Materiały źródłowe

• #1 Atrioventricular Nodal Reentry Tachycardia – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK499936/

  Atrioventricular nodal reentrant tachycardia (AVNRT) is a type of paroxysmal supraventricular tachycardia that results due to the presence of a re-entry circuit within or adjacent to the AV node. […] Atrioventricular nodal reentry tachycardia is usually not prevalent in patients with structural heart disease. The anatomy of the reentrant circuit defines the type of AVNRT present. A slow-fast AVNRT accounts for 90% of AVNRTs with anterograde conduction by the slow AV nodal pathway and retrograde conduction by the fast AV nodal pathway. Fast-slow AVNRT represents approximately 5% to 10% of AVNRTs with anterograde conduction by the fast AV nodal pathway and retrograde conduction by the slow AV nodal pathway. Slow-slow AVNRTs account for 1% to 5% of AVNRTs with anterograde conduction by slow AV nodal pathways and retrograde conduction by slow atrial fibers. […] A reentry circuit requires a difference in conduction velocity and refractory period. A fast conduction pathway has rapid conduction but a slow refractory period, whereas a slow conduction pathway has a rapid refractory period coupled with slow conduction.

• #2 Atrioventricular Nodal Reentry Tachycardia – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/sites/books/NBK499936/

  Atrioventricular nodal reentrant tachycardia (AVNRT) is a type of paroxysmal supraventricular tachycardia that results due to the presence of a re-entry circuit within or adjacent to the AV node. […] A reentry circuit requires a difference in conduction velocity and refractory period. A fast conduction pathway has rapid conduction but a slow refractory period, whereas a slow conduction pathway has a rapid refractory period coupled with slow conduction. […] Atrioventricular nodal reentry tachycardia is usually not prevalent in patients with structural heart disease. The anatomy of the reentrant circuit defines the type of AVNRT present. A slow-fast AVNRT accounts for 90% of AVNRTs with anterograde conduction by the slow AV nodal pathway and retrograde conduction by the fast AV nodal pathway. Fast-slow AVNRT represents approximately 5% to 10% of AVNRTs with anterograde conduction by the fast AV nodal pathway and retrograde conduction by the slow AV nodal pathway. Slow-slow AVNRTs account for 1% to 5% of AVNRTs with anterograde conduction by slow AV nodal pathways and retrograde conduction by slow atrial fibers. […] Despite being examined, it remains controversial whether fast and slow AV nodal conduction pathways share anatomical distinction or whether they represent functional diversity in the nodal structure.

• #3 Paroxysmal Supraventricular Tachycardia: Background, Etiology, Epidemiology

  https://emedicine.medscape.com/article/898876-overview

  AV nodal reentrant tachycardia (AVNRT) is diagnosed in 50-60% of patients who present with regular narrow QRS tachyarrhythmia and is often in people older than 20 years. […] An understanding of the electrophysiology of AV nodal tissue is very important in comprehending the mechanism of AVNRT. In most people, the AV node has a single conducting pathway that conducts impulses in an anterograde manner to depolarize the bundle of His. In certain cases, AV nodal tissue may have 2 conducting pathways with different electrophysiologic properties. One pathway (alpha) is a relatively slow conducting pathway with a short refractory period, while the second pathway (beta) is a rapid conducting pathway with a long refractory period. […] The coexistence of these functionally different pathways serves as the substrate for reentrant tachycardia.

• #4 Typical atrioventricular nodal reentrant and orthodromic atrioven

  https://www.openaccessjournals.com/articles/typical-atrioventricular-nodal-reentrant-and-orthodromic-atrioventricular-tachycardias-electrocardiographic-electrophysiological-d.html

  Typical atrioventricular (AV) nodal reentrant tachycardia is responsible for 50-60% of tachycardias narrow QRS in adults and 15% of supraventricular tachycardias in pediatric patients, predominantly from adolescence onwards. […] The hypothesis of nodal reentry has been postulated by Mines in 1913. Goldreyer and others showed the location and the electrophysiological properties of the nodal reentry in humans, resulting in the concept of dissociation of the AV node. […] Electrical stimulation goes through fast pathway during sinus rhythm. When there is a supraventricular extra systole, the stimulus is conducted by the slow pathway (antegrade conduction) because it reaches earlier AV node. The retrograde conduction occurs over the fast pathway and there is almost simultaneous contraction of the atria and the ventricles. This circuit occurs in 90% of AV nodal reentrant tachycardia (AVNRT); it is the typical form.

