Expert cardiologists cannot distinguish between Brugada phenocopy and Brugada syndrome electrocardiogram patterns.
OBJECTIVE
Brugada phenocopies (BrPs) are electrocardiogram (ECG) patterns that are identical to true Brugada syndrome (BrS) but are induced by various clinical conditions. The concept that both ECG patterns are visually identical has not been formally demonstrated. The aim of our study was to determine if experts on BrS were able to accurately distinguish between the BrS and BrP ECG patterns.


RESULTS
Six ECGs from confirmed cases of BrS and six ECGs from previously published cases of BrP were included in the study. Surface 12-lead ECGs were scanned, saved in JPEG format, and sent to 10 international experts on BrS for evaluation (no clinical history provided). Evaluators were asked to label each case as a Brugada ECG pattern or non-Brugada ECG pattern by visual interpretation alone. The overall accuracy was 53 ± 33% for all cases. Within the BrS cases, the mean accuracy was 63 ± 34% and within the BrP cases, the mean accuracy was 43 ± 33%. Intra-observer repeatability was moderate (κ = 0.56) and inter-observer agreement was fair (κ = 0.36) while evaluator accuracy vs. the true diagnosis was only marginally better than chance (κ = 0.05). Similarly, diagnostic operating characteristics were poor (sensitivity 62%, specificity 43%, +LR 1.1, -LR 0.9).


CONCLUSIONS
Our results provide strong evidence that BrP and BrS ECG patterns are visually identical and indistinguishable. These findings support the use of systematic diagnostic criteria for differentiating BrP vs. BrS as an erroneous diagnosis may have a negative impact on patient morbidity and mortality.
Department of Cardiology, Cardiac Electrophysiology and Pacing, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada K7L 2V7.
Byron H
BH
Gottschalk
Department of Cardiology, Cardiac Electrophysiology and Pacing, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada K7L 2V7.
Daniel D
DD
Anselm
Hospital Clínic, University of Barcelona, Barcelona, Spain.
Josep
J
Brugada
Heart Rhythm Management Center, UZ Brussels-VUB, Brussels, Belgium.
Pedro
P
Brugada
Heart Centre AMC, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands Princess Al-Jawhara Al-Brahim Centre of Excellence in Research of Hereditary Disorders, Jeddah, Kingdom of Saudi Arabia.
Arthur A
AA
Wilde
Division of Cardiology, Hospital Ramos Mejia, Buenos Aires, Argentina.
Pablo A
PA
Chiale
Cardiology Discipline, ABC Medical Faculty, ABC Foundation, Santo André, São Paulo, Brazil.
Andres R
AR
Pérez-Riera
Division of Cardiology, Hospital Ramos Mejia, Buenos Aires, Argentina.
Marcelo V
MV
Elizari
Cardiovascular Research Center, CSIC-ICCC, Hospital de la Santa CreuiSant Pau, Barcelona, Spain.
Antoni Bayés
AB
De Luna
Division of Cardiology, University of British Columbia, Vancouver, BC, Canada.
Andrew D
AD
Krahn
Heart Centre AMC, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands.
Hanno L
HL
Tan
Heart Centre AMC, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands.
Pieter G
PG
Postema
Department of Cardiology, Cardiac Electrophysiology and Pacing, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada K7L 2V7 barancha@kgh.kari.net.
Adrian
A
Baranchuk
D053840:Brugada Syndrome / Q000175:diagnosis* / Q000503:physiopathology*; D000072096:Cardiologists; D003937:Diagnosis, Differential; D004562:Electrocardiography; D006801:Humans; D010641:Phenotype; D012680:Sensitivity and Specificity
Brugada ECG pattern; Brugada phenocopy; Brugada syndrome