title: Diagnosis and mortality prediction in pulmonary hypertension: the value of the electrocardiogram-derived ventricular gradient.
abstract: OBJECTIVE
  The aim of this study was to investigate the use of the electrocardiogram-derived ventricular gradient, projected on the x-axis (VGx), for detection of pulmonary hypertension (PH) and for prediction of all-cause mortality in PH patients.
  
  
  METHODS
  In patients referred for PH screening (n = 216), the VGx was calculated semiautomatically from the electrocardiogram and was defined as abnormal when less than 24 mV · ms. The VGx of PH patients was compared with the VGx of patients without PH. The association between a reduced VGx and mortality was investigated in PH patients.
  
  
  RESULTS
  Patients with PH (n = 117) had a significantly reduced VGx: 14 ± 27 vs 45 ± 23 mV · ms, P < .001. Furthermore, a severely reduced VGx (<0 mV · ms) was associated with increased mortality in PH patients: hazard ratio, 1.025 (95% confidence interval, 1.006-1.045; P = .012) per mV·ms VGx decrease.
  
  
  CONCLUSIONS
  Reduced VGx is associated with the presence of PH and, more importantly, within PH patients, a severely reduced VGx predicts mortality.
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Roderick W C
authors.initials: RW
authors.lastname: Scherptong
authors.forename: Ivo R
authors.initials: IR
authors.lastname: Henkens
authors.forename: Gijs F L
authors.initials: GF
authors.lastname: Kapel
authors.forename: Cees A
authors.initials: CA
authors.lastname: Swenne
authors.forename: Klaas W
authors.initials: KW
authors.lastname: van Kralingen
authors.forename: Menno V
authors.initials: MV
authors.lastname: Huisman
authors.forename: Annemie J M
authors.initials: AJ
authors.lastname: Schuerwegh
authors.forename: Jeroen J
authors.initials: JJ
authors.lastname: Bax
authors.forename: Ernst E
authors.initials: EE
authors.lastname: van der Wall
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Schalij
authors.forename: Hubert W
authors.initials: HW
authors.lastname: Vliegen
mesh_terms: D015897:Comorbidity; D004562:Electrocardiography / Q000379:methods* / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis* / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D015995:Prevalence; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D015996:Survival Rate; D018754:Ventricular Dysfunction / Q000175:diagnosis* / Q000401:mortality*