Mărgulescu AD, et al. - In a prospective study of 72 individuals categorized into in four equal groups ie, group 1, left ventricular (LV) ejection fraction (LVEF) ≥ 50%, healthy; group 2, LVEF ≥ 50%, presence of cardiovascular disease and/or risk factors; group 3, LVEF 30%–49%; and group 4, LVEF ≤ 29%, researchers evaluated the reproducibility of combined acquisition and measurements of longitudinal peak systolic segmental strain (LPSS) across the spectrum of LVEF. On average, across groups, the intraobserver and test-retest intraclass correlation coefficients and mean absolute differences of repeated acquisition and measurement of LPSS were comparable. Nonetheless, interobserver intraclass correlation coefficients and mean absolute differences reduced in group 4 vs groups 1 to 3. Of all LV segments, particularly in group 4, in which LPSS was not reproducible in most segments, the intraobserver, test-retest and interobserver coefficients of variation became worse as LVEF declined. In comparison with apical segments, the reproducibility of LPSS in basal LV segments was worse. Hence, the clinical applicability of LPSS was concluded to be limited by suboptimal reproducibility, even when a single spectator repeats both acquisition and measurements. Moreover, advances in LPSS during patient follow-up should be evaluated with care.