atrioventricular node

..05 for both). CONCLUSIONS: Permanent para-Hisian pacing is feasible and safe. Compared with conventional right apical pacing, it allows an improvement in functional and hemodynamic parameters over long-term follow-up...

..Little is currently known, however, about the effects of acidosis on the cellular electrophysiology of the atrioventricular node (AVN)...

..03) for group 1 vs group 2, respectively. CONCLUSIONS: Echocardiography-guided AV delay optimization using the aortic Doppler VTI improves clinical outcomes at 3 months compared to an empiric AV delay program of 120 ms...

..The atrioventricular node, but not the atrioventricular bundle, was found to derive from Tbx2+ cells...

..However, comparatively little is known about the role of intracellular Ca(2+) in the atrioventricular node (AVN)...

..It is concluded that IKr may participate in both AP repolarisation and the pacemaker depolarisation in AVN cells, whilst in ventricular myocytes, IKr and IK1 participate in controlling early and final AP repolarisation respectively...

..action potential models have been developed for most regions of the heart, there is no model for the atrioventricular node (AVN). We have developed action potential models for single atrio-nodal, nodal, and nodal-His cells...

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..An additional improvement was obtained by tailored biventricular pacing. The optimal AVds were significantly shorter during right ventricular preactivation than during left ventricular preactivation...

..During cardiac resynchronization therapy (CRT), cardiac performance is dependent on an optimized atrioventricular delay (AVD). However, the optimal AVD at different heart rates has not been defined yet during CRT...

..iNa), "rapidly activating" delayed rectifier K+ current (iKr) and ultrarapid delayed rectifier potassium current (IKur) on the pacemaker activity of the sinoatrial node (SAN) and the atrioventricular node (AVN) in the mouse.

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In the normal heart, the atrioventricular node (AVN) is part of the sole pathway between the atria and ventricles. Under normal physiological conditions, the AVN controls appropriate frequency-dependent delay of contractions...

..However, antagonism of ET-1 by BQ-123 unmasks the effect of ET-1 on maintenance of vasomotor tone, which in turn may affect heart rate and sinus node automaticity in the intact pig...

..Within the axis, the atrioventricular node delays the impulse, allowing the ventricles to be filled before their contraction is initiated...

..We examined the effects of acute endothelin receptor-A blockade on the sinus node, the atrioventricular node and on the ventricular myocardium, in patients with single-vessel coronary artery disease and preserved ..

..In view of the prominent percentage and electrical properties, tiny spindle and slender spindle cells were presumed to play important roles...

The electrical activity of the atrioventricular node (AVN) is functionally heterogeneous, but how this relates to distinct cell types and the 3-dimensional structure of the AVN is unknown...

Because of its complexity, the atrioventricular node (AVN), remains 1 of the least understood regions of the heart. The aim of the study was to construct a detailed anatomic model of the AVN and relate it to AVN function...

The atrioventricular node (AVN) can act as a subsidiary cardiac pacemaker if the sinoatrial node fails...

..The atrial musculature in the cavotricuspid isthmus is a part of posterior inputs to the AV node. In patients with typical atrial flutter, effects of radiofrequency ablation of this isthmus on AV node conduction are still unknown...

..A variety of techniques are used to estimate optimum AV/VV intervals; however, the precision of their estimates and the ramifications of an imprecise estimate have not been characterized previously...

..as inappropriate sinus tachycardia has been reported to occur following slow pathway ablation for atrioventricular node tachycardia...

..The optimal pacing mode with either single chamber atrial pacemaker (AAI or AAIR) or dual chamber pacemaker (DDD or DDDR) is still not clear in sinus-node dysfunction (SND) and intact atrioventricular (AV) conduction...

..The development of LV dyssynchrony was associated with deterioration in heart failure symptoms, systolic LV function, and LV dilatation...

..This case illustrates the stand-alone use of one of the new non-fluoroscopic navigation systems for a complete procedure such as AV ablation and pacemaker implantation...

..The measurement of the maximal VTI of mitral inflow is the most accurate method...

..Complete elimination of the tachycardia was achieved with RF energy application from this site...

..Findings from animal studies and small series of patients support the greater safety of cryoenergy over radiofrequency in the ablation of arrhythmic substrates near the AV node...

..The purpose of this study was to investigate the electrophysiologic characteristics of the inferior extensions of the human atrioventricular (AV) node and their possible relationship to slow pathway conduction...

..In patients with atrial fibrillation that is refractory to drug therapy, radio-frequency ablation of the atrioventricular node and implantation of a permanent pacemaker are an alternative therapeutic approach...

..Immunolabeling revealed that the FP and SP are formed by Cx43-expressing bundles surrounded by tissue without Cx43. Cx43-expressing posterior nodal extensions are the substrate of AVNR during both intranodal and extranodal reentry...

..g., atrial fibrillation) by preventing rapid conduction to the ventricles potentially associated with hemodynamic deterioration...

