A mathematical model of phase 2 reentry: role of L-type Ca current

2003 ◽  
Vol 284 (4) ◽  
pp. H1285-H1294 ◽  
Author(s):  
Shunichiro Miyoshi ◽  
Hideo Mitamura ◽  
Kana Fujikura ◽  
Yukiko Fukuda ◽  
Kojiro Tanimoto ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Brugada Syndrome ◽  
Field Potential ◽  
Outward Current ◽  
Transient Outward Current ◽  
Ca Channel ◽  
Phase 2 ◽  
Ca Current ◽  
St Segment Elevation ◽  
St Segment

Phase 2 reentry (P2R) is known to be one of the mechanisms of malignant ventricular arrhythmias, especially those associated with Brugada syndrome. However, little is known about the underlying mechanism for P2R. Our aim in this study was to simulate P2R in a mathematical model to enable us to understand its mechanism and identify a potential therapeutic target. A mathematical model of the L-type Ca current was composed according to whole cell current data from guinea pig ventricular myocytes recorded at 37°C. Our mathematical model was incorporated into the modified Luo-Rudy phase 2 model. We set a dispersion in transient outward current ( I to) density within the theoretical fiber, composed of 80 serially arranged epicardial cells with gap junctions and then observed the P2R. The dispersion in I todensity within an only 0.8-cm epicardial theoretical fiber generated P2R with our Ca channel but not with the original model. When the P2R developed in the theoretical fiber, the calculated extracellular field potential showed coved-type ST segment elevation. We succeeded in generating P2R in our model for the first time. The local epicardial P2R may contribute the genesis of coved-type ST segment elevation in the Brugada syndrome.

scholarly journals Fever Unmasked Brugada Syndrome in Pediatric Patient: A Case Report

2020 ◽  
Vol 4 (2) ◽  
pp. 244-246
Author(s):  
Orhay Mirzapolos ◽  
Perry Marshall ◽  
April Brill
Keyword(s):  
Emergency Medicine ◽  
Case Report ◽  
Brugada Syndrome ◽  
Ventricular Arrhythmias ◽  
Cardiac Monitoring ◽  
St Segment Elevation ◽  
Cardioverter Defibrillator ◽  
St Segment ◽  
Viral Illness ◽  
Automatic Implantable Cardioverter Defibrillator

Introduction: Brugada syndrome is an arrhythmogenic disorder that is a known cause of sudden cardiac death. It is characterized by a pattern of ST segment elevation in the precordial leads on an electrocardiogram (EKG) due to a sodium channelopathy. Case Report: This case report highlights the case of a five-year-old female who presented to the emergency department with a febrile viral illness and had an EKG consistent with Brugada syndrome. Discussion: Fever is known to accentuate or unmask EKG changes associated with Brugada due to temperature sensitivity of the sodium channels. Conclusion: Febrile patients with Brugada are at particular risk for fatal ventricular arrhythmias and fevers should be treated aggressively by the emergency medicine provider. Emergency medicine providers should also consider admitting febrile patients with Brugada syndrome who do not have an automatic implantable cardioverter-defibrillator for cardiac monitoring.

scholarly journals Genetic and biophysical basis for bupivacaine-induced ST segment elevation and VT/VF. Anesthesia unmasked Brugada syndrome

Heart Rhythm ◽  
2006 ◽  
Vol 3 (9) ◽  
pp. 1074-1078 ◽  
Author(s):  
Kevin Vernooy ◽  
Serge Sicouri ◽  
Robert Dumaine ◽  
Kui Hong ◽  
Antonio Oliva ◽  
...  
Keyword(s):  
Brugada Syndrome ◽  
St Segment Elevation ◽  
St Segment

scholarly journals Sudden Cause of Cardiac Death—Be Aware of Me: A Case Report and Short Review on Brugada Syndrome

2010 ◽  
Vol 2010 ◽  
pp. 1-3 ◽  
Author(s):  
Jagadeesh K. Kalavakunta ◽  
Vishwaroop Bantu ◽  
Hemasri Tokala ◽  
Mihas Kodenchery
Keyword(s):  
Brugada Syndrome ◽  
Past History ◽  
Short Review ◽  
Case Presentation ◽  
St Segment Elevation ◽  
First Case ◽  
St Segment ◽  
The Right ◽  
Malignant Arrhythmias

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.

scholarly journals Electrocardiographic Effects of Propofol versus Etomidate in Patients with Brugada Syndrome

