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Massumi R, Shehata M. Doubling of the ventricular rate by interpolated junctional extrasystoles resembling supraventricular tachycardia. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2010; 33:945-9. [PMID: 20497352 DOI: 10.1111/j.1540-8159.2010.02763.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In a study of seven cases of paroxysmal supraventricular tachycardia, it was noted that the fast rate was not caused by the mechanism of rapid firing, reentry, or dual atrioventricular nodal conduction but by an abrupt doubling of the rate by interpolation of junctional extrasystoles between adjacent sinus beats while the sinus mechanism remained undisturbed. Dual ventricular response to a single atrial depolarization was seriously considered in each case. The intervals separating the junctional extrasystoles tended to be quite fixed, thus conforming to the pattern of junctional parasystole with an intrinsic rate very close to the rate of the dominant sinus rhythm. The paroxysms of tachycardia were transient, lasting a few seconds to 3.5 minutes. The onset and termination of the paroxysms were completely unpredictable and appeared unrelated to any change in the basic sinus rate or other identifiable mechanism. In only one case, case 7, the concept of dual ventricular response appeared tenable. However, as will be discussed later, the mechanism of junctional parasystole was found to be physiologically more acceptable.
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Affiliation(s)
- Rashid Massumi
- Cedars Sinai Heart Institute, Los Angeles, California, USA.
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Katritsis DG, Ellenbogen KA, Becker AE, Camm AJ. Retrograde slow pathway conduction in patients with atrioventricular nodal re-entrant tachycardia. ACTA ACUST UNITED AC 2007; 9:458-65. [PMID: 17478461 DOI: 10.1093/europace/eum067] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
AIMS To study retrograde slow pathway conduction by means of right- and left-sided septal mapping. METHODS AND RESULTS Nineteen patients with slow-fast atrioventricular nodal re-entrant tachycardia (AVNRT) were studied before and after slow pathway ablation. Simultaneous His bundle recordings from right and left sides of the septum, using trans-aortic and trans-septal electrodes, were made during right ventricular pacing. Pre-ablation, decremental retrograde ventriculo-atrial (VA) conduction without jumps or discontinuities was recorded in eight patients (group 1). In six patients, retrograde conduction jumps were demonstrated (group 2) and in the remaining four patients, there was minimal prolongation of stimulus to atrium (St-A) intervals (group 3). The maximal difference (Delta St-A) between St-A intervals obtained with pacing at a constant cycle length of 500 ms and at the cycle length with maximal retrograde VA prolongation was significantly longer measured from the right His compared with the left His (122 +/- 25 vs. 110 +/- 33 ms, P = 0.02, respectively) in group 1 and group 2 (140 +/- 23 vs. 110 +/- 35 ms, P = 0.03), but not in group 3 (10 +/- 4 vs. 13 +/- 8 ms, P = 0.35). Post-ablation, Delta St-A intervals were similar between right and left His recordings (77 +/- 37 vs. 76 +/- 33 ms, P = 0.53, respectively) in group 1, (100 +/- 24 vs. 103 +/- 21 ms, P = 0.35) group 2, and (63 +/- 32 vs. 66 +/- 33 ms, P = 0.35) group 3. CONCLUSION In patients with typical AVNRT, retrograde conduction through the slow pathway results in earliest retrograde atrial activation on the left side of the septum and catheter ablation in the right inferoparaseptal area abolishes this pattern. These findings are compatible with the concept of slow pathway conduction by means of the inferior AV nodal extensions.
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Gupta N, Kangavari S, Peter CT, Chen PS. Mechanism of eccentric retrograde atrial activation sequence during atypical atrioventricular nodal reciprocating tachycardia. Heart Rhythm 2005; 2:754-7. [PMID: 15992735 DOI: 10.1016/j.hrthm.2005.04.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2005] [Accepted: 04/06/2005] [Indexed: 10/25/2022]
Affiliation(s)
- Nigel Gupta
- Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center, UCLA School of Medicine, Los Angeles, California 90048-1865, USA
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Strieper MJ, Frias P, Goodwin N, Huber G, Costello L, Balfour G, Campbell RM. Radiofrequency Modification for Inducible and Suspected Pediatric Atrioventricular Nodal Reentry Tachycardia. J Interv Card Electrophysiol 2005; 13:139-43. [PMID: 16133841 DOI: 10.1007/s10840-005-0241-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2004] [Accepted: 05/04/2005] [Indexed: 10/25/2022]
Abstract
INTRODUCTION AV Node Reentry Tachycardia (AVNRT) is the second most common supraventricular tachycardia (SVT) undergoing pediatric radiofrequency ablation behind accessory pathway reentry tachycardias. AVNRT can be difficult to induce during electrophysiology study (EPS) and dual atrioventricular nodal (AVN) pathways physiology may not be demonstrated in young patients. PURPOSE This report is the largest single center long term pediatric experience of radiofrequency modification of slow AVN input fibers for inducible or suspected (non-inducible) AVNRT. RESULTS One hundred thirty-two patients underwent slow input AVN modification from 1993 to 2002. The mean patient age was 13.7 years (4-20 yrs) with 62M/70F. Outpatient tachycardia was documented by ambulatory monitoring in all patients. AVNRT was induced in 98/132 patients during EPS (group A) with mean SVT cycle length of 324 msec (230-570 msec). Initial AVN modification (group A) was successful in 97/98 patients (99%). During 34/132 EPS, AVNRT was non-inducible; dual AVN physiology was present in 19/34 (group B), and 15/34 did not show evidence for dual AVN physiology (group C). These 34 patients underwent empiric AVN modification following discussion with patients' families. Freedom of recurrence from SVT at 1 year was 96% for group A (94/98), 89% (17/19) for group B and 93% (14/15) for group C. 1 major and 6 minor complications occurred. CONCLUSIONS AVN modification for AVNRT can be performed safely and effectively in pediatric patients with good long-term results. Empiric slow pathway AVN modification for non-inducible SVT results in a high rate of freedom from recurrence of tachycardia.
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Affiliation(s)
- Margaret J Strieper
- Sibley Heart Center Cardiology at Children's Healthcare of Atlanta, Emory University School of Medicine, Atlanta, Georgia 30329, USA.
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Katritsis DG, Becker AE, Ellenbogen KA, Karabinos I, Giazitzoglou E, Korovesis S, Camm AJ. Right and left inferior extensions of the atrioventricular node may represent the anatomic substrate of the slow pathway in humans. Heart Rhythm 2004; 1:582-6. [PMID: 15851223 DOI: 10.1016/j.hrthm.2004.07.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2004] [Accepted: 07/10/2004] [Indexed: 11/24/2022]
Abstract
OBJECTIVES 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. BACKGROUND The human heart contains right and left inferior extensions of the AV node that relate to right and left atrial inputs. METHODS Fourteen patients admitted for catheter ablation of left-sided accessory pathways were studied. Atrial pacing was performed from multiple sites in both atria, and simultaneous His-bundle recordings from right and left sides of the septum were made. RESULTS Significant differences of A-H and stimulus to His (St-H) intervals with pacing at various sites were found. St-H intervals were similar during constant pacing from the low right atrium or the left inferoparaseptal area (112 +/- 28 ms vs 112 +/- 26 ms, P = .8, for right His recordings and 114 +/- 23 ms vs 111 +/- 25 ms, P = .9, for left His recordings). At maximum decrement, there were significantly shorter St-H intervals during left inferoparaseptal pacing compared to low right atrial pacing (201 +/- 24 ms vs 218 +/- 44 ms, P = .02, for right His recordings, and 200 +/- 24 ms vs 219 +/- 41 ms, P = .009, for left His recordings). Differences on right His recordings between St-H intervals at maximum decrement and at constant pacing from the low right atrium were significantly higher than corresponding differences on left His recordings during pacing from the left inferoparaseptal area (P = .035). CONCLUSIONS Our findings support the concept that the right and left inferior extensions of the human AV node may represent the anatomic substrate of the slow pathway as defined electrophysiologically.
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Strohmer B, Hwang C, Peter CT, Chen PS. Selective atrionodal input ablation for induction of proximal complete heart block with stable junctional escape rhythm in patients with uncontrolled atrial fibrillation. J Interv Card Electrophysiol 2003; 8:49-57. [PMID: 12652178 DOI: 10.1023/a:1022344032001] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND 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. METHODS AND RESULTS We attempted atrionodal input ablation in 76 consecutive patients with uncontrolled atrial fibrillation. Fast and slow pathways were first ablated. If there was no AV block, additional energy applications were done between fast and slow pathway locations. The patients were followed for 42 +/- 11 months. Group I (n = 57) comprised patients with complete heart block and junctional escape rhythm (53 +/- 4 beats/min) at the end of the procedure. The escape rhythm remained stable throughout follow-up. Group II (n = 15) were patients who failed the stepwise atrionodal input ablation and required AV junctional ablation guided by His bundle potential to achieve complete heart block. Four patients showed a slow escape rhythm after ablation (33 +/- 4 beats/min). Others had no escape rhythm. All 15 pts remained pacemaker dependent. The total death rate of groups I and II was 18/57 (31.6%) vs 10/15 (66.7%), respectively (p < 0.02). These differences could not be explained by a difference of left ventricular ejection fraction (0.42 +/- 0.07 vs 0.41 +/- 0.04, respectively, p = NS). CONCLUSIONS (1) In most patients, ablation of both fast and slow pathways did not result in complete heart block, indicating the presence of multiple atrionodal inputs. (2) Ablation of all atrionodal inputs may result in complete heart block with stable junctional escape rhythm. (3) As compared with AV junctional ablation, atrionodal input ablation was associated with a lower mortality rate on long-term follow up.
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Affiliation(s)
- Bernhard Strohmer
- Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center and UCLA School of Medicine, Los Angeles, CA, USA.
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Katoh T, Kinoshita S, Tsujimura Y, Sasaki Y. Atypical atrioventricular Wenckebach periodicity caused by conduction through triple atrioventricular junctional pathway as a probable mechanism. J Electrocardiol 2003; 36:73-9. [PMID: 12607199 DOI: 10.1054/jelc.2003.50000] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Electrocardiograms were taken from an 84-year-old man with right bundle branch block in whom atypical atrioventricular Wenckebach periodicity was frequently occurred. The electrocardiographic findings as mentioned below suggested that the atypical periodicity was caused by conduction through triple atrioventricular junctional pathways as a probable mechanism. When a P wave was blocked after a markedly prolonged PR interval of 0.64 s, the RP interval containing this blocked P wave ranged between 0.84 s and 0.86 s, and the next P wave was followed by a QRS complex of the same configuration, with the PR interval of 0.35 s. On the other hand, when a P wave was blocked after a PR interval of 0.49 s or 0.52 s, the RP interval containing this blocked P wave was comparatively long, ie, 0.95 s or 0.98 s, and the next P wave was followed by a QRS complex of somewhat different configuration showing borderline left axis deviation, with a shorter PR interval of 0.21 s or 0.23 s. These findings suggest that longitudinal dissociation occurred not only in the atrioventricular junction but also in the His bundle. This is the first report suggesting triple atrioventricular junctional pathways probably associated with longitudinal dissociation in the His bundle.
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Affiliation(s)
- Takakazu Katoh
- Katoh Cardiovascular Clinic, Ohtsu; Hokkaido Women's University, Ebetsu, Hokkaido, Japan
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Taniguchi Y, Yeh SJ, Wen MS, Wang CC, Lin FC, Wu D. Variation of P-QRS relation during atrioventricular node reentry tachycardia. J Am Coll Cardiol 1999; 33:376-84. [PMID: 9973017 DOI: 10.1016/s0735-1097(98)00576-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES The main objective of this study was to characterize the phenomenon of variation in the P-QRS relation during atrioventricular node reentry tachycardia. BACKGROUND Variation of P-QRS relation during tachycardia has been observed occasionally in atrioventricular node reentry tachycardia. However, the incidence, the characteristics and the mechanisms of this phenomenon have not been investigated previously. METHODS Retrospective analysis was performed in 311 consecutive patients with slow-fast form and 108 patients with atypical or multiple form of atrioventricular node reentry tachycardia to examine whether variation of P-QRS relation with changes in AH, HA and AH/HA (A = atria; H = His bundle) ratio occurred during tachycardia. RESULTS A total of 28 patients, 8 with slow-fast and 20 with atypical or multiple tachycardias, were found to manifest this phenomenon. There were 6 males and 22 females, with an average age of 38+/-16 years. In 10 patients, this phenomenon occurred transiently following electrical induction of the tachycardia. In 15 patients, changes in AH, HA and AH/HA ratio were associated with the occurrence of Wenckebach or 2:1 block proximal to the His bundle (H) recording site without interruption of the tachycardia. In nine patients, three with nonsustained tachycardia and six after administration of adenosine triphosphate, this phenomenon was observed at the termination of the tachycardia. This phenomenon was usually accompanied by a mild lengthening of the tachycardia cycle length. CONCLUSIONS Variation of P-QRS relation with or without block may occur during atrioventricular node reentry tachycardia, especially in atypical or multiple-form tachycardias. It was postulated that decremental conduction in the distal common pathway, which exists between the distal link of the reentry circuit and the H, is primarily responsible for this phenomenon.
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Affiliation(s)
- Y Taniguchi
- Department of Medicine, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taipei, Taiwan
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Nawata H, Yamamoto N, Hirao K, Miyasaka N, Kawara T, Hiejima K, Harada T, Suzuki F. Heterogeneity of anterograde fast-pathway and retrograde slow-pathway conduction patterns in patients with the fast-slow form of atrioventricular nodal reentrant tachycardia: electrophysiologic and electrocardiographic considerations. J Am Coll Cardiol 1998; 32:1731-40. [PMID: 9822103 DOI: 10.1016/s0735-1097(98)00433-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES This study sought to define the electrophysiologic and electrocardiographic characteristics of fast-slow atrioventricular nodal reentrant tachycardia (AVNRT). BACKGROUND In fast-slow AVNRT the retrograde slow pathway (SP) is located in the posterior septum, whereas the anterograde fast pathway (FP) is located in the anterior septum; however, exceptions may occur. METHODS Twelve patients with fast-slow AVNRT were studied. To determine the location of the retrograde SP, atrial activation during AVNRT was examined while recording the electrograms from the low septal right atrium (LSRA) on the His bundle electrogram and the orifice of the coronary sinus (CS). Further, to investigate the location of the anterograde FP, single extrastimuli were delivered during AVNRT both from the high right atrium and the CS. RESULTS The CS activation during AVNRT preceded the LSRA in six patients (posterior type); LSRA activation preceded the CS in three patients (anterior type), and in the remaining three both sites were activated simultaneously (middle type). In the anterior type, CS stimulation preexcited the His and the ventricle without capturing the LSRA electrogram (atrial dissociation between the CS and the LSRA), suggesting that the anterograde FP was located posterior to the retrograde SP. In the posterior and middle types, high right atrial stimulation demonstrated atrial dissociation, suggesting that the anterograde FP was located anterior to the SP. In the posterior and middle types, retrograde P waves in the inferior leads were deeply negative, whereas they were shallow in the anterior type. CONCLUSIONS Fast-slow AVNRT was able to be categorized into posterior, middle and anterior types according to the site of the retrograde SP. The anterior type AVNRT, where an anteriorly located SP is used in the retrograde direction and a posteriorly located FP in the anterograde direction, appears to represent an anatomical reversal of the posterior type which uses a posterior SP for retrograde and an anterior FP for anterograde conduction. Anterior type AVNRT should be considered in the differential diagnosis of long RP (RP > PR intervals) tachycardias with shallow negative P waves in the inferior leads.
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Affiliation(s)
- H Nawata
- The First Department of Internal Medicine, Tokyo Medical and Dental University, Japan
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10
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Suzuki F, Toshida N, Nawata H, Yamamoto N, Hirao K, Miyasaka N, Kawara T, Hiejima K, Harada T. Coronary sinus pacing initiates counterclockwise atrial flutter while pacing from the low lateral right atrium initiates clockwise atrial flutter. Analysis of episodes of direct initiation of atrial flutter. J Electrocardiol 1998; 31:345-61. [PMID: 9817217 DOI: 10.1016/s0022-0736(98)90020-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
INTRODUCTION Rapid atrial pacing in sinus rhythm may directly induce atrial flutter without provoking intervening atrial fibrillation, or initiate atrial flutter indirectly, by a conversion from an episode of transient atrial fibrillation provoked by rapid atrial pacing. The present study was performed to examine whether or not the direct induction of clockwise or counterclockwise atrial flutter was pacing-site (right or left atrium) dependent. METHODS AND RESULTS We analyzed the mode of direct induction of atrial flutter by rapid atrial pacing. In 46 patients with a history of atrial flutter, rapid atrial pacing with 3 to 20 stimuli (cycle length = 500 - 170 ms) was performed in sinus rhythm to induce atrial flutter from 3 atrial sites, including the high right atrium, the low lateral right atrium, and the proximal coronary sinus, while recording multiple intracardiac electrograms of the atria. Direct induction of atrial flutter by rapid atrial pacing was a rare phenomenon and was documented only 22 times in 15 patients: 3, 11, and 8 times during stimulation, respectively, from the high right atrium, low lateral right atrium, and the proximal coronary sinus. Counterclockwise atrial flutter (12 times) was more frequently induced with stimulation from the proximal coronary sinus than from the low lateral right atrium (8 vs 1, P = .0001); clockwise atrial flutter (10 times) was induced exclusively from the low lateral right atrium (P = .0001 for low lateral right atrium vs proximal coronary sinus, P = .011 for low lateral right atrium vs high right atrium). CONCLUSIONS Direct induction of either counterclockwise or clockwise atrial flutter was definitively pacing-site dependent; low lateral right atrial pacing induced clockwise, while proximal coronary sinus pacing induced counterclockwise atrial flutter. Anatomic correlation between the flutter circuit and the atrial pacing site may play an important role in the inducibility of counterclockwise or clockwise atrial flutter.
