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Reentrant Tachycardia (reentrant + tachycardia)

Distribution by Scientific Domains

Medical Sciences	100%

Kinds of Reentrant Tachycardia

atrioventricular nodal reentrant tachycardia

atrioventricular reentrant tachycardia

av nodal reentrant tachycardia

nodal reentrant tachycardia

Selected Abstracts

Spontaneous Onset of Ventricular Fibrillation during Atrioventricular Nodal Reentrant Tachycardia

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2009
CHRISTIAN VON BARY M.D.
No abstract is available for this article. [source]

Differentiating Atrioventricular Nodal Reentrant Tachycardia from Junctional Tachycardia: Novel Application of the Delta H-A Interval

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2008
KOMANDOOR SRIVATHSAN M.D.
Introduction: Junctional tachycardia (JT) and atrioventricular nodal reentrant tachycardia (AVNRT) can be difficult to differentiate. Yet, the two arrhythmias require distinct diagnostic and therapeutic approaches. We explored the utility of the delta H-A interval as a novel technique to differentiate these two tachycardias. Methods: We included 35 patients undergoing electrophysiology study who had typical AVNRT, 31 of whom also had JT during slow pathway ablation, and four of whom had spontaneous JT during isoproterenol administration. We measured the H-A interval during tachycardia (H-AT) and during ventricular pacing (H-AP) from the basal right ventricle. Interobserver and intraobserver reliability of measurements was assessed. Ventricular pacing was performed at approximately the same rate as tachycardia. The delta H-A interval was calculated as the H-AP minus the H-AT. Results: There was excellent interobserver and intraobserver agreement for measurement of the H-A interval. The average delta H-A interval was ,10 ms during AVNRT and 9 ms during JT (P < 0.00001). For the diagnosis of JT, a delta H-A interval , 0 ms had the sensitivity of 89%, specificity of 83%, positive predictive value of 84%, and negative predictive value of 88%. The delta H-A interval was longer in men than in women with JT, but no gender-based differences were seen with AVNRT. There was no difference in the H-A interval based on age , 60 years. Conclusion: The delta H-A interval is a novel and reproducibly measurable interval that aids the differentiation of JT and AVNRT during electrophysiology studies. [source]

Acute Blood Pressure Changes After the Onset of Atrioventricular Nodal Reentrant Tachycardia: A Time-Course Analysis

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 10 2005
MEHDI RAZAVI M.D.
Introduction: We aimed to characterize blood pressure (BP) response at the beginning of atrioventricular nodal reentrant tachycardia (AVNRT) and its relationship to orthostatic challenge and variable atrioventricular interval. Methods and Results: In this prospective study of 17 consecutive patients with documented AVNRT, mean BP was analyzed in the supine and upright positions during sinus rhythm, AVNRT, and pacing with atrioventricular delay of 150 msec (AV150) and 0 msec (AV0). Mean BPs were compared at 3,5 seconds, 8,10 seconds, and 28,30 seconds after the onset of AVNRT or pacing. BP decreased immediately after AVNRT initiation, with gradual recovery during the first 30 seconds from 71.9 ± 16.5 mmHg to 86 ± 13.8 mmHg, P < 0.01. A similar pattern was observed during AV0, but not during AV150, pacing. While supine, mean BP decrease was more pronounced during AVNRT and AV0 pacing (,26.1% and ,32.1%, respectively) than during AV150 pacing (,8%, P = 0.02 and P = 0.07, respectively). This difference subsided 30 seconds after the onset of AVNRT or pacing. When upright, the mean BP time course was similar, but mean BP recovery during AVNRT was slower, and the difference between mean BP during AVNRT and AV150 persisted at 30 seconds. Conclusions: The initial mean BP decrease during AVNRT recovered gradually within 30 seconds. A short atrioventricular interval is associated with a greater mean BP decrease at the onset of tachycardia. These observations may explain clinical symptoms immediately after the onset of AVNRT. [source]

Spontaneous Transition of 2:1 Atrioventricular Block to 1:1 Atrioventricular Conduction During Atrioventricular Nodal Reentrant Tachycardia:

