Lateral Accessory Pathway Research Articles

Three Sisters, One Pathway

We present the first reported case of an entire family, 3 sisters, all presenting with symptomatic atrioventricular reciprocating tachycardia during a 15-year period, all were found at electrophysiological study to have identically located left lateral accessory pathway, all successfully treated with radiofrequency ablation. This rare familial clustering suggests a genetic contribution to pathway formation.

Tachycardia induction with ventricular extrastimuli differentiates atypical atrioventricular nodal reentrant tachycardia from orthodromic reciprocating tachycardia

Differentiating atypical atrioventricular nodal reentrant tachycardia (AVNRT) from septal orthodromic reentrant tachycardia (ORT(Septal)) is challenging in nonsustained tachycardia. When sustained, the postpacing interval minus tachycardia cycle length following entrainment (PPI(Entrainment) - TCL) and stimulation to atrial interval minus ventriculoatrial interval (Stim-A(Entrainment) - VA) are utilized. We hypothesized that the first tachycardia cycle after tachycardia induction with right ventricular apical extrastimulation would yield comparable information to entrainment, precluding the need for sustained tachycardia. Twenty-four patients with AVNRT (age 47 ± 18 years), 19 with ORT(Septal) (age 42 ± 17 years), and 15 with ORT over a left lateral accessory pathway (ORT(Left)) (age 41 ± 16 years) were included. The ventricular extrastimulus to atrial depolarization at tachycardia initiation (Stim-A(Initiation)) and tachycardia VA interval were measured to establish the Stim-A(Initiation) minus VA interval (Stim-A(Initiation) - VA). The ventricular extrastimulus to the subsequent right ventricular apical depolarization (postpacing interval at initiation, PPI(Initiation)) was utilized to obtain the PPI(Initiation) minus TCL (PPI(Initiation) - TCL). The AH interval associated with the PPI(Initiation) minus the AH in tachycardia was utilized to establish a corrected PPI(Initiation) minus TCL (cPPI(Initiation) - TCL). The intervals after tachycardia initiation were longer for AVNRT than for ORT: mean PPI(Initiation) - TCL (193 ± 44 vs 91 ± 73; P <.001), cPPI(Initiation) - TCL (174 ± 44 ms vs 88 ± 50 ms; P <.001), and Stim-A(Initiation) - VA (161 ± 45 ms vs 69 ± 53 ms; P <.001). The correlation coefficient for Stim-A(Initiation) minus VA against Stim-A(Entrainment) minus VA was 0.79 and for cPPI(Initiation) minus TCL against PPI(Entrainment) minus TCL was 0.71. cPPI(Initiation) minus TCL <115 ms or Stim-A(Initiation) - VA <85 ms was observed only in ORT. The converse was observed in AVNRT but also in ORT(Septal) over decremental accessory pathways and ORT(Left). Stim-A(Initiation) - VA < 85 ms or cPPI(Initiation) - TCL < 115 ms excludes AVNRT.

The case of successful catheter ablation using only the approach from the upper part of the subject's body, with meandering aorta and implanted IVC filter

A 79-year-old female had paroxysmal supraventricular tachycardia. However, she was implanted with an inferior vena cava filter and her descending aorta had significant meandering. It was thought that the insertion of the catheters would be difficult from the femoral vessels. Therefore we inserted electrode catheters from the right subclavian vein and internal jugular vein. As a result of an electrophysiology study, we diagnosed atrioventricular reciprocating tachycardia with a left lateral concealed accessory pathway (AP). An ablation catheter was introduced retrogradely through the left brachial artery and it was pushed forward under the mitral valve. Furthermore, it was put into the part where the earliest retrograde atrial deflection was recorded under the right ventricular apex pacing, and we succeeded in ablation of the AP. All catheters were inserted only from the upper part of the person's body. As for catheter operability, electric potential, operation time, and fluoroscopy time, there was no change in the case of either approach from the femoral vessels. Because we did not puncture the inguinal region, the patient was able to return to her ward on foot after the operation. In addition, we were able to perform a radical cure without complications.

A Simple and Accurate Algorithm for Localizing Accessory Pathways in Patients with Wolff-Parkinson-White Syndrome

Introduction: A new and simple algorithm is proposed for localizing accessory pathways (APs) using only the R/S ratio. Methods: This study consisted of 101 patients with a single anterogradely conducting AP on 12-lead ECG. R/S ratios in V1, V2 and aVF were analyzed. A new algorithm was developed by correlating the 12-lead ECG findings with successful ablation sites in the 40 initial patients. This algorithm was subsequently tested in the 61 residual patients. Results: Among 61 patients, all 37 patients with left free wall APs showed the R/S ratio in V1 ≥0.5 (sensitivity 100%). Left anterior and lateral APs were associated with the R/S ratio in aVF ≥1 (sensitivity 97%). If the R/S ratio in V1 was <0.5 and the R/S ratio in V2 was ≥0.5, the AP location was midseptal or posteroseptal (sensitivity 100%). If the R/S ratio in both V1 and V2 was <0.5, it was right free wall or right anteroseptal (sensitivity 89%). Right anterior, lateral, and anteroseptal APs were associated with the R/S ratio in aVF ≥1 (sensitivity 98%). Overall sensitivity was 93% and specificity was 99%. Conclusions: This novel algorithm using only the R/S ratio provides a simple and accurate way to identify the AP localization.

Mitral Stenosis with WPW Syndrome

The catheter ablation of accessory pathways in patient with underlying structural heart disease is essential and it can provide permanent cure. A 32 year farmer with WPW type A with recurrent supraventricular tachycardia with severe rheumatic mitral stenosis was investigated. Firstly, PTMC (Percutaneous Trans-catheter Mitral Commissurotomy) was performed successfully in this patient improving mitral valve area from 1.1 cm2 to 2.29 cm2 with 10 mmHg dropped in invasive mean left atrial and pulmonary pressure. After PTMC, basic EP (Electrophysiology) study with 4 catheters at coronary sinus (CS), right ventricular and atrium, and His was carried out. The earliest ventricular activation at sinus rhythm and atrial activation with ventricular pacing were observed both at CS-1 position. The inducible tachycardia was consistent with AVRT (Atrio-Ventricular Reentrant Tachycardia) involving the left lateral free wall accessory pathway. Mapping was performed around the CS-1 below the mitral valve with retrograde aortic approach. Radiofrequency energy was applied where ventricular activation was earlier than delta wave in surface ECG and retrograde atrial activation was earlier than CS 1 with ventricular pacing. The delta wave was disappeared and ventriculo-atrial dissociation was observed with ventricular pacing immediately after ablation indicating the successful ablation of left lateral free wall accessory pathway. Conclusively, successful radiofrequency ablation of accessory pathway in patients with structural heart disease is valuable and PTMC is a treatment option in selected cases of mitral stenosis.

Assessing Reduction in Left Ventricular Activation Time with His-Bundle Pacing Utilizing a Novel Left Lateral Accessory Pathway Model

Aims: Right ventricular pacing results in a prolongation of the left ventricular activation time, which is attributed to delayed activation of the left ventricular lateral wall. Left ventricular activation time has only been indirectly recorded in human subjects. The objective of this study was to model to directly measure left ventricular activation time utilizing a novel left lateral accessory pathway model and assess its shortening with His-bundle pacing, a proposed physiological pacing modality. Materials and Methods: Consecutive adults with a pure retrograde conducting left lateral accessory pathway and both His-bundle as well as isolated myocardial capture were included. The interval from the pacing stimulus to the atrial activation in the left lateral region was measured as the left ventricular activation time, which was then compared during His-bundle versus myocardial pacing using paired t-test for means. Results: A total of 50 subjects were found eligible for inclusion (Males=27; mean age=39±14). His-bundle pacing resulted in a significant reduction of left ventricular activation time when compared to myocardial pacing (122±15 vs 152±17; p<0.001). Conclusion: Left ventricular activation time can be directly recorded in human subjects utilizing a pure-retrograde left lateral accessory pathway model and is significantly reduced with His-bundle pacing.

208 Reappearance of the preexcitation syndrome after ablation; significance

Accessory pathway (AP) ablation is the treatment of choice of symptomatic patients (pts) with a Wolff-Parkinson-White (WPW) syndrome or pts with a malignant form at electrophysiological study (EPS). WPW can reappear after ablation. The purpose of the study was to look for the risk factors of AP reappearance and the clinical consequences. AP ablation was performed in 327 pts aged from 8 to 77 years (37 ± 16), with a WPW. Ablation failed in 6 pts. In other pts, the anterograde and retrograde conduction disappeared after AP radiofrequency ablation. Reappearance of AP occurred in 48 pts from several hours to several years. Their data were studied. There were no significant clinical differences between pts with and without reappearance of AF, concerning the age (33 ± 16 years vs 36 ± 16), the gender (male gender 28/48 vs 166/280), the reason of ablation (spontaneous malignant form: 10/48 vs 70/280; spontaneous AV reentrant tachycardia (AVRT): 29/48 vs 176/280, asymptomatic with electrophysiological signs of malignancy: 9/48 vs 38/280), the location of AP (left lateral AP: 21/48 vs 125/280, posteroseptal AP: 22/47 vs 119/280, anteroseptal: AP 5/47 vs 27/280). During the follow up, among 9 of 45 pts asymptomatic before ablation but with only inducible rapid AF at EPS, 2 pts became symptomatic and had inducible AVRT at the control. 29 of 202 pts with spontaneous AVRT presented recurrences of AVRT, except one and a 2 nd procedure was required. Among 10 of 79 with syncope and signs of malignancy or spontaneous rapid AF, 2 pts have lost the signs of malignancy at 2 nd EPS; 2 pts who presented only with rapid AF, had an AP with long refractory period but developed incessant AVRT's; 6 pts had still signs of malignancy, requiring a second procedure. There was no significant clinical or electrophysiological cause that explains the reappearance of AP after ablation. The reappearance of conduction is generally associated with reappearance of all properties of AP associated with malignancy or AVRT, except in some cases. Pts without AVRT before ablation may become symptomatic and develop this AVRT after AP ablation.

To the Editor—Response: Orthodromic reciprocating tachycardia

We would like to thank the author for the kind comments. We agree with the author that care needs to be taken when assessing electrocardiographic (ECG) morphologies. All 12 ECG leads would need to be reviewed carefully to ascertain the first purely paced right ventricular (RV) beat or fixed fusion RV beat. However, in most of our cases of orthodromic reciprocating tachycardia (ORT), the tachycardia cycle length (TCL) was advanced to the paced cycle length (PCL) even before achieving fixed fusion in patients with right-sided as well as septal accessory pathways (AP). 1 Dandamudi G. Mokabberi R. Assal C. et al. A novel approach to differentiating orthodromic reciprocating tachycardia from atrioventricular nodal reentrant tachycardia. Heart Rhythm. 2010; 7: 1326-1329 Abstract Full Text Full Text PDF PubMed Scopus (55) Google Scholar However, this was not the case in any of the atrioventricular nodal reentry tachycardia (AVNRT) patients. Therefore, this difference makes it less likely to result in erroneous interpretation. However, this may be more of an issue with left lateral APs, in which usually the first fixed RV fusion beat results in acceleration of the TCL to the PCL. To the editor: Differentiating orthodromic reciprocating tachycardia from atrioventricular nodal reentrant tachycardiaHeart RhythmVol. 8Issue 3PreviewI read the article by Dandamudi et al1 with great interest. Congratulations for exploiting a very well known phenomenon in the electrophysiology laboratory and setting up criteria on the basis of that, and then validating this on a good number of patients to differentiate orthodromic reciprocating tachycardia (ORT) and atrioventricular nodal reentrant tachycardia (AVNRT). A few points are worth mentioning. Full-Text PDF

Prolongation of local ventriculoatrial conduction during left lateral accessory pathway ablation: What is the mechanism?

Prolongation of local ventriculoatrial conduction during left lateral accessory pathway ablation: What is the mechanism?

Risk Factors of Adverse Presentation as the First Arrhythmia in Wolff-Parkinson-White Syndrome

The aim of the study was the evaluation of the predictors of adverse presentation as first arrhythmia in Wolff-Parkinson-White syndrome; they usually affect young patients with septal or multiple accessory pathways (AP). Our population comprised 645 patients with a preexcitation syndrome. Among them, adverse presentation (sudden death, hemodynamically not tolerated atrial fibrillation [AF]) occurred in 60 (9%) (group I). Their clinical and electrophysiological features were compared to group II patients, which consisted of 75 patients with syncope (IIa), 287 with reentrant tachycardia (RT) (IIb), 211 asymptomatic patients (IIc), and 12 with well-tolerated AF. Sixteen group I patients had triggering factors. Group I patients were older (40 ± 18.5) than group II (34 ± 16) (P = 0.02). Male gender was as frequent in both groups (63%, 59%). Free wall left AP was more frequent in group I (65%) than in group II (37%) (P < 0.001), septal AP less frequent (27% vs 47%) (P = 0.004), multiple APs exceptional. RT was more frequent in group I (57%) than in group IIc (12%) (P < 0.001), less frequent than in group IIb (90.5%) (P < 0.001). AF was more frequent in group I (85%) than in group IIc (22%), or IIb (19%) (P < 0.001). Maximal rate through AP was higher in group I than in group II (P < 0.001). Adverse presentation in WPW may affect patients older than 35 years of both sexes, with a single free wall lateral AP. All could have been identified by an electrophysiological study.

Atrioventricular Nodal Reentrant Tachycardia

Atrioventricular nodal reentrant tachycardia (AVNRT) represents the most common regular supraventricular arrhythmia in humans.1 The precise anatomic site and nature of the pathways involved have not yet been established, and several attempts to provide a reasonable hypothesis based on anatomic or anisotropic models have been made.2 There has been considerable evidence that the right and left inferior extensions of the human atrioventricular (AV) node and the atrionodal inputs they facilitate may provide the anatomic substrate of the slow pathway, and a comprehensive model of the tachycardia circuit for all forms of AVNRT based on the concept of atrionodal inputs has been proposed.2 Still, however, the circuit of AVNRT remains elusive. Recently, time-honored conventional schemes for the diagnosis and classification of the various forms of the arrhythmia have been refuted in part by evolving evidence. Recognition of the various types of AVNRT is important, however, to expedite diagnosis and allow implementation of appropriate ablation therapy without complications. We present an update on AVNRT with a particular emphasis on electrophysiological criteria used for the differential diagnosis of regular, supraventricular tachycardias. Typically, AVNRT is a narrow-complex tachycardia, ie, QRS duration <120 ms, unless aberrant conduction, which is usually of the right bundle-branch type, or a previous conduction defect exists. Tachycardia-related ST depression and RR-interval variation may be seen. RR alternans in AVNRT has been attributed to the proposed model of a figure of 8 reentry with continuous crossing over of antegrade activation through an inferior input to the contralateral superior input via the node.2 In the typical form of AVNRT (slow-fast), abnormal (retrograde) P′ waves are constantly related to the QRS and in the majority of cases are indiscernible or very close to the QRS complex (RP′/RR <0.5). Thus, P′ waves are either masked by the QRS complex or …

Changing QRS Morphology in a Patient with Wolff-Parkinson-White Syndrome.

A case of Wolff-Parkinson-White syndrome with supraventricular tachycardia is presented in which 2 atrioventricular (AV) reentry circuits are identified. The first circuit used the AV node in the antegrade limb and a left lateral accessory pathway in the retrograde limb. The second circuit used an atriofascicular accessory pathway as the antegrade limb and the left lateral accessory pathway as the retrograde limb. The characteristics of these tachycardias are described, along with diagnostic maneuvers used in the electrophysiology laboratory. Mapping and ablation of both of these accessory pathways is also described. This article is aimed at clinical electrophysiologists interested in management of complex supraventricular tachycardias in the electrophysiology laboratory.

Wolff-Parkinson-White ablation after a prior failure: a 7-year multicentre experience