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Affiliation(s)
- F Suzuki
- First Department of Internal Medicine, Tokyo Medical and Dental University, Japan
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Medkour D, Becker AE, Khalife K, Billette J. Anatomic and functional characteristics of a slow posterior AV nodal pathway: role in dual-pathway physiology and reentry. Circulation 1998; 98:164-74. [PMID: 9679723 DOI: 10.1161/01.cir.98.2.164] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The AV node is frequently the site of reentrant rhythms. These rhythms arise from a slow and a fast pathway for which the anatomic and functional substratum remain debated. This study proposes a new explanation for dual-pathway physiology in which the posterior nodal extension (PNE) provides the substratum for the slow pathway. METHODS AND RESULTS The anatomic and functional properties of the PNE were studied in 14 isolated rabbit heart preparations. A PNE was found in all studied preparations. It appeared as an elongated bundle of specialized tissues lying along the lower side of Koch's triangle between the coronary sinus ostium and compact node. No well-defined boundary separated the PNE, compact node, and lower nodal cell bundle. The electric properties of the PNE were characterized with a premature protocol and surface potential recordings from histologically controlled locations. The PNE showed cycle-length-dependent posteroanterior slow activation with a shorter refractory period (minimum local cycle length) than that of the compact node. During early premature beats resulting in block in transitional tissues, the markedly delayed PNE activation could propagate to maintain or resume nodal conduction and initiate reentrant beats. A shift to PNE conduction resulted in different patterns of discontinuity on conduction curves. Transmembrane action potentials recorded from PNE cells in 6 other preparations confirmed the slow nature of PNE potentials. CONCLUSIONS The PNE is a normal anatomic feature of the rabbit AV node. It constitutes a cycle-length-dependent slow pathway with a shorter refractory period than that of the compact node. Propagated PNE activation can account for a discontinuity in conduction curves, markedly delayed AV nodal responses, and reentry. Finally, the PNE provides a substratum for the slow pathway in dual-pathway physiology.
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Affiliation(s)
- D Medkour
- Department of Physiology, Faculty of Medicine, University of Montreal, Canada
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12
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Haïssaguerre M, Jaïs P, Shah DC, Hocini M, Takahashi A, Gaïta F, Barold SS, Clémenty J. Analysis of electrophysiological activity in Koch's triangle relevant to ablation of the slow AV nodal pathway. Pacing Clin Electrophysiol 1997; 20:2470-81. [PMID: 9358489 DOI: 10.1111/j.1540-8159.1997.tb06087.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Atrioventricular junctional reentrant tachycardia (AVJRT) is the most common form of paroxysmal regular supraventricular tachycardia. In patients with disabling, drug refractory AVJRT, catheter ablation has evolved rapidly from a last-resort treatment in the form of interruption of atrioventricular (AV) conduction to selective modification of AV nodal function as an ideal treatment. This article will focus on the frequently unappreciated electrophysiological activities recordable in man in Koch's triangle during ablation of the so-called slow pathway.
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Affiliation(s)
- M Haïssaguerre
- Department of Hopital Cardiologique du Haut-Lévêque, Bordeaux-Pessac, France
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Tchou PJ, Cheng YN, Mowrey K, Efimov IR, Van Wagoner DR, Mazgalev TN. Relation of the atrial input sites to the dual atrioventricular nodal pathways: crossing of conduction curves generated with posterior and anterior pacing. J Cardiovasc Electrophysiol 1997; 8:1133-44. [PMID: 9363816 DOI: 10.1111/j.1540-8167.1997.tb00999.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
INTRODUCTION The usually accepted definition of the dual pathway electrophysiology requires the presence of conduction curves with a discontinuity ("jump"). However, AV nodal reentrant tachycardia has been observed in patients with "smooth" conduction curves, whereas discontinuity of the conduction curve does not guarantee induction of stable reentry. We hypothesize that the duality of AV nodal conduction can be revealed by careful choice of stimulation sites during the generation of AV nodal conduction curves. METHODS AND RESULTS In 21 rabbit heart atrial-AV nodal preparations, programmed electrical stimulation with S1-S2-S3 pacing protocol was applied either posteriorly at the crista terminalis input site (CrT) or anteriorly at the lower interatrial septum input site (IAS), or (in 8 preparations with surgically divided input sites) at both. We found that in intact preparations with "smooth" conduction curves, pacing at long coupling intervals produced shorter AV nodal conduction times from the IAS (56 +/- 9.8 msec vs 69 +/- 10.1 msec; P < 0.01). At short coupling intervals, in contrast, shorter conduction times were obtained from the CrT (173 +/- 21.8 msec vs 188 +/- 22.8 msec; P < 0.01). This resulted in a characteristic crossing of the superimposed IAS and CrT conduction curves. After division of the inputs, the IAS site had rapid conduction to the His bundle but a longer refractory period, whereas the CrT site had long conduction times and shorter refractory periods. Wavefronts entering the AV node from these two inputs can summate, resulting in improved conduction. CONCLUSION Pacing protocols designed to accentuate the asymmetry between the AV nodal inputs can help to reveal the functional difference between the dual pathways and thus to better assess the properties of AV nodal conduction.
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Affiliation(s)
- P J Tchou
- Department of Cardiology, The Cleveland Clinic Foundation, Ohio 44195, USA
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Lee SH, Chen SA, Tai CT, Chiang CE, Wen ZC, Chen YJ, Yu WC, Fong AN, Huang JL, Cheng JJ, Chang MS. Atrioventricular node reentrant tachycardia in patients with a long fast pathway effective refractory period: clinical features, electrophysiologic characteristics, and results of radiofrequency ablation. Am Heart J 1997; 134:387-94. [PMID: 9327692 DOI: 10.1016/s0002-8703(97)70071-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Twenty-two patients (group 1) with AV node reentrant tachycardia and a baseline fast pathway effective refractory period (ERP) > or = 500 msec were compared with 30 consecutive patients (group 2) with AV node reentrant tachycardia and a fast pathway ERP < 500 msec. Both groups underwent slow pathway ablation. In the patients with complete elimination of slow pathway, the fast pathway ERP and shortest 1:1 conduction cycle length shortened significantly after ablation but was greater in group 1 (n = 14) than in group 2 (n = 21) (125 +/- 78 msec vs 48 +/- 29 msec, p < 0.001 and 103 +/- 72 msec vs 52 +/- 30 msec, p < 0.001, respectively). In group 1, the shortening of fast pathway ERP was correlated to baseline difference between anterograde fast and anterograde slow ERP (r = 0.806, p < 0.001, slope = 1.08), and the shortening of fast pathway shortest 1:1 conduction cycle length was correlated to baseline difference between anterograde fast and anterograde slow shortest 1:1 conduction cycle length (r = 0.885, p < 0.001, slope = 1.47). During follow-up bradycardia did not develop in any patient and no one required pacing. This shortening of the fast pathway ERP and shortest 1:1 conduction cycle length after complete elimination of slow pathway reduced the concern of subsequent impairment of AV node conduction.
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Affiliation(s)
- S H Lee
- Division of Cardiology, National Yang-Ming University, Veterans General Hospital, Taipei, Taiwan, Republic of China
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Hwang C, Martin DJ, Goodman JS, Gang ES, Mandel WJ, Swerdlow CD, Peter CT, Chen PS. Atypical atrioventricular node reciprocating tachycardia masquerading as tachycardia using a left-sided accessory pathway. J Am Coll Cardiol 1997; 30:218-25. [PMID: 9207645 DOI: 10.1016/s0735-1097(97)00114-9] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVES The study was performed to document that atrioventricular node reciprocating tachycardia (AVNRT) can be associated with eccentric retrograde left-sided activation, masquerading as tachycardia using a left accessory pathway. BACKGROUND The eccentric retrograde left-sided activation during tachycardia is thought to be diagnostic of the presence of a left free wall accessory pathway. However, it is not known whether AVNRT can occur with eccentric retrograde left-sided activation. METHODS We studied 356 patients with AVNRT who underwent catheter ablation. Retrograde atrial activation during tachycardia and ventricular pacing were determined by intracardiac recordings, including the use of a decapolar coronary sinus catheter. RESULTS The retrograde atrial activation was eccentric in 20 patients (6%). Eight of these patients had the earliest retrograde atrial activation recorded in the lateral coronary sinus leads, and 12 had the earliest retrograde atrial activation recorded in the posterior coronary sinus leads, with the most proximal coronary sinus electrode pair straddling the coronary sinus orifice. These tachycardias were either the fast-slow or the slow-slow form of AVNRT. The slow-fast form of AVNRT was also inducible in 17 of the 20 patients. Successful ablation of the slow pathway in the right atrial septum near the coronary sinus ostium prevented the induction and clinical recurrence of reciprocating tachycardia in all patients. CONCLUSIONS Atypical AVNRT with eccentric retrograde left-sided activation was demonstrated in 6% of all patients with AVNRT masquerading as tachycardia using a left-sided accessory pathway. Ablation of the slow pathway at the posterior aspects of the right atrial septum resulted in a cure in these patients.
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Affiliation(s)
- C Hwang
- Central Utah Valley Medical Clinic, Utah Valley Cardiology, Provo 84604, USA
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16
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Amellal F, Billette J. Selective functional properties of dual atrioventricular nodal inputs. Role in nodal conduction, refractoriness, summation, and rate-dependent function in rabbit heart. Circulation 1996; 94:824-32. [PMID: 8772707 DOI: 10.1161/01.cir.94.4.824] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND The atrioventricular node receives its activation signal from the low crista terminalis and low interatrial septum, the summation of which is believed to favor conduction. A functional asymmetry between the inputs is also believed to be involved in nodal reentrant rhythms. We studied the selective functional characteristics of nodal inputs and determined their role in nodal conduction, refractoriness, summation, and rate-dependent function. METHODS AND RESULTS The nodal properties of recovery, facilitation, and fatigue were characterized with stimulation protocols applied with varying phases between the two inputs in isolated rabbit heart preparations. The effects of the input phase, nodal functional state, and input reference on the nodal conduction time, recovery time, and refractory periods were assessed with multifactorial ANOVAs. It was found that the phase of stimulation significantly affected nodal conduction time but not the refractory periods or the time constant of the recovery. Each input could show longer and shorter conduction time than the other depending on the stimulation phase, input reference, and coupling interval. These effects were similar for different nodal functional states. However, pacing and recording from the low crista resulted in similar conduction and refractory values than did pacing and recording from the low septum. Input summation did not increase the otherwise equal efficacy of individual input in activating the node. Nodal surface recordings confirmed this functional symmetry and equivalent efficacy of the inputs and showed that input effects were confined to the proximal node. CONCLUSIONS The two nodal inputs have equivalent functional properties and are equally effective in activating the rate-dependent portion of the node. Input interaction affects perinodal activation but not the rate-dependent nodal function.
