Grace Xu1, Byron H Gottschalk2, Andrés Pérez-Riera3, Raimundo Barbosa-Barros4, Gregory Dendramis5, Aldo G Carrizo6, Sahil Agrawal7, Antonio Bayés de Luna8, Marek Jastrzębski9, János Tomcsányi10, Adrian Baranchuk1. 1. Department of Medicine, Queen's University, Kingston, Ontario, Canada. 2. Department of Anesthesiology and Perioperative Medicine, Western University, London, Ontario, Canada. 3. Laboratory Design of Studies and Scientific Writing, ABC Faculty of Medicine, ABC Foundation, Santo André, São Paulo, Brazil. 4. Coronary Center of the Messejana's Hospital Dr. Carlos Alberto Studart Gomes, Fortaleza, Ceará, Brazil. 5. Cardiovascular Division, Pietro Cosma Hospital, ULSS 6 Euganea, Camposampiero, Padova, Italy. 6. Cardiology Division, McMaster University, Hamilton, Ontario, Canada. 7. Department of Cardiology, St. Luke's University Health Network, Bethlehem, Pennsylvania. 8. Institut Català Ciències Cardiovasculars-St. Pau Hospital, and Quiron Barcelona Hospital, Autonomous University of Barcelona, Barcelona, Spain. 9. First Department of Cardiology, Interventional Electrocardiology and Hypertension, Medical College, Jagiellonian University, Cracow, Poland. 10. Cardiology Department, St. John of God Hospital, Budapest, Hungary.
Abstract
BACKGROUND: Brugada phenocopies clinical entities that have indistinguishable electrocardiographic (ECG) patterns from true congenital Brugada syndrome. However, they are induced by other clinical circumstances such as myocardial ischemia. The purpose of our study was to examine the clinical features and pathogenesis of ischemia-induced Brugada phenocopy (BrP). METHODS: Data from 17 cases of ischemia-induced BrP were collected from the International Registry (www.brugadaphenocopy.com). Data were extracted from these publications and authors were contacted to provide further insight into each case. RESULTS: Of the patients included in this study, 71% were male. Mean age was 59 ± 11 years (range: 38-76). Type-1 Brugada ECG pattern occurred in 15/17 (88%) of the cases, while a type-2 Brugada ECG pattern was observed in the other 2/17 (12%). In all cases, the Brugada ECG pattern resolved upon correction of the ischemia, indicating ischemia as the inducing circumstance. No arrhythmic events have been detected acutely or during the follow-up. Reported time to resolution ranged from 2 minutes to 5 hours. Provocative challenges using sodium channel blocking agents were performed in 7/17 cases (41%), and all failed to induce a Brugada ECG pattern (BrP Class A). The remaining 10/17 cases (59%) did not undergo provocative testing due to various clinical reasons. CONCLUSIONS: Myocardial ischemia is a commonly reported etiology of BrP. Importantly, this study found no association between BrP induced by myocardial ischemia and sudden cardiac death or malignant ventricular arrhythmias.
BACKGROUND:Brugada phenocopies clinical entities that have indistinguishable electrocardiographic (ECG) patterns from true congenital Brugada syndrome. However, they are induced by other clinical circumstances such as myocardial ischemia. The purpose of our study was to examine the clinical features and pathogenesis of ischemia-induced Brugada phenocopy (BrP). METHODS: Data from 17 cases of ischemia-induced BrP were collected from the International Registry (www.brugadaphenocopy.com). Data were extracted from these publications and authors were contacted to provide further insight into each case. RESULTS: Of the patients included in this study, 71% were male. Mean age was 59 ± 11 years (range: 38-76). Type-1 Brugada ECG pattern occurred in 15/17 (88%) of the cases, while a type-2 Brugada ECG pattern was observed in the other 2/17 (12%). In all cases, the Brugada ECG pattern resolved upon correction of the ischemia, indicating ischemia as the inducing circumstance. No arrhythmic events have been detected acutely or during the follow-up. Reported time to resolution ranged from 2 minutes to 5 hours. Provocative challenges using sodium channel blocking agents were performed in 7/17 cases (41%), and all failed to induce a Brugada ECG pattern (BrP Class A). The remaining 10/17 cases (59%) did not undergo provocative testing due to various clinical reasons. CONCLUSIONS:Myocardial ischemia is a commonly reported etiology of BrP. Importantly, this study found no association between BrP induced by myocardial ischemia and sudden cardiac death or malignant ventricular arrhythmias.