• #5 AV nodal reentrant tachycardia – Wikipedia

  https://en.wikipedia.org/wiki/AV_nodal_reentrant_tachycardia

  AV-nodal reentrant tachycardia (AVNRT) is a type of abnormal fast heart rhythm. It is a type of supraventricular tachycardia (SVT), meaning that it originates from a location within the heart above the bundle of His. AV nodal reentrant tachycardia is the most common regular supraventricular tachycardia. […] AVNRT occurs when a reentrant circuit forms within or just next to the atrioventricular node. The circuit usually involves two anatomical pathways: the fast pathway and the slow pathway, which are both in the right atrium. The slow pathway (which is usually targeted for ablation) is located inferior and slightly posterior to the AV node, often following the anterior margin of the coronary sinus. The fast pathway is usually located just superior and posterior to the AV node. These pathways are formed from tissue that behaves very much like the AV node, and some authors regard them as part of the AV node.

• #6 AV Nodal Reentrant Tachycardia (AVNRT)

  http://www.washingtonhra.com/arrhythmias/av-nodal-reentrant-tachycardia-avnrt.php

  AV nodal reentrant tachycardia, AVNRT, is the most common cause of supraventricular tachycardia (SVT). Patients with AVNRT have at least two pathways of tissue in their AV node that allows for an abnormal electrical circuit to perpetuate within their AV node. It is this spinning circuit that goes round-and-round enclosed in the AV node that allows for rapid stimulation of the ventricles through the normal His bundle, bundle branches, and ultimately Purkinje fibers to the ventricular muscle. […] AV nodal reentry tachycardia can be diagnosed by your physician via an electrocardiogram or an Ambulatory monitoring device, i.e. Holter or Event monitor, specifically during an arrhythmia episode. […] AV nodal reentry tachycardia, as an isolated rhythm disturbance, is not considered a life-threatening condition. […] The long-term success rate for catheter ablation of AVNRT is well above 90%. However, recovery of tissue function months to years later is possible as the heart attempts to heal itself, with a delayed return of AVNRT.

• #7 AVNRT for two • LITFL • ECG Library Diagnosis

  https://litfl.com/avnrt-for-two/

  Atrioventricular Nodal Reentrant Tachycardia is a type of supraventricular tachycardia (ie it originates above the level of the Bundle of His) and is the commonest cause of palpitations in patients with hearts exhibiting no structurally abnormality. […] AVNRT is caused by a reentry circuit in or around the AV node. […] The circuit is formed by the creation of two pathways forming the re-entrant circuit, namely the slow and fast pathways. […] The fast pathway is usually anteriorly situated along septal portion of tricuspid annulus with the slow pathway situated posteriorly, close to the coronary sinus ostium. […] Sustained reentry occurs over a circuit comprising the AV node, His Bundle, ventricle, accessory pathway and atrium. […] The various forms of AVNRT can be described in terms of ECG appearance such as R-P intervals or Slow/Fast pathway dominance.

• #8 Paroxysmal Supraventricular Tachycardia: Background, Etiology, Epidemiology

  https://emedicine.medscape.com/article/898876-overview

  The onset of AVNRT is triggered by a premature atrial impulse. A premature atrial impulse may reach the AV node when the fast pathway (beta) is still refractory from the previous impulse but the slow pathway (alpha) may be able to conduct. […] After the impulse conducts in an anterograde manner through the slow pathway (alpha), it may find the fast pathway (beta) recovered. The impulse then conducts in a retrograde manner via the fast (beta) pathway. If the slow pathway (alpha) has repolarized by the time the impulse completes the retrograde conduction, the impulse can reenter the slow pathway (alpha) and initiate AVNRT. […] Importantly, note that AVNRT does not involve the ventricles as part of the reentry circuit; the necessity of perinodal atrial tissue to the circuit is controversial. Because the impulse typically conducts in an anterograde manner through the slow pathway and in a retrograde manner through the fast pathway, the PR interval is longer than the RP interval. Thus, in patients with typical AVNRT, the P wave is usually located at the terminal portion of the QRS complex. […] In patients with atypical AVNRT, anterograde conduction is via the fast pathway, while retrograde conduction is via the slow pathway. For these atypical patients, the RP interval is longer than the PR interval.

• #9 Atrioventricular nodal reentry tachycardia (AVNRT): ECG features & management – The Cardiovascular

  https://ecgwaves.com/topic/av-atrioventricular-nodal-reentrant-tachyarrrhythmia-reentry/

  AVNRT is caused by reentry in the atrioventricular (AV) node. […] Atrioventricular nodal reentrant tachycardia (AVNRT) is caused by a re-entry within the atrioventricular node. In most cases, the re-entry is induced by a premature atrial beat reaching the atrioventricular node while some fibers are still refractory. […] The impulse may subsequently circulate within the atrioventricular node, as long as it encounters excitable tissue. […] The three types of AVNRT are now discussed. […] In typical AVNRT the pathway with antegrade conduction is the slow pathway, whereas retrograde conduction is fast (hence called slow-fast AVNRT). […] In atypical AVNRT the fast pathway conducts the impulse in antegrade direction while the slow pathway conducts it in the retrograde direction. […] In this case, both pathways are slow and the P-wave occurs somewhere on the ST-T-segment. […] Typical AVNRT has a short RP interval (i.e shorter than half the RP interval). Atypical and very atypical AVNRT has a long RP interval (i.e longer than half the RP interval).

• #10 Atrioventricular Nodal Reentrant Tachycardia (AVNRT): Symptoms, Diagnosis, and Treatment

  https://angolodeldottorino.it/en/Medicine/Cardiology/heart-rhythm-disorders/atrioventricular-nodal-reentrant-tachycardia.php

  Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common type of paroxysmal supraventricular tachycardia, characterized by a reentry circuit within the atrioventricular node. […] Its occurrence is associated with the presence of dual conduction pathways within the AV node, a congenital condition present in approximately 30% of the general population. […] AV nodal reentrant tachycardia (AVNRT) is due to the presence of a dual conduction pathway within the atrioventricular node, creating an electrophysiological substrate predisposed to reentry circuit formation. […] When an atrial beat occurs at a moment when the fast pathway is still refractory, the impulse propagates exclusively along the slow pathway. […] The initiation of AVNRT is often triggered by an atrial premature beat (extrasystole), propagating unidirectionally along the slow pathway while the fast pathway is still refractory.

• #11 Atrioventricular Nodal Reentrant Tachycardia (AVNRT) – AF-ABLATION

  https://af-ablation.org/en/arrhythmological-disorders/supraventricular-tachycardia/atrioventricular-nodal-reentrant-tachycardia-avnrt/

  Atrioventricular Nodal Reentrant Tachycardia […] The AV node in patients with NRT behaves functionally as if it were made up of two distinct ways through which the impulse can travel. The two pathways (alpha and beta) differ from each other by their electrophysiological characteristics. The alpha, or slow path, usually has a relatively short effective refractory period (ERP) and leads slowly. The beta, or rapid pathway, instead has a relatively long effective refractory period and a higher conduction velocity. This condition is known as nodal conduction duplicity. In patients with nodal conduction duplication, a normal sinus beat will be conducted to the ventricles via the beta, or rapid, path of the AV node, as this leads faster than the alpha pathway. Otherwise, a sufficiently early atrial impulse can reach the AV node when the beta, or rapid, pathway is still refractory, due to the effect of conduction from the previous beat, and can therefore be conducted to the ventricles only through the alpha, or slow, pathway. In this case, the impulse will be conducted through the AV node with a modest delay compared to a normal beat, due to the lower conduction speed of the beta, or slow, path. This phenomenon occurs on the surface ECG with prolongation of the PR interval following an atrial extrasystole. If the delay in the propagation of the impulse produced by conduction through the slow path is such that it reaches the distal portion of the node when the beta, or rapid, path has regained its ability to conduct (i.e. it has reached the end of the refractory period), it will be able to travel retrogradely the fast way, giving rise to an atrial echo beat. This echo beat can behave like the initial atrial impulse and repeat the conduction cycle in an antegrade direction through the slow path and retrograde through the rapid path giving rise to a re-entry mechanism through the AV node.

• #12 Atrioventricular Nodal Reentry Tachycardia: Background, Etiology, Epidemiology

  https://emedicine.medscape.com/article/160215-overview

  Atrioventricular nodal reentry tachycardia (AVNRT) is the most common type of reentrant supraventricular tachycardia (SVT). The substrate for AVNRT is the presence of dual AV nodal pathways that are bounded by Kochs triangle generally a slow and a fast pathway but sometimes two slow pathways. […] In patients with AVNRT, two pathways connect into the AV node and help form part of the reentrant circuit. […] In the majority of patients with AVNRT, antegrade conduction occurs over the slow pathway, and retrograde conduction occurs over the fast pathway during AVNRT. […] Although many patients may have a dual pathway physiology, for AVNRT to occur, the fast pathway must have a longer refractory period antegrade than the slow conducting pathway. […] In approximately 10% of patients, AVNRT is induced by premature ventricular stimulation. In addition to the typical mechanism of AV nodal reentry described above, atypical AV nodal reentry can occur in the opposite direction, with antegrade conduction in the fast pathway and retrograde conduction in the slow pathway. Less commonly, the reentrant circuit can be over two slow pathways, the so-called slow-slow AV nodal reentry.

