Real-World Feasibility and Challenges in Using LAS for Stress EchocardiographyDear Editor,Fitzgerald et al. (2025) investigate left atrial strain (LAS) in stress echocardiography to evaluate diastolic dysfunction and myocardial ischemia. This critique examines the unaddressed methodological gaps that affect the reliability and clinical utility of LAS. [1]The study neglects to assess inter-observer and intra-observer variability in LAS measurements, despite using semi-automated speckle-tracking echocardiography with manual adjustments. This omission undermines claims of LAS reproducibility, as operator variability could compromise measurement consistency across clinical settings. Edwards et al. (2024) showed that novices produce less consistent LAS measurements than experts [2]. Ha et al. (2020) noted that variability in echocardiographic techniques can affect diagnostic reliability [3]. Cameli et al. (2016) highlighted that operator-dependent factors impact LAS reproducibility, critical for clinical adoption [4]. Without such data, the study’s findings lack robustness for universal application.The study assumes abnormal LAS responses indicate elevated LA filling pressures or dysfunction but lacks invasive validation (e.g., LA/LV pressure measurements). This speculative physiological basis weakens LAS’s validity as a diagnostic marker. Invasive measurements are crucial to confirm diastolic dysfunction or ischemia. Ha et al. (2020) emphasized invasive validation for non-invasive markers like LAS [3]. Cameli et al. (2016) stressed invasive correlation for LAS’s clinical utility [4]. Edwards et al. (2024) noted that unvalidated assumptions about echocardiographic markers limit their diagnostic reliability [2]. This gap hinders LAS’s clinical applicability.While Fitzgerald et al.’s work offers valuable insights into LAS in stress echocardiography, addressing observer variability and incorporating invasive validation would strengthen reproducibility, enhance physiological validity, and improve its potential for broader clinical application.References1. Fitzgerald, B.T., Chan, J., Lam, A.K. and Scalia, G.M. (2025), Assessing the Use of Left Atrial Strain Before and After Treadmill Exercise Stress Echocardiography. Echocardiography, 42: e70253. https://doi.org/10.1111/echo.702532. Edwards NF, et al. The Learning Curve for Left Atrial Strain Analysis. Journal of the American Society of Echocardiography. 2024;37(10):1014–1016.3. Ha JW, et al. Diastolic Stress Test: Invasive and Noninvasive Testing. JACC Cardiovascular Imaging. 2020;13(1 Pt 2):272–292.4. Cameli M, et al. Left Atrial Strain: A New Parameter for Assessment of Left Ventricular Filling Pressure. Heart Failure Reviews. 2016;21(1):65–76.Author detailMuhammad Mudasir AtifAffiliationJinnah Sindh Medical University