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 12 2003
Evidence Supporting the Intra-Hisian or Infra-Hisian Area as the Site of Block
Introduction: The incidence of spontaneous transition of 2:1 AV block to 1:1 AV conduction during AV nodal reentrant tachycardia has not been well reported. Among previous studies, controversy also existed about the site of the 2:1 AV block during AV nodal reentrant tachycardia. Methods and Results: In patients with 2:1 AV block during AV nodal reentrant tachycardia, the incidence of spontaneous transition of 2:1 AV block to 1:1 AV conduction and change of electrophysiologic properties during spontaneous transition were analyzed. Among the 20 patients with 2:1 AV block during AV nodal reentrant tachycardia, a His-bundle potential was absent in blocked beats during 2:1 AV block in 8 patients, and the maximal amplitude of the His-bundle potential in the blocked beats was the same as that in the conducted beats in 4 patients and was significantly smaller than that in the conducted beats in 8 patients (0.49 ± 0.25 mV vs 0.16 ± 0.07 mV, P = 0.007). Spontaneous transition of 2:1 AV block to 1:1 AV conduction occurred in 15 (75%) of 20 patients with 2:1 AV block during AV nodal reentrant tachycardia. Spontaneous transition of 2:1 AV block to 1:1 AV conduction was associated with transient right and/or left bundle branch block. The 1:1 AV conduction with transient bundle branch block was associated with significant His-ventricular (HV) interval prolongation (66 ± 19 ms) compared with 2:1 AV block (44 ± 6 ms, P < 0.01) and 1:1 AV conduction without bundle branch block (43 ± 6 ms, P < 0.01). Conclusion: The 2:1 AV block during AV nodal reentrant tachycardia is functional; the level of block is demonstrated to be within or below the His bundle in a majority of patients with 2:1 AV block during AV nodal reentrant tachycardia, and a minority are possibly high in the junction between the AV node and His bundle. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1337-1341, December 2003) [source]

Irregular Atrial Activation During Atrioventricular Nodal Reentrant Tachycardia:

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2003
Evidence of an Upper Common Pathway
Controversy continues regarding the precise nature of the reentrant circuit of AV nodal reentrant tachycardia, especially the existence of an upper common pathway. In this case report, we show that marked variation and irregularity in atrial activation (maximum AA interval variation of 80 msec) can exist with fixed and constant activation of the His bundle and ventricles during AV nodal reentrant tachycardia in a 45-year-old female patient. We propose that irregular atrial activation is due to variable and inconsistent conduction from the AV node to the atria through the perinodal transitional cell envelope extrinsic to the reentrant circuit. Our observations support the concept of an upper common pathway, at least in some patients with AV nodal reentrant tachycardia.(J Cardiovasc Electrophysiol, Vol. 14, pp. 309-313, March 2003) [source]

Estimation of Entrainment Response Using Electrograms from Remote Sites: Validation in Animal and Computer Models of Reentrant Tachycardia

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2003
PETER E. HAMMER M.S.
Estimation of Entrainment Response. Introduction: Studies suggest that entrainment response (ER) of reentrant tachycardia to overdrive pacing can be estimated using signals from sites other than the paced site. Methods and Results: A formula for estimation of ER using remote sites against the difference between the postpacing interval (PPI) and tachycardia cycle length (TCL) determined solely from the paced site signal was validated in experimental data and using a simple two-dimensional cellular automata model of reentry. The model also was used to study the behavior and features of entrained surfaces, including the resetting of tachycardia phase by single premature paced stimuli. Experimental results from 1,484 remote sites in 115 pacing sequences showed the average of the median ER estimate error at each pacing site was,2 ± 5 msec, and the median ER estimate was within 10 msec of PPI,TCL for 94% of pacing sites. From simulation results, ER at the paced site was accurately estimated from >99.8% of 20,764 remote sites during pacing at 24 sites and three paced cycle lengths. Intervals measured from remote electrograms revealed whether the site was activated orthodromically or nonorthodromically during pacing, and results of simulations illustrated that the portion of the surface activated nonorthodromically during pacing increased with distance from the pacing site to the circuit. The phenomenon of nonorthodromic activation of reentrant circuits predicted by modeling was discernible in measurements taken from the animal model of reentrant tachycardia. Results also showed that, for single premature stimuli that penetrated the tachycardia circuit, phase reset of the tachycardia was linearly related to distance between the central obstacle and the paced site. Conclusion: The ER is a complex but predictable perturbation of the global activation sequence of reentrant tachycardias. This predictability allows calculations of the response from anywhere on the perturbed surface. These findings suggest new techniques for measurement of the ER, which may lend themselves to computer-based methods for accurate and rapid mapping of reentrant circuits. [source]

Atrioventricular Nodal Reentrant Tachycardia in Children: Effect of Slow Pathway Ablation on Fast Pathway Function

