Brugada-like changes in the peripheral leads during diagnostic ajmaline test in patients with suspected Brugada syndrome.
BACKGROUND
Although cases of Brugada-type electrocardiographic (ECG) pattern in peripheral (limb) leads have been reported ("atypical" Brugada syndrome [BS]), their incidence in patients investigated for BS is unknown.


METHODS
We retrospectively analyzed an ECG database collected during ajmaline test in 143 patients (89 men) with suspected BS. In 42 patients, 12-lead ECGs were recorded, whereas in 101 patients, leads V1-V3 from the third intercostal space were also recorded. The presence of types 1, 2, and 3 Brugada pattern in each limb and precordial lead was noted and the PR, QRS, and QTc intervals were calculated.


RESULTS
There were 114 (79.7%) negative and 29 (20.3%) positive tests. Type 1 pattern developed in >or=1 limb lead in six patients (4.2%) (3/29 with positive tests, 10.3%); all of them were male, symptomatic, and/or with family history of BS or sudden cardiac death. Their pre- and posttest QRS were significantly longer compared with the rest with positive (n = 26) or negative (n = 111) test (pretest: 129 +/- 31 ms vs 101 +/- 11 ms and 97 +/- 12 ms, P < 0.001; posttest: 175 +/- 44 ms vs 134 +/- 14 ms and 131 +/- 19 ms, P < 0.001). The posttest QTc was longer in patients with peripheral changes compared with the rest (507 +/- 47 ms vs 453 +/- 22 ms and 447 +/- 24 ms, P < 0.001). The pretest QTc and pre- and posttest heart rate and PR intervals were not significantly different between the three groups.


CONCLUSIONS
Type 1 Brugada pattern in the peripheral leads was observed in 4.2% of patients during ajmaline test (10.3% of positive tests) and was associated with longer QRS and greater QTc prolongation compared with the rest of the patients.
Batchvarov
Velislav N
VN
Division of Cardiac and Vascular Sciences, St. George's University of London, London, UK. vbatchva@sgul.ac.uk
Govindan
Malini
M
Camm
A John
AJ
Behr
Elijah R
ER
D000328:Adult; D000404:Ajmaline; D000889:Anti-Arrhythmia Agents; D053840:Brugada Syndrome / Q000175:diagnosis* / Q000453:epidemiology*; D004562:Electrocardiography / Q000295:instrumentation* / Q000379:methods* / Q000706:statistics & numerical data*; D004566:Electrodes; D005260:Female; D006801:Humans; D015994:Incidence; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D006113:United Kingdom / Q000453:epidemiology
D000889:Anti-Arrhythmia Agents; D000404:Ajmaline