Disease relevance of Atrioventricular Node

• Propafenone prolonged refractoriness and slowed conduction of the atrium, the atrioventricular node, and accessory atrioventricular bypass tracts, and these effects provided antiarrhythmic action to halt tachycardia [1].
• CONCLUSIONS: Adenosine in graded doses up to 12 mg rapidly and effectively terminates acute episodes of paroxysmal supraventricular tachycardia in which the atrioventricular node is an integral part of the re-entrant circuit [2].
• Consequently, in cardiac arrhythmias where the AV node is part of the reentry circuit, a beneficial effect of diltiazem and verapamil can be demonstrated [3].
• Flecainide is effective against certain supraventricular arrhythmias (atrial fibrillation and atrioventricular [AV] node reentrant tachycardia), but its mechanisms of action are unknown [4].
• In conclusion, epinephrine in physiologic doses shortens the effective refractory period of the atrium, AV node and ventricle, improves AV node conduction and may facilitate the induction of sustained ventricular tachycardia [5].

Psychiatry related information on Atrioventricular Node

• In the presence of acetylcholine released by vagal endings or infused into the coronary blood, an increase in plasma calcium concentration from 2.50 to 4.60 mmol/l after a 80 micrograms/kg dose of digoxin considerably depressed conduction in the AV node and automatism in the SA node [6].

High impact information on Atrioventricular Node

• These data indicate that NKX2-5 is important for regulation of septation during cardiac morphogenesis and for maturation and maintenance of atrioventricular node function throughout life [7].
• In addition, an entire population of connexin40(-)/connexin45(+) cells is missing in the atrioventricular node of Nkx2-5 heterozygous KO mice [8].
• We conclude that postnatal downregulation of calreticulin is essential in the development of the cardiac conductive system, in particular in the sinus and AV nodes, when an inward Ca(2+) current is required for activation [9].
• Our results demonstrate that the A-V node and the His-Purkinje regions of the conduction system are specifically compromised by DMPK loss [10].
• Injections of amiodarone into the AV node artery during sinus rhythm regularly increased AV conduction time sometimes causing 2 degrees AV block at the highest concentration used [11].

Chemical compound and disease context of Atrioventricular Node

• In conclusion, rate-dependent atrioventricular node depression by diltiazem results in greater tachycardia slowing and higher rates of termination during atrioventricular reentrant tachycardias with faster initial rates and shorter retrograde conduction intervals [12].
• In a second protocol, the effects of intravenous dipyridamole were evaluated in another group of six patients who had supraventricular tachycardia (SVT) in which the AV node was part of the reentrant circuit.(ABSTRACT TRUNCATED AT 250 WORDS)[13]
• Noninvasive diagnosis of dual AV node physiology in patients with AV nodal reentrant tachycardia by administration of adenosine-5'-triphosphate during sinus rhythm [14].
• The results of the present study indicate that AV rhythm in the AV node originates in the area supplied by the anterior septal artery and that the area supplied by the posterior septal artery, which has extremely low automaticity, is highly responsive to l-norepinephrine, resulting in nodal tachycardia [15].
• METHODS: In consecutive patients with AV node reentrant tachycardia, the incidence of 2:1 AV block and the response to atropine and a single ventricular extrastimulus was observed [16].

Biological context of Atrioventricular Node

• OBJECTIVE: To study the actions of adenosine on the electrophysiology of spontaneously active, rod-shaped cells enzymatically isolated from rabbit atrioventricular (AV) node [17].
• A Langendorff guinea pig heart preparation served for the assay of agonist activity of a series of 24 2-alkoxyadenosines at the A1 and A2 adenosine receptors of, respectively, the atrioventricular node (conduction block) and coronary arteries (vasodilation) [18].
• Effects of TTX and verapamil on the upstroke components of the action potential from the atrioventricular node of the rabbit [19].
• To control heart rate, we ablated the atrioventricular node by injecting formalin into the region of the node, and paced the right ventricle at a baseline heart rate of 200 beats/min [20].
• Effects of l-propranolol, racemic propranolol and practolol have been determined on transmembrane potentials recorded in guinea-pig left atrium and in sinoatrial and atrioventricular nodes of the rabbit heart [21].

