Brugada Syndrome: Progress in Diagnosis and Management

Brugada Syndrome: Anesthetic Implications in an Incidentally Diagnosed Patient

Brugada syndrome (BS) is characterized by abnormal repolarization in cardiac cells, occurring in the absence of structural heart disease, which elevates the risk of ventricular arrhythmias and sudden cardiac death. While most BS patients are asymptomatic, a notable percentage experience syncope or sudden cardiac death. Diagnosis is primarily based on electrocardiographic (ECG) findings. A 40-year-old male with a history of syncope and a family history of sudden cardiac death was scheduled for urgent clavicle osteosynthesis. Preoperative ECG revealed type 1 BS. A multidisciplinary approach was taken, and anesthetic management involved combined general and regional anesthesia, utilizing ultrasound-guided clavipectoral and superficial cervical blocks. Postoperative pain was managed with paracetamol and ketorolac. The patient remained stable throughout the procedure, was monitored for 36 hours postoperatively, and was discharged without complications. BS poses significant perioperative risks, necessitating careful anesthetic management. This case report highlights the successful use of combined general and regional anesthesia in a BS patient, contributing to the limited evidence on safe anesthesia practices for this pathology.

Association between the number of altered late potential criteria and increased arrhythmic risk in Brugada syndrome patients

BACKGROUND

Brugada syndrome (BrS) is associated with abnormal electrophysiological properties at right ventricular epicardium, consisting of fragmented electrograms extending well beyond QRS termination. We aimed to evaluate the utility of signal-averaged electrocardiogram (SA-ECG) for the noninvasive assessment of late potentials (LP) and risk stratification of BrS patients.

METHODS

A prospective, observational, single-center study of BrS patients is submitted to SA-ECG with the determination of the total filtered QRS duration (fQRS), root mean square voltage of the 40 ms terminal portion of the QRS (RMS40), and duration of the low-amplitude electric potential component of the terminal portion of the QRS (LAS40). LP were considered positive when above standard cut-offs: fQRS > 114 ms, RMS40 < 20 µV, and LAS40 > 38 ms. The rates of malignant arrhythmic events (MAEs), defined as sudden death or appropriate shocks, were compared in relation to clinical characteristics and SA-ECG findings.

RESULTS

A total of 106 BrS patients (mean age, 48 ± 12 years, 67.9% male) were studied, 49% with type-1 spontaneous pattern and 81% asymptomatic. During a median follow up of 4.7 years, 10 patients (7.1%) suffered MAEs, including 4 sudden deaths. The presence of LP was significantly associated with the arrhythmic risk, which increased with the number of altered LP criteria. In comparison to the patients who had none or 1 altered LP criterium, MAE risk was 4.7 times higher in those with 2 altered criteria and 9.4 times higher in those with 3 altered LP criteria.

CONCLUSIONS

SA-ECG may be a useful tool for risk stratification in BrS. The presence of 2 or 3 abnormal LP criteria could identify a subset of asymptomatic patients at high risk of arrhythmic events.

Molecular Autopsy With Banked Cord Blood Reveals Brugada Syndrome in Past Sudden Death Case

Molecular autopsy has recently been gaining attention as a means of postmortem diagnosis; however, it is usually performed using the victim's blood sample at the time of death. Here, we report the first case of a deceased infant with Brugada syndrome whose diagnosis was made with banked cord blood. A seemingly healthy 1-year-old male infant collapsed while having a fever; this collapse was witnessed by his mother. Despite cardiopulmonary resuscitation, he died of ventricular fibrillation. No abnormalities of cardiac structure were identified on autopsy. Genomic samples were not stored at the time because of a lack of suspicion for familial arrhythmia. Five years later, his sister showed Brugada electrocardiogram pattern while febrile from Kawasaki disease. Their father showed a spontaneous type 1 Brugada electrocardiogram pattern. A heterozygous SCN5A p.R893C variant was found by genetic testing in the proband's father and sister. Furthermore, the proband's genetic testing was performed using his banked cord blood, which identified the same variant. Family history of Brugada syndrome with an SCN5A-R893C variant and clinical evidence led to a postmortem diagnosis of Brugada syndrome in the proband. Identification of this variant in this case later contributed to verifying SCN5A-R893C as a pathogenic variant through data accumulation. Banked cord blood may prove useful for conducting molecular autopsies in previously undiagnosed cases of sudden death in which genomic samples were not stored.