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2002
GEORGE F. VAN HARE M.D.
AV Nodal Reentry in Children.Introduction: Prior studies in adults have shown significant shortening of the fast pathway effective refractory period after successful slow pathway ablation. As differences between adults and children exist in other characteristics of AV nodal reentrant tachycardia (AVNRT), we sought to characterize the effect of slow pathway ablation or modification in a multicenter study of pediatric patients. Methods and Results: Data from procedures in pediatric patients were gathered retrospectively from five institutions. Entry criteria were age < 21 years, typical AVNRT inducible with/without isoproterenol infusion, and attempted slow pathway ablation or modification. Dual AV nodal pathways were defined as those with > 50 msec jump in A2-H2 with a 10-msec decrease in A1-A2. Successful ablation was defined as elimination of AVNRT inducibility. A total of 159 patients (age 4.4 to 21 years, mean 13.1) were studied and had attempted slow pathway ablation. AVNRT was inducible in the baseline state in 74 (47%) of 159 patients and with isoproterenol in the remainder. Dual AV nodal pathways were noted in 98 (62%) of 159 patients in the baseline state. Ablation was successful in 154 (97%) of 159 patients. In patients with dual AV nodal pathways and successful slow pathway ablation, the mean fast pathway effective refractory period was 343 ± 68 msec before ablation and 263 ± 64 msec after ablation. Mean decrease in the fast pathway effective refractory period was 81 ± 82 msec (P < 0.0001) and was not explained by changes in autonomic tone, as measured by changes in sinus cycle length during the ablation procedure. Electrophysiologic measurements were correlated with age. Fast pathway effective refractory period was related to age both before (P = 0.0044) and after ablation (P < 0.0001). AV block cycle length was related to age both before (P = 0.0005) and after ablation (P < 0.0001). However, in dual AV nodal pathway patients, the magnitude of change in the fast pathway effective refractory period after ablation was not related to age. Conclusion: Lack of clear dual AV node physiology is common in pediatric patients with inducible AVNRT (38%). Fast pathway effective refractory period shortens substantially in response to slow pathway ablation. The magnitude of change is large compared with adult reports and is not completely explained by changes in autonomic tone. Prospective studies in children using autonomic blockade are needed. [source]

Incidence and Clinical Significance of Inducible Atrial Tachycardia in Patients with Atrioventricular Nodal Reentrant Tachycardia

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 5 2001
CHRISTIAN STICHERLING M.D.
Significance of Atrial Tachycardia.Introduction: The purpose of this prospective study was to determine the prevalence and clinical significance of inducible atrial tachycardia in patients undergoing slow pathway ablation for AV nodal reentrant tachycardia who did not have clinically documented episodes of atrial tachycardia. Methods and Results: Twenty-seven (15%) of 176 consecutive patients who underwent slow pathway ablation for AV nodal reentrant tachycardia were found to have inducible atrial tachycardia with a mean cycle length of 351 ± 95 msec. The atrial tachycardia was sustained in 7 (26%) of 27 patients and was isoproterenol dependent in 20 patients (74%). The atrial tachycardia was not ablated or treated with medications, and the patients were followed for 9.7 ± 5.8 months. Six (22%) of the 27 patients experienced recurrent palpitations during follow-up. In one patient each, the palpitations were found to be due to sustained atrial tachycardia, nonsustained atrial tachycardia, recurrence of AV nodal reentrant tachycardia, paroxysmal atrial fibrillation, sinus tachycardia, and frequent atrial premature depolarizations. Thus, only 2 (7%) of 27 patients with inducible atrial tachycardia later developed symptoms attributable to atrial tachycardia. Conclusion: Atrial tachycardia may be induced by atrial pacing in 15% of patients with AV nodal reentrant tachycardia. Because the vast majority of patients do not experience symptomatic atrial tachycardia during follow-up, treatment for atrial tachycardia should be deferred and limited to the occasional patient who later develops symptomatic atrial tachycardia. [source]

Patterns of Accelerated Junctional Rhythm During Slow Pathway Catheter Ablation for Atrioventricular Nodal Reentrant Tachycardia: Temperature Dependence, Prognostic Value, and Insights into the Nature of the Slow Pathway

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2000
ALAN B. WAGSHAL M.D.
Slow Pathway Accelerated Junctional Rhythm. Introduction: Although accelerated junctional rhythm (AJR) is a knuwn marker for successful slow pathway (SP) ablation sites. AJR may just be a regional effect of the anisotropic conduction properties of this area of the heart. We believe that detailed assessment of the AJR might provide insight into the SP specificity of this AJR and perhaps the nature of the SP itself. Methods and Results: Our ablation protocol consisted of 30-second, 70°C temperature-controlled ablation pulses with assessment after each pulse. Serial booster ablations were performed at the original successful site and at least 2 to 3 nearby sites to assess for residual AJR after the procedure in 50 consecutive SP ablations. We defined three distinct patterns of AJR: continuous AJR that persisted until the end of energy delivery (group 1, 25 patients); alternating or "stuttering" AJR that persisted throughout energy delivery (group II, 9 patients); and AJR that ended abruptly during energy delivery (group III, 16 patients). Mean ablation temperatures in the three groups was 57°± 5°C, 54°± 5°C, and 63°± 5°C, respectively (P = 0.0002 for groups I and II vs group III). Ten of 34 (29%) patients in groups I and II ("low-temperature ablation") exhibited residual SP (jump and/or single echo heats) despite tachycardia noninducibility, and 25 of 34 (73%) patients had residual AJR during the booster ablations, but neither of these was seen in any group III patients. Conclusion: Ablation temperature correlates with the pattern of AJR produced during SP ablation. That higher temperature lesions simultaneously abolish all SP activity as well as the focus of AJR suggests that this AJR is specific for the SP and is not a nonspecific regional effect. [source]

Need for Fast Pathway Ablation in Typical Irregular AV Nodal Reentrant Tachycardia in a Patient with Multiple AV Nodal Pathways

JOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 2 2000
PETER WEISMÜLLER M.D.
A case of a 60-year-old male with irregular AV nodal reentrant tachycardia of the common type is reported. Electrophysiological study revealed multiple antegrade slowly conducting AV nodal pathways and one exclusively retrogradely conducting fast AV nodal pathway. Despite the recommendation for slow pathway ablation as the treatment of choice in patients with AVNRT, first pathway ablation was successfully performed in this case due to the risk of total A V block of ablating the slow pathways. The present report shows that there is the rare patient in whom fast pathway ablation is required for curative treatment of AV nodal reentrant tachycardia. [source]

Analysis of Atrioventricular Nodal Reentrant Tachycardia with Variable Ventriculoatrial Block: Characteristics of the Upper Common Pathway

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 4 2009
KENJI MORIHISA M.D.
Background: The precise nature of the upper turnaround part of atrioventricular nodal reentrant tachycardia (AVNRT) is not entirely understood. Methods: In nine patients with AVNRT accompanied by variable ventriculoatrial (VA) conduction block, we examined the electrophysiologic characteristics of its upper common pathway. Results: Tachycardia was induced by atrial burst and/or extrastimulus followed by atrial-His jump, and the earliest atrial electrogram was observed at the His bundle site in all patients. Twelve incidents of VA block: Wenckebach VA block (n = 7), 2:1 VA block (n = 4), and intermittent (n = 1) were observed. In two of seven Wenckebach VA block, the retrograde earliest atrial activation site shifted from the His bundle site to coronary sinus ostium just before VA block. Prolongation of His-His interval occurred during VA block in 11 of 12 incidents. After isoproterenol administration, 1:1 VA conduction resumed in all patients. Catheter ablation at the right inferoparaseptum eliminated antegrade slow pathway conduction and rendered AVNRT noninducible in all patients. Conclusion: Selective elimination of the slow pathway conduction at the inferoparaseptal right atrium may suggest that the subatrial tissue linking the retrograde fast and antegrade slow pathways forms the upper common pathway in AVNRT with VA block. [source]

Abnormal Atrioventricular Node Conduction and Atrioventricular Nodal Reentrant Tachycardia in Patients Older Versus Younger Than 65 Years of Age

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2009
MIHAELA GRECU M.D.
Study Objective: We examined the possible role of atrioventricular node (AVN) conduction abnormalities as a cause of AVN reentrant tachycardia (RT) in patients >65 years of age. Study Population: Slow pathway radiofrequency catheter ablation (RFCA) was performed in 104 patients. Patients in group 1 (n = 14) were >65 years of age and had AV conduction abnormalities associated with structural heart disease. Patients in group 2 (n = 90) were <65 years of age and had lone AVNRT. Results: Patients in group 1 versus group 2 (66% vs. 46% men) had a first episode of tachycardia at an older age than in group 2 (68 ± 16.8 vs 32.5 ± 18.8 years, P = 0.007). The history of arrhythmia was shorter in group 1 (5.4 ± 3.8 vs 17.5 ± 14, P = 0.05) and was associated with a higher proportion of patients with underlying heart disease than in group 2 (79% vs 3%, P < 0.001). The electrophysiological measurements were significantly shorter in group 2: atrial-His interval (74 ± 17 vs 144 ± 44 ms, P = 0.005), His-ventricular (HV) interval (41 ± 5 vs 57 ± 7 ms, P = 0.001), Wenckebach cycle length (329 ± 38 vs 436 ± 90 ms, P = 0.001), slow pathway effective refractory period (268 ± 7 vs 344 ± 94 ms, P = 0.005), and tachycardia cycle length (332 ± 53 vs 426 ± 56 ms, P = 0.001). The ventriculoatrial block cycle length was similar in both groups. The immediate procedural success rate was 100% in both groups, and no complication was observed in either group. One patient in group 2 had recurrence of AVNRT. One patient with a 98-ms HV interval underwent permanent VVI pacemaker implantation before RFCA procedure. Conclusion: In patients undergoing RFCA for AVNRT at >65 years of age had a shorter history of tachycardia-related symptoms than patients with lone AVNRT. The longer AVN conduction intervals and refractory period might explain the late development of AVNRT in group 1. [source]

