Assessment of left ventricular rotation and torsion with two-dimensional speckle tracking echocardiography.
BACKGROUND
Speckle tracking echocardiography (STE) has a unique feature of angle independence and, thus, may provide a powerful means of assessing left ventricular (LV) torsion (LVtor). The aims of this study were to assess: (1) the feasibility of 2-dimensional STE in the measurement of LVtor; and (2) the relationship of LVtor with age and conventional echocardiographic parameters.


METHODS
We consecutively recruited 160 healthy volunteers. After obtaining conventional echocardiographic parameters, apical and basal short-axis rotations were assessed with STE. LVtor was defined as the net difference between rotation angles in the two short-axis planes normalized for LV longitudinal length.


RESULTS
Reliable LVtor measurement was possible only in 56 volunteers (35%). This low feasibility was largely a result of the failure to obtain reliable basal rotation values. In 56 volunteers who were finally enrolled in this study, a significant correlation was found between LV ejection fraction and LVtor (r = 0.56, P < .001) and this correlation was attributed to apical (r = 0.47, P < .001) but not basal (P = .14) rotation. There was no significant change in LVtor with aging. However, initial counterclockwise motion (r = -0.51, P = .001) and its interval (r = -0.44, P = .001) in the basal rotation gradually decreased with aging, and correlated with early transmitral inflow velocity (r = 0.44 and 0.49, respectively) and its deceleration time (r = -0.43 and -0.48, respectively) (all P < .001). In contrast, such correlations were not found for initial clockwise motion and its interval in the apical rotation.


CONCLUSIONS
Currently, STE has limited feasibility in the measurement of LVtor. There was no significant age-related change in LVtor. In LV rotations, basal rotation was affected by the age-related changes in the LV early diastolic filling, whereas apical rotation was mainly related to LV systolic performance.
Kim
Hyung-Kwan
HK
Division of Cardiology, Department of Internal Medicine, Seoul National University College of Medicine, Cardiovascular Center, Seoul National University Hospital, Seoul, Korea.
Sohn
Dae-Won
DW
Lee
Sang-Eun
SE
Choi
Su-Yeon
SY
Park
Jin-Shik
JS
Kim
Yong-Jin
YJ
Oh
Byung-Hee
BH
Park
Young-Bae
YB
Choi
Yun-Shik
YS
D000328:Adult; D000367:Age Factors; D015331:Cohort Studies; D004452:Echocardiography / Q000379:methods*; D017548:Echocardiography, Transesophageal / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011336:Probability; D012016:Reference Values; D012680:Sensitivity and Specificity; D014102:Torsion Abnormality / Q000000981:diagnostic imaging*; D016277:Ventricular Function, Left / Q000502:physiology*