Brugada syndrome: a review and the role of epicardial ablation in management

BACKGROUND

Brugada syndrome (BrS) is an inherited arrhythmogenic syndrome characterized by cove-shaped ST-segment elevation in leads V1-V3 and incomplete or complete right bundle branch block. BrS exhibits autosomal dominant inheritance with incomplete penetrance and a male predominance. It carries a significant risk of sudden cardiac death due to ventricular fibrillation (VF).

MAIN BODY

Recent studies have highlighted the presence of epicardial fibrosis as a proarrhythmic substrate in BrS, revolutionizing our understanding of the disease's pathophysiology. Catheter ablation has emerged as a crucial intervention for symptomatic BrS patients experiencing recurrent episodes of ventricular tachycardia (VT) or VF. By potentially obviating the need for implantable cardioverter-defibrillator (ICD) implantation, epicardial ablation offers a promising therapeutic approach.

CONCLUSION

This review emphasizes the significance of current evidence and ongoing research in shaping the role of epicardial ablation as a curative strategy in BrS management, highlighting its potential benefits and the necessity for further investigation.

Electrocardiographic temporo-spatial assessment of depolarization and repolarization changes after epicardial arrhythmogenic substrate ablation in Brugada syndrome

Aims

In Brugada syndrome (BrS), with spontaneous or ajmaline-induced coved ST elevation, epicardial electro-anatomic potential duration maps (epi-PDMs) were detected on a right ventricle (RV) outflow tract (RVOT), an arrhythmogenic substrate area (AS area), abolished by epicardial-radiofrequency ablation (EPI-AS-RFA). Novel CineECG, projecting 12-lead electrocardiogram (ECG) waveforms on a 3D heart model, previously localized depolarization forces in RV/RVOT in BrS patients. We evaluate 12-lead ECG and CineECG depolarization/repolarization changes in spontaneous type-1 BrS patients before/after EPI-AS-RFA, compared with normal controls.

Methods and results

In 30 high-risk BrS patients (93% males, age 37 + 9 years), 12-lead ECGs and epi-PDMs were obtained at baseline, early after EPI-AS-RFA, and late follow-up (FU) (2.7-16.1 months). CineECG estimates temporo-spatial localization during depolarization (Early-QRS and Terminal-QRS) and repolarization (ST-Tpeak, Tpeak-Tend). Differences within BrS patients (baseline vs. early after EPI-AS-RFA vs. late FU) were analysed by Wilcoxon signed-rank test, while differences between BrS patients and 60 age-sex-matched normal controls were analysed by the Mann-Whitney test. In BrS patients, baseline QRS and QTc durations were longer and normalized after EPI-AS-ATC (151 ± 15 vs. 102 ± 13 ms, P < 0.001; 454 ± 40 vs. 421 ± 27 ms, P < 0.000). Baseline QRS amplitude was lower and increased at late FU (0.63 ± 0.26 vs. 0.84 ± 13 ms, P < 0.000), while Terminal-QRS amplitude decreased (0.24 ± 0.07 vs. 0.08 ± 0.03 ms, P < 0.000). At baseline, CineECG depolarization/repolarization wavefront prevalently localized in RV/RVOT (Terminal-QRS, 57%; ST-Tpeak, 100%; and Tpeak-Tend, 61%), congruent with the AS area on epi-PDM. Early after EPI-AS-RFA, RV/RVOT localization during depolarization disappeared, as Terminal-QRS prevalently localized in the left ventricle (LV, 76%), while repolarization still localized on RV/RVOT [ST-Tpeak (44%) and Tpeak-Tend (98%)]. At late FU, depolarization/repolarization forces prevalently localized in the LV (Terminal-QRS, 94%; ST-Tpeak, 63%; Tpeak-Tend, 86%), like normal controls.

Conclusion

CineECG and 12-lead ECG showed a complex temporo-spatial perturbation of both depolarization and repolarization in BrS patients, prevalently localized in RV/RVOT, progressively normalizing after epicardial ablation.

A large population-based study on the prevalence of electrocardiographic abnormalities: A result of Mashhad stroke and heart atherosclerotic disorder cohort study

BACKGROUND

Twelve-lead electrocardiogram (ECG) is a common and inexpensive tool for the diagnostic workup of patients with suspected cardiovascular disease, both in clinical and epidemiological settings. The present study was designed to evaluate ECG abnormalities in Mashhad population.

