Evaluation of Brugada syndrome by cardiac magnetic resonance

Brugada syndrome (BrS) has been originally considered to occur in structural normal hearts. However recent pathological and imaging data suggest that structural and functional changes may be present in this syndrome. This study was designed to elucidate whether any macroscopic heart abnormality is detectable in patients with BrS. For this purpose we used cardiac magnetic resonance (CMR). Twenty-nine patients displaying the BrS type-1 ECG pattern and 29 healthy controls underwent CMR (1.5 Tesla). Left (LV) and right ventricular (RV) dimensions, function and regional contractility were evaluated. Late-gadolinium-enhancement (LGE) imaging was obtained in 24 patients. We found no difference between BrS patients and controls regarding LV and RV dimensions and ejection fraction. RV wall motion abnormalities (WMA) were detected in 19 patients (65.5%) and in 22 control subjects (75.9%). The majority of these WMA were attributable to areas of hypokinesia and found in the RV inferior wall. None of the patients showed LGE. No differences were detected between controls and the different subgroups of BrS patients according to symptoms, family history and spontaneous type-1 ECG pattern. BrS patients do not differ from normal subjects with regard to dimensions and global function of both LV and RV. BrS patients may show RV-WMA, however similar changes are also present in healthy subjects and may therefore represent a physiological behaviour of RV. The lack of LGE further confirms the absence of myocardial structural damage. Our results indicate that BrS seems to occur in individuals with structurally and functionally normal heart

Risk stratification in Brugada Syndrome Results of the PRELUDE Registry

The PRELUDE (PRogrammed ELectrical stimUlation preDictive valuE) prospective registry was designed to assess the predictive accuracy of sustained ventricular tachycardia/ventricular fibrillation (VTs/VF) inducibility and to identify additional predictors of arrhythmic events in Brugada syndrome patients without history of VT/VF. Background Brugada syndrome is a genetic disease associated with increased risk of sudden cardiac death. Even though its value has been questioned, inducibility of VTs/VF is widely used to select candidates to receive a prophylactic implantable defibrillator, and its accuracy has never been addressed in prospective studies with homogeneous enrolling criteria. Methods Patients with a spontaneous or drug-induced type I electrocardiogram (ECG) and without history of cardiac arrest were enrolled. The registry included 308 consecutive individuals (247 men, 80%; median age 44 years, range 18 to 72 years). Programmed electrical stimulation was performed at enrollment, and patients were followed-up every 6 months. Results During a median follow-up of 34 months, 14 arrhythmic events (4.5%) occurred (13 appropriate shocks of the implantable defibrillator, and 1 cardiac arrest). Programmed electrical stimulation performed with a uniform and pre-specified protocol induced ventricular tachyarrhythmias in 40% of patients: arrhythmia inducibility was not a predictor of events at follow-up (9 of 14 events occurred in noninducible patients). History of syncope and spontaneous type I ECG (hazard ratio [HR]: 4.20), ventricular refractory period  200 ms (HR: 3.91), and QRS fragmentation (HR: 4.94) were significant predictors of arrhythmias. Conclusions Our data show that VT/VF inducibility is unable to identify high-risk patients, whereas the presence of a spontaneous type I ECG, history of syncope, ventricular effective refractory period  200 ms, and QRS fragmentation seem useful to identify candidates for prophylactic implantable cardioverter defibrillator.