Diagnostic utility of bipolar precordial leads during ajmaline testing for suspected Brugada syndrome.
BACKGROUND
Leads V(1) and V(2) recorded from the standard position (fourth intercostal space) have insufficient sensitivity to detect the diagnostic type 1 Brugada ECG pattern.


OBJECTIVE
The purpose of this study was to compare the sensitivity of bipolar leads with a positive pole at V(2) and a negative pole at V(4) or V(5) with that of the standard unipolar lead V(2) for detection of the type 1 Brugada pattern.


METHODS
We analyzed digital 15-lead ECGs (12 standard leads plus leads V(1) to V(3) recorded from the third intercostal space [V(1h) to V(3h)]) acquired during diagnostic ajmaline testing in 128 patients (80 men, age 37 +/- 15 years) with suspected Brugada syndrome and standard 12-lead ECGs recorded in 229 healthy subjects (111 men, age 33 +/- 4 years). Bipolar leads between V(2) (positive pole) and V(4) or V(5) (leads V(2-4), V(2-5)) were derived by subtracting leads V(4) and V(5) from V(2). All ECGs were examined for the presence of type 1 Brugada pattern.


RESULTS
During 21 (16.4%) positive ajmaline tests, type 1 pattern was observed in lead V(2h) during 20 tests (95.2%) and in V(2) during 10 tests (47.6%). Type 1 pattern appeared in lead V(2-4) or V(2-5) in all tests when it was present in V(2) and in seven tests during which it was observed in lead V(2h) but not V(2) (17 tests [81%]). Type 1-like pattern was observed in lead V(2-4) or V(2-5) during two nonpositive tests (1.9%) and in one healthy subject (0.4%).


CONCLUSIONS
Bipolar leads V(2-4) and V(2-5) are more sensitive than lead V(2) for detection of the type 1 Brugada pattern.
St. George's University of London, London, UK. vbatchva@sgul.ac.uk
Velislav N
VN
Batchvarov
Malini
M
Govindan
Peter
P
Macfarlane
A John
AJ
Camm
Elijah R
ER
Behr
D000328:Adult; D000404:Ajmaline; D000889:Anti-Arrhythmia Agents; D053840:Brugada Syndrome / Q000175:diagnosis*; D016009:Chi-Square Distribution; D004562:Electrocardiography / Q000295:instrumentation*; D004566:Electrodes; D005260:Female; D006801:Humans; D008297:Male; D012680:Sensitivity and Specificity
D000889:Anti-Arrhythmia Agents; D000404:Ajmaline