Segmental myocardial strain in myocarditis in young adultsKirn, Borut (Avtor) Strašek, Katja (Avtor) Awais, Kanza (Avtor) Černe Čerček, Andreja (Avtor) medicineheartmyocarditisIntroduction: Myocardial segmental peak strain (pkS) is used in detection and characterization of myocarditis; however, its clinical diagnostic values are inconclusive. To reveal potential causes of positive and negative study results and evaluate the diagnostic potential of pkS, we quantified its natural variability and compared it to the change in pkS caused by myocarditis. Methods: The study included 34 patients (sex: 29 M, age: 30 ± 7.5 years) with diagnosed myocarditis which underwent two-dimensional speckle tracking echocardiography (2D-STE) in three apical echocardiographic planes at the time of diagnosis (M0) and 6 months (M6) following treatment. In total, 18 longitudinal segmental strain patterns were extracted at each session and a pkS was found as a minimum strain value during systole. The average natural variability (▫$\mathrm{\overline{NVm}}$▫) was calculated from sector values of all unique pkS absolute differences separately at M0 and M6, and myocarditis signal (▫$\mathrm{\overline{MC}}$▫) was calculated from pkS difference in the same patient between M6 and M0. A signal-to-noise ratio was calculated as (▫$\mathrm{\overline{MC}/\overline{NV(M6)}}$▫). Results: We found that the average pkS at M0 and M6 were different (−19% ± 5% and −20% ± 5%, p < 0.05), and the difference was largest around the basal-posterior segment. There was no difference in (▫$\mathrm{\overline{NV}}$▫) between M0 and M6 (5.1% ± 4.2% and 5.0% ± 4.2%, p > 0.05), but they were both significantly larger than (▫$\mathrm{\overline{MC}}$▫) (−1.3% ± 5.3%, p < 0.05). The average signal-to-noise ratio was 0.3, and it was largest in the basal-lateral region and lowest in the anterior-septal region. Conclusion: We found that natural variability in pkS is significantly larger than the change of pkS due to myocarditis. Thus, information about inflammation severity and location from pkS alone needs further investigation.20252026-03-26 13:49:46Neznano28630sl