Clinical observations of supraventricular arrhythmias in patients with brugada syndrome.

OBJECTIVE To study various types of supraventricular arrhythmias in patients with Brugada Syndrome. METHODS Forty six patients with ECG of spontaneous type Brugada and with ventricular and/or supraventricular tachyarrhythmia, without structural heart diseases which were excluded by echocardiography, underwent 24 h-Holter recording, electrophysiological study and/or radiofrequency ablation. RESULTS There were thirty-nine male and seven female (mean age 37.44 years) among total forty-six patients. Twenty one patients had family histories of tachycardia, twentythree patients experienced episodes of syncope, and three patients were resuscitated from cardiac arrest. One patient had ventricular fibrillation and third degree atrioventricular block, eleven patients had polymorphic ventricular tachycardia and five patients had monomorphic ventricular tachycardia. Fourteen patients had atrial tachyarrhythmia, paroxysmal supraventricular tachycardia was found in five patients including four Wolf-Parkinson-White syndrome, two patients hadventricular tachycardia and third degree atrioventricular block, one of them had atrial fibrillation, two patients had both supraventricular tachycardia and ventricular tachycardia, three patients had both atrial tachyarrhythmia and supraventricular tachycardia, two third degree atrioventricular block patients had atrial flutter, one patienthad both atrial tachyrhythmia and ventricular tachycardia. Radiofrequency blation was performed in thirty-nine patients and succeed in thirty-two, four patients were implanted with pacemakers, and four patients had implantable cardioverter defibrillators. CONCLUSION In addition to ventricular tachycardia and ventricular fibrillation, patients with Brugada syndrome exhibit various supraventricular tachyarrhythmia and third degree atrioventricular block. In patients with Brugada syndrome, the dysfunction of the cardiac ion channel, which related to mutation of cardiac sodium channelgene, is not limited in His Purkinje system and ventricular myocardium, but also in the atrium and atrioventricular node, which may serves as a cause of dispersion of repolarization and phase 2 reentry leading to various arrhythmias.