scholarly journals Experimental Models of Brugada syndrome

2019 ◽  
Vol 20 (9) ◽  
pp. 2123 ◽  
Author(s):  
Sendfeld ◽  
Selga ◽  
Scornik ◽  
Pérez ◽  
Mills ◽  
...  

Brugada syndrome is an inherited, rare cardiac arrhythmogenic disease, associated with sudden cardiac death. It accounts for up to 20% of sudden deaths in patients without structural cardiac abnormalities. The majority of mutations involve the cardiac sodium channel gene SCN5A and give rise to classical abnormal electrocardiogram with ST segment elevation in the right precordial leads V1 to V3 and a predisposition to ventricular fibrillation. The pathophysiological mechanisms of Brugada syndrome have been investigated using model systems including transgenic mice, canine heart preparations, and expression systems to study different SCN5A mutations. These models have a number of limitations. The recent development of pluripotent stem cell technology creates an opportunity to study cardiomyocytes derived from patients and healthy individuals. To date, only a few studies have been done using Brugada syndrome patient-specific iPS-CM, which have provided novel insights into the mechanisms and pathophysiology of Brugada syndrome. This review provides an evaluation of the strengths and limitations of each of these model systems and summarizes the key mechanisms that have been identified to date.

2010 ◽  
Vol 2010 ◽  
pp. 1-3 ◽  
Author(s):  
Jagadeesh K. Kalavakunta ◽  
Vishwaroop Bantu ◽  
Hemasri Tokala ◽  
Mihas Kodenchery

Introduction. Brugada syndrome accounts for about 4% of sudden cardiac deaths (SCD). It is characterized by an ST-segment elevation in the right precordial electrocardiogram (EKG) leads.Case Presentation. We describe a 39-year-old healthy Caucasian man who was admitted to the intensive care unit after being cardioverted from ventricular fibrillation (VF) arrest. His past history was significant for an episode of syncope one month prior to this presentation for which he was admitted to an outlying hospital. EKG during that admission showed ST elevations in V1 and V2 leads, a pattern similar to Type 1 Brugada. A diagnosis of Brugada syndrome was missed and the patient had a cardiac arrest a month later. We discuss a short review of Brugada syndrome and emphasize the need to look for it in patients presenting with SCD and malignant arrhythmias.Conclusion. Physicians should always consider Brugada syndrome in the differential diagnosis of ST-segment elevation in anterior precordial leads of EKG and associated VT/VF. Although more than 17 years have passed since the first case was reported, increased awareness of this syndrome is needed to identify patients with EKG changes and treat them accordingly to prevent incidence of (SCD) and its deleterious complications.


2020 ◽  
Vol 132 (3) ◽  
pp. 440-451 ◽  
Author(s):  
Panagiotis Flamée ◽  
Varnavas Varnavas ◽  
Wendy Dewals ◽  
Hugo Carvalho ◽  
Wilfried Cools ◽  
...  

Abstract Background Brugada Syndrome is an inherited arrhythmogenic disease, characterized by the typical coved type ST-segment elevation in the right precordial leads from V1 through V3. The BrugadaDrugs.org Advisory Board recommends avoiding administration of propofol in patients with Brugada Syndrome. Since prospective studies are lacking, it was the purpose of this study to assess the electrocardiographic effects of propofol and etomidate on the ST- and QRS-segments. In this trial, it was hypothesized that administration of propofol or etomidate in bolus for induction of anesthesia, in patients with Brugada Syndrome, do not clinically affect the ST- and QRS-segments and do not induce arrhythmias. Methods In this prospective, double-blinded trial, 98 patients with established Brugada syndrome were randomized to receive propofol (2 to 3 mg/kg-1) or etomidate (0.2 to 0.3 mg/kg-1) for induction of anesthesia. The primary endpoints were the changes of the ST- and QRS-segment, and the occurrence of new arrhythmias upon induction of anesthesia. Results The analysis included 80 patients: 43 were administered propofol and 37 etomidate. None of the patients had a ST elevation greater than or equal to 0.2 mV, one in each group had a ST elevation of 0.15 mV. An ST depression up to −0.15mV was observed eleven times with propofol and five with etomidate. A QRS-prolongation of 25% upon induction was seen in one patient with propofol and three with etomidate. This trial failed to establish any evidence to suggest that changes in either group differed, with most percentiles being zero (median [25th, 75th], 0 [0, 0] vs. 0 [0, 0]). Finally, no new arrhythmias occurred perioperatively in both groups. Conclusions In this trial, there does not appear to be a significant difference in electrocardiographic changes in patients with Brugada syndrome when propofol versus etomidate were administered for induction of anesthesia. This study did not investigate electrocardiographic changes related to propofol used as an infusion for maintenance of anesthesia, so future studies would be warranted before conclusions about safety of propofol infusions in patients with Brugada syndrome can be determined. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New


2019 ◽  
Vol 58 (21) ◽  
pp. 3099-3102
Author(s):  
Akihito Ideishi ◽  
Masahiro Ogawa ◽  
Yoshihisa Nagata ◽  
Yoshiaki Idemoto ◽  
Tomo Komaki ◽  
...  

2012 ◽  
Vol 140 (1-2) ◽  
pp. 84-90
Author(s):  
Vesna Bisenic ◽  
Sasa Hinic ◽  
Mirjana Krotin ◽  
Branislav Milovanovic ◽  
Jelena Saric ◽  
...  

Introduction. Brugada syndrome is an arrhythmogenic disease characterized by coved ST segment elevation and J point elevation of at least 2 mm in at least two of the right precordial ECG leads (V1-3) and ventricular arrhythmias, syncope, and sudden death. Risk stratifications of patients with Brugada electrocardiogram are being strongly debated. Case Outline. A 23-year-old man was admitted to the Coronary Care Unit of the Clinical Centre ?Bezanijska kosa? due to weakness, fatigue and chest discomfort. The patient suffered from fainting and palpitations. There was a family history of paternal sudden death at 36 years. Electrocardiogram showed a coved ST segment elevation of 4 mm in leads V1 and V2, recognised as spontaneous type 1 Brugada pattern. Laboratory investigations revealed normal serum cardiac troponin T and serum potassium, and absence of inflammation signs. Echocardiographic finding was normal, except for a mild enlargement of the right atrium and ventricle. The diagnosis of Brugada syndrome was made by Brugada-type 1 electrocardiogram and the family history of sudden death <45 years. The patient was considered as a high risk, because of pre-syncope and palpitations. He underwent ICD implantation (Medtronic MaximoVR7232Cx) using the standard procedure. After implantation, noninvasive electrophysiology study was done and demonstrated inducible VF that was interrupted with the second 35 J DC shock. The patient was discharged in stable condition with beta-blocker therapy. After a year of pacemaker check-ups, there were no either VT/ VF events or ICD therapy. Conclusion. Clinical presentation is the most important parameter in risk stratification of patients with Brugada electrocardiogram and Brugada syndrome.


2006 ◽  
Vol 84 (8-9) ◽  
pp. 795-802 ◽  
Author(s):  
E. Herbert ◽  
M. Chahine

Brugada syndrome (BS) is an inherited cardiac disorder characterized by typical electrocardiographic patterns of ST segment elevation in the precordial leads, right bundle branch block, fast polymorphic ventricular tachycardia in patients without any structural heart disease, and a high risk of sudden cardiac death. The incidence of BS is high in male vs. female (i.e., 8–10/1: male/female). The disorder is caused by mutations in the SCN5A gene encoding Nav1.5, the cardiac sodium channel, which is the only gene in which mutations were found to cause the disease. Mutations in SCN5A associated with the BS phenotype usually result in a loss of channel function by a reduction in Na+ currents. We review the clinical aspects, risk stratification, and therapeutic management of this important syndrome.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Jonathan M Cordeiro ◽  
Mark Marieb ◽  
Ryan Pfeiffer ◽  
Kirstine Calloe ◽  
Elena Burashnikov ◽  
...  

Background: Ion channelopathies are responsible for a number of genetic cardiac arrhythmia syndromes. Recent work demonstrated an association between mutations in CACNA1c and CACNB2b, the genes that encode the α and β subunits of the L-type calcium channel, and the Brugada syndrome (BrS). The mutations previously described all caused a loss of function secondary to a major reduction in peak calcium channel current (I Ca ). In the present study we describe a novel CACNB2b mutation associated with BrS in which loss of function was caused by accelerated inactivation of I Ca . Methods and Results: The proband, a 32 yo male, displayed a saddleback ST segment elevation in the right precordial leads that converted to a coved-type ECG following a procainamide challenge. His EP study was positive with double extrastimuli inducing polymorphic VT/VF. He was also diagnosed with vasovagal syncope. Genomic DNA was isolated from blood lymphocytes. All exons and intron borders of 12 ion channel genes were amplified and sequenced. The only mutation uncovered was a missense mutation (T11I) in CACNB2b. The effect of this mutation was studied by expression of WT or T11I CACNB2b in TSA201 cells co-transfected with WT CANCA1c and CACNA2d. Patch clamp analysis showed no difference in I Ca density between WT and T11I (17.9±1.8 vs 22.5±4.3 pA/pF, respectively at +20mV). Similarly, steady-state inactivation and channel recovery was not different between WT and T11I mutant channels. However, both the fast and slow decay of I Ca produced by T11I mutant were significantly faster compared to WT at potentials between −10 to +30 mV, suggesting a reduction in depolarizing current during the course of an action potential. Application of action potential voltage clamp pulses confirmed that T11I total charge was reduced by 42±2.3% compared to WT (p<0.05). Conclusion: We report the first Brugada syndrome mutation in CaCNB2b resulting in accelerated inactivation of the L-type calcium channel. The T11I mutation caused a faster decay of cardiac L-type calcium current but did not significantly alter the magnitude of the peak current. Our results suggest that a reduced total charge carried by I Ca during the plateau of the action potential predisposes to the Brugada phenotype.


Medicina ◽  
2013 ◽  
Vol 49 (3) ◽  
pp. 24 ◽  
Author(s):  
Dagmara Reingardienė ◽  
Jolita Vilčinskaitė ◽  
Diana Bilskienė

Brugada syndrome was described in 1992 as a new clinical and electrocardiographic syndrome involving susceptibility to ventricular arrhythmias and sudden cardiac death in patients with no obvious structural heart disease. Brugada syndrome is characterized by a hereditary anomaly in the sodium ion channel (mutation of the SCN5A gene) identified by a wide QRS associated with the ST-segment elevation and the T‑wave inversion in the right precordial leads. The Brugada-like electrocardiographic pattern can be caused by sodium channel-blocking drugs and electrolyte disorders. Hyperkalemia may produce multiple ECG abnormalities, including the ST-segment elevation and pseudomyocardial infarction with a resolution of these abnormalities after the correction of hyperkalemia. This article describes 8 cases of pseudoanteroseptal myocardial infarction in acute renal insufficiency with hyperkalemia. The ST-segment elevation related to hyperkalemia is resolved by the reduced serum potassium level. Clinicians should recognize that hyperkalemia is one of the etiologies of the Brugada-like electrocardiographic pattern.


2011 ◽  
Vol 21 (5) ◽  
pp. 591-594 ◽  
Author(s):  
Timothy Nguyen ◽  
John Smythe ◽  
Adrian Baranchuk

AbstractBrugada syndrome is a channelopathy characterised electrocardiographically by distinctive coved ST-segment elevation in the right precordial leads and is associated with a predisposition for sudden death secondary to ventricular arrhythmias in otherwise healthy patients. Previously known as Brugada-like patterns, Brugada phenocopies include agents and conditions that mimic true Brugada syndrome, presenting with an acquired Brugada Type-1 ECG pattern. We describe the first reported case of a 17-month-old female with an asymptomatic rhabdomyoma of the interventricular septum that presented as a Brugada phenocopy.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Mark G Hoogendijk ◽  
Mark Potse ◽  
Andre C Linnenbank ◽  
Arie O Verkerk ◽  
Hester M den Ruijter ◽  
...  

Introduction: Brugada-type ST segment elevation has been associated with reduced sodium channel function and structural heart disease and is a risk marker for sudden cardiac death. Depolarizing and repolarizing abnormalities in the right ventricular wall have been described in patients. The mechanism of ST segment elevation however, is still debated. We determined depolarization and repolarization characteristics in an isolated heart of a young patient carrying a sodium channel mutation previously described in a family with Brugada syndrome. Methods and Results: A 15-year old female patient with a loss-of-function mutation (G752R) in the gene encoding the cardiac sodium channel underwent cardiac transplantation for end-stage heart failure in dilated cardiomyopathy. The explanted, perfused heart was submerged in perfusion fluid. We simultaneously recorded an “Einthoven” configuration pseudo-ECG and 194 unipolar electrograms from the endo- and epicardium of both ventricles. At baseline, a single shortly coupled premature stimulus resulted in more fractionated electrograms in the right than left ventricle (38 vs 6%, p < 0.001, Z-test). After sodium channel blockade by ajmaline, ST segment elevation of 0.3 mV was observed in pseudo-aVR which coincided with the virtual disappearance of the QRS complex in unipolar electrograms at the basal epicardium of the right ventricle followed by monophasic ST segment elevation. The local origin of this phenomenon was demonstrated by Laplacian electrograms. Neither early repolarization nor late activation correlated with the ST-change. Marked epicardial fatty infiltration was present at sites of local ST segment elevation, but not elsewhere. Simulations in a bidomain whole-heart computer model showed that either sodium current reduction or random replacement of 50% of the right ventricular epicardium by fat alone does not cause ST segment elevation. In combination however, part of the epicardial myocardium was not excited throughout the cardiac cycle by current-to-load mismatch resulting in Brugada-type ST segment elevation. Conclusions: Brugada-type ST segment elevation after sodium channel blockade is caused by excitation failure in discontinuous myocardium at the right ventricular epicardium.


2012 ◽  
Vol 1 ◽  
pp. 17 ◽  
Author(s):  
Vincent Probst ◽  
Stéphanie Chatel ◽  
Jean-Baptiste Gourraud ◽  
Hervé Le Marec ◽  
◽  
...  

Brugada syndrome (BrS) is a clinical entity characterised by an incomplete right bundle branch block associated with an ST segment elevation in the right precordial leads and a risk of ventricular arrhythmia and sudden death in the absence of structural abnormalities. Patients with a personal history of sudden death have an annual arrhythmia risk of recurrence as high as 10 %. Similarly, the presence of syncope is consistently associated with an increased arrhythmic risk. This risk can be estimated at about 1.5 % per year. The risk is lower in asymptomatic patients. Regarding the relatively high rate of complication of Implantable cardioverter defibrillator (ICD) implantation, in most of the cases, asymptomatic patients with a Brugada syndrome revealed during ajmaline challenge do not need to be implanted. The situation is more complex in patients with a spontaneous type 1 aspect since the risk could be estimated to be around 0.8 % per year. For these patients, a careful evaluation of the arrhythmic risk using all the different tools available is mandatory.


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