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At least 217 records · Page 12Linked to original sources
PubMed1987

[Analysis of the duration of the cell cycle periods of slowly proliferating myocytes of the conduction system in the developing mouse heart].

Cell cycle parameters of myocytes of the heart conduction system (CS) and working ventricular (WM) myocytes were determined using different autoradiographic methods. By the labeled mitoses technique, no significant difference in the mean durations of G2 + 1/2 M and S phases was found between myocytes from CS and WM. The double labeling method (with 14C- and 3H-thymidine) has given the mean durations of the S-phase of the same order as did labeled mitoses technique in both CS and WM. Label dilution experiment has shown that at each stage under investigation the mean values of cell cycle duration are rather similar in CS and WM myocytes and increase in both the compartments from the 15th day of embryonal development up to the 7th day post partum. These results suggest that the lower indices of labeled nuclei in CS, as compared with WM, may be explained mainly by the smaller fraction of proliferating cells among the total cell population.

Animals↗
PubMed1988

Clinical application of a new vital staining method for the conduction system during heart operations.

A new method for vital staining of the conduction system during heart operations, the iodine gas method, was used in 12 patients. The right bundle branch stained well in all cases, and could be confirmed by the naked eye. The conduction system was not damaged by the staining procedure. The iodine gas used in this method had no adverse effects on thyroid function (thyroxine, triiodothyronine, thyroxine binding globulin, protein bound iodine) or liver function (serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, lactic dehydrogenase). This method, therefore, was found to be valuable and without complication for preventing conduction disturbances during cardiac operations.

Cardiac Surgical Procedures↗
PubMed2003

The conduction system in hearts with pulmonary atresia and intact ventricular septum.

BACKGROUND: Although a regular course of the conduction system is anticipated in hearts with pulmonary atresia and intact ventricular septum (PAIVS), it has never been demonstrated anatomically. In view of one of the surgical options in repair being debulking of the right ventricular wall, it is important to establish the location of the major conduction pathways. METHODS: Four hearts belonging to fetuses aged 18, 20, 22, and 29 weeks were examined. Entire hearts were serially sectioned and step sections were stained. The sinus node and atrioventricular conduction bundles were identified and their locations described. RESULTS: The conduction system in hearts with PAIVS is similar to that in normal hearts, although there was a minor variation in one of them. This was a heart affected by Ebstein malformation of the tricuspid valve. In this case, the right bundle branch terminated abruptly soon after its origin. CONCLUSIONS: Confirmation of the regular course of the cardiac conduction system is important to the development of strategies for surgical repair of PAIVS.

Ebstein Anomaly↗
PubMed1985

The landmarks to the atrioventricular conduction system in hearts with absence or unroofing of the coronary sinus.

Histologic studies were made of the conduction system of two hearts, one with absence and the other unroofing of the coronary sinus. The findings show that, when present, the triangle of Koch and the orifice of the coronary sinus are usually good guides to the atrioventricular conduction axis. However, when these landmarks are malformed, or there is malalignment of the atrial and ventricular septal structures, a better guide is the fusion point of the ventricular septum with the atrioventricular junction.

Autopsy↗
PubMed2002

[Characteristics of general anesthesia in the investigation of heart electrophysiology].

Investigating electrophysiological properties of the heart under acute experimental conditions, dogs are affected by operative stress because of traumatic surgical manipulations, so investigations are performed under general anaesthesia. Many anaesthetics together with their main function have desintegrating influence on autonomic regulation mechanisms. That is why anaesthetics used during experiments must fullfil such requirement--have minimal influence on autonomic nervous system (ANS) and heart conductivity system (HCS) interaction parameters or to make this influence insignificant. We did not found common anaesthesia methodics that can fullfil that requirements, so we decided to prepare new common anaesthesia methodics, which could fullfil requirements mentioned above. We choose medicaments according to their pharmacokinetics and pharmacodynamics action. For methodics optimization we've used 2 groups of dogs (mongrel dogs males weight 7-15 kg) (n = 10). We've applied different anaesthesia schemas on each group. Premedication in the I-st group was performed with intramuscle (i.m.) combination of diazepam, ketamine and phentanyl and for anaesthesia continuous intravenous (i.v.) infusion of thiopental and ketamine. In II-nd group premedication was performed with i.m. injection of ketamine/phentanyl combination and for anaesthesia--continuous i.v. infusion of thiopental. Induction in both groups was performed with i.v. thiopental injection. Suitability of premedication and anaesthesia was valued by adequativity of haemodynamics (heart rate 1/min) and surgical manipulations during experiments. Our conclusion is: investigating interaction of ANS and HCS methodics used in the I-st group of dogs is more suitable.

