The Cardiac Conduction System and the His Bundle Electrogram.

1976 ◽  
Vol 85 (1) ◽  
pp. 140
Keyword(s):  
Conduction System ◽  
Cardiac Conduction ◽  
Cardiac Conduction System ◽  
His Bundle

scholarly journals Measurement of cAMP in the cardiac conduction system of rats.

1995 ◽  
Vol 43 (6) ◽  
pp. 601-605 ◽  
Author(s):  
A Sugiyama ◽  
S McKnite ◽  
P Wiegn ◽  
K G Lurie
Keyword(s):  
Atrioventricular Node ◽  
Conduction System ◽  
Cardiac Conduction ◽  
Cardiac Conduction System ◽  
Camp Production ◽  
Adrenergic Stimulation ◽  
Beta Adrenergic ◽  
His Bundle ◽  
Freeze Dried ◽  
Camp Levels

To characterize differences in regional cAMP production in the cardiac conduction system, 18 rats were anesthetized with pentobarbital (65 mg/kg IP) and randomized into a control (n = 9) and a stimulated group (n = 9). The stimulated group received aminophylline (20 mg/kg SC) and isoproterenol (16 micrograms/kg SC). The concentration of cAMP in freeze-dried, micro dissected pieces (1-3 micrograms) of cardiac tissue was measured using a new microanalytical method. The cAMP contents in right atrium, atrioventricular node, His bundle, and left ventricle (fmol/microgram dry weight, mean +/- SE) were 38.9 +/- 2.5, 39.0 +/- 4.3, 46.4 +/- 6.1, and 41.4 +/- 3.3 in controls and 72.9 +/- 6.7, 86.1 +/- 2.9, 115.0 +/- 11.5, and 79.5 +/- 7.3 in the stimulated group, respectively. Basal cAMP levels were similar throughout the heart, whereas isoproterenol increased cAMP levels in all regions (p < 0.01). Furthermore, cAMP levels in His bundle, after isoproterenol, were higher than in any other region (p < 0.05). These results demonstrate that: (a) cAMP can be measured in discrete portions of the cardiac conduction system; (b) there are significant regional differences of beta-adrenergic control in the cardiac conduction system; and (c) cAMP production after beta-adrenergic stimulation was lower than expected in the AV nodal region, based on previously described beta-adrenoceptor density measurements.

Abstract 1462: Lineage Analysis of Mesp1 Expressing Cells in Cardiac Conduction System

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Reza Rafie ◽  
Amir R Hajrasouliha ◽  
Sina Tavakoli ◽  
Kamal Kotak ◽  
Mohammad Pashmforoush
Keyword(s):  
Sinoatrial Node ◽  
Atrioventricular Node ◽  
Conduction System ◽  
Cardiac Conduction ◽  
Cardiac Conduction System ◽  
Transgenic Mouse Line ◽  
His Bundle ◽  
Reporter Mice ◽  
A Minor ◽  
Lineage Analysis

Mesp1 is the earliest transcription factor detected in cardiac precursor cells considered to play a key role in their early specification. The lineage analysis, using Mesp1- Cre transgenic mouse line, has shown that there is a minor contribution of Mesp1 non-expressing cells to the formation of ventricular conduction system. The purpose of the present study is to evaluate the contribution of Mesp1 -expressing and non-expressing cells to the development of sinoatrial node, atrioventricular node and His bundle in embryonic, neonatal and adult heart. In this study, the contribution of Mesp1 -expressing cells was evaluated by a lineage analysis using the cross of Mesp1 -Cre and ROSA26R reporter mice. Different components of the cardiac conduction system were identified by a combination of histological (hematoxylin/eosin), acetylcholinesterase, and immunofluorescent stainings for specific markers (HCN4 and connexin40). Sinoatrial and atrioventricular nodes as well as His bundle are derived almost exclusively from Mesp1- expressing cells as evident by β-gal activity. The contribution of Mesp1 non-expressing cells becomes prominent, though still less than Mesp1 -expressing cells, in the distal components of cardiac conduction system (i.e. bundle branches). This pattern was consistent in embryonic and neonatal stages as well as adult hearts. Unlike the distal components of cardiac conduction system, which is composed of a mixed population of Mesp1 -expressing and non-expressing cells, sinoatrial node, atrioventricular node and His bundle are derived almost exclusively from Mesp1 -expressing cells.

scholarly journals Physiological electrocardiostimulation of the ventricles by the method of selective stimulation of the His bundle

