title: Left ventricular torsional dynamics post exercise for LV diastolic function assessment.
abstract: OBJECTIVE
  2D speckle tracking echocardiography allows for assessment of left ventricular (LV) torsional deformation as a composite function of the radial, longitudinal and circumferential fibres. We test the hypothesis that post-exercise LV torsional dynamics are more sensitive markers for myocardial dysfunction than resting measures, and better predictors for exercise capacity compared to post-exercise LV diastolic filling pressure (E/e').
  
  
  METHODS
  We studied 88 patients referred for stress echocardiogram. Treadmill exercise was performed using Bruce protocol, and echo images were acquired using GE Vivid 7. LV rotational dynamics were analysed by speckle tracking method using the GE ECHOPAC software. Tertiles were defined according to exercise capacity measured by the achieved metabolic equivalents (METS) adjusted for age and gender. Comparison was made between LV torsional dynamics and E/e' to correlate with METS to predict exercise capacity.
  
  
  RESULTS
  Mean age of the study population was 58 years, 48% females. Patients with systolic dysfunction or evidence of ischaemia were excluded from the analysis. No significant correlation was found between METS and LV torsion measures at rest. There was statistically significant correlation between METS and post-exercise LV torsion (r=0.34, p=0.001), twist velocity increase (r=0.27, p=0.01), and incremental change in torsion (r=0.22, p<0.05). In addition, a correlation was also shown between post-exercise E/e' and METS (r=-0.33, p=0.002).
  
  
  CONCLUSIONS
  Post-exercise LV torsional dynamics correlate with exercise capacity and may be a useful tool for assessing LV myocardial function in subjects with normal LVEF.
authors: Department of Cardiology, The Northern Hospital, 185 Cooper Street, Melbourne, Victoria 3076, Australia. asrar.ulhaq@me.com.
authors: Muhammad
authors: M
authors: Asrar ul Haq
authors: Vivek
authors: V
authors: Mutha
authors: Tina
authors: T
authors: Lin
authors: Konstantinos
authors: K
authors: Profitis
authors: Zoe
authors: Z
authors: Tuer
authors: Kwang
authors: K
authors: Lim
authors: David L
authors: DL
authors: Hare
authors: Chiew
authors: C
authors: Wong
mesh_terms: D000328:Adult; D004452:Echocardiography / Q000379:methods; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods; D005080:Exercise Test; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008297:Male; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D014102:Torsion Abnormality / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology*