OBJECTIVE: To analyze the specific risk for the variables: type 1 spontaneous pattern, type 1 induced pattern, type 1 pattern with spontaneous variability, syncope, family history of sudden death, atrial fibrillation and atrial flutter with the subsequent development of malignant arrhythmic events. METHODS: Forty-three Brugada patients (90% males; mean age 40.4 years), with a type 1 spontaneous pattern (74.4%) or induced by ajmaline (25.6%) were retrospectively analyzed. Of these, 58.1% presented spontaneous variability, 18.6% had family history of sudden death, 39.5% were symptomatic, and 18.6% presented atrial fibrillation or atrial flutter. The antecedents of resuscitated cardiac arrest, sudden death or appropriate shock from implantable automatic defibrillator were considered malignant arrhythmic events. During a mean follow up of 51 months, no deaths were recorded, 6.9% of the patients presented a malignant arrhythmic event, and all of them were appropriate shocks. The annual rate of events in patients with syncope was 1.7%, with a spontaneous type 1 pattern was 2.79%, and spontaneous variability was 2.87%. No malignant arrhythmic event was observed in asymptomatic patients or in those with a persistent pattern or induced type 1 pattern. The annual rate of events with positive or negative history of family sudden death was 2.94 and 1.7%, respectively. In the presence of atrial fibrillation, atrial flutter and atrial fibrillation/atrial flutter were 7.3, 15.69 and 10%, respectively. In the absence of atrial fibrillation/atrial flutter no malignant arrhythmic events were observed. CONCLUSION: Of the variables analyzed, the one that was most related to a malignant arrhythmic event was the presence of atrial fibrillation (P=.046) and atrial flutter (P=.03).