Brugada Syndrome Electrocardiogram Pattern Research Articles

Epicardial ablation in patients with Brugada syndrome: a single centre experience

Abstract Introduction Brugada syndrome (BrS) is a rare disease associated with an increased risk of ventricular fibrillation (VF), ventricular tachycardia (VT), and sudden cardiac death (SCD). The standard prevention of SCD in patients with BrS is the implantation of an implantable cardioverter-defibrillator (ICD), especially in patients who have previously suffered cardiac arrest or arrhythmogenic syncope. Catheter ablation is an effective method to prevent recurrences of VF/VT in these patients. Purpose Retrospective analysis of the results of catheter ablation by epicardial approach and genetic testing in patients with a diagnosis of BrS and repeated adequate ICD interventions. Methods In 2013-2024, catheter ablation by epicardial approach was performed in our centre in 9 patients diagnosed with Brugada syndrome (mean age 41±6 years, nine males, left ventricular ejection fraction 57±4%). All patients had an ICD implanted for secondary prevention of SCD and presented with adequate ICD therapies (mean 9±11 shocks/patient in the last six months before catheter ablation). Before catheter ablation, two patients were treated with quinidine. Patients underwent cardiogenetic testing by next-generation sequencing of 228 genes. Results Type 1 electrocardiogram (ECG) pattern was present at baseline ECG in four (44%) patients; in five (56%) patients, type 1 was induced after ajmaline administration. Genetic testing was performed in seven patients, and only one patient (14%) was found to have a relevant pathogenic mutation in the SCN5A gene. Prior to ablation, sustained VT/VF could be induced by programmed electrical stimulation in three patients (33%). Epicardial ablation was targeted at areas of abnormal electrograms located over the right ventricular outflow tract. No complications were noted. The mean follow-up period was 25±30 months. In one patient (11%), reablation was required to suppress ventricular arrhythmias successfully. After the last ablation, no recurrence of VT/VF was observed in any patient. Conclusions Epicardial ablation is an effective method that leads to the suppression of ventricular arrhythmias in patients with a diagnosis of BrS and repeated ICD interventions. Despite the malignant arrhythmic phenotype, patients in our cohort had a rather low prevalence of signs associated with a high risk of VT/VF, such as spontaneous ECG pattern of BrS, inducibility of VT/VF during electrical programmed stimulation, or the presence of a causative genetic mutation.

Monitoring the electrophysiological effects of hydroquinidine non-invasively in patients with Brugada syndrome

Abstract Background Quinidine and it’s derivative hydroquinidine are the only drugs shown to reduce arrhythmic events in patients with Brugada syndrome (BrS). There is currently no standardised approach to monitoring the effect of pharmacotherapy in BrS to guide dosing and evaluate an individual’s response to therapy. Purpose To investigate if the electrophysiological effects of Hydroquinidine can be detected on non-invasive testing and identify parameters that may be used to study a non-invasive strategy for monitoring pharmacotherapy in BrS. Methods Patients with a diagnosis of BrS underwent multimodality non-invasive assessment with electrocardiogram (ECG), signal averaged ECG, 24 hour 12-lead Holter monitor and electrocardiographic imaging (ECGi – a method of non-invasive electroanatomical mapping), at baseline and "on treatment" with hydroquinidine (300mg BD) therapy. A medication survey was used to recorded adverse drug reactions and serum hydroquinidine levels were determined using liquid chromatography mass spectrometry. Results Twelve patients with BrS (11 male, mean age 47.6±10.9 years) with spontaneous type 1 BrS pattern or drug inducible type 1 BrS pattern and resuscitated cardiac arrest participated in the study. The mean Shanghai score was 4.6±1.4 and two patients had disease-causing SCN5A variants. During hydroquinidine therapy, there was a significant increase in QRS duration (110.7msec vs 117.8msec, p=0.004) and in mean activation time in the area of late activation in the right ventricular outflow tract (RVOT, 90.9ms to 97.7ms, p=0.020). In nine (75%) patients, the area of late activation (defined as >80ms after initial activation) in the RVOT also increased with hydroquinidine. Repolarisation parameters were also affected by hydroquinidine with an increase in QT interval corrected for heart rate (369.5msec vs 434.8msec, p<0.0001) and T-wave width (232.8msec to 271.2msec p=0.003) and a significant reduction in T-wave amplitude (0.4mV to 0.2mV p=0.001) on treatment. The reduction in T-wave amplitude precluded computation of repolarisation time in the RVOT by ECGi on treatment. No difference in the burden of type 1 BrS ECG pattern over 24 hours was seen on 12-lead Holter monitor between baseline and on treatment assessment. No significant difference in serum hydroquinidine level was detected between those who experienced side effects and those who did not (2.9µmol vs 3.1µmol, p=0.790). Conclusion Hydroquinidine affects both ventricular activation and repolarisation in patients with BrS and these effects can be detected non-invasively. Further work is required to determine clinical significance of these observed effects and investigate the feasibility of non-invasive monitoring strategy of pharmacotherapy in BrS.ECGi activation maps

Abstract 12128: Catheter Ablation Outperforms Implantable Cardioverter Defibrillator Therapy in Improving Arrhythmic Outcomes of Brugada Syndrome

Background: Brugada syndrome (BrS) is characterized by ventricular arrhythmias that pose a significant risk to affected individuals. While ICD therapy is the primary treatment, it does not prevent VF episodes. Catheter ablation (CA) has shown promise in improving arrhythmic outcomes. This study aims to compare the efficacy of CA with ICD therapy in symptomatic BrS patients. Methods: A total of 49 symptomatic BrS patients were enrolled, with 21 patients undergoing CA and 28 patients receiving ICD therapy. Substrate modification techniques, including endocardial and epicardial approaches, were utilized along with VF-triggering PVC ablation strategies. The primary outcomes assessed were the occurrence of VF episodes and sudden cardiac death during the follow-up period. Results: The study population had a mean age of 44.3±10.4 years, with 44 patients (89.8%) being male. Among the participants, 40 (81.6%) exhibited the typical type 1 BrS electrocardiogram pattern, and 12 (24.5%) had a positive SCN5A mutation. VF-triggering PVCs were successfully ablated in 3 patients (14.3%), while VF substrates were eliminated in 18 patients (85.7%). Epicardial ablation was performed in 14 patients (66.7%). During a median follow-up of 46.2 (15.6-68.8) months, the primary outcomes occurred more frequently in the ICD group compared to the CA group (4.8% vs. 57.1%, Log-rank P = 0.006). Conclusion: Our findings suggest that CA is a more effective therapy for improving arrhythmic outcomes in symptomatic BrS patients compared to ICD implantation. These results highlight the potential of CA as a first-line therapeutic approach for managing symptomatic BrS.

Outcomes of catheter ablation in high-risk patients with Brugada syndrome refusing an implantable cardioverter defibrillator implantation.

The aim of this study was to investigate the outcomes of catheter ablation (CA) in preventing arrhythmic events among patients with symptomatic Brugada syndrome (BrS) who declined implantable cardioverter defibrillator (ICD) implantation. A total of 40 patients with symptomatic BrS were included in the study, of which 18 refused ICD implantation and underwent CA, while 22 patients received ICD implantation. The study employed substrate modification (including endocardial and epicardial approaches) and ventricular fibrillation (VF)-triggering pre-mature ventricular contraction (PVC) ablation strategies. The primary outcomes were a composite endpoint consisting of episodes of VF and sudden cardiac death during the follow-up period. The study population had a mean age of 43.8 ± 9.6 years, with 36 (90.0%) of them being male. All patients exhibited the typical Type 1 BrS electrocardiogram pattern, and 16 (40.0%) were carriers of an SCN5A mutation. The Shanghai risk scores were comparable between the CA and the ICD groups (7.05 ± 0.80 vs. 6.71 ± 0.86, P = 0.351). Ventricular fibrillation-triggering PVCs were ablated in 3 patients (16.7%), while VF substrates were ablated in 15 patients (83.3%). Epicardial ablation was performed in 12 patients (66.7%). During a median follow-up of 46.2 (17.5-73.7) months, the primary outcomes occurred more frequently in the ICD group than in the CA group (5.6 vs. 54.5%, Log-rank P = 0.012). Catheter ablation is an effective alternative therapy for improving arrhythmic outcomes in patients with symptomatic BrS who decline ICD implantation. Our findings support the consideration of CA as an alternative treatment option in this population.

