Impaired Impulse Formation

2012 ◽  
Vol 21 (4) ◽  
pp. 293-294
Author(s):  
Michele M. Pelter ◽  
Teri M. Kozik ◽  
Salah S. Al-Zaiti ◽  
Mary G. Carey
Keyword(s):  
Impulse Formation

Disorders of impulse conduction and impulse formation caused by hyperkalemia in man

1975 ◽  
Vol 89 (4) ◽  
pp. 501-509 ◽  
Author(s):  
Howard C. Cohen ◽  
Kenneth M. Rosen ◽  
Alfred Pick
Keyword(s):  
Impulse Conduction ◽  
Impulse Formation

scholarly journals Antiarrhythmic drugs: mechanisms of action, clinical effects, indications for use

2019 ◽  
Vol 26 (2) ◽  
pp. 76-90
Author(s):  
G. M. Solovyan ◽  
T. V. Mikhalieva
Keyword(s):  
Clinical Practice ◽  
Cardiac Arrhythmias ◽  
Antiarrhythmic Drugs ◽  
Mechanisms Of Action ◽  
Current Evidence ◽  
Clinical Effects ◽  
Trigger Activity ◽  
Impulse Formation ◽  
Indications For Use

The lecture is devoted to one of the most difficult problems of modern cardiology – the use of antiarrhythmic therapy in clinical practice. The basic mechanisms of arrhythmias, aspects of their onset, maintenance and termination are briefly described. The current evidence on the electrophysiological mechanisms of cardiac arrhythmias – re-entry, abnormal impulse formation, and trigger activity – is presented. The article contains information about the remodeling of ion channels properties. The Sicilian gambit is analyzed, in which the mechanisms of arrhythmias are compared to the mechanisms of anti-arrhythmic action of drugs. Classification of anti-arrhythmic drugs, their mechanisms of action, indications and contraindications, side effects, and interaction with other drugs are presented.

Abstract 1509: Inducible TBX3 Overexpression As A Tool For Biopacemaker Engineering

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Gerard J Boink ◽  
Martijn L Bakker ◽  
Arie O Verkerk ◽  
Diane Bakker ◽  
Jacques M de Bakker ◽  
...  
Keyword(s):  
Cardiac Myocytes ◽  
Heart Development ◽  
Single Gene ◽  
Neonatal Rat ◽  
Pcr Analysis ◽  
Patch Clamp Technique ◽  
Impulse Propagation ◽  
Transfer Strategies ◽  
Impulse Formation

Introduction: Currently constructed biopacemakers based on single gene transfer strategies function suboptimally, with periods of slow heart rates and instabilities during rest. In the sinoatrial node (SAN), the dominant native pacemaker, multiple genes are required for proper impulse formation and impulse propagation. TBX3 is an important regulator of the SAN gene program during heart development. We examined the effects of inducible TBX3 overexpression in adult hearts and in vitro we explored whether lentiviral TBX3 overexpression may be used in biopacemaker engineering. Methods: In vivo atrial and ventricular expression levels of the connexin isoforms Cx43 and Cx40 (impulse propagation) and SCN5A were studied in mice with tamoxifen inducible overexpression of TBX3 using quantitative PCR analysis. Single neonatal rat cardiac myocytes were transduced with TBX3 expressing lentivirus to analyze the effects of TBX3 on action potentials and membrane currents (impulse formation) using the perforated patch-clamp technique. Results: In vivo, Cx43, Cx40 and SCN5A, which are not or only moderately expressed in the native SAN, were severely down-regulated to 20%, 15%, and 40%, respectively, by TBX3 (n=12; p<0.01). Single neonatal cardiac myocytes overexpressing TBX3 exhibited faster spontaneous beating rates, along with decreased maximum diastolic potential, inward rectifier potassium current (I K1 ), and fast sodium current (I Na ). These properties are typical of SAN pacemaker cells. Conclusions: TBX3 can act as a strong repressor of the working myocardium gene program in the adult heart. Overexpression of TBX3 might be a useful tool in biopacemaker gene and cell therapy.

scholarly journals Simulation on Spacecraft Formation Flight and Formation Reconfiguration

2018 ◽  
Vol 160 ◽  
pp. 05011
Author(s):  
Chao Li Ye Yan ◽  
Yue-neng Yang
Keyword(s):  
Absolute Error ◽  
Formation Flight ◽  
Orbital Dynamics ◽  
Dynamics Model ◽  
Simulation Test ◽  
Spacecraft Formation ◽  
Formation Reconfiguration ◽  
Ground Investigation ◽  
Spatial Exploration ◽  
Impulse Formation

Spacecraft formation flight refers to two or more spacecraft according to a certain formation or arrangement of flight, it has important application value for deep spatial exploration, spatial science experiment, ground investigation and military and so. This paper studies the spacecraft formation flight design and formation reconfiguration based on STK. Firstly, the Clohessy-Wiltshire (CW) equation is used to describe the relative motion of the near-circular orbit and deduce the relative orbital dynamics model. Then, based on the dynamic method of the CW equation, the spatial circular formation is designed and the STK is applied to simulate it. Finally, based on the above formation, a simple multi-impulse formation reconfiguration is performed and the simulation test is verified by STK. The simulation results show that the absolute error of orbital elements of the spacecraft is calculated by the relative orbital dynamics model is less than 10-5, and the expected formation can be completed under the condition of two-body environment, and the feasibility of simple multi-pulse formation reconfiguration is proved successfully.

Clinical significance of disorders of impulse formation and conduction in the atrioventricular junction

1963 ◽  
Vol 11 (3) ◽  
pp. 384-391 ◽  
Author(s):  
Leonard S. Dreifus ◽  
Michael Katz ◽  
Yoshio Watanabe ◽  
William Likoff
Keyword(s):  
Clinical Significance ◽  
Atrioventricular Junction ◽  
Impulse Formation
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