METHODS

ECGs were taken as part of MASHAD cohort study (phase1) and were coded according to the Minnesota coding criteria. Data were analyzed using SPSS.

RESULTS

Total 9035 ECGs were available for final analysis including 3615 (40.0%) male and 5420 (60.0%) female. Among ECG abnormalities precordial Q wave, major T-wave abnormalities, inferior Q wave, sinus bradycardia, and left axis deviation were the most prevalent abnormalities. The frequency of precordial and inferior Q wave, inferior QS pattern, major and minor ST abnormalities, major and minor T abnormalities, Wolff-Parkinson-White and Brugada pattern, sinus bradycardia, sinus tachycardia, left axis deviation, ST elevation, and tall T wave were significantly different between two genders. Moreover, the frequency of Q wave in precordial and aVL leads, QS pattern in precordial and inferior leads, major and minor T-wave abnormalities, Wolff-Parkinson-White, atrial fibrillation, sinus bradycardia, left axis deviation, and ST elevation were significantly different in different age groups. A comparison of the heart rate, P-wave duration, and QRS duration between men and women indicated that there was a significant difference.

CONCLUSIONS

Our finding indicated that the prevalence ECG abnormalities are different between men and women and also it varied in different age groups.

Unravelling Novel SCN5A Mutations Linked to Brugada Syndrome: Functional, Structural, and Genetic Insights

Brugada Syndrome (BrS) is a rare inherited cardiac arrhythmia causing potentially fatal ventricular tachycardia or fibrillation, mainly occurring during rest or sleep in young individuals without heart structural issues. It increases the risk of sudden cardiac death, and its characteristic feature is an abnormal ST segment elevation on the ECG. While BrS has diverse genetic origins, a subset of cases can be conducted to mutations in the SCN5A gene, which encodes for the Nav1.5 sodium channel. Our study focused on three novel SCN5A mutations (p.A344S, p.N347K, and p.D349N) found in unrelated BrS families. Using patch clamp experiments, we found that these mutations disrupted sodium currents: p.A344S reduced current density, while p.N347K and p.D349N completely abolished it, leading to altered voltage dependence and inactivation kinetics when co-expressed with normal channels. We also explored the effects of mexiletine treatment, which can modulate ion channel function. Interestingly, the p.N347K and p.D349N mutations responded well to the treatment, rescuing the current density, while p.A344S showed a limited response. Structural analysis revealed these mutations were positioned in key regions of the channel, impacting its stability and function. This research deepens our understanding of BrS by uncovering the complex relationship between genetic mutations, ion channel behavior, and potential therapeutic interventions.

Autolytic attempt mimicking Brugada type 1 electrocardiogram pattern due to flecainide toxicity. A case report

Background

Brugada phenocopies are a group of heterogeneous disorders that mimic Brugada syndrome (BrS) electrocardiogram (ECG) changes elicited by reversible clinical conditions. We report a novel case on flecainide toxicity causing an ECG signature of Brugada type 1 pattern in the paediatric age.

Case summary

A 13-year-old Caucasian boy with untreated attention-deficit/hyperactivity disorder referred to the Pediatric Emergency Department (PED) after unknown antiarrhythmic drug overdose. He deliberately ingested 10 tablets from a labelled white box of a 100-mg single dose. The ECG showed a coved-type ST-segment elevation in right precordial leads and prolongation of PR segment with a QTc limit interval. Values of troponins gradually increased and echocardiogram was normal. The altered ECG pattern was explained by the stabilizing membrane effect of flecainide involving the inhibition of rapid Na+ channels. After offending drug removal, regression of ECG changes was observed and no cardiac events were documented during follow-up.

Discussion

Flecainide-induced Brugada type 1 ECG pattern may occur in patients with no evidence of genetic susceptibility receiving a toxic dosage of this drug. With increasing dose, its action on conduction pathways manifests as prolongation of PR interval and QT and QRS complex duration and may cause BrS mimicry. A detailed clinical history considering symptoms and ECG findings may support early-raised suspicion for flecainide ingestion. The therapeutic approach implies primary detoxification, prevention of potential triggers, and management of eventual cardiotoxicity events. Finally, risk stratification for BrS should be always measured according to the clinical scenario and surveillance considered in a timely manner.

Automated Patch-Clamp and Induced Pluripotent Stem Cell-Derived Cardiomyocytes: A Synergistic Approach in the Study of Brugada Syndrome

The development of high-throughput automated patch-clamp technology is a recent breakthrough in the field of Brugada syndrome research. Brugada syndrome is a heart disorder marked by abnormal electrocardiographic readings and an elevated risk of sudden cardiac death due to arrhythmias. Various experimental models, developed either in animals, cell lines, human tissue or computational simulation, play a crucial role in advancing our understanding of this condition, and developing effective treatments. In the perspective of the pathophysiological role of ion channels and their pharmacology, automated patch-clamp involves a robotic system that enables the simultaneous recording of electrical activity from multiple single cells at once, greatly improving the speed and efficiency of data collection. By combining this approach with the use of patient-derived cardiomyocytes, researchers are gaining a more comprehensive view of the underlying mechanisms of heart disease. This has led to the development of more effective treatments for those affected by cardiovascular conditions.

Pathogenesis and Management of Brugada Syndrome: Recent Advances and Protocol for Umbrella Reviews of Meta-Analyses in Major Arrhythmic Events Risk Stratification

Brugada syndrome (BrS) is a primary electrical disease associated with life-threatening arrhythmias. It is estimated to cause at least 20% of sudden cardiac deaths (SCDs) in patients with normal cardiac anatomy. In this review paper, we discuss recent advances in complex BrS pathogenesis, diagnostics, and current standard approaches to major arrhythmic events (MAEs) risk stratification. Additionally, we describe a protocol for umbrella reviews to systematically investigate clinical, electrocardiographic, electrophysiological study, programmed ventricular stimulation, and genetic factors associated with BrS, and the risk of MAEs. Our evaluation will include MAEs such as sustained ventricular tachycardia, ventricular fibrillation, appropriate implantable cardioverter–defibrillator therapy, sudden cardiac arrest, and SCDs from previous meta-analytical studies. The protocol was written following the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) guidelines. We plan to extensively search PubMed, Embase, and Scopus databases for meta-analyses concerning risk-stratification in BrS. Data will be synthesized integratively with transparency and accuracy. Heterogeneity patterns across studies will be reported. The Joanna Briggs Institute (JBI) methodology, A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR 2), and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) are planned to be applied for design and execution of our evidence-based research. To the best of our knowledge, these will be the first umbrella reviews to critically evaluate the current state of knowledge in BrS risk stratification for life-threatening ventricular arrhythmias, and will potentially contribute towards evidence-based guidance to enhance clinical decisions.

Pyrexia Unmasking Brugada Syndrome: A Literature Review

Brugada syndrome (BrS) is an inherited arrhythmia syndrome in which asymptomatic patients tend to develop fatal arrhythmias leading to sudden cardiac death (SCD) in asymptomatic or undiagnosed cases. This review tries to shed light on pyrexia being one of the triggers to cause SCD secondary to fatal arrhythmias in patients of BrS. Pyrexia, electrolyte imbalance, alcohol intake, and drugs are common triggering factors for fatal arrhythmias in patients with BrS. Most patients are asymptomatic, while the most common form of presentation that brings the patient under medical attention is syncope or SCD. Hence, patients, especially young, who present with syncope or aborted episode of SCD with typical EKG patterns, should undergo further workup. It is essential to educate patients about the condition, possible triggers, and the importance of refraining them.

Brugada Syndrome: Warning of a Systemic Condition?