Fever following Covid-19 vaccination in subjects with Brugada syndrome: Incidence and management.

BackgroundFever is a potential side effect of the Covid‐19 vaccination. Patients with Brugada syndrome (BrS) have an increased risk of life‐threatening arrhythmias when experiencing fever. Prompt treatment with antipyretic drugs is suggested in these patients.Aim of the studyTo evaluate the incidence and management of fever within 48 h from Covid‐19 vaccination among BrS patients.MethodsOne hundred sixty‐three consecutive patients were enrolled in a prospective registry involving five European hospitals with a dedicated inherited disease ambulatory.ResultsThe mean age was 50 ± 14 years and 121 (75%) patients were male. Prevalence of Brugada electrocardiogram (ECG) pattern type‐1, ‐2, and ‐3 was 32%, 44%, and 24%, respectively. Twenty‐eight (17%) patients had an implantable cardioverter‐defibrillator (ICD). Fever occurred in 32 (19%) BrS patients after 16 ± 10 h from vaccination, with a peak of body temperature of 37.9° ± 0.5°. Patients with fever were younger (39 ± 13 vs. 48 ± 13 years, p = .04). No additional differences in terms of sex and cardiovascular risk factors were found between patients with fever and not. Twenty‐seven (84%) out of 32 patients experienced mild fever and five (16%) moderate fever. Pharmacological treatment with antipyretic drugs was required in 18 (56%) out of 32 patients and was associated with the resolution of symptoms. No patient required hospital admission and no arrhythmic episode was recorded in patients with ICD within 48 h after vaccination. No induced type 1 BrS ECG pattern and new ECG features were found among patients with moderate fever.ConclusionFever is a common side effect in BrS patients after the Covid‐19 vaccination. Careful evaluation of body temperature and prompt treatment with antipyretic drugs may be needed.

Multisite conduction block in the epicardial substrate of Brugada syndrome.

The Brugada pattern manifests as a spontaneous variability of the electrocardiographic marker, suggesting a variability of the underlying electrical substrate. The purpose of this study was to investigate the response of the epicardial substrate of Brugada syndrome (BrS) to programmed ventricular stimulation and to Na blocker infusion. We investigated 6 patients (all male; mean age 54 ± 14 years) with BrS and recurrent ventricular fibrillation. Five had no type 1 BrS electrocardiogram pattern at admission. They underwent combined epicardial-endocardial mapping using multielectrode catheters. Changes in epicardial electrograms were evaluated during single endocardial extrastimulation and after low-dose ajmaline infusion (0.5 mg/kg in 5 minutes). All patients had a region in the anterior epicardial right ventricle with prolonged multicomponent electrograms. Single extrastimulation prolonged late epicardial components by 59 ± 31 ms and in 4 patients abolished epicardial components at some sites, without reactivation by surrounding activated sites. These localized blocks occurred at an initial coupling interval of 335 ± 58 ms and then expanded to other sites, being observed in up to 40% of epicardial sites. Ajmaline infusion prolonged electrogram duration in all and produced localized blocks in 62% of sites in the same patients as during extrastimulation. Epicardial conduction recovery after ajmaline occurred intermittently and at discontinuous sites and produced beat-to-beat changes in local repolarization, resulting in an area of marked electrical disparity. These changes were consistent with models based on microstructural alterations under critical propagation conditions. In BrS, localized functional conduction blocks occur at multiple epicardial sites and with variable patterns, without being reactivated from the surrounding sites.

Evaluating the Use of Genetics in Brugada Syndrome Risk Stratification.

The evolution of the current dogma surrounding Brugada syndrome (BrS) has led to a significant debate about the real usefulness of genetic testing in this syndrome. Since BrS is defined by a particular electrocardiogram (ECG) pattern, after ruling out certain possible causes, this disease has come to be defined more for what it is not than for what it is. Extensive research is required to understand the effects of specific individual variants, including modifiers, rather than necessarily grouping together, for example, “all SCN5A variants” when trying to determine genotype-phenotype relationships, because not all variants within a particular gene act similarly. Genetic testing, including whole exome or whole genome testing, and family segregation analysis should always be performed when possible, as this is necessary to advance our understanding of the genetics of this condition. All considered, BrS should no longer be considered a pure autosomal dominant disorder, but an oligogenic condition. Less common patterns of inheritance, such as recessive, X–linked, or mitochondrial may exist. Genetic testing, in our opinion, should not be used for diagnostic purposes. However, variants in SCN5A can have a prognostic value. Patients should be diagnosed and treated per the current guidelines, after an arrhythmologic examination, based on the presence of the specific BrS ECG pattern. The genotype characterization should come in a second stage, particularly in order to guide the familial diagnostic work-up. In families in which an SCN5A pathogenic variant is found, genetic testing could possibly contribute to the prognostic risk stratification.

Prevalence and Clinical Significance of Latent Brugada Syndrome in Atrial Fibrillation Patients Below 45 Years of Age.

Aim: This study aims to describe prevalence and clinical significance of latent Brugada syndrome (BrS) in a young population with atrial fibrillation (AF).Methods: Between September 2015 and November 2017, among 111 AF patients below 45 years of age, those without pre-existing pathologies and/or known risk factors were selected for the study. Based on baseline 12-lead−24-h Holter electrocardiogram (ECG), previous class 1C antiarrhythmic drug therapy, or ajmaline testing, patients were stratified as latent type 1 BrS or not.Results: Within the 78 enrolled patients, 13 (16.7%; group 1) revealed a type 1 BrS ECG pattern, while 65 (83.3%; group 2) did not. Mean age was 37 ± 8 vs. 35 ± 7 (p = 0.42), and males were 7 (54%) vs. 54 (83%) (p = 0.02) in the two groups, respectively. Family history of BrS was significantly more common within group 1 patients (2, 15% vs. 0; p = 0.03), and 4 (31%) patients experienced syncope in group 1 vs. 5 (8%) in group 2 (p = 0.02). After a mean follow-up of 42 ± 18 months from the index AF event, more than 80% of the patients, in both study groups, were in sinus rhythm.Conclusion: In young patients with AF without pre-existing pathologies and/or known risk factors, latent BrS should be suspected. Syncope and a family history of BrS emerge as easily identifiable factors related to BrS. Long-term sinus rhythm maintenance appears satisfactory, either in the presence or not of BrS.

Brugada-like electrocardiogram pattern in a young man taking a proton-pump inhibitor

The Brugada syndrome (BrS) is an electrical heart disease with complex inheritance (some cases with SCN5A mutations), characterized by specific electrocardiogram (ECG) markers and high risk of associated lethal ventricular arrhythmias [1]. The ECG signature of BrS consists of right precordial ST-segment elevation (≥2 mm) followed by negative T waves [1]. It sometimes includes the findings of right bundle branch block (RBBB). In certain cases, the typical ECG pattern is present intermittently which creates a potential problem for reaching the diagnosis of BrS. Another problem in diagnosing BrS is the presence of so-called Brugada phenocopies (BrPs), i.e. an acquired Brugada-like ECG pattern that are visually identical and indistinguishable from true BrS [2]. This ECG pattern can be caused by other conditions including ischemia of the ventricular septum and/or right ventricle or by taking certain medications [2]. Proton-pump inhibitors (PPIs) are widely prescribed, often for prolonged use, and have been associated with electrolyte disturbances and cardiac arrhythmias [3,4]. We hereby present for the first time the case of a patient with an ECG suggestive of BrS while taking PPI; but no other medication known to cause BrS. The BrS ECG pattern disappeared a few months after stopping the medication.

P5529Difference of late potentials detected by signal-averaged ECG in patients with spontaneous or drug-induced type 1 electrocardiogram pattern of Brugada syndrome

Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017.