2020 ◽  
Vol 132 (3) ◽  
pp. 440-451 ◽  
Author(s):  
Panagiotis Flamée ◽  
Varnavas Varnavas ◽  
Wendy Dewals ◽  
Hugo Carvalho ◽  
Wilfried Cools ◽  
...  
Keyword(s):  
Brugada Syndrome ◽  
St Segment Elevation ◽  
St Depression ◽  
St Segment ◽  
Qrs Prolongation ◽  
Significant Difference ◽  
Electrocardiographic Changes ◽  
St Elevation ◽  
The Right ◽  
Double Blinded

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

scholarly journals Augmented ST-Segment Elevation during Recovery from Exercise Predicts Cardiac Events in Patients with Brugada Syndrome

2011 ◽  
Vol 27 (Supplement) ◽  
pp. JAAC_3 ◽  
Author(s):  
Hisaki Makimoto ◽  
Eiichiro Nakagawa ◽  
Hiroshi Takaki ◽  
Yuko Yamada ◽  
Hideo Okamura ◽  
...  
Keyword(s):  
Brugada Syndrome ◽  
Cardiac Events ◽  
St Segment Elevation ◽  
St Segment

scholarly journals Experimental Models of Brugada syndrome

2019 ◽  
Vol 20 (9) ◽  
pp. 2123 ◽  
Author(s):  
Sendfeld ◽  
Selga ◽  
Scornik ◽  
Pérez ◽  
Mills ◽  
...  
Keyword(s):  
Brugada Syndrome ◽  
Experimental Models ◽  
Model Systems ◽  
Patient Specific ◽  
Canine Heart ◽  
Stem Cell Technology ◽  
St Segment Elevation ◽  
St Segment ◽  
Cardiac Sodium Channel ◽  
The Right

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.

scholarly journals Long-Term Prognosis of Individuals With Right Precordial ST-Segment–Elevation Brugada Syndrome

Circulation ◽  
2005 ◽  
Vol 111 (3) ◽  
pp. 257-263 ◽  
Author(s):  
Lars Eckardt ◽  
Vincent Probst ◽  
Jeroen P.P. Smits ◽  
Eric Schulze Bahr ◽  
Christian Wolpert ◽  
...  
Keyword(s):  
Brugada Syndrome ◽  
St Segment Elevation ◽  
St Segment ◽  
Long Term Prognosis

scholarly journals Properties of "creep currents" in single frog atrial cells.

1986 ◽  
Vol 87 (6) ◽  
pp. 833-855 ◽  
Author(s):  
J R Hume ◽  
A Uehara
Keyword(s):  
Time Course ◽  
Outward Current ◽  
Membrane Current ◽  
K Channel ◽  
Transient Outward Current ◽  
Ca Channel ◽  
Purkinje Fibers ◽  
Atrial Cells ◽  
Cardiac Purkinje Fibers ◽  
Inward Currents

Changes in membrane current in response to an elevation of [Na]i were studied in enzymatically dispersed frog atrial cells. Na loading by either intracellular dialysis or exposure to the Na ionophore monensin produces changes in membrane current that resemble the "creep currents" originally observed in cardiac Purkinje fibers during exposure to low-K solutions. Na loading induces a transient outward current during depolarizing voltage-clamp pulses, followed by an inward current in response to repolarization back to the holding potential. In contrast to cardiac Purkinje fibers, Na loading of frog atrial cells induces creep currents without accompanying transient inward currents. Creep currents induced by Na loading are insensitive to K channel antagonists like Cs and 4-aminopyridine; they are not influenced by doses of Ca channel antagonists that abolish iCa, but are sensitive to changes in [Ca]o or [Na]o. A comparison of the time course of development of inward creep currents are not tail currents associated with iCa. Inward creep currents can also be induced by experimental interventions that increase the iCa amplitude. Exposure to isoproterenol enhances the iCa amplitude and induces inward creep currents; both can be attenuated by Ca channel antagonists. Both inward and outward creep currents are blocked by low doses of La, independently of La's ability to block iCa. It is concluded that (a) creep currents are not mediated by voltage-gated Na, Ca, or K channels or by an electrogenic Na,K pump; (b) inward creep currents induced either by Na loading or in response to an increase in the amplitude of iCa are triggered by an elevation of [Ca]i; and (c) creep currents may be generated by either an electrogenic Na/Ca exchange mechanism or by a nonselective cation channel activated by [Ca]i.

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