Brugada syndrome: Delineating the differences for optimal diagnosis and management

Brugada syndrome (BrS) is a genetic disorder known for its characteristic electrocardiogram (ECG) patterns and increased risk of sudden cardiac death. Brugada phenocopy (BrP) presents similar ECG patterns but is distinguished by its reversible nature when the underlying conditions are resolved. This article delineates the intricacies of BrP, emphasizing its etiology, clinical presentation, diagnosis, treatment, and prognosis. The article categorizes BrP based on various underlying causes, including metabolic disturbances, myocardial infarction, and mechanical compression, among others. It also underscores the critical importance of differentiating BrP from BrS to avoid misdiagnosis and inappropriate treatment, such as unnecessary implantation of cardioverter-defibrillators. The reversible aspect of BrP underlines the necessity for an etiology-specific approach to treatment, which not only prevents cardiac death but also highlights the significance of understanding the dynamic nature of ECG patterns. Through an exploration of case studies and current research, this review advocates for increased awareness and further investigation into BrP. It aims to enhance the diagnostic accuracy and management strategies, thereby improving the prognosis for patients presenting with Brugada-like ECG patterns. The review culminates in a call for further research to close existing knowledge gaps and improve patient outcomes.

Brugada phenocopy associated with multiple psychotic drugs

Brugada phenocopy (BrP) is a clinical condition characterized by transient ECG changes of Brugada syndrome (BrS), which can be due to various clinical conditions. We describe a case report of BrP due to psychotic drugs.

A case of Brugada phenocopy alteration induced by immune checkpoint inhibitors

Immunotherapy has shown remarkable efficacy in various cancer treatments. However, enhanced T-cell immune surveillance can lead to aberrant immune responses, resulting in severe immune checkpoint inhibitor-related adverse events. This is a case report of a patient previously treated with immune checkpoint inhibitors who presented with ST-segment elevation without abnormal troponin and cardiac enzyme spectrum test results. Cardiac toxicity of immune checkpoint inhibitors mainly manifests as acute immune-mediated myocarditis. While Brugada phenocopy is commonly caused by fever, electrolyte abnormalities, tricyclic/tetracyclic antidepressants, and marijuana use, we suspect that it was induced by immune checkpoint inhibitors in the current case.

Diagnostic and therapeutic dilemmas in a patient with myocarditis, Brugada syndrome and arrhythmic syncope

We present a case of a previously healthy 23-year-old male who presented with chest pain, palpitations and spontaneous type 1 Brugada electrocardiographic (ECG) pattern. Positive family history for sudden cardiac death (SCD) was remarkable. Initially, clinical symptoms in combination with myocardial enzymes elevation, regional myocardial oedema with late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) and inflammatory lymphocytoid-cell infiltrates in the endomyocardial biopsy (EMB) suggested the diagnosis of a myocarditis-induced Brugada phenocopy (BrP). Under immunosuppressive therapy with methylprednisolone and azathioprine, a complete remission of both symptoms and biomarkers was accomplished. However, the Brugada pattern did not resolve. The eventually spontaneous Brugada pattern type 1 established the diagnosis of Brugada syndrome (BrS). Due to his previous history of syncope, the patient was offered an ICD that he declined. After his discharge he experienced a new episode of arrhythmic syncope. He was readmitted and received an ICD.

Captagon-induced Brugada phenocopy: A report of two cases

Brugada phenocopies (BrP) represent electrocardiogram changes identical to those of true congenital Brugada syndrome but are induced by reversible clinical conditions. Previous cases have been reported in patients following recreational drug use. This report presents two cases of type 1B BrP associated with Fenethylline abuse, a recreational drug known by its trade name, Captagon.

Brugada phenocopy in pulmonary embolism - clinicopathological case study and literature review

Brugada syndrome (BrS) is an inherited channelopathy characterized on ECG by coved (type 1) or saddle-back (type 2) ST-segment elevation (STE) of 2 or more mm in the right precordial leads and is associated with an increased risk of malignant ventricular arrhythmias. The term Brugada phenocopy (BrPh) indicates conditions that may reversibly induce Brugada-like ECG pattern in patients without true BrS; e.g.: metabolic abnormalities, mechanical heart compression, ischemia, myocarditis/pericarditis, and pulmonary embolism (PE). Only 9 cases of BPh associated with PE have been described so far. The authors present another case of a 41-year-old-male and analyze the clinical data of all 10 subjects (7 males and 3 females). Type 1 of ECG Brugada pattern was present in 7 patients (including ours), type 2 was found in 2 persons; in 1 case ECG pattern was not defined. In 7 patients STE was prominent (5 mm or more in at least 1 lead). STE was limited to V1-V2 leads in 4 persons, extended to V3 in 3 patients and even to V4 in 3 other patients, which correlated with the significant right ventricular (RV) dilatation. Concomitant left ventricular (LV) systolic dysfunction was reported only in 1 patient, which suggested that paradoxical embolization of coronary artery was not the mechanism of BrS-like STE. Clinical course of PE was usually severe (5 individuals were treated with thrombolysis) and in 3 cases it ended with death. The autopsy was only performed on our patient. It showed diffuse (ischemic) injury of RV and LV secondary to RV overload, decreased cardiac output and severe oxygen deficiency in myocardium, which could have led to BrS pattern in ECG.

A dynamic Brugada sign due to left anterior descending coronary artery occlusion

Brugada phenocopies (BrP) include several conditions with a common electrocardiographic (ECG) pattern that are indistinguishable from classical Brugada syndrome (BrS). In this report, we describe two cases of acute myocardial infarction (AMI) presenting as BrP. The majority of cases of BrP in AMI have been reported due to right coronary artery (RCA) occlusion. Rarely, the left anterior descending artery (LAD) is incriminated as the cause. In both our cases of BrP, LAD was the culprit vessel.

Case Report: Coexistent Wolff-Parkinson-White Syndrome and Brugada Phenocopy in a Patient With Pneumonia and Myocarditis

Background: In recent years, Wolff-Parkinson-White (WPW) syndrome and Brugada electrocardiogram (ECG) patterns have been reported as coexistent in the same patient. In most cases, the two waveforms appeared separately. Here, we described combinations of different waveforms on one ECG, such as the Brugada pattern with delta waves and the Brugada pattern with paroxysmal supraventricular tachycardia (PSVT). Importantly, we recorded an alternate conversion of these combined ECG waveforms, which has not previously been reported in the literature. At the same time, we confirmed that the change in the waveform was related to fever by analyzing Holter data.

Case: A 48-year-old male was admitted to our hospital due to palpitations and fever. The patient had a history of a cold 3 days ago. Laboratory examinations showed an elevated neutrophil percentage (85%) and troponin I level (0.86 ng/ml). A chest computed tomography (CT) scan showed inflammation in the right lung. The diagnosis of pneumonia and myocarditis was made. ECG indicated WPW syndrome and the Brugada pattern. We recorded the dynamic changes in this combination of delta waves and Brugada waves with a Holter monitor, and we found the changes would happen when the patient's body temperature rose. The doctors thought that the patient's pulmonary infection led to fever, which caused the changes in waveform. After treatment with antibacterial therapy and supportive care, his body temperature returned to normal. The various laboratory indicators also gradually returned to normal. The doctor recommended that the patient undergo further pre-excitation bypass radiofrequency ablation treatment, but the patient refused and was discharged.

Conclusion: Delta waves and Brugada ECG patterns could appear on one ECG at the same time. There were dynamic changes of QRS complex, relating to fever.

A case of cardiac sarcoidosis mimiking Brugada syndrome

A 17-year-old boy was admitted for management of ventricular fibrillation (VF) with intermittent Brugada pattern on ECG. On evaluation, cardiac MRI revealed myocardial scar and mediastinal lymphadenopathy. 18-Fluorodeoxyglucose positron emission tomography scan showed inflammation in the heart, lungs, and lymph nodes. He was diagnosed as a case of cardiac sarcoidosis (CS) and treated with steroids. However, there was a reactivation of cardiac inflammation and the development of a second VF storm. Following catheter ablation, the patient's arrhythmia improved. This report highlights the inflammation due to CS mimicking channelopathic features.

Ajmaline-induced Brugada Phenocopy, Right Bundle Branch Block, or Both?

In equivocal or suspected cases of Brugada syndrome (BrS), ajmaline testing is frequently used in the diagnostic approach. However, the administration of sodium channel blockers can not only elicit the coved ST-segment elevation characteristic of type 1 Brugada pattern but also induce right bundle branch block (RBBB), which can preclude the electrocardiographic manifestations of BrS. We describe a case report wherein RBBB posed a diagnostic challenge during the ajmaline test for suspected BrS.

