New Approach for Rotational Dyssynchrony Using Three‐Dimensional Speckle Tracking Echocardiography

Abstract

Left ventricular (LV) twist can be evaluated using two-dimensional speckle tracking echocardiography (2DSTE) by analyzing difference between apical and basal rotation. However, it is unable to evaluate global rotational dyssynchrony because it cannot assess mid-wall rotation. Recently developed three-dimensional STE (3DSTE) can investigate LV global rotational dyssynchrony. In this study, we investigated the role of torsion on the long-term effects of cardiac resynchronization therapy (CRT) using 3DSTE. We evaluated 43 patients by 3DSTE: 12 CRT responders, 14 CRT nonresponders, and 17 healthy normal controls. Regional torsion and rotation were assessed using 3DSTE across 16 segments during CRT-off (native conduction) and CRT-on. The following parameters were calculated: global peak twist, Δ global peak twist (difference between CRT-on and CRT-off), and torsion delay index. The torsion delay index was considered to be the rotational energy lost by rotational dyssynchrony. Global peak twist did not show significant differences between the responders and nonresponders during CRT-off (4.0 ± 3.4° vs. 2.8 ± 2.3°, P = 0.295), but it significantly improved in responders compared to nonresponders after CRT-on (5.4 ± 3.5° vs. 2.6 ± 2.6°, P = 0.029). The torsion delay index during CRT-off was significantly higher in responders compared to nonresponders and normal controls (18.5 ± 11.3 vs. 8.6 ± 3.8 and 7.8 ± 5.5, P = 0.010 and P = 0.004, respectively). The torsion delay index during CRT-off significantly correlated with the Δ global peak twist (r = 0.503, P = 0.009). Improvement in LV global peak twist, which is one of the mechanisms for the long-term effects of CRT correlated with the torsion delay index during native conduction that can only be calculated by 3DSTE.

The implementation of speckle tracking echocardiography for cardiac resynchronization therapy optimization. A rotational myocardial mechanics interpretation

“…However, it is still uncertain what is the best echocardiographic index of cardiac asynchrony, although recently STE and 3D echocardiography have provided reliable and more predictive data than those used prior to these innovative imaging modalities (16). LV myocardial torsional mechanics are known to be compromised in HF patients (17,18,19), though an increasing interest for its role in assessing improvement to CRT is recently noticed (20). The reasons of this investigating hesitancy might be the low reproducibility of measurements, the complex helical ventricular architecture and contraction and the different vectors' software tools that frequently provide contradictory data of identical phenomena.…”

Acute Modifications of Left Ventricular Torsional Mechanics Induced by Cardiac Resynchronization Therapy Affect Short-Term Reverse Remodeling

“…The TDI is considered to represent the amount of rotational energy lost by dyssynchrony. 10 Finally, LV torsion curves were filtered by polynomial interpolation and analytically derived to measure the untwisting rate (UTR) value and recoil rate (i.e., the slope of the linear regression of recoil (i.e., untwisting) vs. time in early diastole). 18 Receiver-operating curves (ROC) were used to assess the capacity of a given measurement to assess the presence/ absence of the LV remodeling response at follow-up.…”

“…Another interesting aspect to this study is the relation between torsional regional mechanics and the degree of dyssynchrony of dysfunctional ventricles. Retracing Lee et al's study, 10 we analyzed the TDI and its variations in our population with CRT-off/on. Unfortunately, we did not find any significant interaction for this parameter between the 2 patients' groups, although we could detect an overall significant reduction in dyssynchrony with CRT-on as compared with CRT-off (P=0.001, Table 2).…”

The value of STE-LDDSE to detect viable myocardium

“…Due to its angle-independent nature, STE can provide more accurate assessments of local and global myocardial function, making it highly valuable for detecting viable myocardium. The combination of STE and LDDSE further enhances the sensitivity and speci city, maximizing the detection of viable myocardium (9)(10)(11)(12).…”