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Table 3 Strain parameters derived from Philips echocardiographic images

From: Comparison of strain parameters in dyssynchronous heart failure between speckle tracking echocardiography vendor systems

  Philips QLAB (n = 88) TomTec 2DCPA (n = 88) COV ICC (p-value) Bland-Altman (mean diff ±SD)
LV
 1) Pre-stretch (%) 0.0 (0.0–0.0) 0.0 (0.0–0.2) 4.125 −0.052 (0.684) −0.1 ± 0.6
 2) Peak strain (%) −7.7 ± 2.7 −7.7 ± 3.3 −0.350 0.749 (<0.001) 0.0 ± 2.1
 3) Systolic strain (%) −6.8 ± 3.0 −7.0 ± 3.5 −0.435 0.802 (<0.001) 0.2 ± 2.0
 4) TTPmax (ms) 527 (444–592) 492 (396–559) 0.185 0.376 (<0.001) 34 ± 113
 5) TTPfirst (ms) 361 (112–438) 361 (118–413) 0.567 0.165 (0.061) 2 ± 213
Septum
 1) Pre-stretch (%) 0.0 (0.0–0.0) 0.0 (0.0–0.4) 3.990 −0.035 (0.627) −0.3 ± 0.9
 2) Peak strain (%) −7.6 ± 2.7 −8.0 ± 3.7 −0.363 0.626 (<0.001) 0.5 ± 2.8
 3) Systolic strain (%) −6.5 ± 3.0 −7.0 ± 3.9 −0.468 0.667 (<0.001) 0.5 ± 2.9
 4) TTPmax (ms) 541 (442–598) 477 (346–575) 0.202 0.109 (0.155) 61 ± 179
 5) TTPfirst (ms) 361 (118–426) 161 (114–342) 0.534 0.232 (0.014) 84 ± 185
Lateral wall
 1) Pre-stretch (%) 0.0 (0.0–0.1) 0.3 (0.0–0.8) 2.728 0.324 (<0.001) −0.5 ± 1.0
 2) Peak strain (%) −8.0 (−9.4 - -6.1) −9.0 (−11.1 - -6.3) −0.345 0.631 (<0.001) 1.3 ± 3.0
 3) Systolic strain (%) −6.4 (−9.0 - -5.2) −8.0 (−11.1 - -4.9) −0.436 0.680 (<0.001) 1.5 ± 3.0
 4) TTPmax (ms) 542 (454–597) 476 (434–538) 0.175 0.531 (<0.001) 36 ± 87
 5) TTPfirst (ms) 376 (107–461) 433 (216–481) 0.550 0.060 (0.290) −41 ± 239
Dyssynchrony
 a) SL-delay (ms) 0 (0–0) −20 (−121–120) −10.694 0.025 (0.409) 24 ± 180
 b) SRSsept (%) 0.7 (0.3–1.2) 1.7 (0.6–3.3) 1.030 0.419 (<0.001) −1.5 ± 2.1
 c) SSI (%) 0.8 (0.4–1.5) 2.3 (1.1–4.2) 1.024 0.421 (<0.001) −2.0 ± 2.4
 d) LBBB type (n, %)      
  LBBB-1 33 (38.4%) 33 (37.5%)    
  LBBB-2 3 (3.5%) 11 (12.5%)    
  LBBB-3 50 (58.1%) 44 (50.0%)    
  1. Means and standard deviations are given with ± symbol, for non-normal distributed data, the median is given with the interquartile range between brackets
  2. COV coefficient of variation, ICC intra-class correlation coefficient, diff: difference, SD standard deviation, LV strain derived from global LV in apical four chamber view, TTP max time to maximal peak shortening, TTP first time to first peak shortening, SL-delay time delay between septal and lateral peak shortening, SSI systolic stretch index, SRSsept septal systolic rebound stretch, LBBB type type of LBBB strain patterns, based on definition by Leenders et al. [23]