Catheter ablation for Wolff-Parkinson-White syndrome (WPW) can be challenging and is associated with failure in approximately 1-5% of cases. We analysed the reasons for failure. All patients (89 patients, 28 +/- 16 years old) referred for WPW ablation after a prior failure were studied. Reasons for the prior failure as well as for the acute success were analysed. The repeat procedure was successful in 81 (91%) patients. Multiple (2.7 +/- 0.9) or large accessory pathways (APs) were seen in 13 patients. For left lateral APs, inaccurate mapping and lack of transseptal access during the index procedure accounted for failure (n = 15). An irrigated-tip catheter was required for epicardial APs (n = 7). In addition, seven posteroseptal APs required bi-atrial and coronary sinus (CS) applications in order to succeed. For parahisian and midseptal APs, radiofrequency was cautiously titrated from 5 to 30 W, eliminating the AP in three patients. Cryoablation was used in seven patients (acute success in six but delayed recurrences in three of these). For patients with CS AP, irrigated ablation in the CS was crucial to deliver adequate power. For anteroseptal and right lateral APs, a successful outcome was achieved with long sheaths (n = 5) or a left subclavian approach (anteroseptal, n = 4). Failure in WPW ablation may be due to a variety of reasons but catheter manipulation and inaccurate mapping remain the two major causes. Knowledge of the reasons for failure depending on the location of the WPW may facilitate a successful outcome.

Coronary Artery Spasm During Radiofrequency Ablation of a Left Lateral Accessory Pathway

A 16-year-old female patient with Wolff-Parkinson-White syndrome and supraventricular tachycardia underwent radiofrequency (RF) catheter ablation of an accessory pathway in the left lateral area. During RF ablation she developed reversible ST segment elevation secondary to coronary artery spasm. Coronary angiography demonstrated the ablation catheter in close proximity to the circumflex coronary artery, with no evidence of coronary artery injury. Subsequently, conduction by way of the accessory pathway was successfully eliminated with cryoablation with no further coronary spasm or injury.

210 Incidence and significance of antidromic tachycardia induction in the Wolff-Parkinson-White syndrome

Electrophysiological study (EPS) is recommended in Wolff-Parkinson-White syndrome (WPW). Induction of orthodromic AV reentrant tachycardia (AVRT) is the most frequent. Atrial fibrillation (AF) induction is associated with the prognosis of WPW. Less is known on the induction of antidromic tachycardia (ATD). The purpose of the study was to determine the clinical and electrophysiological data of patients (pts) with a WPW and inducible ATD. EPS was performed in 637 pts with a WPW either for tachycardias (n=335) or syncope (n=88); other pts were asymptomatic (n=213). In control state (CS), the higher rate conducted through accessory pathway (AP) was measured; programmed atrial stimulation with 1 and 2 extrastimuli was performed. The protocol was repeated after isoproterenol infusion. ATD was induced in 45 pts (7%) (group I). The group was compared to remaining pts without inducible ATD (group II). Group I differed from group II by the following data: female sex was less frequent in group I (29.5%) than in group II (47%)(p<0.01); AP was more frequently left lateral sided in group I (54%) than in group II (38%)(p<0.05). AVRT was induced less frequently in group I (34%) than in group II (57%) (p<0.01); maximal rate conducted through AP was higher in group I (214±51 b/min) than in group II (189±61.5) in CS and after isoproterenol (280±56.5 in group I vs 237±61 in group II) (p <0.001). Some data were similar: age was similar in group I (34±20 years) and II (34.5±17); EPS indications were similar: syncope, reentrant tachycardia, spontaneous AF or asymptomatic WPW were the reasons of evaluation respectively in 16%, 43%, 11%, 25% of group I pts and 14%, 46%, 5.5%, 35% of group II pts (NS); left and right posteroseptal AP, anteroseptal AP, right lateral AP and other locations were similar in both groups; AF was induced as frequently in group I (27%) as in group II (23%). ATD was induced more frequently in men than in women and in pts with a left lateral-sided AP, which conducted more rapidly than in pts without inducible ATD. Clinical presentation, age and AF induction were similar in pts with and without inducible ATD.

Mitral isthmus conduction block: intriguing result of radiofrequency catheter ablation for a left concealed accessory pathway

We report on our experience with complete mitral isthmus conduction block achieved inadvertently during radiofrequency (RF) catheter ablation for a left lateral concealed accessory pathway (AP) mimicking concentric retrograde activation. This rare condition should be acknowledged to avoid misdiagnosis of another concomitant AP and to avoid RF applications in inappropriate areas.