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Affiliation(s)
- F Amellal
- Department of Physiology, Faculty of Medicine, University of Montreal, Quebec, Canada
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17
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Zeng W, Glass L. Statistical properties of heartbeat intervals during atrial fibrillation. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 54:1779-1784. [PMID: 9965257 DOI: 10.1103/physreve.54.1779] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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18
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Sheahan RG, Klein GJ, Yee R, Le Feuvre CA, Krahn AD. Atrioventricular node reentry with 'smooth' AV node function curves: a different arrhythmia substrate? Circulation 1996; 93:969-72. [PMID: 8598088 DOI: 10.1161/01.cir.93.5.969] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Some patients with otherwise typical AV node reentry do not manifest discontinuous AV node function curves. We examined the effects of an ablation in the slow-pathway region in patients with smooth AV node function curves. METHODS AND RESULTS Fifteen patients with AV node reentrant tachycardia (AVNRT) and discontinuous AV node function curves were compared with 15 patients with AVNRT and smooth AV node function curves. In the group with discontinuous curve, the "net" anterograde effective refractory period (AERP) of the AV node increased (270 +/- 28 versus 304 +/- 37 ms, P = .03) and AERP of the remaining fast pathway decreased (367 +/- 100 versus 304 +/- 37 ms, P = .026) after the ablation. In the group with a smooth curve, the AERP of the AV node increased (266 +/- 42 versus 299 +/- 76 ms, P = .07) and the anterograde Wenckebach cycle length increased (336 +/- 66 versus 379 +/- 86 ms, P = .008) after the ablation. Retrograde conduction over the AV node was similar in both groups and was unchanged after ablation. The longest attainable AH interval (AHmax) measured during atrial extrastimulus testing was more prolonged in patients with a discontinuous curve than in patients with a smooth curve (326 +/- 48 versus 250 +/- 70 ms, P = .002). The AHmax shortened in both groups after ablation (326 +/- 48 versus 173 +/- 34 ms, P < .0001, and 250 +/- 70 versus 179 +/ 34 ms, P < .0003, respectively) and were similar. Successful ablation in the slow-pathway zone in patients with a smooth AV node function curve resulted in the loss of the "tail" of the curve representing the slow pathway. CONCLUSIONS These data suggest that the smooth AV node function curve consists of two distinct components representing both fast and slow AV node pathways even when the typical discontinuity is absent.
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Affiliation(s)
- R G Sheahan
- Department of Medicine, University of Western Ontario, London, Canada
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19
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Lai WT, Lee CS, Sheu SH, Hwang YS, Sung RJ. Electrophysiological manifestations of the excitable gap of slow-fast AV nodal reentrant tachycardia demonstrated by single extrastimulation. Circulation 1995; 92:66-76. [PMID: 7788919 DOI: 10.1161/01.cir.92.1.66] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Although AV nodal reentrant tachycardia (AVNRT) is a well-known rhythm disorder, its anatomic substrate and electrophysiological mechanism remain to be defined. Previously, the description of the excitable gap (EG) of AVNRT was based on electrical stimulation performed from sites remote from the reentrant circuit. In the present study, we characterized the EG of AVNRT by atrial extrastimulation close to the putative reentrant circuit in the AV junction. METHODS AND RESULTS In 16 patients (3 men, 13 women; mean age, 45 +/- 13 years) with inducible slow-fast AVNRT (mean cycle length, 353 +/- 52 ms), single extrastimuli with a 10-ms decrement in the premature coupling interval were delivered from the anterosuperior interatrial septum (fast pathway area) and the posteroinferior interatrial septum (slow pathway area) from late diastole until atrial refractoriness. An EG was considered present when resetting or termination of AVNRT was induced by single atrial extrastimulation. The study showed that the duration of the EG of AVNRT was wide, measuring 121 +/- 56 and 123 +/- 47 ms and occupying 33 +/- 11% and 34 +/- 9% of the tachycardia cycle length during single extrastimulation from the slow pathway area and the fast pathway area, respectively. The resetting pattern most commonly manifested as the sum of the coupling interval and the return cycle being less than a fully compensatory pause (two times the basic tachycardia cycle length). However, patterns equal to and greater than a fully compensatory pause were also observed. Of note, in 2 of the 16 patients, atrial extrastimulation from either the fast or slow pathway area also affected the preceding tachycardia cycle length (HH interval), indicating alteration of the anterograde input. In all patients, the curve derived from plotting the coupling interval of extrastimuli against the return cycle during resetting exhibited an "increasing" pattern. The mode of tachycardia termination usually occurred when the premature atrial impulse was orthodromically blocked in the anterograde slow pathway. CONCLUSIONS The EG of slow-fast AVNRT is relatively wide, as demonstrated by single atrial extrastimulation from the interatrial septum near the AV junction. Overall, the electrophysiological manifestations of the EG of AVNRT are very similar to those described in AV reciprocating tachycardia incorporating an accessory connection. These findings lend further support to the notion that, in humans, AVNRT involves a reentrant mechanism with a wide excitable gap.
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Affiliation(s)
- W T Lai
- Department of Internal Medicine, Kaohsiung Medical College, Taiwan, Republic of China
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Shih-Ann C, Tsu-Juey W, Chern-En C, Ching-Tai T, Chuen-Wang C, Kwo-Chang U, Shih-Huang L, Chen-Chuan C, Zu-Chi W, Mau-Song C. Recurrent tachycardia after selective ablation of slow pathway in patients with atrioventricular nodal reentrant tachycardia. Am J Cardiol 1995. [DOI: 10.1016/s0002-9149(99)80044-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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21
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Yeh SJ, Wang CC, Wen MS, Lin FC, Chen IC, Wu D. Radiofrequency ablation therapy in atypical or multiple atrioventricular node reentry tachycardias. Am Heart J 1994; 128:742-58. [PMID: 7942445 DOI: 10.1016/0002-8703(94)90273-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Electrophysiologic study and radiofrequency ablation therapy were performed in 23 patients with atypical (8 patients) or multiple (15) atrioventricular node reentry tachycardias. Dual pathways with anterograde fast and slow pathway conductions were demonstrated in 16 patients. Studies on retrograde conduction revealed the presence of three different pathways, including fast (15 patients), intermediate (17), and slow (16). The radiofrequency current was applied to the inferior aspect, one-third anterior two-thirds posterior between the His bundle and the ostium of the coronary sinus, of Koch's triangle along the tricuspid annulus in all patients. Application of the current resulted in selective ablation or modification of both retrograde intermediate and slow pathway conductions in 20 patients. In two patients retrograde fast pathway conduction was also modified. Complete atrioventricular block occurred in the remaining patient. Sixteen patients had no induction of tachycardia or echo, 4 had induction of a single echo, and 2 had induction of the slow-fast form tachycardia; one of those 2 patients underwent a second trial and was successful. A median application of 2 was delivered at a power of 25 +/- 5 W and a duration of 18 +/- 4 sec. The total fluoroscopic time was 25 +/- 21 minutes. The anterograde fast pathway conduction was unaffected; the shortest atrial paced cycle length that sustained 1:1 fast pathway conduction was 329 +/- 65 msec and 330 +/- 68 msec before and after ablation, respectively. A follow-up electrophysiologic study was performed in 16 patients 60 +/- 15 days after ablation. Eleven had no induction of tachycardia or echo, and five had induction of < 3 echoes. This study demonstrated that radiofrequency ablation with the inferior approach is effective and safe in atypical or multiple atrioventricular node reentry tachycardias. It resulted in ablation of the slow pathway and retrograde intermediate pathway conduction with preserved atrioventricular conduction.
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Affiliation(s)
- S J Yeh
- Department of Medicine, Chang Gung Memorial Hospital, Chang Gung Medical College, Taipei, Taiwan
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22
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Luzza F, Oreto G. Pseudo-atrioventricular dissociation caused by interpolated ventricular extrasystoles in the presence of dual atrioventricular nodal pathway. Chest 1994; 105:1587-9. [PMID: 7514118 DOI: 10.1378/chest.105.5.1587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
This report describes a patient manifesting with ventricular extrasystoles. The pause occasioned by extrasystoles often is followed by narrow QRS complexes not preceded by P waves, but at times is followed by a sinus P wave. At first glance, the pattern suggests a diagnosis of atrioventricular (A-V) junctional escape complexes. Analysis reveals that ventricular extrasystoles are, in fact, interpolated; the sinus P wave that follows the extrasystole is conducted to the ventricles with a very prolonged P-R interval (up to 0.80 s). The phenomenon is due to the presence of a dual A-V nodal pathway. The sinus impulse that follows the extrasystole is blocked in the fast pathway but may still be conducted to the ventricles through the slow pathway, resulting i a very prolonged P-R interval.
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Affiliation(s)
- F Luzza
- Cattedra di Malattie Cardiovascolari, Università di Messina, Italy
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23
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Racker DK. To the editor. J Cardiovasc Electrophysiol 1994. [DOI: 10.1111/j.1540-8167.1994.tb01167.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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McGuire MA, Yip AS, Lau KC, Lo CW, Richards DA, Uther JB, Ross DL. Posterior ("atypical") atrioventricular junctional reentrant tachycardia. Am J Cardiol 1994; 73:469-77. [PMID: 8141088 DOI: 10.1016/0002-9149(94)90677-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The aim of this study was to characterize a relatively rare type of atrioventricular (AV) junctional reentrant tachycardia (AVJRT). Posterior AVJRT is a type of AV nodal tachycardia in which the site of earliest atrial activation is posterior to the AV node near the coronary sinus orifice. The mechanism of this tachycardia is not well understood. The characteristics of posterior AVJRT (n = 15) were compared with those of anterior ("common") AVJRT (n = 146) and supraventricular tachycardia using single posterior septal accessory pathways (n = 13). During posterior AVJRT, the AH interval was longer than the retrograde conduction time (His to earliest atrial activity) in 11 cases (73%), indicating that these tachycardias were not fast-slow types of AVJRT. The mean ventriculoatrial (VA) interval in posterior AVJRT (93 +/- 41 ms) was longer than in anterior AVJRT (11 +/- 20 ms; p < 0.005), but was similar to that in tachycardias using accessory pathways (106 +/- 16 ms; p = NS). The site of earliest atrial activation during posterior AVJRT was similar to that in tachycardias using accessory pathways. In all cases of accessory pathway-mediated tachycardia, atrial activation could be advanced by ventricular extrastimuli delivered coincident with the His deflection, but atrial activation was not advanced in any case of posterior AVJRT unless the extrastimulus was delivered > 80 ms before the His deflection. Anterograde conduction was similar in the posterior and anterior AVJRT groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M A McGuire
- Cardiology Unit, Westmead Hospital, Sydney, New South Wales, Australia
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25
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Abstract
Until recently only two types of media have been considered to provide the nonuniformities necessary to initiate cardiac reentry: (1) continuous isotropic media with intrinsic repolarization inhomogeneities; and (2) continuous isotropic media free of inhomogeneities in which repolarization nonuniformities are introduced transiently. The purpose of this article is to establish cellular coupling as a basis for arrhythmias by placing a new type of inhomogeneity, nonuniform anisotropy due to sparse side-to-side coupling between cells, in an overall perspective with the other nonuniformities that lead to reentry. Review of experimental and theoretical models of reentry leads to the following picture: with slowed conduction, reentrant circuits diminish in size and the nonuniformities necessary for reentry are provided by nonuniform anisotropy. Repolarization nonuniformities create functionally different pathways for reentrant circuits of relatively large size (> 30-50 mm2). Nonuniform anisotropic cellular coupling, which is associated with underlying microfibrosis, makes it possible for reentry to occur in small areas (< 10-15 mm2). A general property found in nonuniform anisotropic bundles is the presence of functionally different pathways in the absence of intrinsic repolarization inhomogeneities--one of fast longitudinal conduction with a longer refractory period, and another of "very slow" transverse conduction with a shorter refractory period. Since it is not known if nonuniform anisotropy exists in the AV node, the best known structure with small reentrant circuits, we performed microscopic extracellular measurements in the AV node of the rabbit. The transitional zone of the AV node was found to have markedly nonuniform anisotropic conduction properties. The analysis provides the view that functionally different pathways of small reentrant circuits, including those of the AV node, need to be reevaluated in terms of the role of nonuniform anisotropic cellular coupling.
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Affiliation(s)
- M S Spach
- Department of Pediatrics, Duke University Medical Center, Durham, North Carolina 27710
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26
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Leffler CT, Saul JP. NASPE Young Investigator Awardee-1993. Computer model of the atrioventricular node predicts reentrant arrhythmias. Pacing Clin Electrophysiol 1994; 17:113-30. [PMID: 7511226 DOI: 10.1111/j.1540-8159.1994.tb01359.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
INTRODUCTION Following atrial premature beats, the AV node may exhibit sustained reentrant tachyarrhythmias, isolated echo beats, or discontinuities in the recovery curve (the plot of conduction time versus atrial cycle length). A computer model was used to examine the hypothesis that spatial variation of AV nodal passive electrical resistance may account for these phenomena. METHODS AND RESULTS A computer model of a rectangular lattice of electrotonically linked elements whose ionic kinetics simulated nodal ionic flux was developed. The model showed that there exists a resistance value that minimizes the effective refractory period, because high resistance prevents depolarization of distal elements, while low resistance allows leakage of depolarizing current by electrotonic transmission, preventing activation of proximal elements. High resistances stabilized reentry by slowing conduction. Simulations incorporating equal resistance values between elements predicted increased AV nodal conduction times with increasing prematurity of atrial impulses. A model with a gradual change in resistance between fibers produced discontinuities and tachycardia, but not both simultaneously. Uniform anisotropy produced preferential transverse block, leading to echo beats and "fast-slow" tachycardia, but not recovery curve discontinuities. Nonuniform anisotropy could produce reentry, but tachycardia often occurred without discontinuities. Dividing the lattice into two electrotonically linked parallel pathways with different resistance values ("dual pathway model") predicted recovery curve discontinuities, echo beats, and tachycardia. At critical atrial cycle lengths, only the (high resistance) slow pathway conducted antegradely, while the fast pathway conducted retrogradely, to generate the typical "slow-fast" tachycardia. Responses of the dual pathway model to ablation were consistent with clinical data, including the previous observation of a decrease in fast pathway effective refractory period after slow pathway ablation. CONCLUSION Differences in passive electrical resistance of electronically linked dual pathways within the AV node may account for functional longitudinal dissociation, reentrant arrhythmias, and responses to catheter ablation therapy.
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Affiliation(s)
- C T Leffler
- Division of Health Sciences and Technology, Harvard Medical School-Massachusetts Institute of Technology
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27
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Wu D, Yeh SJ, Wang CC, Wen MS, Lin FC. Double loop figure-of-8 reentry as the mechanism of multiple atrioventricular node reentry tachycardias. Am Heart J 1994; 127:83-95. [PMID: 8273761 DOI: 10.1016/0002-8703(94)90513-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Seven patients with multiple atrioventricular node reentry tachycardia were analyzed to unravel the mechanism of these tachycardias. Six of the seven patients showed anterograde dual atrioventricular node pathways and one showed anterograde conduction through the fast pathway. Three types of retrograde pathways were noted among these seven patients: (1) the fast pathway with the earliest atrial activation at the His bundle area; (2) the intermediate pathway with the earliest atrial activation at the ostium of the coronary sinus; and (3) the slow pathway with the earliest atrial activation at the ostium of the coronary sinus. All seven patients used the intermediate pathway for retrograde conduction. However, one patient showed evidence of retrograde slow pathway conduction with demonstrable retrograde dual pathways, and another showed evidence of retrograde fast pathway conduction with a shift of atrial activation sequence when conduction switched to the intermediate pathway. Four different types of reentry circuits using either the fast or the slow pathway as the anterograde limb and one of the three retrograde pathways as the retrograde limb were demonstrated in these seven patients, resulting in two types of tachycardias in four patients and three types of tachycardias in three patients. A change in tachycardia type could be induced with atrial or ventricular stimulation. A radiofrequency current delivered to the inferior aspect of Koch's triangle along the tricuspid anulus in five patients resulted in selective ablation or modification of the intermediate pathway or the slow pathway, with preservation of anterograde atrioventricular conduction and abolition of tachycardias. The findings suggest that a double loop figure-of-8 reentry circuit including a fast pathway, a slow pathway, and an intermediate pathway is responsible for multiple atrioventricular node reentry tachycardias.
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Affiliation(s)
- D Wu
- Department of Medicine, Chang Gung Memorial Hospital, Chang Gung Medical College, Taipei, Taiwan, Republic of China
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Wu D, Yeh SJ, Wang CC, Wen MS, Lin FC. A simple technique for selective radiofrequency ablation of the slow pathway in atrioventricular node reentrant tachycardia. J Am Coll Cardiol 1993; 21:1612-21. [PMID: 8496527 DOI: 10.1016/0735-1097(93)90376-c] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVES A simple technique was designed for radiofrequency ablation therapy of atrioventricular (AV) node reentrant tachycardia. BACKGROUND This technique was based on the hypothesis that slow pathway conduction reflects conduction through the compact node and its posterior atrial input. METHODS A total of 100 consecutive patients were studied; there were 37 men and 63 women, with a mean age of 48 +/- 15 years. All 100 patients had induction of sustained tachycardia with (51 patients) or without (49 patients) administration of isoproterenol or atropine, or both. The ablation catheter was initially manipulated to record the largest His bundle deflection from the apex of Koch's triangle. It was then curved downward and clockwise to the area of the compact node when His deflection was no longer visible and the ratio of atrial to ventricular electrogram was < 1. The radiofrequency current was delivered from the 4-mm tip electrode a mean of 5 +/- 7 times at a power of 25 +/- 4 W for a duration of 21 +/- 4 s. The total fluoroscopic time was 19 +/- 11 min. RESULTS Selective ablation (56 patients) or modification (26 patients) of the slow pathway without affecting anterograde and retrograde fast pathway conduction was achieved in 82 patients. Ablation or modification of both the retrograde fast pathway and the slow pathway but with preservation of anterograde fast pathway conduction was noted in 12 patients. Ablation or modification of the retrograde fast pathway alone or both anterograde and retrograde fast pathway conduction was noted in three patients. Complete AV node block occurred in three patients. Seventy-three patients had no induction of echo beats or tachycardia and 24 patients had induction of a single echo beat after ablation. Follow-up study was performed in 62 patients 76 +/- 18 days after ablation. Thirty-nine patients had no induction of echo beats or tachycardia, 22 had induction of echo beats alone and 1 patient had induction of sustained tachycardia. CONCLUSION Selective ablation of the slow AV node pathway can be achieved by a simple procedure with a high success rate and few complications.