Coexisting Idiopathic Left Ventricular Tachycardia and Atrioventricular Reentrant Tachycardia in a Patient with Wolff-Parkinson-White Syndrome

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2 2009
HONG EUY LIM M.D., Ph.D.
We report a patient with Wolff-Parkinson-White syndrome who presented with two distinct tachycardias that represented atrioventricular reentrant tachycardia utilizing left lateral accessory pathway (AP) and idiopathic left ventricular tachycardia (ILVT). Two tachycardias with a complete separate mechanism occurred spontaneously as well as following atrial or ventricular pacing. Successful ablation of the left AP and ILVT resulted in a cure of the double tachycardia. [source]

Cryoablation for Atrioventricular Nodal Reentrant Tachycardia in Young Patients: Predictors of Recurrence

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2008
NIKHIL K. CHANANI M.D.
Background: Recurrence rates of atrioventricular nodal reentry tachycardia (AVNRT) after cryoablation continue to remain high despite excellent initial success rates. Our objective was to evaluate the clinical outcomes of cryoablation for AVNRT with the 4-mm and 6-mm tip cryoablation catheters in a young population and to elicit predictors of arrhythmia recurrence. Methods: We retrospectively reviewed all patients who underwent cryoablation for AVNRT at the UCSF/Stanford Pediatric Arrhythmia Center from January 2004 to February 2007. Results: One hundred fifty-four patients (age 13.7 years (3.2,24.4)) underwent cryoablation for AVNRT of which 144 patients had inducible AVNRT (123 sustained and 21 nonsustained) and 10 had presumed AVNRT. Initial success was achieved in 95% (146/154), with no difference between the 4-mm (93%) and 6-mm (98%) cryoablation catheter tips (P = 0.15). There was no permanent atrioventricular (AV) block. Transient third-degree AV block occurred in nine patients (6%), with no difference between the 4-mm (4%) and 6-mm (9%) tip (P = 0.13). AVNRT recurrence was documented in 14% in a median time of 2.5 months (0.25,20). Recurrences were lower with the 6-mm (9%) versus the 4-mm (18%) tip, but this did not reach statistical significance (P = 0.16). With univariate analysis, a longer fluoroscopy time was the only significant factor associated with recurrence. Multivariate analysis failed to identify any significant predictor of AVNRT recurrence. Conclusion: Outcomes of cryoablation for AVNRT continue to be good without the complication of AV block. We could not identify any specific parameter associated with AVNRT recurrence. Further improvements in cryoablation technique will be necessary to reduce recurrences. [source]

"Left-Variant" Adenosine-Sensitive Atrial Reentrant Tachycardia Ablated from the Left Coronary Aortic Sinus

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2 2008
KIYOSHI OTOMO M.D.
Adenosine-sensitive reentrant atrial tachycardia (AT) is usually amenable to ablation at the right superoseptum near the His bundle. We report a case with "left-variant" adenosine-sensitive reentrant AT. The AT was reproducibly induced by atrial extrastimulation with negative correlation between the coupling interval and return cycle, and was terminated by atrial extrastimulation and bolus of 2 mg of adenosine 5'-triphosphate. Ablations at the right superoseptum were unsuccessful; however, the AT was successfully ablated from the left coronary aortic sinus (LCAS) where the earliest atrial activation was recorded. Ablation at the LCAS might be effective in this entity resistant to right-sided ablation. [source]

Upper and Lower Common Pathways in Atrioventricular Nodal Reentrant Tachycardia:

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 11 2007
Refutation of a Legend?
The concepts of upper and lower common pathways represent long-standing controversies of atrioventricular nodal reentrant tachycardia (AVNRT). Over the last years there has been considerable evidence against the presence of a lower and, especially, an upper common pathway as distinct entities that can be identified in most patients with atrioventricular reentrant tachycardia. The mechanism and relevance of these concepts remain speculative. [source]

The Electrophysiological Characteristics in Patients with Ventricular Stimulation Inducible Fast-Slow Form Atrioventricular Nodal Reentrant Tachycardia