Exercise ECG unmasked Brugada sign: manifestation of the risk of sports-associated sudden cardiac arrest (RCD code: V-1A.1)

Sports‑associated sudden cardiac arrest (SCA) constitutes an important problem. Causes of SCA during sport activities include Brugada syndrome (BrS) among others. We describe a 29‑year‑old male, without a history of cardiovascular disease, who suffered from SCA during football training and despite intensive treatment, after almost 4 weeks of hospitalization, unfortunately died. Detailed medical documentation review showed grade I atrioventricular block, intraventricular conduction abnormalities and BrS type 2 morphology of ST-segment elevation on resting 12‑lead electrocardiogram (ECG). The patient had a history of syncope during physical activity. Further echocardiographic study did not reveal significant structural heart disease. Submaximal exercise testing was performed and showed ventricular extrasystoles during physical activity and type 1 BrS morphology of ST-segment elevation during recovery phase. We compared observed ECG changes to those present in a healthy football player and described noticeable similarities. Exercise ECG testing, especially in patients after syncope of probable arrhythmic etiology, may unmask BrS ECG pattern and lead to BrS diagnosis. JRCD 2017; 3 (3): 92–97.

136-72: Late potentials detected by signal-averaged ECG in patients with spontaneous and drug-induced type 1 electrocardiogram pattern of Brugada syndrome

136-72: Late potentials detected by signal-averaged ECG in patients with spontaneous and drug-induced type 1 electrocardiogram pattern of Brugada syndrome

SCN5A(K817E), a novel Brugada syndrome–associated mutation that alters the activation gating of NaV1.5 channel

Brugada syndrome (BrS) is an inherited lethal arrhythmic disorder characterized by syncope and sudden cardiac death from ventricular tachyarrhythmias. Here we identified a novel K817E mutation of SCN5A gene in a man with type 1 BrS electrocardiogram pattern using next-generation sequencing targeted for 73 cardiac disorder-related genes. SCN5A encodes the α-subunit of NaV1.5 voltage-gated Na(+) channel, and some of its mutations are linked to BrS. The proband had no mutation in any of the other arrhythmia-related genes sequenced. We investigated whether the K817E mutation causes a functional change of NaV1.5 channel responsible for the BrS phenotype. We compared the electrophysiological properties of the whole-cell currents mediated by wild-type and mutant channels heterologously expressed in human embryonic kidney 293 cells by using a voltage-clamp technique. The K817E mutation reduced the Na(+) current density by 39.0%-91.4% at membrane potentials from -55 to -5 mV. This reduction resulted from a ~24-mV positive shift in the voltage dependence of activation. The mutation also decelerated recovery from both fast and intermediate inactivation, whereas it had little effect on the cell surface expression, single-channel conductance, voltage-dependence of fast inactivation, entry into intermediate inactivation, use-dependent loss of channel availability, or closed-state inactivation. The K817E mutation of SCN5A gene leads to loss of function of NaV1.5 channel and may underlie the BrS phenotype of the proband.

Sinus node disease in subjects with type 1 ECG pattern of Brugada syndrome

BackgroundThe spectrum of phenotypes related to mutations of the SCN5A gene include Brugada syndrome (BS), long QT syndrome, progressive cardiac conduction defect, and sinus node disease (SND). The present study investigated the incidence of SND in subjects with type 1 electrocardiogram (ECG) pattern of BS. Methods and resultsThe study population consisted of 68 individuals (55 males, mean age 44.8±12.8 years) with spontaneous (n=27) or drug-induced (n=41) type 1 ECG pattern of BS. Twenty-eight subjects were symptomatic with a history of syncope (41.2%). SND was observed in 6 symptomatic subjects (8.8%), and was mainly attributed to sino-atrial block with sinus pauses. Two patients were initially diagnosed with SND, and received a pacemaker. Patients with SND displayed an increased P-wave duration in leads II and V2, PR interval in leads II and V2, QRS duration in leads II and V2, and increased QTc interval in lead V2 (p<0.05). AH and HV intervals as well as corrected sinus node recovery time (cSNRT) were significantly prolonged in subjects with SND (p<0.05). During a mean follow-up period of 5.0±3.6 years, five subjects with a history of syncope suffered appropriate implantable cardioverter defibrillator (ICD) discharges due to ventricular arrhythmias (7.4%). None of those diagnosed with SND suffered syncope or ICD therapies. ConclusionSND is not an uncommon finding in subjects with type 1 ECG pattern of BS. The occurrence of SND in relatively young patients may deserve meticulous investigation including sodium channel blocking test.