Brugada syndrome (BrS) is a hereditary disorder, characterized by a specific electrocardiogram pattern and highly related to an increased risk of sudden cardiac death. BrS has been associated with other cardiac and non-cardiac pathologies, probably because of protein expression shared by the heart and other tissue types. In fact, the most commonly found mutated gene in BrS, SCN5A, is expressed throughout nearly the entire body. Consistent with this, large meals and alcohol consumption can trigger arrhythmic events in patients with BrS, suggesting a role for organs involved in the digestive and metabolic pathways. Ajmaline, a drug used to diagnose BrS, can have side effects on non-cardiac tissues, such as the liver, further supporting the idea of a role for organs involved in the digestive and metabolic pathways in BrS. The BrS electrocardiogram (ECG) sign has been associated with neural, digestive, and metabolic pathways, and potential biomarkers for BrS have been found in the serum or plasma. Here, we review the known associations between BrS and various organ systems, and demonstrate support for the hypothesis that BrS is not only a cardiac disorder, but rather a systemic one that affects virtually the whole body. Any time that the BrS ECG sign is found, it should be considered not a single disease, but rather the final step in any number of pathways that ultimately threaten the patient's life. A multi-omics approach would be appropriate to study this syndrome, including genetics, epigenomics, transcriptomics, proteomics, metabolomics, lipidomics, and glycomics, resulting eventually in a biomarker for BrS and the ability to diagnose this syndrome using a minimally invasive blood test, avoiding the risk associated with ajmaline testing.

Brugada Syndrome: Fatal Consequences of a Must-Not-Miss Diagnosis

BACKGROUND

Brugada syndrome is a genetic disorder of cardiac conduction that predisposes patients to spontaneous ventricular arrhythmia and sudden cardiac death. Although Brugada syndrome is one of the most common causes of sudden cardiac death, patients presenting with the syndrome often go misdiagnosed. This error has potentially fatal consequences for patients, who are at risk for sudden cardiac death without appropriate management.

OBJECTIVE

To increase the critical care professional's knowledge of Brugada syndrome through detailed description of the characteristic electrocardiographic findings, an algorithmic approach to electrocardiogram evaluation, and a case report of a patient with a previously missed diagnosis of Brugada syndrome. The essential concepts of epidemiology, pathophysiology, clinical presentation, risk stratification, and management are reviewed for critical care professionals who may encounter patients with the syndrome.

DIAGNOSIS

Patients typically present with syncope or cardiac arrest and an abnormal electrocardiographic finding of ST-segment elevation in the precordial leads. The diagnosis of Brugada syndrome centers on identification of its electrocardiographic characteristics by critical care professionals who routinely evaluate electrocardiograms. Critical care professionals, especially nurses and advanced practice nurses, should be proficient in recognizing the electrocardiographic appearance of Brugada syndrome and initiating appropriate management.

INTERVENTIONS

Management strategies include prevention of sudden cardiac death through lifestyle modification and placement of an implantable cardioverter-defibrillator. Critical care professionals should be aware of commonly used medications that may exacerbate ventricular arrhythmia and place patients at risk for sudden cardiac death.

CONCLUSION

Increased awareness of Brugada syndrome among critical care professionals can decrease patient morbidity and mortality.

Telemedicine for detecting Brugada Syndrome in eastern Indonesia: A multi-center prospective observational study

BACKGROUND

The incidence of Brugada syndrome has been reported to occur mostly in Asian countries. However, key countries such as Indonesia, the largest-populated Southeast Asian country, have yet to report any existing data regarding the incidence of Brugada syndrome among its population. Detecting these patients has been challenging, especially in primary healthcare settings, which generally have limited resources. Telemedicine may represent an ideal solution for initial diagnosis to determine if a patient may have this condition.

METHODS

We collected and analyzed numerous 12-lead electrocardiograms (ECG) of patients who visited various healthcare centers in Makassar for routine medical check-up between June 2017-April 2018. Electrocardiograms from these centers were sent to the Cardiac Center at Dr. Wahidin Sudirohusodo Hospital in Makassar via telemedicine.

RESULTS

During the period, we successfully obtained 9558 ECGs. While none of the patients were initially suspected of Brugada Syndrome, we found 102 (1.07%) among them to have a Brugada ECG pattern (BrEP). BrEP was more commonly found in males compared to females (67.6% vs. 32.4% of the cases found). There were significant differences in the number of confirmed cases among the types of BrEP for male and female patients. The number of confirmed cases of BrEP in male and female patients were significantly different (p < 0.05), where the number of cases for male vs. female was 8 vs. 4 for type 1, 17 vs. 1 for type 2, and 44 vs. 28 for type 3.

CONCLUSION

Brugada syndrome is a disease that is at grave risk of being frequently underdiagnosed. Our study indicates that telemedicine can become an appropriate tool that can assist physicians in detecting suspected patients. Future efforts should also be directed at studying the possible use of telemedicine for detecting other similarly rare conditions.

