Sign concordance of the Lean RECD tick and Level-3 excess3 on ten pre-VF Holter recordings

Background. Ten SDDB Holter recordings that end in ventricular fibrillation had been contrasted, basal window against approach window, for systemic tau (τs) and for Level-3 excess3. The Lean tick ΔT = g(τs)|τs|, from the Module CT gate g, had not been compared with excess3 on these recordings. Methods. Source windows and anchors were kept (W = 101, stride 5, Bandt-Pompe order 3, delay 1, kn = 0). The sign of ΔA, the approach-minus-basal mean of ΔT, was compared with the sign of Δexcess3 and with the sign of Δτs. The frozen abs-z alarm was applied to both series after a control of sensitivity and median lead time. Lead-time differences are given in hours. Results. The control matched the published sensitivity and medians. The sign of ΔA matched Δexcess3 in 8/10 records, and records 32 and 45 did not match. It matched Δτs in 6/10 records (failures 32, 45, 47 and 50). The alarm of ΔT occurred in 6/10 records, only where excess3 also alarmed, and was absent in records 31, 35, 47 and 50. On the six double alarms the absolute differences were 0.95, 0.01, 0.35, 0.05, 0.07 and 5.15 h. Five are below one hour, and record 51 (1.74 h against 6.89 h) is the hour-scale difference. Conclusion. The sign of ΔA matches Δexcess3 in 8/10 records, with failures in records 32 and 45, and matches Δτs in 6/10. The alarm of ΔT occurs in 6/10 records and adds none. Among double alarms, only record 51 differs on the hour scale. Version 1.1.0 corrects the alarm statement of version 1.0.0 (10.5281/zenodo.23202156). A stride-5 step is five beats and is not an agreement criterion. Correspondence: [email protected]. ORCID: https://orcid.org/0000-0002-5797-6931.