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Torsion has attracted significant attention recently as a potential novel index of cardiac function because it links the helical anatomic arrangement of cardiac fibers with physiologic rotational motion. Several techniques have been used to describe and quantify ventricular torsion in human. Our aim was comparison of the two methods Tissue Doppler Imaging (TDI) and Velocity Vector Imaging (VVI) in assessment of various LV(left ventricular) torsional parameters in healthy human subjects.
47 healthy men and women (41±9 years old) were included in the present study. All volunteers underwent complete echocardiographic study; we analyzed the rotation curves at apex and base and calculated the net twist and torsion of the LV. We also calculated the twist and untwist rates, normalized by LV length and systolic duration in both methods.
Twist degree was significantly lower in VVI method when compared with TDI method (11.05±2.45° vs. 13.95±4.27° p=0.008), but not LV torsion (1.53±0.42°/cm vs. 1.76±0.56 °/cm vs. p=0.132). Twisting rate (75.88±17.25 °/s in VVI vs. 95.79±24.87 °/s in TDI; p=0.004 respectively) and untwisting rate (−73.79±24.45 °/s in VVI vs. −110.96±34.65 °/s in TDI; p=0.000) were lower in VVI. Normalization by systolic duration, but there was no significant difference between two methods in twisting and untwisting rates (p=0.411).
The results showed that VVI gives absolutely lower LV torsional parameters; however, when we normalized them to LV length and systolic duration the values were comparable for both imaging techniques. We have discussed all parameters and all normalization techniques comprehensively.
Poster Sessions, Expo North
Monday, March 11, 2013, 9:45 a.m.-10:30 a.m.
Session Title: Imaging: CRT/New Technology
Abstract Category: 18. Imaging: Echo
Presentation Number: 1312-335
- 2013 American College of Cardiology Foundation