Left Posterior Accessory Pathway Research Articles

Abstract 13210: A Hidden Right Atrial Lipoma in a Patient With Recurrent Sustained Supraventricular Tachycardias

Introduction: Cardiac lipomas, known for their benign nature, compose 8 percent of primary cardiac tumors. Advanced imaging modalities allow improved diagnosis, yet little of their potential complications involving the heart's conduction system is known. Case: A 65-year-old male presented to the Emergency Department with palpitations. History was significant for recurrent sustained orthodromic atrioventricular reentrant tachycardia using a concealed left posterior accessory pathway from a prior EP study. He was treated with ablation twice in the past. The patient was hemodynamically stable on evaluation. ECG showed supraventricular tachycardia (SVT) involving orthodromic re-entry with a ventricular rate of 227 bpm. Computer tomography (CT) of the chest revealed a large, low-attenuated lesion with -102 Hounsfield unit (HU) attached to the right atrial roof, extending to both SVC and IVC. No sparing of foramen ovale was seen. Findings suggest right atrial lipoma. A transthoracic echocardiogram (TTE) visualized the same echo-dense structure without increased vascularity. The patient responded to intravenous Adenosine. We discussed the case with the Cardiothoracic surgery team. Outpatient cardiac MRI and elective surgery were planned. Discussion: The case presented clinically significant atrial arrhythmia in a patient with a massive right atrial lipoma. Although most cardiac lipomas remain asymptomatic, arrhythmias coinciding with the location of involved chambers have been reported. In addition, the recurrence of orthodromic tachycardia despite previous ablation suggests the potential benefit of surgical intervention.

PO-687-04 TRANSJUGULAR ABLATION OF CORONARY SINUS DIVERTICULUM-RELATED ACCESSORY PATHWAYS

Up to 7.5% of posteroseptal or left posterior accessory pathways may demonstrate a coronary sinus diverticulum (CSD), and their presence can make ablation challenging due to oblique course of fibers and may result in failed ablations. It is unclear if a jugular approach to mapping and ablation of coronary sinus (CS) accessory pathways (CSAPs) within CSDs is better than a femoral approach.

A Case of Atrioventricular Reentrant Tachycardia Via a Left Posterior Accessory Pathway Located at Adjacent to the Leftward Extension of the Atrioventricular Node

A Case of Atrioventricular Reentrant Tachycardia Via a Left Posterior Accessory Pathway Located at Adjacent to the Leftward Extension of the Atrioventricular Node

An unusual type of accessory pathway in tricuspid atresia

The occurrence of pre-excitation in tricuspid atresia (TA) is slightly more common than that in normal children. The accessory pathway (AP), when it occurs in the setting of congenital atrioventricular valvar disease, is usually ipsilateral to the side of the abnormal valve. This report describes a patient with TA who had pre-excitation due to a left-sided AP that masked and modified the typical electrocardiographic features. The electrophysiological study confirmed an epicardial left posterior AP that was successfully ablated with radiofrequency energy, through the coronary sinus. Left-sided APs including epicardial ones may rarely be seen in TA and can potentially cause difficulties due to lack of vascular access to the heart after the Fontan surgery if arrhythmias occur. They are amenable to successful radiofrequency ablation and need to be dressed prior to Fontan surgery.<Learning objective: Pre-excitation may become manifest during follow-up even if minimal at initial presentation. Accessory pathways may occur in the left side of the heart in tricuspid atresia, in contrast to the usual notion that APs occur ipsilateral to the side of the abnormal valve. Electrophysiological study may be useful prior to Fontan-type procedures as this helps in identifying and to prognosticate pre-excitation so that ablation of the pathway can be performed prior to the Fontan procedure.>

Catheter ablation for Wolff–Parkinson–White syndrome with coronary sinus diverticulum in a 15-year-old boy

