Body surface potential mapping in patients with Brugada syndrome: right precordial ST segment variations and reverse changes in left precordial leads.
OBJECTIVE
The aim of this study was to perform quantitative signal analysis of high-resolution body surface potential mapping (BSPM) recordings to assess its usefulness for the electrocardiographic characterization of patients with Brugada syndrome. The diagnostic value of the QRS integral and of the gradient of the ST segment have not been elucidated in Brugada syndrome.


METHODS
In 27 subjects (16 with Brugada syndrome and 11 healthy subjects), 120-lead BSPMs were recorded at baseline and after pharmacological provocation with intravenous administration of ajmaline (1 mg/kg). The recordings were analyzed for two regions outside the positions of the standard ECG leads: the right precordial leads (RPL) on the second and third intercostal space (high RPL) and the left precordial leads (LPL) between the fifth and seventh intercostal space (low LPL).


RESULTS
At baseline, in high RPL regions, patients with Brugada syndrome showed more positive QRS integrals (-5+/-8 vs. -16+/-8 mV ms) and a steeper negative ST segment gradient (-0.62+/-0.41 vs. -0.29+/-0.40 mV/s) compared to healthy subjects, P<0.001. In contrast, in low LPL regions, reduced QRS integrals and positive ST segment gradients were observed. These ECG signs were even more pronounced after intravenous ajmaline and showed a better discrimination for patients with Brugada syndrome than differences in RPL or LPL during baseline, respectively.


CONCLUSIONS
In the left precordial leads, patients with Brugada syndrome showed ECG changes which were reversed in relation to the ECG changes observed in right precordial leads. BSPM measurement is a useful tool to improve the understanding of the electrocardiographic changes in the Brugada syndrome.
Bruns
Hans-Jürgen
HJ
Department of Cardiology and Angiology, Hospital of the University of Münster, Germany. brunsh@uni-muenster.de
Eckardt
Lars
L
Vahlhaus
Christian
C
Schulze-Bahr
Eric
E
Haverkamp
Wilhelm
W
Borggrefe
Martin
M
Breithardt
Günter
G
Wichter
Thomas
T
D000328:Adult; D000368:Aged; D000404:Ajmaline; D018780:Body Surface Potential Mapping; D016022:Case-Control Studies; D004562:Electrocardiography; D005260:Female; D006323:Heart Arrest / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D062554:NAV1.5 Voltage-Gated Sodium Channel; D018807:Polymorphism, Single-Stranded Conformational; D011446:Prospective Studies; D012306:Risk; D012815:Signal Processing, Computer-Assisted; D026941:Sodium Channel Blockers; D015222:Sodium Channels / Q000235:genetics; D018709:Statistics, Nonparametric; D013577:Syndrome; D014693:Ventricular Fibrillation / Q000503:physiopathology*
D062554:NAV1.5 Voltage-Gated Sodium Channel; C568320:SCN5A protein, human; D026941:Sodium Channel Blockers; D015222:Sodium Channels; D000404:Ajmaline