Brugada syndrome unmasked by left ventricle posteromedial papillary muscle ventricular tachycardia: Coincidence or consequence

A 46-year-old man presented with left ventricle posteromedial papillary muscle ventricular tachycardia, presyncope, and a type-1 Brugada pattern on the post-electrical cardioversion electrocardiogram. There was a probability of a Brugada syndrome with the expression of its disease in the left ventricle; or a left monomorphic ventricular tachycardia as a part of Brugada phenocopy; or a Brugada syndrome with left monomorphic ventricular tachycardia as an epiphenomenon. Cardiac magnetic resonance, electrophysiological study, and ajmaline test were the key diagnostic tools employed.

Tachycardia dependent early repolarisation pattern in subarachnoid haemorrhage related takotsubo syndrome

We present a case of a patient who suffered subarachnoid haemorrhage (SAH), complicated by takotsubo syndrome, paroxysmal atrial fibrillation and ECG repolarisation abnormality, compatible with Brugada phenocopy. The early repolarisation morphology showed a paradox association with the cardiac cycle length; a relationship not yet documented in SAH. Our observation also sheds light on the genesis of the "spiked helmet" ECG sign.

An unusual ECG change after a car crash

A 34‐year‐old male patient was preparing for splenic artery embolization because of a car crash. Personal or family histories of cardiovascular diseases, sudden cardiac death, or Brugada syndrome were denied. Type 1 Brugada pattern was observed in the preoperative electrocardiogram and gradually resolved within a week. Chest blunt trauma may contribute to the transient ECG changes, and some particular considerations should be taken in this patient.

Brugada phenocopy in a patient with unstable angina and three-vessel coronary artery disease

A 52-year-old male was admitted with unstable angina and three-vessel coronary artery disease. Electrocardiography (ECG) changes consistent with type-1 Brugada ECG pattern were noted during admission. The patient was asymptomatic for syncope and had no family history of sudden cardiac death, ICD implantation, and Brugada syndrome. After coronary by-pass graft the Brugada ECG pattern resolved, and ajmaline test did not elicit type-1 ECG pattern, confirming the suspicion of Brugada phenocopy.

Brugada phenocopy or congenital Brugada syndrome in a patient with spontaneous pneumopericardium and pericarditis

Brugada syndrome (BrS) is characterized by coved ST segment elevation in the right precordial lead (V1-V3). Previous reports have described type-1 or type-2 Brugada ECG pattern as a Brugada phenocopy (BrP) in various clinical condition and once the etiology is resolved, the BrP ECG pattern normalizes. We describe a case report of type-1 Brugada ECG pattern in a patient with acquired immunodeficiency syndrome (AIDS) and active pulmonary tuberculosis, which developed to spontaneous pneumopericardium and pericarditis. The coexistence of type-1 Brugada ECG pattern with spontaneous pneumopericardium and pericarditis is an extremely rare pathological condition that has not been previously described.

A case of anomalous aortic origin of coronary artery associated with a coved-type electrocardiogram

Brugada syndrome (BrS) is a sudden cardiac death syndrome characterized by a coved-type electrocardiogram (ECG). Different disorders, such as ischemia, can emulate a Brugada-pattern ECG (Brugada phenocopy). We report herein, the first case of surgical epicardial electrophysiological mapping in a successfully resuscitated patient with an anomalous aortic origin of the coronary artery (AAOCA) associated with a coved-type ECG. It was debatable whether the coved-type ECG and the abnormal arrhythmogenic substrate in the epicardial right ventricular outflow tract were derived from BrS or from repetitive ischemia due to AAOCA; however, the epicardial electrophysiological mapping helped in deciding the treatment strategy.

The Heart in Diabetic Ketoacidosis: A Narrative Review Focusing on the Acute Cardiac Effects and Electrocardiographic Abnormalities

Diabetic ketoacidosis (DKA) is a serious complication of diabetes mellitus. Hyperglycemia, acidosis, and electrolyte imbalances can directly affect the heart by inducing toxicity, impairing myocardial blood flow, autonomic dysfunction, and altering activation and conduction of electrical impulses throughout the heart, increasing the risk of arrhythmias and ischemia. The electrocardiogram is useful in monitoring patients during and after an episode of DKA, as it allows the detection of arrhythmias and guides metabolic correction. Unfortunately, reports on electrocardiographic abnormalities in patients with DKA are lacking. We found two electrocardiographic patterns that are frequently reported in the literature: a pseudo-myocardial infarction and a Brugada Phenocopy. Both are associated with DKA metabolic anomalies and they resolve after treatment. Because of their clinical relevance and the challenge they represent for clinicians, we analyzed the clinical characteristics of these patients and the mechanisms involved in these electrocardiographic findings.

