title: Peak systolic velocity indices are more sensitive than end-systolic indices in detecting contraction changes assessed by echocardiography in young healthy humans.
abstract: OBJECTIVE
  It remains to be proven whether left ventricular (LV) peak systolic velocity indices (peak systolic annulus tissue velocities, ejection velocity, and strain rate) are more closely related to contraction than LV end-systolic echocardiographic indices (ejection fraction, fractional shortening, systolic annulus displacement, global strain, and ejection velocity time integral). The study aimed to compare the ability of different echocardiographic methods in detecting contraction changes of the LV.
  
  
  RESULTS
  Thirty-three healthy volunteers (20-32 years) were examined by echocardiography at rest, during 10 μg/kg/min dobutamine (n = 20), and after injection of 15 mg metoprolol (n = 20). The effects of dobutamine and metoprolol on peak systolic velocity indices and end-systolic indices were compared. The relative increase from rest to dobutamine stress and the relative decrease after injection of metoprolol were 62 and -15% for peak systolic annulus tissue velocity, 60 and -11% for LV outflow tract (LVOT) peak velocity, 56 and -11% for peak systolic strain rate, 25 and 1% for ejection fraction, 30 and -1% for systolic mitral annulus displacement, 30 and -5% for LVOT velocity time integral, and 21 and -3% for global strain, respectively. The changes of the peak systolic indices were significantly higher (all P < 0.05) than the changes of the end-systolic indices.
  
  
  CONCLUSIONS
  Peak systolic velocity indices (mitral annulus tissue velocities, ejection velocities, and strain rate) exhibited greater variation than end-systolic indices during inotropic alterations from which it is assumed that they better reflected LV contraction.
authors.affiliation: MI Lab and Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway. anders.thorstensen@ntnu.no
authors.forename: Anders
authors.initials: A
authors.lastname: Thorstensen
authors.forename: Håvard
authors.initials: H
authors.lastname: Dalen
authors.forename: Brage H
authors.initials: BH
authors.lastname: Amundsen
authors.forename: Asbjørn
authors.initials: A
authors.lastname: Støylen
mesh_terms: D058665:Adrenergic beta-1 Receptor Agonists / Q000494:pharmacology*; D000328:Adult; D000704:Analysis of Variance; D004280:Dobutamine / Q000494:pharmacology*; D015150:Echocardiography, Doppler; D005260:Female; D006305:Health Status Indicators; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000494:pharmacology*; D009200:Myocardial Contraction / Q000187:drug effects*; D009206:Myocardium; D011446:Prospective Studies; D013566:Sympathomimetics / Q000494:pharmacology*; D013599:Systole; D055815:Young Adult
chemical_list: D058665:Adrenergic beta-1 Receptor Agonists; D013566:Sympathomimetics; D004280:Dobutamine; D008790:Metoprolol