title: The Effect of Habitual Physical Training on Left Ventricular Function During Exercise Assessed by Three-Dimensional Echocardiography.
abstract: BACKGROUND
  Stroke volume (SV) in trained athletes continuously increases with progressive exercise intensity. We studied whether physical training affected left ventricle (LV) function response to exercise using 3D echocardiography and tissue Doppler imaging (TDI).
  
  
  METHODS
  Eleven male university athletes and 12 male university nonathletes were enrolled in this study. After baseline data were collected, subjects performed a symptom-limited supine bicycle ergometer exercise test. Initial workload was 25 Watts (W) and increased 25 W every 3 minutes. At rest and every exercise stage, LV end-systolic and diastolic volume index (LVEDVI and LVESVI), SV index (SVI), cardiac index (CI), LV ejection fraction (LVEF), and early lateral mitral flow velocity (Ea) were evaluated. Heart rate (HR), and systolic and diastolic blood pressure (SBP and DBP) were continuously recorded.
  
  
  RESULTS
  Nonathletes showed a slow increase in CI, and SVI reached a plateau value at a HR of 90 beats per minute (bpm). In contrast, CI and SVI increased progressively and continuously in athletes. Both CI and SVI were significantly higher in athletes than in nonathletes at HRs of 100, 110, and 120 bpm. LVEDVI kept increasing in athletes while it plateaued in nonathletes. In contrast, LVESV decreased continuously during exercise in both groups. There was no significant difference in LVEF, Ea, SBP, or DBP at rest and during exercise between the two groups.
  
  
  CONCLUSIONS
  LV responses to exercise in athletes were different from those of in nonathletes; thus, habitual physical training may play an important role in the increase in both SVI and CI in young individuals.
authors: Nagoya University School of Health Sciences, Nagoya, Japan.
authors: Mari
authors: M
authors: Sugiura Kojima
authors: Department of Biomedical Sciences, Chubu University, Kasugai, Japan.
authors: Akiko
authors: A
authors: Noda
authors: Department of Biomedical Sciences, Chubu University, Kasugai, Japan.
authors: Seiko
authors: S
authors: Miyata
authors: Nagoya University School of Health Sciences, Nagoya, Japan.
authors: Jun
authors: J
authors: Kojima
authors: Nagoya University School of Health Sciences, Nagoya, Japan.
authors: Yuki
authors: Y
authors: Hara
authors: Nagoya University School of Health Sciences, Nagoya, Japan.
authors: Makoto
authors: M
authors: Minoshima
authors: Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors: Toyoaki
authors: T
authors: Murohara
mesh_terms: D000328:Adult; D056352:Athletes / Q000706:statistics & numerical data*; D015150:Echocardiography, Doppler; D019560:Echocardiography, Three-Dimensional; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000706:statistics & numerical data; D006339:Heart Rate / Q000502:physiology; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D013318:Stroke Volume / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology*; D055815:Young Adult
keywords: cardiac output; physical training; stroke volume; three-dimensional echocardiography; tissue Doppler imaging