Ann Noninvasive Electrocardiol. 2026 Jan;31(1):e70137. doi: 10.1111/anec.70137.
ABSTRACT
BACKGROUND: Ajmaline challenge (AC) is used for diagnosing suspected Brugada syndrome (BS) in patients with unexplained syncope, survived cardiac arrest, or for family screening.
PURPOSE: To evaluate baseline ECG markers predicting a positive AC in the absence of a spontaneous diagnostic Brugada ECG.
METHODS: Baseline ECGs of 221 consecutive patients undergoing AC (up to 1 mg/kg bodyweight) were analyzed. ECGs from positive and negative tests were compared, with Q-, R-, S-, J-, and T-wave amplitudes and intervals measured in all 12 leads.
RESULTS: 221 patients underwent AC; the cohort was 71% male, and 7% had survived cardiac arrest. AC was positive in 93 patients (42%). Prominent S-waves in lead II and J-waves in V1 predicted a positive AC (S-wave duration: 36 vs. 22 ms, p < 0.01; J-wave amplitude V1: 0.06 vs. 0.01 mV, p < 0.001). ROC analysis confirmed discriminative value for S-wave duration in lead II (AUC 0.79) and J-wave amplitude in V1 (AUC 0.71). A cut off of ≥ 19 ms for S-wave duration in lead II showed 96% sensitivity for a positive test (OR 17.3, p < 0.001). J-wave amplitude in V1 ≥ 0.05 mV was also significantly associated (OR 5.4, p < 0.001).
CONCLUSION: In patients without a spontaneous diagnostic Brugada ECG, prominent S-waves in lead II and J-waves in V1 are subtle electrical abnormalities that help identify patients and family members with a higher likelihood of positive AC.
PMID:41355478 | PMC:PMC12683172 | DOI:10.1111/anec.70137