Comparison of commonly used echocardiographic techniques / indices to evaluate mechanical dyssynchrony with STOUT- indices.
Evaluation of dyssynchrony
Technique
strenght
Current technologies
TDI /TSI (timing peaks)
TDI-strain (timing peaks)
2-DSE (timing peaks)
3-D (timing min. volumes)
STOUT-reconstruction
Vector on 2-DSE timing
ISF
PSrV
ESR
2-D M-mode / bulls-eyes
Index is physiologic marker of
Spatiotemporal
info / mapping
Temporal
resolution
Estimator of
functional impact
Operator
independency
??
Timing local shortening / ejection
Timing local shortening / ejection
Timing local ejection
+/- (12D/3D)
+/- (12D)
+ (2D)
+ (3D)
<10 ms
<10 ms (<5*)
< 20 ms
35-50 ms
+/+/+/-
+/+/+(+)
Spatial sequence LV ejection
LV shortening/ejection inefficiency
Spatial organization LV inefficiency
Inefficiency (amendable fraction?)
Visual map spatiotemporal shortening
+(+) (23D)
+ (23D)
+(+)
10-15 ms
N.A.
per 20 ms
N.A.
<10-25 ms
+/+(+)
?
+(+)
-
+
+
+(+)
+
+(+)
Legend:
Techniques: TDI: Tissue Doppler (velocity) imaging; TSI: Tissue Synchronization imaging, automated measurement of peak velocities in 6 basal
and 6 mid-ventricular segments; TDI-strain: TDI-derived strain imaging; (*) = if single wall acquisition. 2-DSE: Speckle-derived 2-D strain
imaging as routinely applied on 2-, 3- and 4-chamber sector scans; 3-D: Full volume 3-D echocardiography with automated detection of time to
minimal volumes; STOUT-reconstruction: incorporation of segmental strains obtained from single wall acquisitions into STOUT; ISF: Internal
Strain Fraction; PSrV: Paradoxical strain-rate vector; ESR: early shortening reserve, 2-D M-mode / bulls-eyes :graphical representations of
amplitudes over time, interpolated to 1 ms (M-mode) or divided into RR/25 (ms) see text for details.
Values: (12D) indicates the use of an intrinsically (angle-dependent) 1-D technique enabling comparison in 2D (or 3D by TSI); (23D)
indicates the use of an intrinsically (in plane angle-independent) 2-D technique reconstructed into a 3-D model. Scoring by – denotes poor; by +/moderate or only partially related to; by + good; by +(+) better / specifically designed for. N.A. = Not applicable, the index has no / is little
dependent on temporal characteristics. For operator independency, independency to insonation angle and limited manual interventions by
automation / computerization of technique and measurement are considered beneficiary. See text for details.