scholarly journals Basis for the Induction of Tissue-Level Phase-2 Reentry as a Repolarization Disorder in the Brugada Syndrome

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Alfonso Bueno-Orovio ◽  
Elizabeth M. Cherry ◽  
Steven J. Evans ◽  
Flavio H. Fenton
Keyword(s):  
Action Potential ◽  
Right Ventricular ◽  
Brugada Syndrome ◽  
Action Potentials ◽  
Human Action ◽  
Three Dimensions ◽  
Phase 2 ◽  
Three Dimensional Model ◽  
Right Ventricular Free Wall ◽  
The Right

Aims. Human action potentials in the Brugada syndrome have been characterized by delayed or even complete loss of dome formation, especially in the right ventricular epicardial layers. Such a repolarization pattern is believed to trigger phase-2 reentry (P2R); however, little is known about the conditions necessary for its initiation. This study aims to determine the specific mechanisms that facilitate P2R induction in Brugada-affected cardiac tissue in humans.Methods. Ionic models for Brugada syndrome in human epicardial cells were developed and used to study the induction of P2R in cables, sheets, and a three-dimensional model of the right ventricular free wall.Results. In one-dimensional cables, P2R can be induced by adjoining lost-dome and delayed-dome regions, as mediated by tissue excitability and transmembrane voltage profiles, and reduced coupling facilitates its induction. In two and three dimensions, sustained reentry can arise when three regions (delayed-dome, lost-dome, and normal epicardium) are present.Conclusions. Not only does P2R induction by Brugada syndrome require regions of action potential with delayed-dome and lost-dome, but in order to generate a sustained reentry from a triggered waveback multiple factors are necessary, including heterogeneity in action potential distribution, tissue coupling, direction of stimulation, the shape of the late plateau, the duration of lost-dome action potentials, and recovery of tissue excitability, which is predominantly modulated by tissue coupling.

Action Potential Alternans in the Right Ventricular Outflow Tract in a Patient With Asymptomatic Brugada Syndrome

2009 ◽  
Vol 73 (3) ◽  
pp. 580-583 ◽  
Author(s):  
Masayoshi Kofune ◽  
Ichiro Watanabe ◽  
Sonoko Ashino ◽  
Kimie Ohkubo ◽  
Yasuo Okumura ◽  
...  
Keyword(s):  
Action Potential ◽  
Right Ventricular ◽  
Brugada Syndrome ◽  
Right Ventricular Outflow Tract ◽  
Ventricular Outflow Tract ◽  
Outflow Tract ◽  
The Right

Dormant conduction in the right ventricular outflow tract unmasked by adenosine in a patient with Brugada syndrome

2021 ◽  
Vol 32 (4) ◽  
pp. 1182-1186
Author(s):  
Tsukasa Kamakura ◽  
Josselin Duchateau ◽  
Frédéric Sacher ◽  
Pierre Jais ◽  
Michel Haïssaguerre ◽  
...  
Keyword(s):  
Right Ventricular ◽  
Brugada Syndrome ◽  
Right Ventricular Outflow Tract ◽  
Ventricular Outflow Tract ◽  
Outflow Tract ◽  
Dormant Conduction ◽  
The Right

Association of epicardial fat thickness with left ventricular diastolic function parameters in a community population

2021 ◽  
Author(s):  
Wei Ma ◽  
Baowei Zhang ◽  
Ying Yang ◽  
Litong Qi ◽  
Jin Zhou ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Right Ventricular ◽  
Diastolic Function ◽  
Ventricular Free Wall ◽  
Free Wall ◽  
Right Ventricular Free Wall ◽  
Community Population ◽  
The Mean ◽  
The Right ◽  
The Relationship

Abstract Purpose We examined the relationship between EFT measured by echocardiography and LV diastolic function parameters in a Beijing community population. Methods We included 1004 participants in this study. Echocardiographic parameters including E and A peak velocity, the early diastolic velocities (e’) of the septal and lateral of mitral annulus using tissue doppler imaging, E/e’, and EFT, were measured. EFT1 was measured perpendicularly on the right ventricular free wall at end-diastole in the extension line of the aortic root. EFT2 was the maximum thickness measured perpendicularly on the right ventricular free wall at end-diastole. Multivariate linear regression was used to analyze the relationship between EFT and the mean e’ and E/e’. Results The mean age of the participants was 63.91 ± 9.02 years old (51.4% men). EFT1 and EFT2 were negatively correlated with e’ lat, e’ sep, and e’ mean (p < 0.05), and positively correlated with E/e’ lat, E/e’ sep, and E/e’ mean. Multivariate regression analysis showed that EFT1 and EFT2 were independently and negatively correlated with e’ mean (EFT1: β = −0.089 [95% confidence interval = − 0.177, − 0.000, p = 0.050]; EFT2: β = −0.078 [95% confidence interval = − 0.143, − 0.012, p = 0.020]). There were no interactions between EFT and any covariates, including age or heart groups, sex, BMI, or presence of hypertension, diabetes, or coronary heart disease in relation to LV diastolic dysfunction. Conclusions EFT was negatively and independently correlated with e’ mean, suggesting that more attention to this type of adipose fat is required for cardiovascular disease therapy.

Progressive right ventricular outflow tract fibrosis after repair of tetralogy of Fallot

2020 ◽  
Vol 30 (9) ◽  
pp. 1366-1367
Author(s):  
Gauri R. Karur ◽  
Wadi Mawad ◽  
Lars Grosse-Wortmann
Keyword(s):  
Cardiac Magnetic Resonance ◽  
Right Ventricular ◽  
Tetralogy Of Fallot ◽  
T1 Mapping ◽  
Right Ventricular Outflow Tract ◽  
Ventricular Outflow Tract ◽  
Ventricular Free Wall ◽  
Free Wall ◽  
Right Ventricular Free Wall ◽  
The Right

AbstractObjectives:The objective of this study was to determine the evolution of fibrosis over time and its association with clinical status.Methods:Children with repaired tetralogy of Fallot who had undergone at least two cardiac magnetic resonance examinations including T1 mapping at least 1 year apart were included.Results:Thirty-seven patients (12.7 ± 2.6 years, 61% male) were included. Right ventricular free wall T1 increased (913 ± 208 versus 1023 ± 220 ms; p = 0.02). Baseline cardiac magnetic resonance parameters did not predict a change in imaging markers or exercise tolerance. The right ventricular free wall per cent change correlated with left ventricular T1% change (r = 0.51, p = 0.001) and right ventricular mass Z-score change (r = 0.51, p = 0.001). T1 in patients with late gadolinium enhancement did not differ from the rest.Conclusion:Increasing right ventricular free wall T1 indicates possible progressive fibrotic remodelling in the right ventricular outflow tract in this pilot study in children and adolescents with repaired tetralogy of Fallot. The value of T1 mapping both at baseline and during serial assessments will need to be investigated in larger cohorts with longer follow-up.

Total disconnection of the right ventricular free wall: Physiological consequences in the dog

1984 ◽  
Vol 107 (6) ◽  
pp. 1169-1177 ◽  
Author(s):  
Douglas L. Jones ◽  
Gerard M. Guiraudon ◽  
George J. Klein
Keyword(s):  
Right Ventricular ◽  
Ventricular Free Wall ◽  
Free Wall ◽  
Right Ventricular Free Wall ◽  
The Right
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