Assessment of age-related changes in left ventricular twist by two-dimensional ultrasound speckle tracking imaging

Abstract

To assess the normal value of left ventricular twist (LVtw) and examine the changes with normal aging by 2-dimensional ultrasound speckle-tracking imaging (STI), 121 healthy volunteers were divided into three age groups: a youth group (19–45 y old), a middle-age group (46–64 y old) and an old-age group (≥65 y old). Basal and apical short-axis images of left ventricular were acquired to analyse LV rotation (LVrot) and LVrot velocity. LVtw and LVtw velocity was defined as apical LVrot and LVrot velocity relative to the base. Peak twist (Ptw), twist at aortic valve closure (AVCtw), twist at mitral valve opening (MVOtw), untwisting rate (UntwR), half time of untwisting (HTU), peak twist velocity (PTV), time to peak twist velocity (TPTV), peak untwisting velocity (PUV), time to peak untwisting velocity (TPUV) were separately measured. The results showed that the normal LV performs a wringing motion with a clockwise rotation at the base and a counterclock-wise rotation at the apex (as seen from the apex). The LVtw velocity showed a systolic counterclock-wise twist followed by a diastolic clockwise twist. Peak twist develops near the end of systole (96%±4.2% of systole). With aging, Ptw, AVCtw, MVOtw, HTU and PUV increased significantly (P<0.05) and UntwR decreased significantly (P<0.05). However, no significant differences in TPUV, PTV and TPTV were noted among the 3 groups (P>0.05). It is concluded that LV twist can be measured non-invasively by 2-dimensional ultrasound STI imaging. The age-related changes of LVtw should be fully taken into consideration in the assessment of LV function.

Keywords

echocardiography / speckle tracking imaging / left ventricular / twist / rotation

References

[1] HarveyW.. WillisF. A., KeysT. E.. An anatomical disposition on the motion of the heart and blood in animals, 1628. Cardiac Classics, 1941, London, England, Henry Kimpton: 19-79

[2] NagelE., StuberM., BurkhardB., et al.. Cardiac rotation and relaxation in patients with aortic valve stenosis. Eur Heart J, 2000, 21: 582-589

[3] YoungA. A., KramerC. M., FerrariV. A., et al.. Three-dimensional left ventricular deformation in hypertrophic cardiomyopathy. Circulation, 1994, 90: 854-867

[4] ChungJ., AbraszewskiP., YuX., et al.. Paradoxical increase in ventricular torsion and systolic torsion rate in type 1 diabetic patients under tight glycemic control. J Am Coll Cardiol, 2006, 47: 384-390

[5] DongS., HeesP., HeesP., et al.. MRI assessment of LV relaxation by untwisting rate: a new isovolumic phase measure of tau. Am J Physiol Heart Circ Physiol, 2001, 281: H2002-H2009

[6] MeunierJ., BertrandM.. Ultrasonic texture motion analysis:theory and simulation. IEEE Trans Med Imaging, 1995, 14: 293-300

[7] TaberL. A., YangM., PodszusW. W.. Mechanics of ventricular torsion. J Biomechanics, 1996, 29: 745-752

[8] Torrent-GuaspF., BuckbergG. D., ClementeC., et al.. The structure and function of the helical heart and its buttress wrapping. The normal macroscopic structure of the heart. Semin Thorac Cardiovasc Surg, 2001, 13: 301-319

[9] StevensC., RemmeE., LeGriceI., et al.. Ventricular mechanics in disastole:material parameter sensitivity. J Biomech, 2003, 36: 737-748

[10] LuoA. G., YinL. X., LiC. M., et al.. Measure of left ventricular torsion with cardiac pacing and right bundle branch block patients by two-dimension ultrasound speckle tracking imaging. Chin J Ultrasonogr (Chinese), 2006, 15: 641-645

[11] TakeuchiM., NakaiH., KokumaiM., et al.. Age-related changes in left ventricular twist assessed by two-dimensional speckle-tracking imaging. J Am Soc Echocardiogr, 2006, 19: 1077-1084

[12] NotomiY., SrinathG., ShiotaT., et al.. Maturational and adaptive modulation of left ventricular torsional biomechanics: Dopple tissue imaging observation from infancy to adulthood. Circulation, 2006, 113: 2524-2533

[13] OxenhamH. C., YoungA. A., CowanB. R., et al.. Age-related changes in myocardial relaxation using three-dimensional tagged magnetic resonance imaging. J Cardiovasc Magn Reson, 2003, 5: 421-430