1. Sodium-channel blocker challenge in the familial screening of Brugada syndrome: Safety and predictors of positivity.
- Author
-
Therasse D, Sacher F, Petit B, Babuty D, Mabo P, Martins R, Jesel L, Maury P, Pasquie JL, Mansourati J, Dupuis JM, Kyndt F, Thollet A, Guyomarch B, Barc J, Schott JJ, Le Marec H, Redon R, Probst V, and Gourraud JB
- Subjects
- Adult, Ajmaline administration & dosage, Brugada Syndrome drug therapy, Brugada Syndrome physiopathology, Dose-Response Relationship, Drug, False Positive Reactions, Female, Follow-Up Studies, Humans, Injections, Intravenous, Male, Prognosis, Retrospective Studies, Voltage-Gated Sodium Channel Blockers administration & dosage, Ajmaline pharmacology, Brugada Syndrome diagnosis, Electrocardiography drug effects, Flecainide administration & dosage, Heart Rate drug effects
- Abstract
Background: Sodium-channel blocker challenge (SCBC) is frequently performed to unmask Brugada syndrome., Objective: We aim to identify predictors of positivity and complications of SCBC in the setting of familial screening of Brugada syndrome., Methods: All consecutive patients from 2000 to 2014 who benefit from a sodium-channel blocker and belong to a family with at least 2 subjects affected by the syndrome were enrolled and followed prospectively. Data were reviewed by 2 physicians blinded to the clinical and genetic status., Results: Of the 672 SCBCs performed in 137 families, 337 (50%) were positive. Multivariate analysis identified ajmaline (odds ratio [OR] 2.98; 95% CI 1.65-4.91) and a significant S wave in lead DII (OR 3.11; 95% CI 2.12-4.58), DIII (OR 2.75; 95% CI 1.78-4.25), or V
5 (OR 3.71; 95% CI 2.54-5.44) as predictors of a positive SCBC (P < .0001). Eleven patients (1.6%) presented complications (10 ventricular arrhythmias and 1 atrial flutter), but no deaths occurred. Familial history of complications (OR 41; lower quartile, upper quartile 10, 203; P < .0001), young age (P = .04), and decreased electrocardiographic conduction parameters at baseline (P = .04) were predictors of complications. QRS enlargement during SCBC was not associated with complications. During a median follow-up of 106 months (lower quartile, upper quartile 54, 143 months), 11 life-threatening arrhythmias occurred., Conclusion: SCBC in the screening of familial Brugada syndrome is safe. The risk of complication is considerably increased in the case of familial history of complicated SCBC, in young patients, and in the presence of decreased electrocardiographic conduction parameters. However, QRS enlargement during the test is not directly related to complications and should not be used to prematurely stop the test unless leading to false-negative results., (Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)- Published
- 2017
- Full Text
- View/download PDF