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 10 2006
PI-CHANG LEE M.D.
Background: Atrioventricular nodal reentrant tachycardia (AVNRT) can usually be induced by atrial stimulation. However, it seldom may be induced with only ventricular stimulation, especially the fast-slow form of AVNRT. The purpose of this retrospective study was to investigate the specific electrophysiological characteristics in patients with the fast-slow form of AVNRT that could be induced with only ventricular stimulation. Methods: The total population consisted of 1,497 patients associated with AVNRT, and 106 (8.4%) of them had the fast-slow form of AVNRT and 1,373 (91.7%) the slow-fast form of AVNRT. In patients with the fast-slow form of AVNRT, the AVNRT could be induced with only ventricular stimulation in 16 patients, Group 1; with only atrial stimulation or both atrial and ventricular stimulation in 90 patients, Group 2; and with only atrial stimulation in 13 patients, Group 3. We also divided these patients with slow-fast form AVNRT (n = 1,373) into two groups: those that could be induced only by ventricular stimulation (Group 4; n = 45, 3%) and those that could be induced by atrial stimulation only or by both atrial and ventricular stimulation (n = 1.328, 97%). Results: Patients with the fast-slow form of AVNRT that could be induced with only ventricular stimulation had a lower incidence of an antegrade dual AVN physiology (0% vs 71.1% and 92%, P < 0.001), a lower incidence of multiple form AVNRT (31% vs 69% and 85%, P = 0.009), and a more significant retrograde functional refractory period (FRP) difference (99 ± 102 vs 30 ± 57 ms, P < 0.001) than those that could be induced with only atrial stimulation or both atrial and ventricular stimulation. The occurrence of tachycardia stimulated with only ventricular stimulation was more frequently demonstrated in patients with the fast-slow form of AVNRT than in those with the slow-fast form of AVNRT (15% vs 3%, P < 0.001). Patients with the fast-slow form of AVNRT that could be induced with only ventricular stimulation had a higher incidence of retrograde dual AVN physiology (75% vs 4%, P < 0.001), a longer pacing cycle length of retrograde 1:1 fast and slow pathway conduction (475 ± 63 ms vs 366 ± 64 ms, P < 0.001; 449 ± 138 ms vs 370 ± 85 ms, P = 0.009), a longer retrograde effective refractory period of the fast pathway (360 ± 124 ms vs 285 ± 62 ms, P = 0.003), and a longer retrograde FRP of the fast and slow pathway (428 ± 85 ms vs 362 ± 47 ms, P < 0.001 and 522 ± 106 vs 456 ± 97 ms, P = 0.026) than those with the slow-fast form of AVNRT that could be induced with only ventricular stimulation. Conclusion: This study demonstrated that patients with the fast-slow form of AVNRT that could be induced with only ventricular stimulation had a different incidence of the antegrade and retrograde dual AVN physiology and the specific electrophysiological characteristics. The mechanism of the AVNRT stimulated only with ventricular stimulation was supposed to be different in patients with the slow-fast and fast-slow forms of AVNRT. [source]

Pseudotermination of Atrioventricular Nodal Reentrant Tachycardia Related to Isorhythmic Atrioventricular Dissociation

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 12 2003
MITSUNORI MARUYAMA
Unusual manifestations of the mode of termination were observed in a patient with atrioventricular nodal reentrant tachycardia (AVNRT). After administration of verapamil during AVNRT, isorhythmic atrioventricular dissociation occurred without termination of the tachycardia. The sinus rate was slightly faster than that of the AVNRT, leading to the P wave preceding the QRS complex with a normal PR interval (e.g., pseudotermination). This phenomenon emphasizes the importance of continuous monitoring during an attempt to terminate AVNRT. (PACE 2003; 26:2338,2339) [source]

P Wave Dispersion Predicts Recurrence of Paroxysmal Atrial Fibrillation in Patients with Atrioventricular Nodal Reentrant Tachycardia Treated with Radiofrequency Catheter Ablation

ANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 3 2006
Basri Amasyali M.D.
Background: Paroxysmal atrial fibrillation (AF) recurs in up to one-third of patients with atrioventricular nodal reentrant tachycardia (AVNRT) treated with slow pathway ablation. Therefore, identification of patients at risk for recurrence of AF after slow pathway ablation is important because of the necessity for additional therapies. The purpose of this study was to determine whether successful slow pathway ablation influences P wave parameters and whether these parameters predict the recurrence of paroxysmal AF in patients with both AVNRT and paroxysmal AF after ablation. Methods: Thirty-six patients with AVNRT and documented paroxysmal AF (Group 1) were compared to 36 age-matched controls with AVNRT only (Group 2). P wave durations and P dispersion were measured before and after ablation. Results: No significant differences were observed between P wave parameters observed before and after ablation. Maximum P wave durations (Pmax) and P dispersion (Pdisp) were significantly higher in Group 1 than in Group 2 (P < 0.001 for both) whereas minimum P wave durations did not differ between groups, both before and after ablation. Ten patients (28%) in Group-1 had recurrence of AF during a mean follow-up of 34 ± 11 months. Univariate predictors of AF recurrence were Pdisp ,35.5 ms (P < 0.010), left atrial diameter >40 mm (P < 0.010), mitral or aortic calcification (P < 0.010), Pmax ,112 ms (P < 0.050), valvular heart disease (P < 0.050), and atrial vulnerability (induction of AF lasting >30 second) after ablation (P < 0.050). However, only Pdisp ,35.5 ms (P < 0.050) and left atrial diameter >40 mm (P < 0.010) were independent predictors of AF recurrences. Conclusion: This study suggests that P wave dispersion could identify patients with AVNRT susceptible to recurrence of AF after slow pathway ablation. [source]

Coexistent Right- and Left-Sided Slow Pathways Participating in Distinct AV Nodal Reentrant Tachycardias

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 10 2008
LÁSZLÓ SÁGHY M.D.
We report a patient with two distinct atrioventricular (AV) nodal slow pathways, participating in two different AV nodal reentrant tachycardias,one eliminated from the right, the other only after ablation on the left side of the posterior septum. The case provides support for the concept of the posterior AV nodal extensions,a biatrial structure in most hearts,representing the anatomic basis of slow pathway conduction. [source]

Atrioventricular Nodal versus Atrioventricular Supraventricular Reentrant Tachycardias: Characterization by an Integrated Doppler Electro-physiological Hemodynamic Study

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 12 2000
DONATO MELE
During reentrant Supraventricular tachycardias involving the atrioventricular node (A VN-SVT) or an A V bypass tract (AV-SVT), atrial pressure increases. While in AVN-SVT this increase relates to atrial contraction during ventricular systole, the mechanism remains unclear in AV-SVT. This study sought to clarify this mechanism. During 11 AVN-SVTs and 9 AV-SVTs. anterograde flow through the AV valves and retrograde flow in the pulmonary and hepatic veins were studied by pulsed- wave (PW) Doppler measuring the time interval between the ECG-R wave and (1) the end of venous retrograde flows, and (2) the beginning of valvular anterograde flows. The positive or negative difference between these two time intervals guided recognizing the atrial contraction against open or closed A V valves. Intracavitary pressures and cardiac index were also measured. During AVN-SVTs, venous retrograde flows always ended before the anterograde valvular flows, indicating atrial contraction against closed AV valves. During A V-SVTs, pulmonary retrograde flow ended before the beginning of mitral anterograde flow in five cases, began before but ended during the anterograde flow in three cases, and overlapped to the anterograde flow in one case. A corresponding behavior was observed at the right side of the heart. In both SVTs, atrial pressures increased and end-dias-tolic ventricular pressure and cardiac index decreased similarly. During AVN-SVT, the atrial contraction always occurs against closed A V valves, and during A V-SVT it generally occurs against totally or partially closed A V valves, explaining similar atrial pressure and cardiac index changes in both SVTs. [source]

The Spectrum of Long-term Electrophysiologic Abnormalities in Patients with Univentricular Hearts

CONGENITAL HEART DISEASE, Issue 5 2009
Kathryn K. Collins MD
ABSTRACT Patients with univentricular hearts experience a wide range of electrophysiolgic abnormalities which tend to develop years after cardiovascular surgical interventions. Intra-atrial reentrant tachycardia (atrial flutter) in the Fontan population is the most common arrhythmia and, as such, has the largest body of literature addressing its cause and treatment. However, sinus node dysfunction, other atrial arrhythmias, ventricular arrhythmias, and cardiac dysynchrony also occur in this patient population. The purpose of this article is to review the prevalence, mechanisms, and treatment of these electrophysiologic abnormalities within the single ventricle and Fontan patient. [source]

Utilization of Retrograde Right Bundle Branch Block to Differentiate Atrioventricular Nodal from Accessory Pathway Conduction