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Affiliation(s)
- D Wu
- Department of Medicine, Chang Gung Memorial Hospital, Chang Gung Medical College, Taipei, Taiwan
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Chang HJ, Wang CC, Yeh SJ, Wu D. Double atrial responses to a single ventricular premature impulse resulting from simultaneous ventriculoatrial conductions through the normal pathway and a slow paraseptal accessory pathway. Am Heart J 1993; 125:1434-1436. [PMID: 8480601 DOI: 10.1016/0002-8703(93)91020-f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- H J Chang
- Department of Medicine, Chang Gung Memorial Hospital, Chang Gung Medical College, Taipei, Taiwan
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30
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Abstract
The exact site of the reentrant circuit in AV nodal reentry remains controversial. While recent ablative techniques have yielded information, the interpretation of which suggests that the atrium is required, other explanations for these interpretations are available. Prior pathophysiological studies with three-dimensional reconstruction of the node suggest that it is a highly anisotropic structure and extends through Koch's Triangle. Data from humans suggesting the atria are not necessary include the presence of AV dissociation during supraventricular tachycardia (SVT), depolarization of atrial tissue surrounding the node without affecting SVT, pacing induced AH intervals exceeding those during SVT, and site dependency of a critical AH interval (exceeding atrial refractoriness) that is required for initiation of AV nodal reentry.
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Affiliation(s)
- M E Josephson
- Department of Medicine, University of Pennsylvania, Philadelphia
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31
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Ward DE, Garratt CJ. The substrate for atrioventricular "nodal" reentrant tachycardia: is there a "third pathway"? J Cardiovasc Electrophysiol 1993; 4:62-7. [PMID: 8287237 DOI: 10.1111/j.1540-8167.1993.tb01213.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- D E Ward
- Cardiology Department, St George's Hospital, London, United Kingdom
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Chen SA, Chiang CE, Tsang WP, Hsia CP, Wang DC, Yeh HI, Ting CT, Chuen WC, Yang CJ, Cheng CC. Selective radiofrequency catheter ablation of fast and slow pathways in 100 patients with atrioventricular nodal reentrant tachycardia. Am Heart J 1993; 125:1-10. [PMID: 8417504 DOI: 10.1016/0002-8703(93)90050-j] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
One hundred patients received selective radiofrequency ablation of retrograde fast pathway (32 patients, group I) or slow pathway (68 patients, group II) to treat drug-refractory atrioventricular nodal reentrant tachycardia. In group I, a mean of 6 +/- 3 radiofrequency pulses eliminated the retrograde fast pathway. Thirty patients were free of symptoms and were not receiving antiarrhythmic drugs; two patients had accidental atrioventricular block. One patient had recurrent tachycardia and received a repeated ablation (slow pathway ablation). In group II, a mean of 9 +/- 4 radiofrequency pulses eliminated the slow pathway in 68 patients. All patients were free of symptoms and were not receiving antiarrhythmic drugs. One patient had recurrent tachycardia and received a repeated ablation. Serial follow-up electrophysiologic studies (immediate [20 to 30 minutes], early [5 to 7 days], and late [3 to 6 months]) showed that selective ablation of retrograde fast pathway was associated with nonspecific injury on the antegrade fast pathway (increase of AH interval) without effects on the slow pathway. Selective ablation of slow pathway was associated with nonspecific injury on the retrograde fast pathway in 15 patients (22%), but the antegrade fast pathway conduction parameters did not change significantly. Thus retrograde and antegrade fast pathway may be anatomically similar or have different sensitivities to radiofrequency energy, and slow pathway may be anatomically distinct from fast pathway. We conclude that (1) selective radiofrequency ablation of retrograde fast or slow pathway could cure atrioventricular nodal reentrant tachycardia with a high success rate (98%) and a low recurrence rate (2%) during a follow-up period of 6 to 18 months, but fast pathway ablation was associated with accidental atrioventricular block (5%), and (2) serial follow-up electrophysiologic studies elucidated the possible mechanisms of cure in atrioventricular nodal reentrant tachycardia.
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Affiliation(s)
- S A Chen
- Department of Medicine, National Yang-Ming Medical College, Taipei, Taiwan, Republic of China
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Chen SA, Tsang WP, Yeh HI, Wang TC, Hsia CP, Ting CT, Kong CW, Wang SP, Chiang BN, Chang MS. Reappraisal of electrical cure of atrioventricular nodal reentrant tachycardia--lessons from a modified catheter ablation technique. Int J Cardiol 1992; 37:51-60. [PMID: 1428289 DOI: 10.1016/0167-5273(92)90131-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A modified catheter ablation technique was studied prospectively in 29 patients with atrioventricular (AV) nodal reentrant tachycardia. A His bundle electrode catheter was used for mapping and ablation. Cathodic electroshocks (100-250 J) were delivered from the distal two electrodes (connected in common) of the His bundle catheter to the site selected for ablation. The optimal ablation site recorded the earliest retrograde atrial depolarization, simultaneous or earlier than the QRS complex, with absence of a His bundle deflection during AV nodal reentrant tachycardia. One additional electrical shock was delivered if complete abolition of retrograde VA conduction persisted for more than 30 min and AV nodal reentrant tachycardia was not inducible during isoproterenol and/or atropine administration. With a cumulative energy of 323 +/- 27 J and a mean of 2.3 +/- 0.5 shocks interruption or impairment of retrograde nodal conduction was achieved. Antegrade conduction, although modified, was preserved in 27 patients, with persistence of complete AV block in 2 patients. Two of the 27 patients still need antiarrhythmic agents to control tachycardia, the other 25 patients were free of tachycardia within a mean follow-up period of 13 +/- 2 months (range 7 to 20 months). Twenty-three patients received late follow-up electrophysiological studies (3-6 months after the ablation procedures), and the AV nodal function curves were classified into 4 types. The majority of the patients (15/23) had loss of retrograde conduction. Among the 8 patients with prolongation of retrograde conduction, 4 patients still had antegrade dual AV nodal property but all without inducible tachycardia. In conclusion, preferential interruption or impairment of retrograde conduction was the major, but not the sole, mechanism of electrical cure of AV nodal reentrant tachycardia.
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Affiliation(s)
- S A Chen
- Department of Medicine, National Yang-Ming Medical College, Taipei, Taiwan, ROC
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Wu D, Yeh SJ, Wang CC, Wen MS, Chang HJ, Lin FC. Nature of dual atrioventricular node pathways and the tachycardia circuit as defined by radiofrequency ablation technique. J Am Coll Cardiol 1992; 20:884-95. [PMID: 1527299 DOI: 10.1016/0735-1097(92)90189-t] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVES A comprehensive electrophysiologic study followed by selective radiofrequency ablation from three sites was performed in patients with atrioventricular (AV) node reentrant tachycardia to better delineate the nature of the tachycardia circuit. BACKGROUND We postulated that the retrograde fast pathway is the anterior superficial group of transitional cells and the slow pathway is the compact node with its posterior input of transitional cells. Twenty-three consecutive patients were studied. In nine, the atria could be dissociated from the tachycardia by delivery of an atrial extrastimulus during tachycardia. METHODS Radiofrequency ablation was performed with three approaches. The anterior approach was designed to interrupt the anterior superficial atrial input to the compact node, the posterior approach to interrupt the posterior atrial input to the compact node and the inferior approach to destroy the compact node itself. RESULTS Selective ablation of the retrograde fast pathway was achieved in seven patients, six with the anterior and one with the inferior approach. Anterograde fast pathway conduction was not affected, whereas retrograde fast pathway conduction was either abolished or markedly depressed. None had induction of echoes or tachycardia after ablation. Selective ablation of the slow pathway was successful in 13 patients, 1 with anterior, 3 with posterior and 9 with inferior approaches. In these 13 patients, both anterograde and retrograde fast pathway conduction were not affected, the dual pathway physiology was abolished and the tachycardia was not inducible after ablation. Ablation of both the retrograde fast pathway and the slow pathway occurred with the inferior approach in three patients. CONCLUSIONS We conclude that the retrograde fast pathway is likely to be the anterior superficial group of transitional cells, whereas the slow pathway is the compact node and its posterior input of transitional cells. A barrier seems to exist between the atrium and the tachycardia circuit. In a broad view of the AV node structure, the tachycardia circuit is confined to the node.