Control of ventricular rate by atrioventricular node ablation and pacemaker implantation in patients with drug-refractory atrial fibrillation (AF) is associated with improved left ventricular (LV) function...

..The effect on AV node conduction is substantially enhanced by pretreatment of fibroblasts with TGF-beta1. These data have therapeutic potential for the management of rapid ventricular rate during AF without pacemaker implantation...

..EDP measurements appear to identify potential candidates for CRT, and to confirm the success of system implantation...

..large-scale real-time RT-PCR, we have profiled 71 channels and related genes in the sinoatrial node (SAN), atrioventricular node (AVN), the atria (A) and ventricles (V)...

..Finally, open questions concerning when to combine CRT with implantable cardioverter-defibrillator therapy and the cost-effectiveness of CRT are discussed...

..These data provide insight into the distinct clinical phenotypes resulting from mutation of a single ion channel...

..The histopathological findings confirmed the lesion as a cystic tumor of the atrioventricular nodal region. This is the third known case of this condition diagnosed antemortem and treated successfully with surgical excision...

..Ablation of the AV node is effective with a double freeze-thaw cycle using a percutaneous catheter cryoablation system. Ice mapping of the area allows for identification of the targeted site...

..In addition, a tumour of the atrioventricular node, known as mesothelioma or hemolymphangioma, was discovered...

..As the distribution of Cx40 protein is similar in mouse and human hearts, further functional analysis of Cx40 should yield relevant insights into arrhythmogenesis in human patients...

..This sympathetic overdrive was also found to be present in the sinus node...

..These data suggest that a "typical" nodoventricular pathway, by electrophysiologic criteria, may in fact be an AV pathway with AV node-like conduction properties and a distal right ventricular insertion site...

..Cryoablation is increasingly used to treat atrioventricular nodal reentrant tachycardia (AVNRT). It is unknown whether larger electrode-tip cryocatheters improve outcomes without compromising safety...

..LGE CMR is also useful for identifying the nature of cardiac masses or lesions. We report a case of a rare primary cystic tumor of the atrioventricular node, in which CMR proved to be valuable.

..The studies also showed that reversible "ice mapping" can be performed before creating permanent lesions. We investigated the feasibility and safety of applying this new technology in man...

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..However, already the two types of model are beginning to be used in tandem to reconstruct the activation sequence of the heart both during sinus rhythm and arrhythmias...

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..This study shows the importance of the optimal AV delay setting in patients with an implanted DDD pacemaker, the Doppler index and plasma ANP levels are good indicators for optimizing AV delay...

..6+/-0.5 to 1.4+/-0.5 (p<0.001). CONCLUSIONS: AV delay optimization is important in patients with biventricular pacing and can be easily achieved by the new method...

..No typical AV accessory pathway was found. This is the first report of an accessory AV node that participated in AVRT. It was deeper than typical radiofrequency catheter ablation lesions...

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..Slow formation of a permanent lesion by cryothermal energy application allowed precise modulation of atrioventricular nodal conduction until the endpoints of complete fast pathway ablation were met with long-term cure of the arrhythmia...

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..This conscious HIS-pacing model in dogs is a sensitive, stable, and reproducible method to define ventricular repolarization characteristics over a range of programmable HRs and experimental conditions...

..detailed mapping showed cranial to caudal depolarization of the His bundle, leading to the diagnosis of atrioventricular node re-entrant tachycardia...

..The aim of our study was to evaluate the PM dependence and the incidence of correlated clinical phenomena in a patients population with AV block induced by RF ablation of the AV junction...

..The AP was located on the left side and posterior. The absence of retrograde conduction through the AP and also a long conduction time were demonstrated...

..No data regarding the effects of DEX on the cardiac conduction system are available. We therefore aimed to characterize the effects of DEX on cardiac conduction in pediatric patients...

..DISCUSSION: Overall, the data suggest that an evaluation of the most appropriate correction factor should be applied to each laboratory using their own data collected by their own method in their particular strain of dog...

..In this study, the electro-pharmacological effects of bepridil were compared with those of dl-sotalol, a representative class III antiarrhythmic drug, using the halothane-anesthetized canine model...

..The study tests the hypothesis that ablating all inputs to the atrioventricular (AV) node can result in complete heart block with stable junctional escape rhythm...

..Approximately 30% of all accessory pathways (APs) are located in the septal area, and understanding the electrocardiographic and electrophysiologic of these APs is crucial for safe and effective ablation of these pathways...

..The role for transitional cells as determinants of AH and HA conduction was examined in the superfused rabbit AV junction...

..The precise electrophysiological characteristics and essential effects of left-sided ablation in atrioventricular nodal reentrant tachycardia (AVNRT) with eccentric coronary sinus (CS) activation (ECSA) have not been described...

..The electrophysiologic mechanisms of different ventriculoatrial (VA) block patterns during atrioventricular nodal reentrant tachycardia (AVNRT) are poorly understood...