Brugada phenocopy induced by consumption of yellow oleander seeds - A case report

Brugada phenocopy is a brugada-like pattern in ECG seen in some diseases without an inherited channelopathy. The causes of brugada phenocopy are usually reversible. Once the reversible condition resolves, the ECG pattern disappears. There are many conditions that cause brugada phenocopy like myocardial infarction, hyperkalemia etc. Here we report a case of brugada phenocopy induced by consumption of yellow oleander seeds (T. Peruviana).

Brugada Phenocopy Induced by a Lethal Methanol Intoxication

Brugada phenocopies (BrP) are clinical entities that present with an ECG pattern identical to either the type 1 or type 2 Brugada pattern without true congenital Brugada syndrome. This ECG pattern is associated with an identifiable condition and normalizes upon resolution or treatment of the underlying cause. We present a case of a 54-year-old man with extreme metabolic acidosis, hyperkalaemia and a Brugada type 1 ECG pattern in the setting of a suicidal methanol (MeOH) poisoning. Upon correction of these metabolic derangements with bicarbonate infusions and continuous veno-venous haemodiafiltration (CVVH), the Brugada type 1 ECG pattern normalized. Unfortunately, the patient developed signs of cerebral herniation followed by brain death and died on the first day of ICU admission.

Link between Brugada phenocopy and myocardial ischemia: Results from the International Registry on Brugada Phenocopy

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.

Suspected hyponatremia-induced Brugada phenocopy

Brugada syndrome is a genetic condition that predisposes to an increased risk of ventricular fibrillation and sudden cardiac death in a structurally normal heart. The Brugada type 1 electrocardiogram (ECG) pattern may occur independently of the actual syndrome, and this clinical phenomenon is often referred to as Brugada phenocopy. There are several other factors which have been known to induce this electrocardiographic pattern, and currently, there is a paucity of literature with respect to the pattern that is observed in patients with electrolyte disturbances, specifically hyponatremia. This case report highlights a suspected hyponatremia-induced Brugada type 1 ECG pattern, which subsequently normalized following resolution of the electrolyte derangement.

Cocaine-Induced Brugada Pattern

BACKGROUND

Brugada phenocopies are clinical entities etiologically distinct from congenital Brugada syndrome; differentiation is crucial for management.

CASE

A 29 year-old male with a history of cocaine abuse, brought in by Emergency Medical Services (EMS) after he was found unresponsive and given naloxone. He was found altered but arousable with verbal stimuli. He reported snorting a white powder to get "high". He denied family history of sudden death or previous history of syncope. His ECG on presentation showed coved, ≥2 mm ST elevation with T-wave inversion in V2 consistent with Brugada EKG pattern (Figure 1). His troponin was trending up with elevated creatinine 1.6 mg/dl, liver enzymes and lactic acid, and urine toxicology was positive for cocaine.

DECISION-MAKING

The presentation of altered mental status is multifactorial: metabolic derangement, drugs misuse and Brugada. Finding Brugada EKG pattern should be investigated to differentiate congenital Brugada syndrome and Brugada phenocopies. This patient has no family history of sudden death and no prior history of syncope. Serial EKG showed a gradual resolution of the coved and ST elevation in V2.

CONCLUSION

our case demonstrates the importance of careful history taking including family history, as well as serial ECGs and treating the possible underlying etiology such as drugs abuse or electrolytes abnormality. It is also warranted to differentiate between Brugada phenocopies from congenital Brugada syndrome because therapeutic strategies are quite different with each diagnosis.

Brugada phenocopy associated with left ventricular aneurysm

Brugada phenocopies (BrP) are clinical entities that are characterized by ECG patterns identical to those of Brugada syndrome, but are the result of various clinical conditions. We describe the case of a 41-year-old male who exhibited BrP due to a left ventricular aneurysm in the context of chronic coronary artery disease.

