title: ECG monitoring of treatment response in pulmonary arterial hypertension patients.
abstract: BACKGROUND
  The potential use of the ECG for monitoring treatment effects in patients with pulmonary arterial hypertension (PAH) has not been investigated. We evaluated whether the ECG is useful for monitoring treatment response based on changes in pulmonary vascular resistance (PVR).
  
  
  METHODS
  An ECG was recorded in 81 PAH patients at the time of diagnostic right heart catheterization and after 1 year of treatment. Patients were treated according to the guidelines. Patients were divided into two groups based on PVR (ie, < 500 or > 500 dyne x s x cm(-5)). A positive treatment response was defined as a > 25% decrease in PVR to an absolute PVR of < 500 dyne x s x cm(-5).
  
  
  RESULTS
  At baseline, the 19 patients with a PVR of < 500 dyne x s x cm(-5) had a significantly lower P amplitude in lead II, a less rightward oriented QRS axis, and a more rightward T axis than the 62 patients with a PVR of > 500 dyne x s x cm(-5). Overall (n = 81), the mean (+/- SD) change in PVR was -143 +/- 360 dyne x s x cm(-5) after 1 year of treatment (p < 0.001). Twelve patients (19%) with a baseline PVR of > 500 dyne x s x cm(-5) were classified as responders. Receiver operating characteristic analysis determined that the P amplitude in lead II (area under the curve [AUC], 0.80; 95% confidence interval [CI], 0.67 to 0.94; p < 0.01), QRS axis (AUC, 0.70; 95% CI, 0.52 to 0.89; p = 0.03), and T axis (AUC, 0.90; 95% CI, 0.82 to 0.97; p < 0.001) were important determinants of treatment response. The presence of a P amplitude in lead II of < 0.175 mV and a T axis of >or= 25 degrees combined had a positive and negative predictive value for treatment response of 0.81 (95% CI, 0.37 to 0.96) and 0.94 (95% CI, 0.86 to 0.99), respectively.
  
  
  CONCLUSIONS
  Routine ECG evaluation can be an important contribution in the assessment of treatment response in PAH patients.
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Ivo R
authors.initials: IR
authors.lastname: Henkens
authors.affiliation: Department of Pulmonology, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: C Tji-Joong
authors.initials: CT
authors.lastname: Gan
authors.affiliation: Department of Pulmonology, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Serge A
authors.initials: SA
authors.lastname: van Wolferen
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Miki
authors.initials: M
authors.lastname: Hew
authors.affiliation: Department of Pulmonology, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Anco
authors.initials: A
authors.lastname: Boonstra
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Jos W R
authors.initials: JWR
authors.lastname: Twisk
authors.affiliation: Department of Cardiology, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Otto
authors.initials: O
authors.lastname: Kamp
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Ernst E
authors.initials: EE
authors.lastname: van der Wall
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Schalij
authors.affiliation: Department of Pulmonology, VU University Medical Center, Amsterdam, the Netherlands. Electronic address: a.vonk@vumc.nl.
authors.forename: Anton
authors.initials: A
authors.lastname: Vonk Noordegraaf
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Hubert W
authors.initials: HW
authors.lastname: Vliegen
mesh_terms: D000328:Adult; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D006328:Cardiac Catheterization; D015331:Cohort Studies; D004562:Electrocardiography; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D016896:Treatment Outcome; D014655:Vascular Resistance / Q000502:physiology
chemical_list: D000959:Antihypertensive Agents