Long-term prognosis of asymptomatic individuals with spontaneous or drug-induced type 1 electrocardiographic phenotype of Brugada syndrome

Background Risk stratification of asymptomatic individuals with type 1 electrocardiogram (ECG) phenotype of Brugada syndrome (BS) still remains controversial. This study investigated the long-term prognosis of asymptomatic subjects with spontaneous or drug-induced type 1 ECG pattern of BS. Methods and results Data from 33 apparently healthy individuals (30 males; age, 43.6 ± 13.4 years) with spontaneous (n = 12) or drug-induced (n = 21) type 1 ECG pattern of BS were retrospectively analyzed. Thirteen subjects (39.4%) displayed a positive family history of BS and/or sudden cardiac death. Electrophysiologic study was performed in 16 subjects, and programed right ventricular stimulation induced polymorphic ventricular tachycardia in 9 (56.3%) of them. A cardioverter defibrillator was implanted in 6 cases. During a mean follow-up period of 5.3 ± 2.8 years, all subjects remained asymptomatic. None of them had syncope or cardioverter defibrillator discharges due to ventricular arrhythmias. Conclusions Asymptomatic individuals with spontaneous or drug-induced type 1 ECG phenotype of BS display a benign clinical course during long-term follow-up.

Additional ECG Leads May Not Provide Benefit in Detecting Brugada Syndrome

In a preliminary study, the use of additional electrocardiogram (ECG) leads was no more sensitive than standard 12-lead ECG assessment in detecting the signature ECG pattern of Brugada Syndrome, including right bundle branch block, persistent ST-segment elevation in precordial leads V1 to V3, and normal QT interval.

Predictors of Atrial Tachyarrhythmias in Subjects with Type 1 ECG Pattern of Brugada Syndrome

Previous studies have demonstrated a high incidence of atrial tachyarrhythmias (ATs) in patients with Brugada syndrome (BS). The present study aimed to investigate whether various 12-lead electrocardiogram (ECG) and electrophysiological parameters may help to differentiate subjects with a high probability to develop ATs. The clinical records of 38 individuals (31 males, age 44.4 +/- 13.9) with spontaneous (n = 15) or ajmaline-induced (n = 23) type 1 ECG pattern of BS were analyzed. During a mean follow-up period of 4.6 +/- 2.2 years, nine subjects suffered ATs (24%). Six subjects displayed paroxysmal atrial fibrillation and three typical atrial flutter. Among the studied 12-lead ECG parameters, subjects with ATs exhibited increased values of P-wave duration in lead II, P-wave dispersion, PR interval in leads II, QRS duration in leads II and V(2), Tpeak-end interval in lead II, and Tpeak-end dispersion of the 12 leads in relation to those without ATs (P < 0.05). Among the assessed electrophysiological parameters, atrial-His (AH) and His-ventricular (HV) intervals were significantly prolonged in subjects with ATs (P < 0.05). Multiple Cox proportional hazards analysis revealed that P-wave duration in lead II, P-wave dispersion, Tpeak-end in lead II, Tpeak-end dispersion of the 12 leads, as well as AH and HV intervals are independent predictors of ATs in subjects with BS (P < 0.05). Cut-off point analysis showed that an HV interval>or=56 ms displayed the highest predictive ability (P < 0.01). Our findings demonstrate that simple 12-lead ECG and electrophysiological parameters may easily be applied to identify high-risk subjects with BS ECG phenotype to develop ATs.