Adjuvants, Anesthesia↗
PubMed1990

The heart and conduction system in acute Kawasaki disease: report of fraternal cases--one lethal, one relapsing.

The heart and conduction system were studied in a 4 1/2-year-old boy with Kawasaki disease who died suddenly in the early phase of illness. Severe perivasculitis, neuritis, pancarditis, and involvement of all parts of the specialized conduction system were found. The boy's brother, born a year later, at the age of 12 months had relapsing Kawasaki disease. He received intravenous gamma globulin and recovered.

Aorta↗
PubMed1999

Localisation and quantitation of autonomic innervation in the porcine heart I: conduction system.

This study was prompted by the prospect of transgenic pigs providing donor hearts for transplantation in human recipients. Autonomic innervation is important for the control of cardiac dynamics, especially in the conduction system. Our objective was to assess the relative distribution of autonomic nerves in the pig heart, focusing initially on the conduction system but addressing also the myocardium, endocardium and epicardium (see Crick et al. 1999). Quantitative immunohistochemical and histochemical techniques were adopted. All regions of the conduction system possessed a significantly higher relative density of the total neural population immunoreactive for the general neuronal marker protein gene product 9.5 (PGP 9.5) than did the adjacent myocardium. A similar density of PGP 9.5-immunoreactive innervation was observed between the sinus node, the transitional region of the atrioventricular node, and the penetrating atrioventricular bundle. A differential pattern of PGP 9.5-immunoreactive innervation was present within the atrioventricular node and between the components of the ventricular conduction tissues, the latter being formed by an intricate network of Purkinje fibres. Numerous ganglion cell bodies were present in the peripheral regions of the sinus node, in the tissues of the atrioventricular groove, and even in the interstices of the compact atrioventricular node. Acetylcholinesterase (AChE)-containing nerves were the dominant subpopulation observed, representing 60-70% of the total pattern of innervation in the nodal tissues and penetrating atrioventricular bundle. Tyrosine hydroxylase (TH)-immunoreactive nerves were the next most abundant neural subpopulation, representing 37% of the total pattern of innervation in the compact atrioventricular node compared with 25% in the transitional nodal region. A minor population of ganglion cell bodies within the atrioventricular nodal region displayed TH immunoreactivity. The dominant peptidergic nerve supply possessed immunoreactivity for neuropeptide Y (NPY), which displayed a similar pattern of distribution to that of TH-immunoreactive nerve fibres. Calcitonin gene-related peptide (CGRP)-immunoreactive nerves represented 8-9% of the total innervation of the nodal tissues and penetrating atrioventricular bundle, increasing to 14-19% in the bundle branches. Somatostatin-immunoreactive nerve fibres were relatively sparse (4-13% of total innervation) and were most abundant in the nodes, especially the compact atrioventricular node. The total pattern of innervation of the porcine conduction system was relatively homogeneous. A substantial proportion of nerve fibres innervating the nodal tissues could be traced to intracardiac ganglia indicative of an extensive intrinsic supply. The innervation of the atrioventricular node and ventricular conduction tissues was similar to that observed in the bovine heart, but markedly different to that of the human heart. It is important that we are aware of these findings in view of the future use of transgenic pig hearts in human xenotransplantation.

Acetylcholinesterase↗
PubMed1980

Atrioventricular conduction system in univentricular heart of right ventricular type with right-sided rudimentary chamber.

The conduction tissue in a univentricular heart of the right ventricular type with a right-sided rudimentary chamber was studied. Both an anterior and conventional node were found, the anterior node being positioned in the atrial septum very close to the conventional node. Between the two nodes, a sling of conduction tissue passed through the annulus fibrosus but was not related to the trabecular septum. A non-branching bundle descended on to a free-running trabecula in the main ventricular chamber, the trabecular septum itself being devoid of conduction tissue. We believe it is likely that this trabecula represents the trabecula septomarginalis of the normal right ventricle. It has recently been suggested that during development the primordium of the trabecula septomarginalis is the structure which carries the conduction tissue from the atrioventricular node (whatever its position) to the trabecular septum. The present findings seem to support this.

Atrioventricular Node↗