Longitudinal Strain Has No Ischemic Memory

Background: Subendocardial longitudinal fibers are the most exposed during an ischemic event; therefore, longitudinal deformationis expected to be mainly affected. This would allow detecting subtle changes in myocardial motility visually unnoticed in the recoveryperiod of a positive stress echo.Objective: The aim of this study was to determine whether longitudinal strain by speckle tracking can express ischemic memoryafter the recovery of abnormal myocardial motility during a positive stress echo study.Methods: Positive exercise stress echo studies without previous contractile disorders were included in the study. Resting longitudinalstrain, at 30 seconds after supine exercise, and at 3 and 5 minutes of recovery was analyzed in an EchoPAC workstation.Results: Twenty-one patients with positive stress echo were examined with a total of 101 ischemic segments. Mean longitudinalstrain of ischemic segments at rest was -22.3%±4.3% and in the immediate post-exercise period (<30 seconds) it decreased to16%±3.2%. At 3 minutes of recovery, ischemic segments had higher values than those obtained at rest:-24.3%±5.1% (p=0.047 vs.baseline). Ninety-eight percent of ischemic segments normalized the longitudinal strain after 3 minutes of completing the exercise.Conclusion: Longitudinal strain alterations did not persist after recovery of visually analyzed segment motion abnormalities.