title: Left ventricular long axis tissue Doppler systolic velocity is independently related to heart rate and body size.
abstract: BACKGROUND
  The physiological factors which affect left ventricular (LV) long-axis function are not fully defined. We investigated the relationships of resting heart rate and body size with the peak velocities and amplitudes of LV systolic and early diastolic long axis motion, and also with long-axis contraction duration.
  
  
  METHODS
  Two groups of adults free of cardiac disease underwent pulsed-wave tissue Doppler imaging at the septal and lateral mitral annular borders. Group 1 (n = 77) were healthy subjects <50 years of age and Group 2 (n = 65) were subjects between 40-80 years of age referred for stress echocardiography. Systolic excursion (SExc), duration (SDur) and peak velocity (s') and early diastolic excursion (EDExc) and peak velocity (e') were measured.
  
  
  RESULTS
  SExc was not correlated with heart rate, height or body surface area (BSA) for either LV wall in either group, but SDur was inversely correlated with heart rate for both walls and both groups, and after adjustment for heart rate, males in both groups had a shorter septal SDur. Septal and lateral s` were independently and positively correlated with SExc, heart rate and height in both groups, independent of sex and age. There were no correlations of heart rate, height or BSA with either e` or EDExc for either wall in either group.
  
  
  CONCLUSIONS
  Heart rate and height independently modify the relationship between s` and SExc, but neither are related to EDExc or e`. These findings suggest that s` and SExc cannot be used interchangeably for the assessment of LV long-axis contraction.
authors.affiliation: Monash Cardiovascular Research Centre, MonashHeart and Department of Medicine (School of Clinical Sciences at Monash Medical Centre), Monash University and Monash Health, Clayton, Victoria, Australia.
authors.forename: Roger E
authors.initials: RE
authors.lastname: Peverill
authors.affiliation: Monash Cardiovascular Research Centre, MonashHeart and Department of Medicine (School of Clinical Sciences at Monash Medical Centre), Monash University and Monash Health, Clayton, Victoria, Australia.
authors.forename: Bon
authors.initials: B
authors.lastname: Chou
authors.affiliation: Monash Cardiovascular Research Centre, MonashHeart and Department of Medicine (School of Clinical Sciences at Monash Medical Centre), Monash University and Monash Health, Clayton, Victoria, Australia.
authors.forename: Lesley
authors.initials: L
authors.lastname: Donelan
mesh_terms: D000293:Adolescent; D000328:Adult; D049628:Body Size; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D006339:Heart Rate; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult