Abnormal QT Dynamics and Nocturnal Temporal QT Dispersion in Brugada Syndrome

Abstract

Background:The issue of risk stratification in Brugada syndrome is still unanswered.Methods: In the Piemonte region registry, patients with Brugada sign at ECG were prospectively evaluated. EP study was performed in 78% of the patients. ICD was implanted in patients with previous cardiac arrest or induced sustained ventricular arrhythmias.Results: 70 patients were included, 80% males, mean age 45±15 years, 75% symptomatic and 25% asymptomatic. Of the symptomatic patients, 49% had vasovagal syncope, 25% undetermined syncope, 16% paroxysmal palpitations and 10% cardiac arrest; sustained ventricular arrhythmias were induced in 45%: 42% in symptomatic patients and 3% in asymptomatic. Sustained ventricular arrhythmias were induced in 38% of the patients with vasovagal syncope, as compared to 100% of the patients with cardiac arrest (p=0.039) and to 72% of the patients with undetermined syncope (p=0.06, NS). None of the patients with paroxysmal palpitations was induced. Twenty-five patients underwent ICD implantation. At a mean follow-up of 36±30 months 3 out of 22 symptomatic patients received an appropriate ICD shock. No ICD shock occurred in asymptomatic patients.Conclusions: EP study correctly identified the high risk patients. Vasovagal syncope does not imply per se good prognosis, while paroxysmal palpitations have not prognostic implications.