“Brugada Syndrome”: A Structural Cardiomyopathy or a Functional Electrical Disease?
Five years ago we described a new syndrome characterised by an electrocardiographic pattern consisting of right bundle branch block with elevation of the ST segment in leads V1–V3 and sudden death caused by rapid polymorphic ventricular arrhythmias. None of the initially described patients had any demonstrable form of heart disease. Nowadays, thanks to international cooperation, we have obtained long-term information on a large cohort of patients with this syndrome. Data on 63 patients (57 males, mean age 38 ± 17 years) were analysed. Twenty-seven patients (43%) had a family history of sudden death. Extensive noninvasive and invasive examinations, including echocardiography, left and right ventricular angiography, heart biopsies, ergonovine tests, and nuclear magnetic resonance failed to show any form of structural heart abnormality. Findings during these tests were characteristically different from those in right ventricular dysplasia. The electrocardiographic response to ajmaline or procainamide and the transient normalisation of the electrocardiogram during follow-up were characteristic of this syndrome and not found in right ventricular dysplasia. Genetic testing in a large family with approximately 50% affected members excluded by linkage analysis the gene abnormalities so far described in right ventricular dysplasia. During follow-up up to 10 years, no patient developed or was suspected to develop any form of structural heart disease. In terms of prognosis, this syndrome is associated to a high recurrence of ventricular fibrillation in patients who have already suffered from one or multiple episodes of aborted sudden death. Most worrying is, however, that asymptomatic persons with this electrocardiographic pattern are also at high risk of sudden death. Amiodarone and β-blockers do not protect against sudden death. The only valuable therapy at present is an implantable cardioverter-defibrillator.
KeywordsSudden Death Ventricular Fibrillation Structural Heart Disease Brugada Syndrome Arrhythmic Event
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