How to measure LV Strain
3 imaging planes — 4-ChV, 2-ChV, APLAX
Focus on the LV (“cut off” the atria)
All walls & segments should be visible
Older Software ➜ start with APLAX
Newer Software ➜ looks for the imaging planes and measures itself (if preferred)
CAVE: EKG is still a MUST (P-wave, QRS-complex, T-wave)
Similar heart rates required (difference < 5 heartbeats, multiplane as an alternative in AFIB)
AVC = Aortic valve closure identification works well (vendor dependent)
ROI = region of Interest — thin myocardium ➜ smaller ROI, thick myocardium (e.g., HCMP) ➜ broader ROI (full-wall strain)
Sigmoidal septum CAVE — prone to error in regional measurement in this small area (interference of radial & endocardial layers) ➜ don’t measure per se in endocardial strain or discuss limitation in the report, in full-wall strain CAVE
ROI: 90% of the myocardium (not the pericardium, not the atrial structures, the LVOT ➜ underestimation; blood speckles ➜ overestimation)
Evaluation of plausibility is operator dependent
Experience: 50 measurements are recommended to ensure correct measurements
Layer specific Strain — longitudinal all myocardial layers act the same during contraction, less Speckles (only 1 layer) has to be used with caution and are probably without any relevant additional information (in the PSAX the LV-mechanics are not the same)
Endocardial Strain vs. Full-wall Strain: Endocardial strain is more prone to error in Foreshortening and overall less accurate (less Speckles)
In an automated software, interfere as little as possible, also a not expected regional strain curve should be accepted, otherwise the bias increases, same holds true for manual changes in tracking. If the measurement is globally subotpimal, don’t use it. Personal tip — get used to your software and your vendor (individual strengths and limitations)
