Strain-Based stages of LBBB-induced LV Remodelling
Speckle tracking strain analysis & mechanical events
Definition
≥Systolic stretch + systolic rebound stretch = systolic stretch index
≥ 2,6% ➜ basal & mid-wall segments without the apical segments
Simon et al.,A Strain-Based Staging Classification of Left Bundle Branch Block-Induced Cardiac Remodeling,JACC: Cardiovascular Imaging, 2021
Definition & measurements
Lateral (red) initial positiv (pre-stretch) as the septum initially contracts, afterwards delayed contraction laterally & septal positive value (rebound stretch, turquoise)
Gorcsan, JACC 2019
A calculation example
{(Anterolateral basal + mid-segmental) + (inferolateral basal + mid-segmental)}/2 + {(anteroseptal basal + mid-segmental) + (inferoseptal basal + mid-segmental)}/2 = {(4% + 4%) + (4%+1%)}/2 + {(-1% + -4%) + (7% + -1%)}/2 = 6,5% + 0,5% = 7% systolic stretch index in stage 4 LBBB
