Brugada syndrome behind complete right bundle-branch block.

Area of Science:

• Cardiology
• Electrophysiology
• Medical Diagnostics

Background:

• Brugada syndrome (BS) presents characteristic ECG findings.
• Complete right bundle-branch block (CRBBB) can obscure these BS ECG patterns.
• Diagnostic challenges arise when BS and CRBBB coexist.

Purpose of the Study:

• To investigate the coexistence of Brugada syndrome (BS) and complete right bundle-branch block (CRBBB).
• To determine methods for diagnosing BS when masked by CRBBB.
• To analyze ECG characteristics in patients with both conditions.

Main Methods:

• Study included 11 patients diagnosed with both BS and CRBBB.
• BS diagnosis was established before CRBBB, upon its resolution, or via new ST-segment changes.
• Exclusion of structural heart disease and coronary spasm was performed.
• ECG parameters, including QRS duration and ST-segment elevation, were analyzed and compared to controls.

Main Results:

• BS was diagnosed in 7 patients prior to CRBBB development.
• CRBBB resolution (spontaneous or pacing-induced) aided BS diagnosis in 4 patients.
• New ST-segment elevation indicative of BS was observed in 3 patients, and induced by drugs in 2.
• Patients with BS and CRBBB showed significantly prolonged QRS duration compared to controls.

Conclusions:

• Complete right bundle-branch block (CRBBB) can effectively mask Brugada syndrome (BS).
• BS diagnosis is feasible through CRBBB resolution or specific ST-segment changes.
• Further research is needed to understand the prevalence, mechanisms, and clinical significance of combined CRBBB and BS.