Type 1 Brugada phenocopy in a patient with acute pericarditis

We herein describe a case of an acute pericarditis, in which type 1 Brugada phenocopy (BrP) was documented. The patient was referred to our hospital due to severe chest pain. The twelve-lead electrocardiogram (ECG) on admission showed type 1 Brugada ECG pattern (coved-type) in the precordial leads. Echocardiography only showed mild pericardial effusion. However, his ST segment elevation returned to normal and chest discomfort disappeared 3 weeks later. Our report addresses the possibility that the coved-type ST-segment elevation cannot be a sensitive finding for Brugada syndrome (BrS). Detailed tests are anyway needed to make appropriate diagnostic and therapeutic decisions.

Brugada phenocopy induced by severe pneumothorax

A Brugada phenocopy has been defined as a clinical situation that presents with an abnormal electrocardiogram identical to any of the electrocardiographic patterns found in Brugada syndrome in the absence of the characteristic congenital genetic abnormalities. The first confirmed case of type 1 Brugada phenocopy associated with severe left pneumothorax is presented. A provocative test with ajmaline, which proved to be negative, was performed to confirm the diagnosis. The presence of ST-segment elevation in the context of pneumothorax is most infrequent.

Brugada phenocopy associated with diabetic ketoacidosis in two pediatric patients

Two patients without cardiac history demonstrated type 1 Brugada pattern during hospitalization for diabetic ketoacidosis (DKA). Both patients had normalization of their ECGs after treatment of marked electrolyte abnormalities and metabolic acidosis. In this report, we describe two cases of Brugada phenocopy associated with DKA in children.

Brugada phenocopy caused by a compressive mediastinal tumor

Recently, it has been shown that even experts in electrocardiography cannot differentiate the electrocardiographic pattern of genuine Brugada syndrome (BrS) from Brugada phenocopy (BrP). For this reason, this differentiation depends on the presence of established criteria both for BrS and BrP. In this manuscript, we present a patient with type 1 Brugada electrocardiographic pattern caused by expansive anterior mediastinal non-Hodgkin's lymphoma (NHL) with mechanical compression on the right ventricular outflow tract. The electrocardiographic pattern disappeared rapidly after antineoplastic measures.

Yellow phosphorus-induced Brugada phenocopy

BACKGROUND

Metallic phosphides (of aluminum and phosphide) and yellow phosphorus are commonly used rodenticide compounds in developing countries. Toxicity of yellow phosphorus mostly pertains to the liver, kidney, heart, pancreas and the brain. Cardiotoxicity with associated Brugada ECG pattern has been reported only in poisoning with metallic phosphides.

METHODS AND RESULTS

Brugada phenocopy and hepatic dysfunction were observed in a 29-year-old male following yellow phosphorus consumption. He had both type 1 (day1) and type 2 (day2) Brugada patterns in the electrocardiogram, which resolved spontaneously by the third day without hemodynamic compromise.

CONCLUSION

Toxins such as aluminum and zinc phosphide have been reported to induce Brugada ECG patterns due to the generation of phosphine. We report the first case of yellow phosphorus-related Brugada phenocopy, without hemodynamic compromise or malignant arrhythmia.

Brugada phenocopy during right coronary artery dissection

CASE PRESENTATION

A 68-year-old female presented with non-ST-segment elevation myocardial infarction, and urgency coronary angiography was performed. The procedure was complicated with right coronary artery dissection leading to type-1 Brugada ECG pattern.

DISCUSSION

Brugada phenocopies (BrP) are clinical entities that present with electrocardiograms identical to those found in Brugada Syndrome (BrS) but are the result of different medical conditions. This report provides evidence that atypical causes of myocardial ischemia may induce BrP. Appropriate electrocardiogram and clinical differentiation of Brugada phenocopy from true Brugada syndrome may prevent unnecessary treatments. Although patients with true high-risk BrS are candidates for ICD therapy, the natural history of BrP remains unknown and seems to be more benign, depending on the severity of the underlying condition.

Pectus excavatum: Right ventricular compromise with orthostatic syndrome and Brugada phenocopy

Pectus excavatum (PEXT) consists of an overgrowth of the chondral region with posterior displacement of the inferior part of the sternum, resulting in a concave chest deformity. Characteristic clinical and imaging findings may occur, depending on the compression that right cardiac chambers suffer, when squeezed between the sternum and the column vertebrae.

