Clinical Observation of a Rare Phenotype of Brugada Syndrome

Brugada syndrome is an inherited heart rhythm disorder characterized by ST-segment elevation in
the right precordial leads, right bundle branch block, T wave inversion in the absence of obvious
structural heart diseases. This disease causes sudden cardiac death in 2% of cases annually. Brugada
syndrome is a genetically heterogeneous channelopathy, and it is associated with mutations in genes
encoding subunits of the heart’s sodium, potassium, and calcium channels, and related proteins.
The authors presented a clinical case of a 34-year-old patient with Brugada syndrome, who had a
combination of mutations in the KCNJ8, HCN4, and CASQ2 genes. The diagnosis was confi rmed by
provocative drug test with novocainamide and endocardial EF study, when a steady paroxysm of
polymorphic VT and a typical Brugada pattern with ST-segment elevation were provoked during
programmed ventricular stimulation. The peculiarity of this clinical case was the presence of AVreciprocal
tachycardia in the patient, detected during endocardial EF study. In this regard, she
underwent ablation of the slow pathways of the AV node in order to minimize possible unjustifi ed
ICD responses to AV reciprocal tachycardia. Due to the high risk of recurrence of life-threatening
arrhythmic events, it was decided to implant a cardioverter-defi brillator.