• #13 AVNRT | PPT

  https://www.slideshare.net/slideshow/avnrt/24391766

  Typical AVNRT involves a slow-fast pathway while typical AVRT involves orthodromic conduction over an accessory pathway. […] Atrioventricular nodal reentrant tachycardia (the Jaeggi algorithm), pseudo S/R waves, the RP interval, the lack of significant ST depression in multiple leads a correct diagnosis of typical AVNRT can be made by ECG analysis 76% of the time. […] The refractory periods of both the fast and slow pathways increased. […] The incidence of retrograde conduction through the AV node decreased. […] The cycle length of induced AVNRT increased. […] Dual AV nodal physiology may be distinct anatomic structures, or may be functionally separate fast or beta pathway: conducts rapidly and has a relatively long refractory period. […] Slow or alpha pathway: conducts relatively slowly and has a shorter refractory period.

• #14 AVNRT: AV Nodal Reentrant Tachycardia – The Cardiology Advisor

  https://www.thecardiologyadvisor.com/ddi/avnrt-av-nodal-reentrant-tachycardia/

  AV nodal reentrant tachycardia originates in the AV node. It is due to the presence of an electrical signal pathway called a reentry circuit in the AV node. Patients with AVNRT have 2 functional AV nodal pathways that conduct impulses at different rates and usually are referred to as fast and slow. The 3 primary types of AVNRT can be categorized by the anatomy of the reentry circuit as follows: Slow-fast AVNRT is defined by antegrade (forward-moving) conduction moving through the slow AV nodal pathway and retrograde (backward-moving) conduction moving through the fast pathway. This is the most common type of AVNRT. Fast-slow AVNRT is defined by the reverse pattern (antegrade conduction through the fast pathway and retrograde conduction through the slow pathway). This is a less common type of AVNRT. Slow-slow AVNRT occurs when both anterograde and retrograde conduction move through slow pathways. This is a rare type of AVNRT.

• #15 Atrioventricular Nodal Reentry Tachycardia | Treatment & Management | Point of Care

  https://www.statpearls.com/point-of-care/17974

  Atrioventricular nodal reentrant tachycardia (AVNRT) is a type of paroxysmal supraventricular tachycardia that results due to the presence of a reentry circuit within or adjacent to the AV node. […] Atrioventricular nodal reentry tachycardia is usually not prevalent in patients with structural heart disease. The anatomy of the reentrant circuit defines the type of AVNRT present. A slow-fast AVNRT accounts for 90% of AVNRTs with anterograde conduction by the slow AV nodal pathway and retrograde conduction by the fast AV nodal pathway. Fast-slow AVNRT represents approximately 5% to 10% of AVNRTs with anterograde conduction by the fast AV nodal pathway and retrograde conduction by the slow AV nodal pathway. Slow-slow AVNRTs account for 1% to 5% of AVNRTs with anterograde conduction by slow AV nodal pathways and retrograde conduction by slow atrial fibers.

• #16 Classification, Electrophysiological Features and Therapy of Atrioventricular Nodal Reentrant Tachycardia | AER Journal

  https://www.aerjournal.com/articles/classification-electrophysiological-features-and-therapy-atrioventricular-nodal-reentrant?language_content_entity=en

  Atrioventricular nodal reentrant tachycardia (AVNRT) denotes re-entry in the area of the AV node, and represents the most common regular arrhythmia in the human.1 Although several models have been proposed to explain the mechanism of the arrhythmia in the context of the complex anatomy and the anisotropic properties of the atrioventricular (AV) node and its atrial extensions (see Figure 1),2 the actual circuit of AVNRT still remains elusive. Recent studies suggest a three-dimensional AV node with greater variability in the space constant of tissue and poor gap junction connectivity due to differential expression of connexin isoforms, that provide an explanation of dual conduction and nodal reentrant arrhythmogenesis.3,4 […] The existence of an upper common pathway can now be rather easily refuted by subsequent evidence indicating that multiple atrial breakthroughs are extremely common, and retrograde activation often changes in timing and/or activation without significant alteration in tachycardia cycle, thus negating the notion of a simplistic focal atrial exit site.2123 The perinodal transitional tissue is the route to the atrium, and in this context it may be considered as a common pathway of tissue but not a discrete site. The breakthrough is whatever leads to atrial activation via transitional tissue; thus there are many possibilities (see Figures 36).

• #17 The Upper Common Pathway in Atrioventricular Nodal Reentrant Tachycardia: A Comprehensive Review of Evidence and Current Perspectives

  https://www.imrpress.com/journal/RCM/25/3/10.31083/j.rcm2503109/htm

  Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common form of paroxysmal supraventricular tachycardia, and its diagnostic and therapeutic approaches have been well-established. Traditionally, AVNRT is understood to be an intranodal reentry having two bystander pathways; the upper common pathway (UCP) which connects to the atrium and the lower common pathway which connects to the ventricle. However, the existence of the UCP remains a subject of ongoing debate. The assertion of the UCP’s presence is supported by electrophysiological evidence suggesting that the atrium is not essential for the perpetuation of AVNRT. Nonetheless, numerous anatomical studies have failed to identify any structure that could be conclusively designated as the UCP. The histological and electrophysiological characteristics of the slow and fast pathways, which are the core components of AVNRT, suggest the inclusion of atrial myocardium in the reentry circuit.

• #18 The Upper Common Pathway in Atrioventricular Nodal Reentrant Tachycardia: A Comprehensive Review of Evidence and Current Perspectives

  https://www.imrpress.com/journal/RCM/25/3/10.31083/j.rcm2503109/htm

  The UCP refers to a singular pathway connecting atrioventricular (AV) nodal tissue with the atrium. This concept was introduced to account for various electrophysiological phenomena observed in AVNRTs. A particularly representative phenomenon suggesting the presence of the UCP is the ventriculoatrial (VA) block during AVNRT. Such observations would be inexplicable if the AVNRT’s circuit was not electrically isolated from the atrium. Consequently, AVNRT is commonly understood as an intranodal reentry and has been schematically represented as being connected to the atrium via the hypothetical AV nodal tissue, in other words, the UCP. […] Recent anatomical studies have shown the histological evidence of potential pathways inferred as the FP and SP, and their relationship with the adjacent anatomic structure, including the AVN.

• #19 The Upper Common Pathway in Atrioventricular Nodal Reentrant Tachycardia: A Comprehensive Review of Evidence and Current Perspectives

  https://www.imrpress.com/journal/RCM/25/3/10.31083/j.rcm2503109/htm

  The presence of UCP is supported by evidence that the atrium is not a necessary component to sustain AVNRTs. Various types of VA dissociation during AVNRT have been considered as the representative evidence proving the existence of UCP. […] The primary evidence supporting the absence of UCP stems from anatomical studies that could not present histological evidence to corroborate intranodal reentry. If the circuit of an AVNRT comprises both the FP and SP, and their atrial ends are not linked by electrically isolated tissue from the atrium, it is theoretically challenging to conceive the existence of a UCP. […] The long-standing debate regarding the presence of UCP in AVNRT stems from the discrepancy between the anatomical/electrophysiological findings which suggest the circuit of AVNRT involves perinodal atrium, and rare phenomena during AVNRT that are not consistent with this circuit. However, as knowledge about the AVNRT circuit has accumulated, it has become evident that most AVNRTs do not exhibit behavior consistent with intranodal reentry.

• #20 Classification, Electrophysiological Features and Therapy of Atrioventricular Nodal Reentrant Tachycardia | AER Journal

  https://www.aerjournal.com/articles/classification-electrophysiological-features-and-therapy-atrioventricular-nodal-reentrant?language_content_entity=en

  The lower common pathway, as initially considered by Mendez and Moe, 24 has a more sound physiological basis. The notion of a lower common pathway has been utilised in order to explain phenomena of AV block without recording of a His electrogram as well as retrograde Wenckebach periodicity during AVNRT.2528 The lower common pathway is defined as the conduction path between the distal turnaround point of the AVNRT circuit and the His bundle. The conduction time over the lower common pathway has been usually estimated by subtracting the His to atrium interval during tachycardia (measured from the onset of the His electrogram to the onset of the atrial electrogram) from that during ventricular pacing (measured from the end of the His electrogram to the onset of the atrial electrogram) at the same cycle length and considered a measurable interval in the majority of typical AVNRT cases. Initially, a lower common pathway was demonstrated in up to 75 % of 28 patients with AVNRT who were studied,20 whereas in subsequent studies with the use of para-Hisian pacing, the presence of a lower common pathway was identified in 78 % of 23 patients studied.27 No evidence of a lower common pathway has been detected in typical slow-fast AVNRT.29

• #21 Classification, Electrophysiological Features and Therapy of Atrioventricular Nodal Reentrant Tachycardia | AER Journal

  https://www.aerjournal.com/articles/classification-electrophysiological-features-and-therapy-atrioventricular-nodal-reentrant?language_content_entity=en

  The electrophysiological proof of the existence of a lower common pathway depends on several assumptions that may not be valid, in a way that even if a lower common pathway exists, applied methodologies are unable to accurately detect and measure it.23 Furthermore, there are certain cases in the electrophysiology laboratory where an antegrade, let alone a retrograde, His bundle electrogram may not be reproducibly and reliably recorded.19 Thus, upper and lower common pathways seem to represent concepts the mechanism, relevance and practical applicability of which remain speculative.

• #22 Atrioventricular nodal re-entrant tachycardia with a 2:1 atrioventricular block in a young man: What is the mechanism? | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-024-00114-9

  Atrioventricular nodal re-entrant tachycardia (AVNRT) has different forms of presentation, where the slow-fast type, with a 1:1 atrioventricular (AV) ratio, is the most common. […] The case described is compatible with a typical slow-fast AVNRT with 2:1 AV block. Current evidence suggests the presence of a functional block; however, two questions arise: at what level and why does the block occur? […] Although the proposal of a lower common pathway is still valid, current evidence is in favor of an intrahisian blockade. The absence of his potential in blocked beats can be explained because the initial portion of activated HB is so small that it produces an unrecognizable low voltage potential in the intracavitary registry. […] From everything described above, it seems that the region where the blockage occurs is at the intrahisian level and whose mechanism is a functional phase 3 block at the same level.

• #23 Atrioventricular nodal re-entrant tachycardia with a 2:1 atrioventricular block in a young man: What is the mechanism? | International Journal of Arrhythmia | Full Text

  https://arrhythmia.biomedcentral.com/articles/10.1186/s42444-024-00114-9

  The mechanism of AVNRT with 2:1 AV block may be due to the presence of a lower common pathway or an intrahisian block. The longshort activation sequence phenomenon and the change in AV ratio from 2:1 to 1:1 with continuous programmed ventricular stimulation, suggest a functional phase 3 block at the HB (intrahisian). The absence of HB potential in blocked beats is probably because a small initial HB portion depolarized that produces an unrecognizable low voltage potential in the intracavitary registry.

• #24 Atrioventricular Nodal Reentrant Tachycardia (AVNRT): Symptoms, Diagnosis, and Treatment

  https://angolodeldottorino.it/en/Medicine/Cardiology/heart-rhythm-disorders/atrioventricular-nodal-reentrant-tachycardia.php

  The persistence of the arrhythmia is promoted by several factors modulating AV nodal refractoriness. […] AVNRT is generally benign, but it may have hemodynamic implications in individuals with underlying heart disease. […] Another consequence of AVNRT is an increase in central venous pressure, caused by simultaneous atrial and ventricular contraction. […] Atrioventricular nodal reentrant tachycardia (AVNRT) develops in individuals with an anatomical predisposition characterized by the presence of dual conduction pathways within the AV node. […] Overactivity of the sympathetic nervous system plays a crucial role in modulating AVNRT. […] In patients with recurrent and debilitating episodes or when diagnosis remains unclear despite monitoring, an electrophysiological study (EPS) is the most accurate method to confirm the presence of a reentry circuit within the AV node. […] In patients with frequent episodes, disabling symptoms, or inadequate response to pharmacological therapy, radiofrequency catheter ablation is the treatment of choice. […] AVNRT ablation has a success rate exceeding 95% and carries a low risk of recurrence.

