title: Pulmonary pulse transit time: a novel echocardiographic indicator of hemodynamic and vascular alterations in pulmonary hypertension and pulmonary fibrosis.
abstract: BACKGROUND
  Pulse transit time (PTT) is generally assumed to be a surrogate marker for blood pressure changes and arterial stiffness. The aim was to evaluate whether pulmonary PTT (pPTT) may be noninvasively measured by Doppler echocardiography and whether it might be valuable for detecting pulmonary hemodynamic and vascular alterations.
  
  
  METHODS
  We defined pPTT as the interval between R-wave in the ECG and the corresponding peak late systolic pulmonary vein flow velocity measured by pw-Doppler in the pulmonary vein. Twelve consecutive patients with pulmonary hypertension (PH) and 12 subjects without any cardiovascular or respiratory disease were included in the study. All patients underwent a standard echocardiography including pPTT measurement.
  
  
  RESULTS
  In the PH group, 5 patients had idiopathic pulmonary arterial hypertension (WHO 1), 1 patient PH associated with connective tissue disease (CTD, WHO 1) without pulmonary fibrosis (PF), and 6 patients PH associated with PF either due to CTD (WHO 1) or other etiology (WHO 3). Mean pPTT was significantly shorter in the PH group (138.0 ± 16.78 msec; P < 0.0001) than in the control group (383.5 ± 23.84 msec). Within the PH group, the subgroup of patients with PF showed significantly shorter mean pPTT (93.50 ± 15.47 msec; P = 0.004) than the subgroup of patients with PH without PF (182.6 ± 14.35 msec).
  
  
  CONCLUSIONS
  The results of this study suggest that pPTT might be an interesting surrogate marker of pulmonary hemodynamic and vascular alterations in PH and PF. Further studies are warranted to evaluate the possible influence of other variables on pPTT.
authors.affiliation: Department of Internal Medicine II, University Hospital of Ulm, Ulm, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Wibmer
authors.affiliation: Department of Internal Medicine II, University Hospital of Ulm, Ulm, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Rüdiger
authors.affiliation: Department of Internal Medicine II, University Hospital of Ulm, Ulm, Germany.
authors.forename: Dominik
authors.initials: D
authors.lastname: Scharnbeck
authors.affiliation: Department of Internal Medicine II, University Hospital of Ulm, Ulm, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Radermacher
authors.affiliation: Department of Internal Medicine II, University Hospital of Ulm, Ulm, Germany.
authors.forename: Sinisa
authors.initials: S
authors.lastname: Markovic
authors.affiliation: Department of Internal Medicine II, University Hospital of Ulm, Ulm, Germany.
authors.forename: Kathrin M
authors.initials: KM
authors.lastname: Stoiber
authors.affiliation: Department of Internal Medicine II, University Hospital of Ulm, Ulm, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Rottbauer
authors.affiliation: Department of Internal Medicine II, University Hospital of Ulm, Ulm, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Schumann
mesh_terms: D001783:Blood Flow Velocity; D001794:Blood Pressure; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D011651:Pulmonary Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D011652:Pulmonary Circulation; D011658:Pulmonary Fibrosis / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D063177:Pulse Wave Analysis / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Doppler echocardiography; connective tissue disease; interstitial lung disease; pulse wave velocity