Anatomical context of Atrioventricular Node

• Preoperative secundum atrial septal defect with coexisting sinus node and atrioventricular node dysfunction [22].
• These findings correlated well with extensive oxalate infiltration of the sinoatrial node and its approaches, the atrial preferential pathways, the approaches to the atrioventricular node, the atrioventricular node, and the His bundle and bundle branches [23].
• In the mouse, connexin40 (Cx40) protein has been detected in endothelial cells of lung and heart and in certain heart muscle cells: atrial myocytes, cells of the atrial ventricular (AV) node and cells of the conductive myocardium, which conducts impulses from the AV node to ventricular myocyctes [3] [24].
• In two patients who demonstrated reflux of contrast agent into the distal right coronary artery with selective injections into the AV node artery, transient ST segment elevation developed in the inferior electrocardiographic leads with the infusion of ethanol [25].
• 1. The effects of seven agonist and three antagonist adenosine receptor ligands were compared on the guinea-pig sinoatrial (SA) node (isolated right atrium) and atrioventricular (AV) node (perfused whole heart) [26].

Associations of Atrioventricular Node with chemical compounds

• We conclude that endogenously released adenosine may account for a major fraction of the AV conduction delay and block associated with impaired blood supply to the AV node, and the theophylline and aminophylline reverse the AV conduction defect by antagonizing the effects of adenosine [27].
• Termination of PRJT by either ATP or verapamil was mainly related to a block in the AV node in patients with accessory pathways and to a block in the antegrade slow pathway in patients with AV nodal reentry [28].
• BACKGROUND: ATP and its related nucleoside, adenosine, are ubiquitous biological compounds with potent depressant activity on the atrioventricular node [29].
• Diltiazem also increased the AV conduction system effective refractory period, thereby increasing the potential zone of concealment into the AV node [30].
• Comparative effects of three calcium antagonists, diltiazem, verapamil and nifedipine, on the sinoatrial and atrioventricular nodes. Experimental and clinical studies [31].

Gene context of Atrioventricular Node

• 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 [32].
• There was a higher proportion of ETB receptors in the atrioventricular node and the penetrating and branching bundles of His than in the surrounding interventricular and interatrial septa (p < 0.0001) [33].
• However, conduction is markedly slowed through the atrioventricular canal in the e.d. 10.5 heart, forming the basis for an effective atrioventricular delay before development of the AV node, as rapid ventricular activation occurs after activation of the distal AV canal tissue [34].
• Atrial ERP was reached before AV node ERP in 2 (22%) of 9 of the knockout mice and 5 (71%) of 7 of the controls (P = 0.06) [35].
• No increased or aberrant expression of Ro/SS-A or La/SS-B was observed in either neonatal or adult atrioventricular nodes and bundle branches [36].

Analytical, diagnostic and therapeutic context of Atrioventricular Node

• Recently, supersensitivity of the canine sinus and atrioventricular (AV) nodes to acetylcholine has also been demonstrated after parasympathetic denervation [37].
• In the 3 patients who did not respond to AV node modification, complete AV node ablation and permanent pacemaker implantation was performed in 2 and DC cardioversion after amiodarone loading was performed in 1 [38].
• CONCLUSIONS: Selective vagal denervation of the sinus and AV nodes and atria decreased HRV and eliminated BRS while preserving ventricular innervation [39].
• Characterization of beta 1- and beta 2-adrenoceptor subtypes in the rat atrioventricular node by quantitative autoradiography [40].
• Eight patients (six with tachycardia-induced cardiomyopathy) underwent surgery because of failure of medical treatment (including one patient in functional class I) and one underwent direct current catheter ablation of the atrioventricular (AV) node [41].

References