Abstract 2854: Sudden Arrhythmic Death Syndrome: Use of Higher Intercostal V1 and V2 Leads Increases the Yield of Brugada Syndrome
Background: Brugada syndrome is an established cause of sudden arrhythmic death syndrome (SADS). The use of higher intercostal V1 and V2 leads has been associated with increased surface electrocardiogram (ECG) sensitivity in the detection of the Brugada phenotype, either on the baseline ECG or following provocation using sodium ion channel blocking agents, without compromising specificity. Despite the potential implications, there is a paucity of data relating to the efficacy of this simple methodology in the diagnostic yield of Brugada syndrome in victims of ventricular fibrillation (VF) or 1st-degree relatives of SADS victims.
Design/Methods: We identified 29 families diagnosed with Brugada syndrome based on the presence of a type-1 ECG in ≥1 family member in the context of an unexplained VF arrest or a SADS death in a 1st-degree relative. The 12-lead ECGs of 117 individual members, who underwent comprehensive cardiac investigations including an Ajmaline provocation test, when appropriate, were reviewed. Electrocardiograms were performed with leads V1 and V2 placed in both the conventional 4th and the higher 2nd intercostal space.
Results: Forty-one of the 117 family members (35%) were diagnosed with Brugada syndrome. Only 6 (16%) subjects exhibited a diagnostic baseline ECG, while the great majority required an Ajmaline provocation test to unmask the Brugada phenotype. The Brugada phenotype was detected in the conventional ECG of 18 (44%) individuals, however it was observed in the modified ECG of 40 (98%) individuals using the higher intercostal V1 and V2 leads (p<0.001). Only 14 (48%) of the 29 families were diagnosed on the basis of the standard ECG lead whereas all 29 (100%) families had at least one member with a positive type-1 ECG in the higher intercostal leads (p<0.001).
Conclusion: Utility of higher intercostal leads for the detection of the Brugada phenotype increases the diagnostic yield when screening victims of VF arrest or 1st-degree relatives of SADS victims. In our cohort more than half of the families (52%) and individual members (56%) harbouring the Brugada gene would have remained undetected based on the standard 12-lead ECG alone.