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..Electrophysiological manoeuvres identified the site of block in the lower common pathway of the AV node. This arrhythmia was rendered non-inducible after slow pathway ablation...

..To study the usefulness of incremental atrial pacing for evaluating the effect of radiofrequency catheter ablation on slow pathway conduction in patients with atrioventricular (AV) nodal reentrant tachycardia...

..of differentiating between pathways for retrograde conduction over the accessory pathway (AP) and over the atrioventricular node (AVN)...

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..5-2 cm away from the tricuspid annulus in a three-dimensional reconstruction of the right atrium and right ventricle...

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..In the present article, we summarize the available evidence and propose a comprehensive model of the tachycardia circuit for all forms of atrioventricular nodal reentrant tachycardia based on the concept of atrionodal inputs...

..In conclusion, the site-dependent variations of the unipolar CS atrial electrogram underlie the limited usefulness of the 'PQS pattern' in left posteroseptal accessory pathway localization...

..This patient developed HV block by atrial extrastimulus (S1S1: 600 msec, S1S2 <or= 350 msec). Thus, the patient was diagnosed as having combined atriofascicular and fasciculoventricular connections...

..The incidence and mechanism of the dislocated antegrade fast pathway (A-FP) were examined in various forms of atrioventricular nodal reentrant tachycardia (AVNRT)...

..prolong ventricular repolarization, were selected to evaluate the sensitivity of the conscious chronic atrioventricular node--ablated, His bundle-paced Dog for defining drug induced cardiac repolarization prolongation...

..The retrograde fast pathway in typical atrioventricular nodal reentrant tachycardia (AVNRT) exhibits marked variation in its electrophysiologic properties...

..Patients with sinus node dysfunction should be paced in the atrium alone. There is no indication for use of a device for atrial fibrillation without a conventional indication for pacing...

..In these children, it may be preferable to use single-lead VDD pacing, but for VDD pacing a normal sinus node function is required. Our aim was to study sinus node function in children with CCAVB...

..Successful ablation of atrial tachycardia revealed that SA and AV node properties were in the normal range; therefore no pacemaker implantation was needed...

..During right atrial stimulation, the anterior and posterior approaches provide inputs to the atrioventricular (AV) node. The purpose of the present study was to determine how activation proceeding from the left atrium reaches the AV node...

..02) function groups. Following AVJ ablation, QTdisp increased during a sudden rate drop in patients with reduced LV function, but not in patients with normal LV function...

..6 months. No complications were observed during the procedures. We conclude that radiofrequency ablation is feasible and effective in the ablation of accessory pathways in patients with discordant atrioventricular connections...

..However, it is invasive with possible procedure-related complications. Therefore, it would be helpful to identify patients in whom an electrophysiologic study is useful for diagnosis of syncope...

..In addition, ablation should be started when the catheter is radiologically stable and should not be interrupted in the absence of a junctional rhythm...

..of the left ventricle, initiated from the atrium and traveling through the His-Purkinje system via the atrioventricular node, provides for relatively synchronous activation of ventricular muscle...

..advances in the treatment of supraventricular arrhythmias, the mechanisms governing conduction through the atrioventricular node (AV) remain poorly understood...

..This work will serve as the foundation for development and in-vivo test of a full prototype guidance system in Phase II. ..

..We focus here on the heart because therein lie salient problems that are ready to be addressed by this new technology. However, the wide range of possible applications may lead to the commercialization of this new technology. ..

..As an initial attempt to investigate this theory, we will focus on the atrioventricular node, an anatomically well-defined region where functional changes are easily observed...

..primary role in many types of arrhythmias, including tachycardia and flutter in the atria, ventricles, and atrioventricular node. Reentry may involve anatomical pathways, or it may be functional, with leading circle, figure-eight, ..

..This would benefit patients with pharmacologically resistant or surgically inappropriate treatment of the disease. ..

..This new therapeutic approach could be utilized as a non-invasive application or incorporated into an implantable device for treatment of patients with PAF. ..

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..The overall goal of this project is to develop such a multiscale modeling framework, which will enable the evaluation of potential pharmacological and device-based atrial fibrillation therapies. ..

..By doing so, the proposed work may help improve our understanding of how alternans may trigger cardiac arrhythmias. ..

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..6. To optimize ease of use. To minimize the barrier of entry for beginners and maximize the productivity of experienced users, we will emphasize user-friendliness and develop comprehensive documentation. ..

..This research has the potential to permit identification of individuals at risk for sudden cardiac death and therefore has significant relevance to public health. (End of Abstract) ..

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..The results of our studies could explain the increased mortality associated with AF and should have a great impact on our management of patients with AF and heart failure. ..

..End of Abstract) ..

..Similarly, a reduction in inducibility of ventricular arrhythmias, if present with long term pacing, may have an impact on the survival and on our management of patients with implantable defibrillators and frequent shocks. ..

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..The initial characterization of these interactions will serve as the foundation for studying the role of the nuclear envelope in transcriptional regulation in my own laboratory. ..

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