Electrical space-time abnormalities of ventricular depolarization in patients with Brugada syndrome and patients with complete right-bundle branch blocks studied by magnetocardiography

Background: Both ventricular depolarization abnormalities (QRS complex) and repolarization ones (ST/T) are still controversial in literature. The objective of this study was to clarify the space-time variations that occur in patients carriers of Brugada syndrome using Magnetocardiography and also compare them with cases of complete right-bundle branch block (CRBBB) and individuals without any dromotropic disorder (control group). Methods and Results: Magnetocardiograms (MCGs) of Brugada syndrome patients (n = 16), CRBBB patients (n = 14), and members of a control group (n = 46) at rest were recorded. The MCGs were used to produce a whole-heart electrical-activation diagram (W-HEAD), which can visualize the spatial time-variant activation in the whole heart. In the W-HEAD pattern, three activations were located in the left ventricle, and CRBBB patients had a wide peak with about 65-ms delay on the right anterior side. While the Brugada syndrome pattern has a posteromedian left-ventricle excitation, that is half the amplitude that occurs in CRBBB patients, the electrical conduction rate to the posterosuperior septum area was low. Conclusions: The W-HEAD data made it possible to visualize space-time depolarization abnormalities. These findings suggest that the electrical conduction rate to the posterosuperior septum area in Brugada syndrome cases is low, and this low activation may be a feature of typical Brugada syndrome.