The left posterior and posteroseptal accessory pathways often have an epicardial accessory and are associated with coronary vein anomalies, such as diverticulum, fusiform, or bulbous enlargement. We report the case of a 15-year-old boy who suffered from palpitation due to Wolff–Parkinson–White syndrome with coronary sinus diverticulum. An electrophysiology study revealed a left posterior accessory pathway and orthodromic atrioventricular reciprocating tachycardia. After the transseptal puncture, we performed mapping around the mitral annulus during sinus rhythm. We could not detect typical atrioventricular fusion accompanied with accessory pathway potential and failed to ablate around the mitral annulus. We revealed typical accessory pathway potential in a coronary vein and successfully ablated. After ablation, a right atrium angiography showed a successful ablation site was just at the neck of coronary sinus diverticulum. It is important for a successful and safe ablation to evaluate coronary vein anomalies in patients with left posterior and posteroseptal accessory pathways.<Learning objective: In pediatric patients, Wolff–Parkinson–White syndrome with the posteroseptal accessory pathway with coronary sinus diverticulum is rare. It is important to predict the left posterior and posteroseptal accessory pathways from the polarity of the delta wave; ablation for pediatric patients seems to be more effective and safe in confirming coronary sinus diverticulum by echocardiogram before electrophysiology study and performing coronary vein angiography before mapping of the accessory pathway.>

Successful Cryoablation of Atrioventricular Nodal Reentrant Tachycardia and Coexisting Accessory Pathways without Fluoroscopy

We report the case of a 14-year-old boy patient admitted to our outpatient clinic with palpitations and documented supraventricular tachycardia. Electrophysiological study and ablation were planned. In the electrophysiological study, two tachycardias with different cycle lengths and morphologies were induced. After elimination of the slow pathway, left posterior accessory pathway was detected and successfully ablated. Another pathway was detected following that ablation. Due to the slow retrograde conduction of this pathway, diltiazem infusion was started to uncover the accessory pathway. The second accessory pathway was at the left posteroseptal region and was successfully ablated. After a 30-minute waiting period, no tachycardia was induced. In addition, no fluoroscopy was used during the procedure.

Angiographic patterns of coronary sinus anatomy and its relation to successful ablation sites in accessory pathway patients

The epicardial coronary venous system assumes importance in accessory pathway (AP) ablation especially in case of lengthy or failed attempts of ablation. Epicardial accessory pathways may be related to CS myocardial coat along one of its tributaries or to a CS diverticulum. The purpose of the present study was to use CS angiography to evaluate the relation of different patterns of CS anatomy to successful ablation sites of APs. The CS-angiographic features and incidence of structural anomalies were prospectively studied in 56 patients undergoing AP radiofrequency ablation. Retrograde CS angiography was successfully performed in 46/56 pt (82%), (33 males/13 females). The CS angiographic findings of the 46 patients were compared to the AP localization established by electrophysiological mapping and to the successful ablation sites. CS anomalies were identified in 17 (37%) patients and included the following: CS diverticulum (seven patients), funnel shaped ostium (three patients), CS aneurysm (two patients), subthebasian pouch (one patient), sharp angulation (one patient), and bulbous malformation (one patient). CS diverticuli represented (41%) of the encountered CS anomalies. Seventy-one percent of the CS diverticuli were seen in posteroseptal and left posterior locations of APs. Successful ablation site was related to CS-anomalies in seven (15.2%) patients (five patients with CS diverticulum, one patient with CS aneurysm, and one patient with CS angulation). Successful ablation was achieved from within the CS (coronary sinus – accessory pathway) (CS AP) in 10 patients (21.7%) (in relation to CS tributary in six (13%) and in relation to the neck of a CS diverticulum in four patients). CS AP represented 50% of the encountered posteroseptal and left posterior APs. CS angiography can guide us in reaching successful ablation sites of AP inside or outside the CS. CS diverticulum is the most common CS anomaly in posteroseptal and left posterior APs.