Neurally Mediated Susceptibility in Individuals with Brugada‐Type ECG Pattern

Neurally mediated syncope and Brugada syndrome (BS) share common pathophysiologic mechanisms related to autonomic nervous system modulations, and particularly with increased vagal tone. This study aimed to investigate the incidence of neurally mediated susceptibility in individuals with Brugada-type electrocardiogram (ECG) pattern. Eight asymptomatic male individuals (mean age 41.6 +/- 10.6 years) with spontaneous or procainamide-induced type 1 ECG pattern of BS and structurally normal hearts underwent a drug-free head-up tilt test. Twenty-five healthy male subjects (mean age 37.4 +/- 14.1 years) with normal ECG and without structural heart disease were included in the study, and served as comparative controls. A positive tilt test response was observed in three out of eight subjects with the Brugada-type ECG pattern (37%) and in three out of 25 controls (12%) (P = 0.018). This study demonstrates a high incidence of neurally mediated susceptibility in asymptomatic individuals with Brugada-type ECG pattern. Severe diagnostic and therapeutic dilemmas may rise from this coexistence. A positive tilt test in subjects with Brugada-type ECG displaying a history of syncope may mislead the physician to a false sense of security. Further studies are required to validate our findings and possibly evaluate the role of tilt test in risk stratification of patients with BS.

AVR sign as a risk factor for life-threatening arrhythmic events in patients with Brugada syndrome

Risk stratification in Brugada syndrome (BS) is controversial, especially in asymptomatic individuals. The aim of this study was to evaluate the significance of lead aVR in patients with BS. Twenty-four patients with the electrocardiogram pattern of BS (24 male, mean age 32.1 +/- 13.6 years) and 24 healthy age- and gender-matched controls were studied. Thirteen patients were symptomatic. The R-wave amplitude or R/q ratio in lead aVR was significantly greater in patients experiencing a recurrence compared with those who did not. The aVR sign was defined as R wave >/= 0.3 mV or R/q >/= 0.75 in lead aVR. Most of the recurrences (78%) were in patients with present aVR sign; 84% of BS patients with present aVR sign had events during follow-up. In contrast, only 27% of BS patients with absent aVR sign had events during follow-up. Our study shows significant correlation between a prominent R wave in lead aVR (aVR sign) and risk for development of arrhythmic events in BS. In the presence of BS, prominent R wave in lead aVR may reflect more right ventricular conduction delay and subsequently more electrical heterogeneity, which in turn is responsible for a higher risk of arrhythmia.

Tpeak-Tend and Tpeak-Tend Dispersion as Risk Factors for Ventricular Tachycardia/Ventricular Fibrillation in Patients With the Brugada Syndrome

Our objective in this study was to evaluate Tpeak-Tend interval (Tp-e) and other electrocardiographic parameters as risk factors for recurrence of life-threatening cardiac events in patients with the Brugada syndrome (BS). The Tp-e interval in the electrocardiogram (ECG) has been reported to predict life-threatening arrhythmias in the long QT syndrome. Twenty-nine patients with the ECG pattern of BS and 29 healthy age- and gender-matched controls were studied. The follow-up period was 42.65 +/- 24.42 months (range 11 to 108 months). Upon presentation, five patients had suffered aborted sudden death, five syncope, and two presyncope. Eleven patients with the ECG pattern of BS had a prolonged (>460 ms) QTc in V2 but usually not in inferior or left leads. No patient had abnormally prolonged QT dispersion. Programmed electrical stimulation induced ventricular tachycardia/fibrillation in 5 out of 26 patients. Inducibility did not predict recurrence of events. Cardioverter-defibrillators were implanted in 14 patients (all symptomatic and two asymptomatic). During follow-up, nine symptomatic patients experienced recurrences. Previous cardiac events and a QTc >460 ms in V2 were significant risk factors (p = 0.00002 and p = 0.03, respectively). Tp-e and Tp-e dispersion were significantly prolonged in patients with recurrences versus patients without events (104.4 and 35.6 ms vs. 87.4 and 23.2 ms; p = 0.006 and p = 0.03, respectively) or controls (90.7 and 17.9 ms; p = 0.02 and p = 0.001, respectively). Our study demonstrates significant correlation between previous events, QTc >460 ms in V2, Tp-e, and Tp-e dispersion and occurrence of life-threatening arrhythmic events, suggesting that these parameters may be useful in risk stratification of patients with the Brugada syndrome.