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Affiliation(s)
- D Wu
- Department of Medicine, Chang Gung Memorial Hospital, Chang Gung Medical College, Taipei, Taiwan
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Suzuki F, Harada TO, Nawata H, Ohtomo K, Satoh T, Hirao K, Hiejima K. Retrograde supernormal conduction, gap phenomenon in concealed accessory atrioventricular pathways. Pacing Clin Electrophysiol 1992; 15:1065-79. [PMID: 1378598 DOI: 10.1111/j.1540-8159.1992.tb03100.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We present four patients with the Wolff-Parkinson-White syndrome who exhibited retrograde supernormal conduction or gap phenomenon in concealed accessory pathways. In the first patient, ventricular extrastimulus testing revealed retrograde block at the coupling interval of 520 msec and reappearance of conduction at the coupling interval of 370 msec. In a second patient, 1:1 retrograde conduction was not present but supernormal conduction was demonstrated at coupling intervals of 360 msec to 310 msec during the ventricular extrastimulus testing when the basic drive consisted of atrioventricular (AV) simultaneous pacing. In a third patient, ventricular extrastimulus testing demonstrated retrograde conduction through the accessory pathway only at coupling intervals of 400 msec to 360 msec. In a fourth patient, retrograde block occurred at the coupling interval of 340 msec and retrograde "slow" conduction reappeared at coupling intervals of 300 msec to 250 msec (gap phenomenon) only when the basic drive consisted of AV simultaneous pacing. Thus, concealed accessory pathways may exhibit retrograde supernormal conduction or gap phenomenon. Ventricular extrastimulus testing consisting of AV simultaneous pacing during the basic drive may facilitate demonstration of these unusual properties.
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Affiliation(s)
- F Suzuki
- First Department of Internal Medicine, School of Medicine, Tokyo Medical and Dental University, Japan
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Krishel S, Geninatti M. Dual AV nodal paths leading to AV nodal reentrant tachycardia. J Emerg Med 1992; 10:303-7. [PMID: 1624743 DOI: 10.1016/0736-4679(92)90337-s] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A 27-year-old white female with a history of paroxysmal supraventricular tachycardia presented to the emergency department complaining of intermittent palpitations. Although no tachydysrhythmia was present, she was noted to have two distinct PR intervals during normal sinus rhythm while in the emergency department. The patient was referred for electrophysiologic study. This study demonstrated dual AV nodal paths, and AV nodal reentrant tachycardia was induced and terminated. She was placed on flecainide for outpatient management of her dysrhythmia. Dual AV nodal pathways leading to AV nodal reentrant tachycardia is discussed.
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Affiliation(s)
- S Krishel
- Department of Emergency Medicine, Maricopa Medical Center, Phoenix, Arizona 85008
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37
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Racker DK. Sinoventricular transmission in 10 mM K+ by canine atrioventricular nodal inputs. Superior atrionodal bundle and proximal atrioventricular bundle. Circulation 1991; 83:1738-53. [PMID: 1850667 DOI: 10.1161/01.cir.83.5.1738] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND This study was done to determine the electrical properties of the superior atrionodal bundle (SAB) and the proximal atrioventricular bundle (PAVB). METHODS AND RESULTS Extracellular potentials associated with electrical activity in the SAB and PAVB were identified in electrograms using adult canine atrial preparations in which the AV node (AVN) and distal AV (His) bundle (DAVB) had been exposed. Intracellular potentials and/or electrograms of the sinoatrial node (SAN), SAB, PAVB, AVN, DAVB, and atrial contractions from a pectinate muscle bundle in the high right atrial wall were recorded. The electrograms contained deflections representing discharge of the specific tissues and atrial potentials from the adjacent or overlying atrial contractile myocardium. In superfusates containing 2.7 mM K+, sequential discharge of the tissues resulted in brief SAN-SAB, PAVB-DAVB, and AVN-DAVB intervals and a major delay after discharge of the SAB. The delay was attributed to activation of the PAVB, as reflected in extracellular PAVB potentials of long duration. Atrial potentials and the onset of the contractile event followed discharge of the SAN and SAB but preceded activation of the PAVB, AVN, and DAVB. After transection of the PAVB-AVN connections, the AVN exhibited automaticity, but the SAB, PAVB, atrial potentials in all of the electrograms, and atrial contractions persisted at the sinus rate. During exposure to 10 mM K+, atrial potentials in all of the electrograms and atrial contractions ceased, indicating electrical quiescence of the contractile myocardium; however, the unique pattern of discharge of the SAB, PAVB, AVN, and DAVB persisted at the SA nodal rate. CONCLUSIONS Thus, the SAB and PAVB can be classified as specialized conducting tissues and are intrinsic components of the internodal conductile pathway.
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Affiliation(s)
- D K Racker
- Department of Biophysics and Physiology, University of Health Sciences, Chicago Medical School, Ill
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Wang CC, Yeh SJ, Lin FC, Wu DL. Spontaneous atrioventricular dissociation in atrioventricular nodal reentrant tachycardia. Am Heart J 1990; 119:1426-9. [PMID: 2353631 DOI: 10.1016/s0002-8703(05)80201-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- C C Wang
- Department of Medicine, Chang Gung Memorial Hospital, Chang Gung Medical College, Taipei, Taiwan, Republic of China
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41
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Yeh SJ, Yamamoto T, Lin FC, Wu D. Atrioventricular block in the atypical form of junctional reciprocating tachycardia: evidence supporting the atrioventricular node as the site of reentry. J Am Coll Cardiol 1990; 15:385-92. [PMID: 2299081 DOI: 10.1016/s0735-1097(10)80067-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Serial electrophysiologic studies were performed in 19 patients with the atypical form of supraventricular tachycardia having a long RP and short PR interval. In all 19 patients, supraventricular tachycardia was found to have a 1:1 P-QRS relation during initial control electrophysiologic studies, and in all 19 patients, electrophysiologic studies suggested that junctional reentry was the mechanism of supraventricular tachycardia. Seven of the 19 patients developed atrioventricular (AV) block during initiation of supraventricular tachycardia or after induction of supraventricular tachycardia following various drug administrations in subsequent studies. In three patients, second degree block within the His bundle or block distal to the His bundle recording site occurred after administration of quinidine. In one patient it occurred after procainamide, and in another patient it occurred after atropine. In one patient, 2:1 block proximal to the His deflection occurred after verapamil. In the remaining patient, a transient Wenckebach block proximal to the His deflection was noted after adenosine triphosphate. In this latter patient, 2:1 AV block was also noted after propranolol and digoxin. The site of reentry in these seven patients with AV block during supraventricular tachycardia was confined to the AV node area. Their supraventricular tachycardia did not involve a slowly conducting paraseptal accessory pathway because the distal AV node, His bundle and ventricle were not found to be necessary links in the tachycardia circuit.
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Affiliation(s)
- S J Yeh
- Department of Medicine, Chang Gung Medical College, Taipei, Taiwan
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42
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Racker DK. Atrioventricular node and input pathways: a correlated gross anatomical and histological study of the canine atrioventricular junctional region. Anat Rec (Hoboken) 1989; 224:336-54. [PMID: 2782619 DOI: 10.1002/ar.1092240303] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
To determine the architecture of the atrioventricular (AV) junctional region, structures in atrial preparations were correlated to those in serial sections made either parallel or perpendicular to the long axis of the AV node (AVN)/AV bundle complex. The results demonstrated the following for the first time: 1) A right medial atrial wall (MAW) extends anteriorly from the interatrial septum, superior to the interventricular septum (IVS). 2) An atrial interventricular septum (A-IVS) groove is located between the base of the MAW and the crest of the IVS. 3) Three atrionodal bundles converge to form a proximal AV bundle (PAVB), which in turn is contiguous with the AVN. The atrionodal bundles are associated with the MAW or the superomedial and inferolateral margins of the coronory sinus. Terminal portions of the atrionodal bundles and the PAVB reside within the A-IVS groove. The AV bundle was termed distal (DAVB) to avoid confusion. 4) The location of the AVN/DAVB complex topographically is deep to the apex of the septal cusp of the tricuspid valve subjacent to the MAW. Intracardially, the AVN/DAVB complex is within the central fibrous body. Significantly, this study resulted in the first unequivocal demonstration of discrete bundles of myocardial fibers associated with the atrial end of the AV node. Moreover, it appears likely that the atrionodal AV bundles are continuous with the sinoatrial nodal extensions, thereby forming internodal tracts.
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Affiliation(s)
- D K Racker
- Department of Biophysics and Physiology, University of Health Sciences, Chicago Medical School, Illinois 60064
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Shrier A, Dubarsky H, Rosengarten M, Guevara MR, Nattel S, Glass L. Prediction of complex atrioventricular conduction rhythms in humans with use of the atrioventricular nodal recovery curve. Circulation 1987; 76:1196-205. [PMID: 3677347 DOI: 10.1161/01.cir.76.6.1196] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Theoretical considerations indicate that complex patterns of atrioventricular conduction produced by rapid atrial stimulation can be predicted from changes in atrioventricular conduction produced by premature stimulation of the atrium. The purpose of this study was to evaluate the validity of this theoretical approach in seven patients undergoing electrophysiologic investigation. The atrioventricular nodal recovery curve was determined at two different basic cycle lengths. Subsequently, periodic atrial stimulation was delivered for 30 sec periods over a range of frequencies giving 11, Wenckebach, reverse Wenckebach, and 21 rhythms. The recovery curve data was then used to compute the response to periodic stimulation by an iterative technique. The conduction patterns actually seen during periodic atrial stimulation showed close agreement with the computed patterns. This work thus provides a unified explanation for the appearance of Wenckebach, reverse Wenckebach, alternating Wenckebach, and high grade block rhythms.