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2009
SURAJ KAPA M.D.
Introduction: Defining whether retrograde ventriculoatrial (V-A) conduction is via the AV node (AVN) or an accessory pathway (AP) is important during ablation procedures for supraventricular tachycardia (SVT). With the introduction of ventricular extrastimuli (VEST), retrograde right bundle branch block (RBBB) may occur, prolonging the V-H interval, but only when AV node conduction is present. We hypothesized that when AP conduction was present, the V-A interval would increase less than the V-H interval, whereas with retrograde nodal conduction, the V-A interval would increase at least as much as the V-H interval. Methods and Results: We retrospectively reviewed the electrophysiological studies of patients undergoing ablation for AVN reentrant tachycardia (AVNRT) (55) or AVRT (50), for induction of retrograde RBBB during the introduction of VEST, and the change in the measured V-H and V-A intervals. Results were found to be reproducible between independent observers. Out of 105 patients, 84 had evidence of induced retrograde RBBB. The average V-H interval increase with induction of RBBB was 53.7 ms for patients with AVRT and 54.4 ms for patients with AVNRT (P = NS). The average V-A interval increase with induction of RBBB was 13.6 ms with AVRT and 70.1 ms with AVNRT (P < 0.001). All patients with a greater V-H than V-A interval change had AVRT, and those with a smaller had AVNRT. Conclusions: Induction of retrograde RBBB during VEST is common during an electrophysiological study for SVT. The relative change in the intervals during induction of RBBB accurately differentiates between retrograde AVN and AP conduction. [source]

Electrophysiological Characteristics and Catheter Ablation in Patients with Paroxysmal Supraventricular Tachycardia and Paroxysmal Atrial Fibrillation

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2008
SHIH-LIN CHANG M.D.
Introduction: Paroxysmal supraventricular tachycardia (PSVT) is often associated with paroxysmal atrial fibrillation (AF). However, the relationship between PSVT and AF is still unclear. The aim of this study was to investigate the clinical and electrophysiological characteristics in patients with PSVT and AF, and to demonstrate the origin of the AF before the radiofrequency (RF) ablation of AF. Methods and Results: Four hundred and two consecutive patients with paroxysmal AF (338 had a pure PV foci and 64 had a non-PV foci) that underwent RF ablation were included. Twenty-one patients (10 females; mean age 47 ± 18 years) with both PSVT and AF were divided into two groups. Group 1 consisted of 14 patients with inducible atrioventricular nodal reentrant tachycardia (AVNRT) and AF. Group 2 consisted of seven patients with Wolff-Parkinson-White (WPW) syndrome and AF. Patients with non-PV foci of AF had a higher incidence of AVNRT than those with PV foci (11% vs. 2%, P = 0.003). Patients with AF and atypical AVNRT had a higher incidence of AF ectopy from the superior vena cava (SVC) than those with AF and typical AVNRT (86% vs. 14%, P = 0.03). Group 1 patients had smaller left atrial (LA) diameter (36 ± 3 vs. 41 ± 3 mm, P = 0.004) and higher incidence of an SVC origin of AF (50% vs. 0%, P = 0.047) than did those in Group 2. Conclusion: The SVC AF has a close relationship with AVNRT. The effect of atrial vulnerability and remodeling may differ between AVNRT and WPW syndrome. [source]

Differentiating Atrioventricular Nodal Reentrant Tachycardia from Junctional Tachycardia: Novel Application of the Delta H-A Interval

Acute Blood Pressure Changes After the Onset of Atrioventricular Nodal Reentrant Tachycardia: A Time-Course Analysis

Mechanism of Repolarization Change During Initiation of Supraventricular Tachycardia

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 11 2004
YENN-JIANG LIN M.D.
Introduction: Previous literature has documented the association between narrow QRS supraventricular tachycardia (SVT) and pronounced ST-T segment change. The aim of this study was to evaluate repolarization changes during SVT initiation and demonstrate the possible mechanism. Methods and Results: Fifty-one consecutive patients (20 men and 31 women; mean age 46.1 ± 16.4 years) with narrow QRS SVT (32 patients with AV nodal reentrant tachycardia and 19 patients with AV reentrant tachycardia) were included. We retrospectively analyzed the intracardiac recordings and ST-T segment changes on 12-lead surface ECGs during SVT initiation. Twenty-six (51%) patients developed ST segment repolarization changes during SVT initiation. Patients with shorter baseline sinus cycle length, shorter tachycardia cycle length, elevated systolic blood pressure before tachycardia induction, and greater reduction of systolic blood pressure had a higher incidence of repolarization changes. However, multivariate analysis showed that reduction of systolic blood pressure after SVT induction was the only independent predictor of repolarization changes. Furthermore, the maximal degree of ST segment depression during SVT correlated with the reduction of systolic blood pressure (r = 0.75, P < 0.001). Conclusion: Repolarization changes during SVT initiation were caused mainly by concurrent hemodynamic change after SVT initiation with abrupt cycle length shortening. [source]