Risk Stratification for the Occurrence of Ventricular Fibrillation in Patients with Early Repolarization Syndrome

(background): Several signs of malignant early repolarizations (ERs) have been proposed in patients with ER syndrome (ERS). However, recent reports have challenged the efficacy of these signs in predicting future ventricular fibrillation (VF) in patients with ERS.

(objective): To assess the predictive value of various electrocardiograms (ECG) in predicting future VF events among ERS patients.

(methods): We retrospectively evaluated the clinical characteristics of 44 ERS patients to identify risk factors for VF during follow-up.

(results): Following the initial event, 16 patients experienced VF (VF group), while 28 did not (non-VF group). The VF group had a longer QRS interval, more fragmented QRS (fQRS), and a higher T/R voltage ratio than the non-VF group. Wide J-waves were more prevalent in the VF group; however, other J-wave markers did not differ between the groups. Positive late potentials (LPs) recorded on signal-averaged ECGs were more frequent in the VF group. While none of the patients showed spontaneous Brugada on ECG, the VF group frequently exhibited pilsicainide-induced ST-segment elevation. These ECG markers were significantly associated with the occurrence of VF during follow-up. Patients with multiple ECG factors: including QRS abnormalities (wide QRS or fQRS), wide J waves, and a high T/R ratio, had a worse prognosis than patients without multiple factors, effectively stratifying patient risk.

(conclusions): The occurrence of VF in patients with ERS may be associated with conduction abnormalities such as QRS widening, fQRS, high T/R ratio, positive LPs, and pilsicainide test results. Therefore, ECG factors could be useful in identifying high-risk patients.