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Affiliation(s)
- A Shrier
- Department of Physiology, McGill University, Montreal, Quebec, Canada
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44
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Yeh SJ, Wu YC, Lin FC, Hung JS, Wu D. Pseudosimultaneous fast and slow pathway conduction: a common electrophysiologic finding in patients with dual atrioventricular nodal pathways. J Am Coll Cardiol 1985; 6:927-32. [PMID: 4031309 DOI: 10.1016/s0735-1097(85)80508-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Two ventricular responses following termination of rapid atrial pacing were noted in 24 of 87 patients with dual atrioventricular (AV) nodal pathways and supraventricular tachycardia. In all 24 patients, the AH intervals of the first and second ventricular responses were comparable with those of the fast and slow pathways, respectively. Careful analysis of the whole pacing sequence revealed that, in 21 patients, this phenomenon resulted from sustained slow pathway conduction with long AH intervals. In these patients, as the AH interval of each paced beat was progressively lengthened during pacing, the corresponding His bundle and ventricular responses were pushed one cycle behind the current atrial paced beat, so that the last paced beat was followed by two His bundle and ventricular responses. In only three patients did double ventricular responses result from simultaneous fast and slow pathway conduction. One of these three patients also showed two ventricular responses resulting from sustained slow pathway conduction. Several factors predispose to the occurrence of this phenomenon in patients with dual AV nodal pathways. These include an ability to sustain slow pathway conduction, a longer slow pathway AH interval, a shorter sinus AH interval (fast pathway) and a shorter atrial paced cycle length that sustains slow pathway conduction. In conclusion, sustained slow pathway conduction with resultant long AH intervals is the mechanism of two ventricular responses following termination of atrial pacing in most patients with dual AV nodal pathways. This phenomenon should be distinguished from the rare occurrence of double ventricular responses to an atrial impulse due to simultaneous fast and slow pathway conduction.
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Littmann L, Tenczer J, Temesvári A, Fenyvesi T. Wenckebach periodicity with apparent 1:2 conduction over the atrioventricular node: the problem of interpretation. Am J Cardiol 1985; 55:1429-30. [PMID: 3993586 DOI: 10.1016/0002-9149(85)90522-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Lin FC, Yeh SJ, Wu D. Determinants of simultaneous fast and slow pathway conduction in patients with dual atrioventricular nodal pathways. Am Heart J 1985; 109:963-70. [PMID: 3993531 DOI: 10.1016/0002-8703(85)90236-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Double His bundle and ventricular responses to a single atrial impulse caused by a simultaneous fast and slow pathway conduction was observed during electrophysiologic study in three patients with dual-pathway atrioventricular nodal reentrant paroxysmal supraventricular tachycardia. In patient No. 1 this phenomenon occurred during rapid atrial pacing, in patient No. 2 during both rapid atrial pacing and delivery of a single atrial extrastimulus, and in patient No. 3 during delivery of double atrial extrastimuli. Retrograde unidirectional block in the slow pathway was suggested by retrograde induction of tachycardia at a long ventricular paced cycle length and/or long ventricular coupling interval in all three patients. Our findings suggest that major determinants of this phenomenon include: a sufficient conduction delay in the slow pathway so that the distal tissue is able to respond for the second time, and a retrograde unidirectional block in the slow pathway so that the fast pathway impulse will not enter and collide with the oncoming slow pathway impulse.
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Yeh SJ, Fu M, Lin FC, Lee YS, Hung JS, Wu D. Serial electrophysiologic studies of the effects of oral diltiazem on paroxysmal supraventricular tachycardia. Chest 1985; 87:639-43. [PMID: 3987375 DOI: 10.1378/chest.87.5.639] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
In 16 patients with paroxysmal supraventricular tachycardia, electrophysiologic studies were done before and serially at hourly intervals for eight hours after the third oral dose of 90 mg diltiazem given every eight hours. Diltiazem increased both the longest atrial paced cycle length producing type 1 atrioventricular block and the effective refractory period of the atrioventricular conducting system at all measurements. Before diltiazem, all 16 patients had induction of sustained tachycardia. After diltiazem, sustained tachycardia could not be induced in ten patients at any measurements; in these patients, either echo or nonsustained tachycardia was induced. In the remaining six patients, sustained tachycardia was induced, particularly after six hours. Follow-up observations in 12 patients receiving the same dosage of oral diltiazem for 6 +/- 2 months (mean +/- SD), showed that of the eight patients in whom electrophysiologic testing induced either echo or nonsustained tachycardia, six were asymptomatic and two experienced transient palpitation. Of the other four patients with induction of sustained tachycardia, three had transient palpitation and one had occasional attacks of sustained tachycardia requiring modification of therapy. Thus, oral diltiazem increases atrioventricular nodal refractoriness, with an effect lasting up to eight hours. It is an effective agent for the prophylaxis of paroxysmal supraventricular tachycardia.
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Lin FC, Yeh SJ, Wu D. Double atrial responses to a single ventricular impulse due to simultaneous conduction via two retrograde pathways. J Am Coll Cardiol 1985; 5:168-75. [PMID: 3964802 DOI: 10.1016/s0735-1097(85)80100-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Electrophysiologic studies were performed in two patients. In one patient (Case 1) with ventricular pre-excitation and paroxysmal supraventricular tachycardia, studies after diltiazem administration showed two QRS responses to a single atrial stimulus during atrial pacing at a cycle length of 300 ms. The first QRS response with full pre-excitation and short PR interval was consistent with accessory pathway conduction, while the second QRS response with a normal duration and an atrio-His bundle interval of 350 ms was consistent with normal pathway conduction. The second QRS response was followed by initiation of supraventricular tachycardia. Studies after verapamil administration on a separate day disclosed two atrial responses to a single QRS complex during ventricular pacing at cycle lengths between 330 and 280 ms, suggesting simultaneous retrograde accessory and normal pathway conduction. In Case 2 with a supraventricular tachycardia using a fast atrioventricular nodal pathway for anterograde and a slow ventriculoatrial pathway for retrograde conduction, two atrial responses to a single QRS complex were observed during ventricular pacing at cycle lengths between 500 and 400 ms. The first atrial response showed a stimulus to atrial interval of 120 ms and an atrial activation sequence with the low septal right atrium being earlier than other atrial sites, suggesting retrograde fast pathway conduction. The second atrial response showed a stimulus to atrial interval of 505 ms and an atrial activation sequence with low septal right atrium being simultaneous with the proximal coronary sinus, suggesting retrograde slow pathway conduction.(ABSTRACT TRUNCATED AT 250 WORDS)
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Hung JS, Yeh SJ, Lin FC, Fu M, Lee YS, Wu D. Usefulness of intravenous diltiazem in predicting subsequent electrophysiologic and clinical responses to oral diltiazem. Am J Cardiol 1984; 54:1259-62. [PMID: 6507295 DOI: 10.1016/s0002-9149(84)80076-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Diltiazem, 0.25 mg/kg, was given intravenously during induced tachycardias in 6 patients with atrioventricular (AV) nodal reentrant tachycardia (group I) and in 24 patients with AV reentrant tachycardia incorporating a retrogradely conducting accessory pathway (group II). In all 6 group I and in 15 of 24 group II patients, tachycardias terminated within 1 minute after diltiazem administration, with a weak link in the anterograde direction. In 3 other patients in group II, tachycardias were terminated by a premature ventricular complex within 1 minute. In the remaining 6 patients in group II, in whom tachycardias failed to terminate, rates of tachycardias decreased as a result of suppression of anterograde AV nodal conduction by diltiazem. Electrophysiologic studies were performed subsequently 2 hours after the third dose of 90 mg of diltiazem, which was given orally at 8-hour intervals. In 18 responders to intravenous diltiazem who were subjected to oral diltiazem testing, sustained supraventricular tachycardia (SVT) could be induced in only 2. Of the 6 nonresponders, sustained tachycardias could not be induced in 3. Twelve patients, including 11 responders and 1 nonresponder to intravenous diltiazem who responded to oral diltiazem testing, were discharged with oral diltiazem therapy, 90 mg every 8 hours, with follow-up periods of 2 to 13 months (mean 7 +/- 4 [+/- standard deviation]). The frequency of recurrent SVT decreased significantly; 8 patients were free of tachycardias and 4 had occasional recurrences of SVT that required no hospital visit. In conclusion, intravenous diltiazem is effective in terminating SVT. Termination of SVT by intravenous diltiazem predicts subsequent electrophysiologic and clinical responses to oral diltiazem.
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Gilmour RF, Zipes DP. Basic electrophysiologic mechanisms for the development of arrhythmias. Clinical application. Med Clin North Am 1984; 68:795-818. [PMID: 6088914 DOI: 10.1016/s0025-7125(16)31102-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The mechanisms responsible for the genesis of cardiac arrhythmias are frequently divided into categories of disorders of impulse formation, disorders of impulse propagation, or combinations of both. Classification of arrhythmias into these categories is based largely on the results of experimental studies, where the initiation and perpetuation of an arrhythmia can be studied in some detail in a relatively controlled environment.
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