Brugada syndrome, Brugada phenocopy or none?

Brugada syndrome is a form of inherited arrhythmia syndrome characterized by a distinct ST-segment elevation in the right precordial leads. Brugada phenocopies are clinical entities that present with an electrocardiographic pattern identical to Brugada syndrome and may obey to various clinical conditions. We present a case of a suicidal attempt using a high dose of propafenone causing a Brugada-type electrocardiographic pattern. Is this a Brugada syndrome case, a Brugada phenocopy or something else?

Myotonic dystrophy and Brugada syndrome: A common pathophysiologic pathway?

Type 1 myotonic dystrophy (DM1) is a hereditary neuromuscular disease affecting multiple organs in human adults. Here we report a 42-year-old man diagnosed with DM1. Having a history of progressive muscular weakness and gradual loss of visual acuity, he was referred to us by his ophthalmologist for risk assessment of undergoing cataract surgery. Cardiology workup revealed type 1 Brugada ECG pattern, positive late potentials and inducible ventricular fibrillation in an electrophysiology study. Literature review revealed that those ECG changes may be observed in DM1, suggesting that DM1 and Brugada syndrome may share a common pathophysiologic pathway.

[Brugada phenocopy]

Brugada phenocopies are clinical entities that are different from the true Brugada syndrome which is a channelopathy. Brugada phenocopy has reversible underlying conditions and, if underlying conditions resolve, the ECG pattern disappears. In this paper the author reviews and illustrates the known Brugada phenocopies. The most important etiologic categories of Brugada phenocopy include metabolic abnormalities (most commonly hyperkalemia), myocardial infarction, pulmonary embolism (massive), right ventricular mechanical compression, and others. The most important clinical issue is the different treatment of the Brugada syndrome and phenocopies in order to prevent cardiac death. In Brugada syndrome the implantable cardioverter defibrillator is the only effective treatment, while in Brugada phenocopies early, etiology-specific treatment can prevent cardiac death.

Brugada Phenocopy Induced by Electrolyte Disorder: A Transient Electrocardiographic Sign

Brugada syndrome (BrS) is an important cause of sudden cardiac death (SCD) with well-defined ST-segment elevation patterns on V1 -V3 . Observation of BrS-Type-electrocardiogram (ECG) patterns in medical conditions without true BrS is called "Brugada Phenocopy" (BrP). We present a case of 61-year-old male patient with hyperkalemia, hyponatremia, and BrS-Type-1 ECG pattern in the setting of acute postrenal failure. He was denying any syncope or family history of SCD. With normalization of electrolyte levels, BrS-Type-1-ECG resolved. Electrolyte disturbances are one of the most common reasons of BrP. Being aware of BrPs and differentiating from an unmasked BrS-ECG pattern could prevent patients from lethal consequences and unnecessary treatments.

Brugada syndrome and Brugada phenocopy. The importance of a differential diagnosis

To date Brugada syndrome (BrS) is considered a primary electrical heart disease and the diagnosis is based on precise clinical and electrocardiographic features. Many other diseases and conditions can lead to a Brugada-like ECG pattern but the vast majority of patients with BrS possess a structurally normal heart, which is consistent with the notion that this is a primary electrical heart disease. Presently, the terminology used in the literature to describe Brugada type 1 ECG pattern induced in patients without BrS is diverse and variable. Brugada phenocopies (BrP) are clinical entities that present with identical ECG patterns to those of true BrS but are elicited by various other clinical circumstances. They form a group of heterogeneous conditions that are perhaps the most difficult to differentiate from true congenital BrS due to identical ECG patterns and recently has been proposed an updated classification of conditions that may induce BrP and many criteria useful to differentiate BrP from BrS. A systematic diagnostic approach is crucial to avoid diagnostic errors that involve expenditure of time and resources, but above all it is useful to avoid to send patients without a real BrS to inopportune diagnostic and therapeutic paths that are sometimes burdened by considerable risks.

New methodologies for measuring Brugada ECG patterns cannot differentiate the ECG pattern of Brugada syndrome from Brugada phenocopy

BACKGROUND

Brugada phenocopies (BrP) are clinical entities characterized by ECG patterns that are identical to true Brugada syndrome (BrS), but are elicited by various clinical circumstances. A recent study demonstrated that the patterns of BrP and BrS are indistinguishable under the naked eye, thereby validating the concept that the patterns are identical.

