title: Novel insights into the pathophysiology of different forms of stress testing.
abstract: BACKGROUND
  The impact of different forms of cardiac stress testing (exercise versus pharmacological stress testing) on cardiac wall stress and myocardial ischemia is incompletely understood.
  
  
  METHODS
  In a prospective study, 331 consecutive patients with suspected myocardial ischemia referred for nuclear perfusion imaging were enrolled: 266 underwent exercise (bicycle) stress testing and 65 adenosine stress testing. Levels of B-type natriuretic peptide (BNP) measured before and 1 min after stress testing, ischemic ECG changes, and typical angina symptoms were used to compare the 2 testing modalities.
  
  
  RESULTS
  Cardiac wall stress as quantified by changes in BNP levels significantly increased in the exercise stress group, but not in the adenosine group (increase in BNP levels 22 pg/ml (IQR 6-46) versus -3 pg/ml (IQR -3 to 28); p<0.001). In the bicycle exercise stress group, patients with reversible defects on nuclear perfusion imaging more often had angina symptoms (25% vs. 9%, p=0.0001) and ischemic ECG changes (33% vs. 12%, p=0.0001) during the stress test, and a greater increase in BNP levels (28 (IQR 11-58) versus 16 (IQR 3-34) pg/ml, p=0.001) compared to those without reversible defects. Those differences between patients with and without reversible defects were not observed with the adenosine protocol (p-values all >0.05).
  
  
  CONCLUSIONS
  Exercise stress testing but not adenosine stress results in an increase of cardiac wall stress, angina symptoms and ECG changes. The absence of these surrogates of myocardial ischemia suggests that adenosine stress does not induce acute myocardial ischemia, but rather displays relative perfusion differences.
authors.affiliation: Department of Cardiology, University Hospital Basel, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hochgruber
authors.affiliation: Department of Cardiology, University Hospital Basel, Switzerland; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Tobias
authors.initials: T
authors.lastname: Reichlin
authors.affiliation: Department of Cardiology, University Hospital Basel, Switzerland.
authors.forename: Mariusz
authors.initials: M
authors.lastname: Wasila
authors.affiliation: Department of Cardiology, University Hospital Basel, Switzerland.
authors.forename: Eliane
authors.initials: E
authors.lastname: Vogler
authors.affiliation: Department of Cardiology, University Hospital Basel, Switzerland.
authors.forename: Raphael
authors.initials: R
authors.lastname: Twerenbold
authors.affiliation: Department of Cardiology, University Hospital Basel, Switzerland.
authors.forename: Seoung Mann
authors.initials: SM
authors.lastname: Sou
authors.affiliation: Department of Cardiology, University Hospital Basel, Switzerland.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Roost
authors.affiliation: Department of Cardiology, University Hospital Basel, Switzerland.
authors.forename: Gino
authors.initials: G
authors.lastname: Lee
authors.affiliation: Department of Cardiology, University Hospital Basel, Switzerland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Fischer
authors.affiliation: Department of Laboratory Medicine, University Hospital Basel, Switzerland.
authors.forename: Heike
authors.initials: H
authors.lastname: Freidank
authors.affiliation: Department of Cardiology, University Hospital Basel, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Osswald
authors.affiliation: Department of Cardiology, University Hospital Basel, Switzerland.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Zellweger
authors.affiliation: Department of Cardiology, University Hospital Basel, Switzerland. Electronic address: Christian.Mueller@usb.ch.
authors.forename: Christian
authors.initials: C
authors.lastname: Mueller
mesh_terms: D000368:Aged; D000787:Angina Pectoris / Q000097:blood / Q000000981:diagnostic imaging; D004562:Electrocardiography; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood / Q000000981:diagnostic imaging / Q000503:physiopathology*; D009206:Myocardium / Q000473:pathology; D020097:Natriuretic Peptide, Brain / Q000097:blood; D011877:Radionuclide Imaging; D014463:Ultrasonography
chemical_list: D020097:Natriuretic Peptide, Brain
keywords: Diagnosis; Exercise; Ischemia; Natriuretic peptide; Perfusion