• #25 Typical atrioventricular nodal reentrant and orthodromic atrioven

  https://www.openaccessjournals.com/articles/typical-atrioventricular-nodal-reentrant-and-orthodromic-atrioventricular-tachycardias-electrocardiographic-electrophysiological-d.html

  The refractory period of the slow pathway is shorter in women, resulting in a greater difference between the fast and slow pathway refractory periods. This may explain the higher incidence of tachycardia in women. […] The electrocardiogram shows the presence of retrograde atrial activation (P’) as pseudo R wave in V1 or pseudo S in the inferior leads in about 60% of cases during tachycardia. […] Atrial pacing with extra stimuli at progressively shorter coupling intervals is used for the electrophysiological study for diagnosis of double nodal pathway. […] To reversal to sinus rhythm, vagal maneuver can succeed when made at the beginning of tachycardia. […] If these first-line interventions are not effective, the pharmacological treatment should be done with the intravenous administration of adenosine or calcium channel blocker of the phenylalkylamine.

• #26 European Journal of Translational and Clinical Medicine

  https://ejtcm.gumed.edu.pl/articles/115072

  Atrioventricular nodal reentry tachycardia (AVNRT) is the most common paroxysmal supraventricular tachycardia. […] The reentrant mechanism of this arrhythmia results from the existence of the fast and slow atrioventricular nodal entry pathways, differing in conduction velocity and refractory period. […] The slow pathway ablation is a highly-effective method, with a success-rate of over 91-95%, minor recurrence index and a very low complication rate of 0.2-0.7%. […] The aim of the study was to analyze the gender-related differences among patients undergoing the radiofrequency catheter ablation (RFCA) of slow pathway entrance to the atrioventricular node. […] In our study, women undergoing RFCA were younger than men, what can be explained by the earlier onset of symptoms in women. […] The differences in AV conduction properties are probably the reason of different incidence of AVNRT.

• #27 European Journal of Translational and Clinical Medicine

  https://ejtcm.gumed.edu.pl/articles/115072

  In women Wenckebach block point was lower than in men. […] The duration of fluoroscopy did not differ between sexes, but there was a difference in radiation exposure between men and women. […] Younger age of women in comparison to men during RFCA of AVNRT reflects earlier onset of symptoms in women. […] Sex-related difference in radiation dose that we have observed may result from the greater volume of the men’s chest.

• #28 Familial Occurrence of Atrioventricular Nodal Reentrant Tachycardia in Mother, Father and Their Daughter – Bulletin of Cardiovasculer Academy

  https://kvbulten.com/articles/familial-occurrence-of-atrioventricular-nodal-reentrant-tachycardia-in-mother-father-and-their-daughter/doi/kvbulten.galenos.2023.00719

  Main mechanism of atrioventricular nodal reentrant tachycardia (AVNRT) results from the competition of two functional simultanously working pathways consisting of fast and slow ones in AV node and is one of the most prevalent form of supraventricular tachycardias seen in the clinic. […] On the other hand, there is no certain evidence that indicates AVNRT has such hereditary etiology so far.

• #29 About Atrioventricular Nodal Reentrant Tachycardia (AVNRT)

  https://www.verywellhealth.com/atrioventricular-nodal-reentrant-tachycardia-avnrt-1746235

  Atrioventricular nodal reentrant tachycardia (AVNRT) is a rapid, regular heartbeat that starts suddenly and without warning and may stop just as abruptly. […] The electrical impulses that lead to AVNRT occur in otherwise healthy hearts, although it can occur in the context of heart disease. […] AVNRT is a reentrant tachycardia. This means that an atypical electrical impulse becomes captured within the heart’s firing system, and it fires repeatedly within the circuit. […] In AVNRT, the extra connection and the entire reentrant circuit that produces the arrhythmia is located within or very close to the tiny atrioventricular node (AV node) hence the name, AV nodal reentrant tachycardia. […] Research continues into the causes of AVNRT, and there may be an underlying genetic reason for why you may develop the arrhythmia.

• #30 Establishing the Mechanism of Supraventricular Tachycardia in the Electrophysiology Laboratory

  https://www.innovationsincrm.com/cardiac-rhythm-management/2013/april/430-supraventricular-tachycardia-in-the-electrophysiology-laboratory

  Supraventricular tachycardia (SVT) is a common disorder, affecting 570,000 people each year. […] The vast majority of SVTs are one of three types of arrhythmia, atrioventricular nodal re-entrant tachycardia or AVNRT (responsible for approximately 65% of cases), atrioventricular reciprocating tachycardia or AVRT (responsible for approximately 30% of cases), and atrial tachycardia or AT (responsible for approximately 5% of cases). […] Before radiofrequency ablation can be performed, however, an electrophysiologic study should be performed to correctly diagnose the mechanism of the SVT. […] The demonstration of dual AV nodal physiology during electrophysiology study has a positive predictive value of 86% for AVNRT as the mechanism of the tachycardia. […] A sudden increase in the AH or VH interval with the delivery of a slightly decrementing single extrastimulus implies the presence of dual AV nodal pathways and is strongly suggestive of AVNRT as the mechanism of the SVT with a PPV of 91%.