Examining the causes of ablation failure in the Wolff-Parkinson-White syndrome

the His-bundle at a midseptal or anteroseptal location, increasing the risk of inadvertent complete atrioventricular block. The use of a long sheath may facilitate catheter stability if the accessory pathway is located along the right midseptal or anteroseptal region. In these cases, we favour advancement of the ablation catheter from the right jugular vein, since this site of access is in direct alignment with the location of the accessory pathway. Stable wall contact is accomplished by counterclockwise torque of the catheter. In addition, we found that an anteroseptal pathway may be successfully ablated from the non-coronary cusp. 7 Some operators prefer to use cryothermia. Our laboratory routinely uses RF current when ablating para-Hisian pathways. A His potential is practically always recorded at the earliest site of accessory pathway activation. However, the His bundle is protected by fibrous tissue, whereas the accessory pathway is superficially located, making damage to the His bundle very unlikely with the judicious use of RF energy. An epicardial accessory pathway location may not be amenable to a routine endocardial approach. If a posteroseptal accessory pathway is suspected, coronary sinus angiography will facilitate proper anatomic delineation and catheter ablation. In 21% of patients with a suspected posteroseptal or left posterior accessory pathway, coronary sinus angiography demonstrated a diverticulum originating from the middle cardiac vein, coronary sinus, or both. 8 Ablation is performed by advancing the ablation catheter into the coronary sinus, targeting the neck of the diverticulum. In rare cases, an epicardial accessory pathway may mimic electrocardiographic criteria of a manifest right anteroseptal accessory pathway. Clues to the correct diagnosis during endocardial

Differences in accessory pathway location by sex and race

The etiology of accessory pathway (AP) formation is generally unknown. The purpose of this study was to test the hypothesis that AP formation is genetically mediated by examining whether AP location differs by sex and/or race, using sex and race as proxies to distinguish genetically different individuals. This was a single-center, retrospective cohort study of 282 consecutive patients undergoing their first electrophysiology study that revealed at least one AP between 2004 and 2008. Sex and race were compared with AP location determined by invasive electrophysiology study. Eighty-nine (52%) males and 40 (36%) females had a left posterior AP (P = .006). Sixty-four (57%) females had a right annular AP, compared with 55 (32%) males (P <.001). After adjusting for age and race, females had 2.8-fold greater odds of having a right annular AP compared with males (95% confidence interval [CI] 1.70-4.65 greater odds; P <.001). While right anterior (free-wall) pathways were rare in all other races (12%), a significantly larger proportion of Asians (n = 10, 26%) had a right anterior AP (P = .017). After adjusting for sex and age, Asians had 3.8-fold greater odds of having a right anterior AP compared with other races (95% CI 1.5-9.4 greater odds; P = .004). Females more commonly had right annular APs, and Asians had right anterior APs substantially more frequently than other races. These findings suggest that the pathogenesis of AP formation may have a genetic component.

Catheter ablation of an atrioventricular bypass tract connecting a funnel-shaped bilobular left atrial appendage with the ventricular free wall

A female patient with Wolff-Parkinson-White syndrome and frequent episodes of atrioventricular reentrant tachycardia was referred for electrophysiologic evaluation and interventional treatment. Twelve-lead surface ECG showed preexcitation with a negative delta wave in leads I and aVL and positive delta waves in the inferior leads and leads V1–V6, indicating a left posterior accessory pathway (AP) localization. After confirmation of a left posterior AP localization by an eccentric activation in the coronary sinus (CS) during both sinus rhythm and retrograde stimulation, the left atrium (LA) was accessed via a transseptal puncture for an anterograde approach.

