Diagnosis and long-term follow-up of the Brugada syndrome in patients withidiopathic ventricular fibrillation

Aims Some patients with idiopathic ventricular fibrillation may suffer from the Brugada syndrome. The diagnostic criteria for the Brugada syndrome are uncertain and arbitrarily set. Therefore, we studied the prevalence of the Brugada syndrome using various diagnostic criteria and long-term follow-up in 37 idiopathic ventricular fibrillation patients. Methods and Results Idiopathic ventricular fibrillation was diagnosed after thorough clinical evaluation in 37 survivors of an out-of-hospital cardiac arrest referred to our institute (UMC Utrecht). Retrospectively, nine pati ents (24% group I) were classified as potentially having the Brugada syndro me based on the presence of (in)complete right bundle branch block and ST-s egment elevation in leads V-1-V-3 of greater than or equal to1 mm. Only thr ee patients (8%, group II) showed (in)complete right bundle branch block an d greater than or equal to2 mm ST-segment elevation. With the intermittent presence of these ECG features and/or their (re)appearance with class I ant iarrhythmic drugs included as criteria, the percentage of the Brugada syndr ome was attenuated in group I (2/37; 5%) and group II (1/37; 3%). Sixteen ( 43%) of all idiopathic ventricular fibrillation patients (mean follow-up 77 +/-41 months) had a recurrent episode of syncope, ventricular tachyarrhythm ias or sudden death. Recurrence rate was 3/9 (33%) in Brugada patients grou p I, 2/3 (66%) in group II and 13/28 (46%) in patients without the Brugada syndrome (P=ns). Conclusions Depending on the diagnostic criteria used, the Brugada syndrome was observed in 3% to 24% of patients with idiopathic ventricular fibrilla tion, underlining the importance of defining the precise diagnostic criteri a in these patients. For all idiopathic ventricular fibrillation patients, the ventricular tachyarrhythmia recurrence rate was substantial during an a verage Follow-up of more than 6 years. (Eur Heart J 2001; 22: 400-409, doi: 10.1053/cuhj.2000.2366) (C) 2001 The European Society of Cardiology.