• #31 Establishing the Mechanism of Supraventricular Tachycardia in the Electrophysiology Laboratory

  https://www.innovationsincrm.com/cardiac-rhythm-management/2013/april/430-supraventricular-tachycardia-in-the-electrophysiology-laboratory

  If the tachycardia continues during development of VA block, AVRT as the mechanism of the tachycardia is excluded because of the need for ventricular participation. […] This occurrence highly favors the diagnosis of AVNRT and atrial tachycardia with a PPV value of 60% and 40%, respectively. […] Development of left bundle branch block (BBB) favors the diagnosis of AVRT with a positive predictive value of 92%. […] An increase in the VA interval of more than 20 ms during development of BBB has a positive predictive value of nearly 100% for AVRT and also helps with the localization of the accessory pathway. […] A His-synchronous premature ventricular contraction (PVC) advances the next atrial signal without terminating the tachycardia. […] A PI1 of 100 is consistent with the diagnosis of AVNRT. […] A difference greater than 85 ms supports the diagnosis of AVNRT as the mechanism of tachycardia. […] A value of more than 0 always occurs in AVNRT.

• #32 What is AVNRT (AV Nodal Reentrant Tachycardia)?

  https://en.taylanakgun.com/avnrt

  AVNRT treatment is addressed in two stages: acute episode management and long-term treatment. During acute episodes, vagal maneuvers (Valsalva maneuver, cold application to face) can be tried first. When these methods are insufficient, medications such as adenosine, beta blockers, or calcium channel blockers are used. In very rare cases, cardioversion may be necessary. […] The most effective and permanent treatment method is ablation. The success rate of AVNRT ablation is over 95% and provides a permanent solution for many patients. […] If AVNRT is not treated, it can lead to persistent symptoms such as palpitations, dizziness, and fatigue, which may significantly impact quality of life. In rare cases, prolonged or frequent episodes can result in tachycardia-induced cardiomyopathy, weakening the heart muscle. Additionally, the rapid heart rate might increase the risk of complications like blood clots or stroke. Therefore, timely treatment is important to prevent these potential risks. […] AVNRT is generally a benign rhythm disorder and is not life-threatening. However, it can pose a risk if there is an underlying heart condition such as heart failure, coronary artery disease, or serious valve problems.

• #33 High incidence of atrial fibrillation after successful catheter ablation of atrioventricular nodal reentrant tachycardia: a 15.5-year follow-up | Scientific Reports

  https://www.nature.com/articles/s41598-019-47980-1

  Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common type of supraventricular tachycardia. […] The present long-term observational study after successful SP ablation of AVNRT confirms its clinical value reflected by low recurrence and complication rates. […] The unexpectedly high incidence of new-onset AF (11.9%) may impact long-term follow-up and requires further clinical attention. […] However, it is known that AVNRT can coexist with atrial fibrillation (AF), the most frequent sustained arrhythmia which is associated with an increase in all-cause mortality and morbidity. […] Possible mechanisms of AF initiation in these patients include enhanced atrial vulnerability and degeneration of AVNRT into AF. […] An unexpected observation was that 11.9% of patients developed new-onset AF after successful SP ablation.

• #34 High incidence of atrial fibrillation after successful catheter ablation of atrioventricular nodal reentrant tachycardia: a 15.5-year follow-up | Scientific Reports

  https://www.nature.com/articles/s41598-019-47980-1

  In conclusion, the present study which is the largest long-term follow-up study after ablation for AVNRT confirms that SP-ablation has a high success rate also more than fifteen years after ablation. The unexpectedly high incidence of new-onset AF may impact long-term follow-up and requires further clinical attention.

• #35 AVNRT: AV Nodal Reentrant Tachycardia – The Cardiology Advisor

  https://www.thecardiologyadvisor.com/ddi/avnrt-av-nodal-reentrant-tachycardia/

  AV nodal reentrant tachycardia may complicate the course of treatment and recovery for patients with congenital heart disease (CHD), particularly those affected by volume overload and right heart pressure. In patients with complex CHD, catheter ablation is a riskier procedure, and alternative treatments such as cryoablation may need to be considered.

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