Ablation of Posteroseptal and Left Posterior Accessory Pathways Guided by Left Atrium–Coronary Sinus Musculature Activation Sequence

While some posteroseptal and left posterior accessory pathways (APs) can be ablated on the tricuspid annulus or within the coronary venous system, others require a left-sided approach. "Fragmented" or double potentials are frequently recorded in the coronary sinus (CS), with a smaller, blunt component from left atrial (LA) myocardium, and a larger, sharp signal from the CS musculature. Forty patients with posteroseptal or left posterior AP were included. The LA-CS activation sequence was determined at the earliest site during retrograde AP conduction. Eleven APs (27.5%) were ablated on the tricuspid annulus (right endocardial), 9 (22.5%) inside the coronary venous system (epicardial), and 20 (50%) on the mitral annulus (left endocardial). A "fragmented" or double "atrial" potential was recorded in all patients inside the CS at the earliest site during retrograde AP conduction. Sharp potential from the CS preceded the LA blunt component (sharp/blunt sequence) in all patients with an epicardial AP, and in 10 of 11 (91%) patients with a right endocardial AP. Therefore, 18 of 19 (95%) APs ablated by a right-sided approach produced this pattern. The reverse sequence (blunt/sharp) was recorded in 19 of 20 (95%) patients with a left endocardial AP. During retrograde AP conduction, the sequence of LA-CS musculature activation-as deduced from analysis of electrograms recorded at the earliest site inside the CS-can differentiate posteroseptal and left posterior APs that require left heart catheterization from those that can be eliminated by a totally venous approach.

A new algorithm for concealed accessory pathway localization using T-wave-subtracted retrograde P-wave polarity during orthodromic atrioventricular reentrant tachycardia

AP localization can be predicted by analyzing the polarity of the delta wave, QRS polarity, and R/S ratio in patients with Wolff-Parkinson-White syndrome. However, the estimation of AP location is limited in patients with concealed pathways during atrioventricular reentrant tachycardias (AVRT). Thus, we analyzed retrograde P-wave polarity during orthodromic AVRT and developed an algorithm to predict the localization of concealed accessory pathways (AP). A total number of 131 patients with a single AP and inducible orthodromic AVRT were included. The initial 61 patients were analyzed retrospectively for algorithm development, whereas 70 patients were evaluated prospectively. The retrograde P-wave polarity was analyzed by subtracting the superimposing T-wave during orthodromic AVRT using custom-designed software. Four leads of the surface electrocardiogram (ECG) were identified to accurately distinguish AP locations assigned to four different regions around each AV annulus: I, aVR, aVL, and V(1). Lead V(1) was used to differentiate right (negative or isoelectric) from left (solely positive) APs. Retrograde P-wave in lead I was negative in left posterior APs exclusively and became more positive with an AP location shifting towards right anterior. P-wave polarity in lead aVR demonstrated a shift from a positive polarity from left APs to isoelectric in right APs. The opposite direction (shift from positive to isoelectric) was observed for lead aVL. The subsequently developed algorithm for concealed AP localization using these surface ECG leads demonstrated a high sensitivity, specificity, and positive predictive value particularly for common AP localizations (left posterior and inferior, and right septal) when applied in a prospective fashion. Concealed AP localization can be accurately predicted by the analysis of retrograde P-wave polarity during orthodromic AVRT using the algorithm derived from the presented study.

Effect of left atrial-coronary sinus musculature connections on the coronary sinus activation pattern via retrograde conduction in patients with WPW syndrome.

Double potential (DP) activation patterns observed in coronary sinus (CS) electrograms recorded during left lateral atrial pacing, were explained by an initial low-frequency left atrial (LA) activation potential and secondary high-frequency CS musculature activation potential in canine hearts. Moreover, the connections between the LA and CS musculature vary greatly in size and location in the human heart. The purpose of this study was to investigate the relationship between the CS activation pattern during retrograde conduction via an accessory pathway (AP) and the location of left-sided APs. Fifty-one patients (31 males, mean age 48.6 years) who underwent radiofrequency catheter ablation of left-sided APs were divided into two groups according to the successful ablation site. The CS electrograms during retrograde AP conduction were classified into 3 types; single, fractionated, and DP activation patterns. A DP pattern was identified in 10 of 12 patients (83.3%) with posteroseptal to posterolateral APs, and in particular, 9 had a divergent sequence. Twenty-six of 39 patients (66.7%) with lateral to anterolateral APs, demonstrated a single pattern. The number of radiofrequency applications was significantly higher in patients with a DP pattern than in those with a single pattern (3.4 +/- 3.3 vs. 7.8 +/- 6.8, p < 0.01). Misleading information obtained when mapping for optimal ablation sites might result from DP patterns with a divergent sequence produced by discrete muscular connections between the LA and CS musculature. Ablation around left posterior APs may require meticulous observation of the CS activation patterns.

