title: Right ventricular dyssynchrony predicts clinical outcomes in patients with pulmonary hypertension.
abstract: BACKGROUND
  RV dyssynchrony has been described in patients with pulmonary hypertension (PH) and is an independent predictor of clinical worsening; however, the optimal method for measuring RV dyssynchrony has not been fully established. This study aimed to investigate whether RV dyssynchrony is correlated with hemodynamics and prognosis in PH patients and to identify the best parameter for evaluating RV dyssynchrony.
  
  
  METHODS
  This study assessed 100 PH patients, measuring mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR), and cardiac index (CI) by right heart catheterization (RHC). RV strain curves were obtained using two-dimensional speckle-tracking echocardiography (2DSTE), and time from QRS onset to maximum peak longitudinal strain (Tmax) or time to first peak (Tfirst) was measured. Difference in time between the earliest and the latest segment (TD) and standard deviation (SD) of T in 6 segments with RV apex (-SD6) and 4 segments without RV apex (-SD4) were also assessed.
  
  
  RESULTS
  Among all RV dyssynchrony parameters, Tmax-SD6 showed the strongest correlation with RV hemodynamics such as mPAP (R2=0.27, P<0.0001) and PVR (R2=0.22, P<0.0001). Univariate and multivariate Cox proportional hazard analyses showed that Tmax-SD6 significantly correlated with and independently predicted event-free survival in patients with PH.
  
  
  CONCLUSIONS
  RV dyssynchrony is a useful index for RV function and an independent predictor of clinical outcomes in patients with PH. In addition, the inclusion of apical motion is essential for the optimal assessment of RV dyssynchrony.
authors.affiliation: Department of Laboratory Medicine, School of Medicine, Keio University, Tokyo, Japan; Department of Cardiology, School of Medicine, Keio University, Tokyo, Japan. Electronic address: muratam@keio.jp.
authors.forename: Mitsushige
authors.initials: M
authors.lastname: Murata
authors.affiliation: Department of Cardiology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Toshimitsu
authors.initials: T
authors.lastname: Tsugu
authors.affiliation: Department of Cardiology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kawakami
authors.affiliation: Department of Cardiology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Kataoka
authors.affiliation: Department of Cardiology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Yugo
authors.initials: Y
authors.lastname: Minakata
authors.affiliation: Department of Cardiology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Jin
authors.initials: J
authors.lastname: Endo
authors.affiliation: Department of Cardiology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Hikaru
authors.initials: H
authors.lastname: Tsuruta
authors.affiliation: Department of Cardiology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Itabashi
authors.affiliation: Department of Cardiology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Maekawa
authors.affiliation: Department of Cardiology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Fukuda
mesh_terms: D000328:Adult; D000368:Aged; D006328:Cardiac Catheterization / Q000379:methods; D002302:Cardiac Output / Q000502:physiology; D015331:Cohort Studies; D018450:Disease Progression; D004452:Echocardiography / Q000379:methods; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications / Q000000981:diagnostic imaging* / Q000401:mortality*; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D011379:Prognosis; D011669:Pulmonary Wedge Pressure / Q000502:physiology; D012042:Registries; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D015996:Survival Rate; D014655:Vascular Resistance / Q000502:physiology; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging* / Q000209:etiology / Q000401:mortality* / Q000503:physiopathology
keywords: Dyssynchrony; Pulmonary hypertension; Right ventricle; Strain