OBJECTIVE

The aim of our study was to determine whether recently developed ECG criteria would allow for discrimination between type-2 BrS ECG pattern and type-2 BrP ECG pattern.

METHODS

Ten ECGs from confirmed BrS (aborted sudden death, transformation into type 1 upon sodium channel blocking test and/or ventricular arrhythmias, positive genetics) cases and 9 ECGs from confirmed BrP were included in the study. Surface 12-lead ECGs were scanned, saved in JPEG format for blind measurement of two values: (i) β-angle; and (ii) the base of the triangle. Cut-off values of ≥58° for the β-angle and ≥4mm for the base of the triangle were used to determine the BrS ECG pattern.

RESULTS

Mean values for the β-angle in leads V1 and V2 were 66.7±25.5 and 55.4±28.1 for BrS and 54.1±26.5 and 43.1±16.1 for BrP respectively (p=NS). Mean values for the base of the triangle in V1 and V2 were 7.5±3.9 and 5.7±3.9 for BrS and 5.6±3.2 and 4.7±2.7 for BrP respectively (p=NS). The β-angle had a sensitivity of 60%, specificity of 78% (LR+ 2.7, LR- 0.5). The base of the triangle had a sensitivity of 80%, specificity of 40% (LR+ 1.4, LR- 0.5).

CONCLUSIONS

New ECG criteria presented relatively low sensitivity and specificity, positive and negative predictive values to discriminate between BrS and BrP ECG patterns, providing further evidence that the two patterns are identical.

Expert cardiologists cannot distinguish between Brugada phenocopy and Brugada syndrome electrocardiogram patterns

AIMS

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.

METHODS AND 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).

CONCLUSION

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.

Brugada phenocopy: A new electrocardiogram phenomenon

Brugada phenocopies (BrP) are clinical entities that are etiologically distinct from true congenital Brugada syndrome. BrP are characterized by type 1 or type 2 Brugada electrocardiogram (ECG) patterns in precordial leads V1-V3. However, BrP are elicited by various underlying clinical conditions such as myocardial ischemia, pulmonary embolism, electrolyte abnormalities, or poor ECG filters. Upon resolution of the inciting underlying pathological condition, the BrP ECG subsequently normalizes. To date, reports have documented BrP in the context of singular clinical events. More recently, recurrent BrP has been demonstrated in the context of recurrent hypokalemia. This demonstrates clinical reproducibility, thereby advancing the concept of this new ECG phenomenon. The key to further understanding the pathophysiological mechanisms behind BrP requires experimental model validation in which these phenomena are reproduced under strictly controlled environmental conditions. The development of these validation models will help us determine whether BrP are transient alterations of sodium channels that are not reproducible with a sodium channel provocative test or alternatively, a malfunction of other ion channels. In this editorial, we discuss the conceptual emergence of BrP as a new ECG phenomenon, review the progress made to date and identify opportunities for further investigation. In addition, we also encourage investigators that are currently reporting on these cases to use the term BrP in order to facilitate literature searches and to help establish this emerging concept.

Brugada phenocopy clinical reproducibility demonstrated by recurrent hypokalemia

Brugada phenocopies (BrP) are clinical entities that are etiologically distinct from true congenital Brugada syndrome (BrS). BrP are characterized by type 1 or type 2 Brugada electrocardiogram (ECG) patterns in precordial leads V1 -V3 ; however, BrP are elicited by various underlying clinical conditions such as electrolyte disturbances, myocardial ischemia, or poor ECG filters. In this report, we describe the first case of clinically reproducible BrP which is important to the conceptual evolution of BrP.

Brugada phenocopy in a patient with pectus excavatum: systematic review of the ECG manifestations associated with pectus excavatum

Brugada phenocopies (BrP) have emerged as new clinical entities that are etiologically distinct from true Brugada syndrome (BrS). BrP are characterized by an ECG pattern that is phenotypically identical to true BrS (type 1 or type 2); however, BrP are caused by various other factors such as mechanical mediastinal compression, myocardial ischemia, pericarditis, myocarditis, pulmonary embolism, and metabolic disturbances. We report a case of an electrocardiographic BrP in a patient with pectus excavatum deformity in the absence of true BrS using currently defined BrP diagnostic criteria. A systematic review of ECG manifestations associated with pectus excavatum is also discussed.