the heart rate alone. Neither MPI z-score nor S:D z-score correlated with MRI or other echocardiographic indices of systolic or diastolic function with the exception of a negative correlation between central venous pressure and S:D ratio z-score.
authors.affiliation: Division of Imaging Sciences and Biomedical Engineering,  Rayne Institute, Lambeth Wing, St Thomas'  Hospital, Westminster Bridge Road, London SE1 7EH,  UK.
authors.forename: Hannah R
authors.initials: HR
authors.lastname: Bellsham-Revell
authors.forename: Shane M
authors.initials: SM
authors.lastname: Tibby
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Bell
authors.forename: Owen I
authors.initials: OI
authors.lastname: Miller
authors.forename: Reza
authors.initials: R
authors.lastname: Razavi
authors.forename: Gerald F
authors.initials: GF
authors.lastname: Greil
authors.forename: John M
authors.initials: JM
authors.lastname: Simpson
mesh_terms: D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D006305:Health Status Indicators; D006330:Heart Defects, Congenital; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000295:instrumentation; D009200:Myocardial Contraction; D055414:Myocardial Perfusion Imaging / Q000295:instrumentation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013223:Statistics as Topic; D013997:Time Factors; D018608:Ultrasonography, Doppler / Q000295:instrumentation*