Utility of high and standard right precordial leads during ajmaline testing for the diagnosis of Brugada syndrome

Aims: The authors sought to assess the value of the high right precordial leads (RPL) to detect the Type I Brugada ECG pattern in patients suspected of carrying Brugada syndrome (BrS). Methods: Ajmaline testing using 15-lead ECGs was performed in 183 patients suspected of carrying BrS. Standard 12-lead ECG with V1-V3 recorded from the fourth intercostal space and an additional three leads placed over V1-V3 recorded from the third intercostal space were analysed. ECGs were analysed for a Type I ECG pattern in either the standard or high RPLs. Results: Of the 183 tests, 31 (17%) were positive, and 152 were negative. In all positive studies, at least one high RPL became positive. In 13/31 (42%) cases, the Type I ECG pattern could be observed only in the high RPLs. Standard or high V3 were never positive before standard or high V1-V2. In seven patients, a Type I pattern was seen in one standard and one high RPL (vertical relationship). Conclusions: The high RPLs are more sensitive than the conventional 12-lead ECG alone and initial observations suggest that they remain specific for BrS, while standard and high lead V3 offer redundant data. A vertical relationship of type 1 patterns may have a similar diagnostic value to that of a horizontal pair.