Characterization of Cardiac Brain Natriuretic Peptide Release in Patients With Paroxysmal Atrial Fibrillation Undergoing Left Atrial Ablation

Paroxysmal atrial fibrillation (PAF) is associated with elevated levels of brain natriuretic peptide (BNP). The exact cardiac source and implications of this are currently unknown, as are the effects of left atrial ablation on cardiac BNP release. We sought to investigate BNP levels at different cardiac sites in PAF patients before and after left atrial ablation and compare these with a non-atrial fibrillation control cohort. Twenty PAF patients (52+/-10 years, 70% men; left ventricular ejection fraction, 55+/-3%) undergoing ablation were studied, BNP levels were measured at different cardiac sites before and after ablation and compared with a control cohort undergoing ablation for left lateral accessory pathways (10 patients, 41+/-11 years; left ventricular ejection fraction, 55+/-4%). In both cohorts, the coronary sinus BNP levels were the greatest. The PAF cohort had significantly greater BNP levels than the control cohort at all sites before and after ablation. Ablation of the left atrium was associated with a significant decrease in coronary sinus BNP levels (P=0.05) and transcardiac BNP gradient (P=0.03). This was not observed in the control cohort. BNP levels are elevated in PAF, with the highest levels in the coronary sinus. Ablation of the left atrium was associated with an immediate decrease of BNP levels, implicating this as the source.

Octopus Papillary Muscle Associated with a Left Lateral Accessory Pathway

Left ventricular papillary muscle abnormalities are rare malformations. They have been related to significant mitral valve dysfunction and left ventricular midcavitary obstruction. We report our experience with a young adult who presented with palpitations. An echocardiogram on the patient showed an "octopus-like" left ventricular papillary muscle. Subsequent electrophysiologic testing showed evidence of supraventricular tachycardia via a left lateral accessory pathway associated with the abnormal insertion of the papillary muscle attachments.

Not so innocent bystander(s)

A patient with atrial flutter, intermittent non-sustained wide complex tachycardia and 1:1 AV conduction is reported. Electrophysiology testing showed counterclockwise isthmus-dependent right atrial flutter with conduction via the AV node and an innocent bystander left lateral accessory pathway. This explained the observed intermittent wide complex tachycardia. After successful bidirectional cavotricuspid isthmus conduction block, a sustained wide complex tachycardia with identical counterclockwise right atrial activation and rate occurred. This was due to antidromic AV re-entrant tachycardia with innocent bystander activation of the right atrium mimicking atrial flutter. Accessory pathway ablation effectively stopped tachycardia.

G017 Factors associated with the induction of antidromic tachycardia in the wolff-parkinson-white syndrome

Atrioventricular reentrant tachycardia (AVRT) is the most frequent inducible tachycardia in patients with a Wolff-Parkinson-White syndrome (WPW). The incidence and the causes of the induction of antidromic tachycardia (ATD) are unknown. The purpose of the study was to determine the data of patients with a WPW and with inducible ATD. 605 patients had a WPW and tachycardias (n=312) or syncope (n = 85); other patients were asymptomatic (n = 208). Electrophysiological study (EPS) was systematic. In control state (CS), the higher rate conducted through accessory pathway (AP) was measured; programmed atrial stimulation with 1, 2 extrastimuli was performed to induce a tachycardia. Isoproterenol (0.02 to 1 μg. min-1) was infused and the protocol was repeated. ATD was induced in 44 patients (7 %) (group I). Their data were compared to those of remaining patients (group II). Group I differed from group II by the following data: Female sex was less frequent in group I (29.5 %) than in group II (47 %); AP was more frequently left sided in group I (54.5 %) than in group II (38 %) (p < 0.05). AVRT was induced less frequently in group I (34 %) than in group II (57 %) (p < 0.01); maximal rate conducted through AP was higher in group I (215 ± 52 b/min) than in group II (189 ± 61) in control state, and after isoproterenol (281 ± 57 in group I vs 236 ± 61 in group II) (p < 0.001). Some data were similar: Age was not different in group I (33.5 ± 20 years) and II (34.5 ± 17); the indications of EPS were similar (syncope, reentrant tachycardia, atrial fibrillation (AF) or asymptomatic WPW were the reasons for 16 %, 43 %, 11 % and 25 % of group I patients and 14 %, 46 %, 5.5 % and 35 % of group II patients); posteroseptal and right AP locations were similar in both groups; AF was induced as frequently in group I (27 %) as in group II (23 %). antidromic tachycardia was induced more frequently in men than in women, with a left lateral AP which conducted more rapidly than in other patients.