Role of Pharmacogenetics in Adverse Drug Reactions: An Update towards Personalized Medicine

Adverse drug reactions (ADRs) are an important and frequent cause of morbidity and mortality. ADR can be related to a variety of drugs, including anticonvulsants, anaesthetics, antibiotics, antiretroviral, anticancer, and antiarrhythmics, and can involve every organ or apparatus. The causes of ADRs are still poorly understood due to their clinical heterogeneity and complexity. In this scenario, genetic predisposition toward ADRs is an emerging issue, not only in anticancer chemotherapy, but also in many other fields of medicine, including hemolytic anemia due to glucose-6-phosphate dehydrogenase (G6PD) deficiency, aplastic anemia, porphyria, malignant hyperthermia, epidermal tissue necrosis (Lyell's Syndrome and Stevens-Johnson Syndrome), epilepsy, thyroid diseases, diabetes, Long QT and Brugada Syndromes. The role of genetic mutations in the ADRs pathogenesis has been shown either for dose-dependent or for dose-independent reactions. In this review, we present an update of the genetic background of ADRs, with phenotypic manifestations involving blood, muscles, heart, thyroid, liver, and skin disorders. This review aims to illustrate the growing usefulness of genetics both to prevent ADRs and to optimize the safe therapeutic use of many common drugs. In this prospective, ADRs could become an untoward "stress test," leading to new diagnosis of genetic-determined diseases. Thus, the wider use of pharmacogenetic testing in the work-up of ADRs will lead to new clinical diagnosis of previously unsuspected diseases and to improved safety and efficacy of therapies. Improving the genotype-phenotype correlation through new lab techniques and implementation of artificial intelligence in the future may lead to personalized medicine, able to predict ADR and consequently to choose the appropriate compound and dosage for each patient.

Symmetric Projection Attractor Reconstruction analysis of murine electrocardiograms: Retrospective prediction of Scn5a+/- genetic mutation attributable to Brugada syndrome

Background

Life-threatening arrhythmias resulting from genetic mutations are often missed in current electrocardiogram (ECG) analysis. We combined a new method for ECG analysis that uses all the waveform data with machine learning to improve detection of such mutations from short ECG signals in a mouse model.

Objective

We sought to detect consequences of Na⁺ channel deficiencies known to compromise action potential conduction in comparisons of Scn5a^+/- mutant and wild-type mice using short ECG signals, examining novel and standard features derived from lead I and II ECG recordings by machine learning algorithms.

Methods

Lead I and II ECG signals from anesthetized wild-type and Scn5a^+/- mutant mice of length 130 seconds were analyzed by extracting various groups of features, which were used by machine learning to classify the mice as wild-type or mutant. The features used were standard ECG intervals and amplitudes, as well as features derived from attractors generated using the novel Symmetric Projection Attractor Reconstruction method, which reformulates the whole signal as a bounded, symmetric 2-dimensional attractor. All the features were also combined as a single feature group.

Results

Classification of genotype using the attractor features gave higher accuracy than using either the ECG intervals or the intervals and amplitudes. However, the highest accuracy (96%) was obtained using all the features. Accuracies for different subgroups of the data were obtained and compared.

Conclusion

Detection of the Scn5a^+/- mutation from short mouse ECG signals with high accuracy is possible using our Symmetric Projection Attractor Reconstruction method.

Novel CineECG Derived From Standard 12-Lead ECG Enables Right Ventricle Outflow Tract Localization of Electrical Substrate in Patients With Brugada Syndrome

Background:

In Brugada syndrome (BrS), diagnosed in presence of a spontaneous or ajmaline-induced type-1 pattern, ventricular arrhythmias originate from the right ventricle outflow tract (RVOT). We developed a novel CineECG method, obtained by inverse electrocardiogram (ECG) from standard 12-lead ECG, to localize the electrical activity pathway in patients with BrS.

Methods:

The CineECG enabled the temporospatial localization of the ECG waveforms, deriving the mean temporospatial isochrone from standard 12-lead ECG. The study sample included (1) 15 patients with spontaneous type-1 Brugada pattern, and (2) 18 patients with ajmaline-induced BrS (at baseline and after ajmaline), in whom epicardial potential duration maps were available; (3) 17 type-3 BrS pattern patients not showing type-1 BrS pattern after ajmaline (ajmaline-negative); (4) 47 normal subjects; (5) 18 patients with right bundle branch block (RBBB). According to CineECG algorithm, each ECG was classified as Normal, Brugada, RBBB, or Undetermined.

