Shaheed Rajaie Cardiovascular Medical Center,Mellat Park,Vali-AsrAvenue,Tehran,Iran
Background-The Brugada syndrome is a distinct form of idiopathic ventricular fibrillation that consists of ECG abnormalities at baseline or after provocation in the absence of documented structural heart disease.In this article,we present the clinical and electrophysiological data and follow-up of our patients with Brugada syndrome,which is the largest ever reported series in Iran.
Methods-We retrospectively studied the clinical, electrocardiographic and electrophysiologic characteristics of twenty consecutive patients with definitive diagnosis of Brugada syndrome that have been evaluated at our center from September 2001 to December 2003.We also searched for possible discriminate variable(s) between patients with vs. without inducible ventricular arrhythmia during programmed electrical stimulation.
Results-We studied 15 men and 5 women with mean age of 42±9 years.The typical ECG abnormality was recognized in five (25%) patients either after resuscitated cardiac arrest (2 patients) or syncopal episodes (3 patients).Fifteen patients (75%)were asymptomatic.The abnormal ECG was identified spontaneously in 6 (30%) patients and after pharmacological challenge with class IA or IC antiarrhythmic drugs in 14 (70%) patients. The mean values of PR interval, QT interval, and ST-segment elevation were similar in symptomatic and asymptomatic individuals (P=0.75,P=0.18,P=0.26,respectively)The PR intervalwas mildly longer in males compared to females (0.042) but the magnitude of ST-segment elevation was similarin both sexes (P=0.057). Electrophysiologic study was performed in 15 (75%) patients for further risk stratification.The HV interval was longer in males than females (P=0.047).Sustained ventricular arrhythmias were induced in 40% of asymptomatic patients. There was no statistically significant difference in mean age, sex, PR interval, ST elevation, and HV interval of inducible and non-inducible patients. An implantable cardioverter-defibrillator was implanted in 8 (40%) patients with aborted SCD,history of syncope or inducible sustained ventricular arrhythmiasin programmed electrical stimulation. During 16±2 months follow-up, one patient had appropriate device therapy.None of the asymptomatic and non-inducible patients experienced any event.
Conclusions-The asymptomatic and non-inducible individuals with Brugada syndrome have a low risk of cardiac events. The baseline demographic (age, sex), and electrophysiologic (PR, ST elevation,HV) data have no role in predicting inducibility in programmed electrical stimulation.