2019 ◽  
Vol 26 (1) ◽  
pp. 89-93
Author(s):  
B. B. Kravchuk ◽  
O. Z. Paratsii ◽  
A. V. Yakushev ◽  
M. M. Sichik ◽  
V. F. Onischenko ◽  
...  
Keyword(s):  
Negative Impact ◽  
Ventricular Myocardium ◽  
Conduction System ◽  
Cardiac Conduction ◽  
Cardiac Conduction System ◽  
His Bundle ◽  
Purkinje System ◽  
Endocardial Lead ◽  
Stimulation Of

The purpose of this work is to analyze the clinical case of conducting constant pacing of the ventricles by the method of selective implantation of the endocardial lead into the His bundle. The stimulation of His bundle in atrioventricular blockages is grounded on the fact that electrical activation of the ventricular myocardium is normally carried out through its own cardiac conduction system – the His – Purkinje system. Implantation of a stimulating lead directly into the cardiac conduction system prevents the distortion of the physiological sequence of different segments activation of the ventricular myocardium, which in the long term should minimize the negative impact on the ventricular systolic-diastolic function and reduce the risk of heart failure.

scholarly journals Sudden Unexpected Death Associated with Arrhythmogenic Cardiomyopathy: Study of the Cardiac Conduction System

Diagnostics ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1323
Author(s):  
Giulia Ottaviani ◽  
Graziella Alfonsi ◽  
Simone G. Ramos ◽  
L. Maximilian Buja
Keyword(s):  
Fibromuscular Dysplasia ◽  
Ventricular Myocardium ◽  
Conduction System ◽  
Cardiac Conduction ◽  
Future Research ◽  
Cardiac Conduction System ◽  
Arrhythmogenic Cardiomyopathy ◽  
Unexpected Death ◽  
The Past ◽  
The Right

A retrospective study was conducted on pathologically diagnosed arrhythmogenic cardiomyopathy (ACM) from consecutive cases over the past 34 years (n = 1109). The anatomo-pathological analyses were performed on 23 hearts diagnosed as ACM (2.07%) from a series of 1109 suspected cases, while histopathological data of cardiac conduction system (CCS) were available for 15 out of 23 cases. The CCS was removed in two blocks, containing the following structures: Sino-atrial node (SAN), atrio-ventricular junction (AVJ) including the atrio-ventricular node (AVN), the His bundle (HB), the bifurcation (BIF), the left bundle branch (LBB) and the right bundle branch (RBB). The ACM cases consisted of 20 (86.96%) sudden unexpected cardiac death (SUCD) and 3 (13.04%) native explanted hearts; 16 (69.56%) were males and 7 (30.44%) were females, ranging in age from 5 to 65 (mean age ± SD, 36.13 ± 16.06) years. The following anomalies of the CCS, displayed as percentages of the 15 ACM SUCD cases in which the CCS has been fully analyzed, have been detected: Hypoplasia of SAN (80%) and/or AVJ (86.67%) due to fatty-fibrous involvement, AVJ dispersion and/or septation (46.67%), central fibrous body (CFB) hypoplasia (33.33%), fibromuscular dysplasia of SAN (20%) and/or AVN (26.67%) arteries, hemorrhage and infarct-like lesions of CCS (13.33%), islands of conduction tissue in CFB (13.33%), Mahaim fibers (13.33%), LBB block by fibrosis (13.33%), AVN tongue (13.33%), HB duplicity (6.67%%), CFB cartilaginous meta-hyperplasia (6.67%), and right sided HB (6.67%). Arrhythmias are the hallmark of ACM, not only from the fatty-fibrous disruption of the ventricular myocardium that accounts for reentrant ventricular tachycardia, but also from the fatty-fibrous involvement of CCS itself. Future research should focus on application of these knowledge on CCS anomalies to be added to diagnostic criteria or at least to be useful to detect the patients with higher sudden death risks.

scholarly journals Functional suppression of Kcnq1 leads to early sodium channel remodelling and cardiac conduction system dysmorphogenesis

2013 ◽  
Vol 98 (3) ◽  
pp. 504-514 ◽  
Author(s):  
Angel J. de la Rosa ◽  
Jorge N. Domínguez ◽  
David Sedmera ◽  
Bara Sankova ◽  
Leif Hove-Madsen ◽  
...  
Keyword(s):  
Sodium Channel ◽  
Conduction System ◽  
Cardiac Conduction ◽  
Cardiac Conduction System
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