Results:

In patients with spontaneous or ajmaline-induced BrS, CineECG localized the terminal mean temporospatial isochrone forces in the RVOT, congruent with the arrhythmogenic substrate location detected by epicardial potential duration maps. The RVOT location was never observed in normal, RBBB, or ajmaline-negative patients. In most patients with ajmaline-induced BrS (78%), the RVOT location was already evident at baseline. The CineECG classified all normal subjects and ajmaline-negative patients at baseline as Normal or Undetermined, all patients with RBBB as RBBB, whereas all patients with spontaneous and ajmaline-induced BrS as Brugada. Compared with standard 12-lead ECG, CineECG at baseline had a 100% positive predictive value and 81% negative predictive value in predicting ajmaline test results.

Conclusions:

In patients with spontaneous and ajmaline-induced BrS, the CineECG localized the late QRS activity in the RVOT, a phenomenon never observed in normal, RBBB, or ajmaline-negative patients. The possibility to identify the RVOT as the location of the arrhythmogenic substrate by the noninvasive CineECG, based on the standard 12-lead ECG, opens new prospective for diagnosing patients with BrS.

Brugada Phenocopy Type 1 Secondary to Synthetic Cannabinoids

Brugada phenocopies (BrP) are clinical entities that have EKG tracings similar to the congenital Brugada syndrome (BrS) but without ventricular tachyarrhythmias or sudden cardiac death. BrP is caused by various factors such as metabolic disturbances (electrolyte imbalance), drugs, mechanical compression of the mediastinum, and inflammatory conditions such as myocarditis or pericarditis. We present a very rare case of a young patient who had a Brugada phenocopy Type 1 suspected to be secondary to synthetic cannabinoids.

Ablation for the treatment of Brugada syndrome: current status and future prospects

Introduction: Brugada syndrome (BrS) is an inherited disease characterized by an increased risk of sudden cardiac death (SCD). Therapeutic options in symptomatic patients are limited to implantable cardioverter defibrillator (ICD) and quinidine, but catheter ablation of the right ventricular outflow tract (RVOT) offers a potential cure. Different ablation strategies have been used to treat patients with symptomatic Brugada syndrome. Epicardial radiofrequency substrate ablation of the RVOT/right ventricle (RV) has emerged as a promising tool for the management of the disease.Areas covered: The historical management of BrS, endocardial and epicardial ablation techniques, the use of sodium channel blockers (SCB) and complications are summarized here.Expert opinion: Ventricular fibrillation (VF)-triggering premature ventricular contractions (PVCs) in patients with BrS are unpredictable, spontaneous ones are rarely present to be mapped, making this approach impractical. Furthermore, endocardial mapping for BrS substrates does not seem effective due to the epicardial pathological substrate localization. The size variation of the BrS substrate areas during SCB infusion suggests a dynamic process as arrhythmogenic basis and SCB infusion should guide BrS epicardial ablation of all abnormal potentials areas. If BrS epicardial ablation can truly provide long-term prevention of ventricular arrhythmias it may potentially become an alternative to ICD therapy.

Atrial fibrillation and risk of major arrhythmic events in Brugada syndrome: A meta-analysis

BACKGROUND

Brugada syndrome (BrS) is a common cause of sudden cardiac death (SCD). There is recent evidence that atrial fibrillation (AF) is associated with increased risk of SCD in general population. However, whether AF increases a risk of major arrhythmic events (MAE) in patients with BrS is still unclear. We performed a systematic review and meta-analysis to explore the effect of AF on MAE in BrS population.

METHODS

We searched the databases of MEDLINE and EMBASE from inception to March 2019. Included studies were published cohort studies reporting rates of MAE (ventricular fibrillation, sustained ventricular tachycardia, SCD, or sudden cardiac arrest) in BrS patients, with and without previous documented AF. Data from each study were combined using the random-effects model.

RESULTS

Six studies from 1,703 patients were included. There was a significant association between AF and an increased risk of MAE in patients with BrS (pooled OR = 2.37, 95% CI = 1.36-4.13, p-value = .002, I²  = 40.3%).

CONCLUSIONS

Our meta-analysis demonstrated that AF is associated with an increased risk of MAE in patients with BrS.