Coronary sinus-ventricular accessory connections producing posteroseptal and left posterior accessory pathways: incidence and electrophysiological identification.

The coronary sinus (CS) has a myocardial coat (CSMC) with extensive connections to the left and right atria. We postulated that some posteroseptal and left posterior accessory pathways (CSAPs) result from connections between a cuff of CSMC extending along the middle cardiac vein (MCV) or posterior coronary vein (PCV) and the ventricle. The purpose of the present study was to use CS angiography and mapping to define and determine the incidence of CSAPs and determine the relationship to CS anatomy. CSAP was defined by accessory pathway (AP) potential or earliest activation in the MCV or PCV and late activation at anular endocardial sites. A CSAP was identified in 171 of 480 patients undergoing ablation of a posteroseptal or left posterior AP. CS angiography revealed a CS diverticulum in 36 (21%) and fusiform or bulbous enlargement of the small cardiac vein, MCV, or CS in 15 (9%) patients. The remaining 120 (70%) patients had an angiographically normal CS. A CSMC extension potential (CSE), like an AP potential, was recorded in the MCV in 98 (82%), in the PCV in 13 (11%), in both the MCV and PCV in 6 (5%), and in the CS in 3 (2%) of 120 patients. CSMC potentials were recorded between the timing of atrial and CSE potentials. CSAPs result from a connection between a CSMC extension (along the MCV or PCV) and the ventricle. The CS is angiographically normal in most patients.

Atypical form of the fourth criterion for transient entrainment.

The typical fourth criterion for transient entrainment is defined when both a sudden shortening in conduction interval to and a distinct change in electrogram morphology at a bipolar recording site are demonstrated while performing overdrive pacing of a reentrant tachycardia from a single pacing site at two different constant rates. The purpose of this article was to test the hypothesis that if an intracardiac recording site showing both orthodromic and antidromic capture with entrainment pacing is located suitably distant from the circuit, sudden shortening in conduction interval to that site may occur without any significant change in the bipolar electrogram morphology (i.e., atypical form of the fourth criterion). Atrial overdrive pacing of orthodromic tachycardia was performed in 20 patients with either left anterior (12 patients) or left posterior (8 patients) accessory pathways. We investigated the effects of overdrive pacing from the proximal or distal coronary sinus, specifically effects on the electrogram interval and the electrogram morphology at the right atrial appendage. Overdrive pacing of orthodromic tachycardia from the proximal coronary sinus was performed in 10 of the 12 patients with left anterior accessory pathways; those 10 patients demonstrated the first entrainment criterion at the right atrial appendage site. Overdrive pacing of orthodromic tachycardia at still shorter cycle lengths demonstrated a sudden shortening in conduction interval to the right atrial appendage site. Despite shortening in conduction interval the morphology of the right atrial appendage electrogram was completely or almost identical to that during orthodromic tachycardia, indicating an atypical form of the fourth criterion. This criterion was not demonstrated in patients with left posterior accessory pathways. Thus, atypical fourth entrainment criterion was demonstrated during overdrive pacing of orthodromic tachycardia from the proximal coronary sinus only in patients with left anterior accessory pathways. Demonstration of atypical fourth criterion seems largely dependent on the location of the accessory pathway, the pacing, and the recording sites.

Coronary sinus stenosis as a late complication of catheter ablation in Wolff‐Parkinson‐White syndrome

This report describes a patient who developed stenosis of coronary sinus and cardiac veins five years after application of electric shock currents to the posterior mitral annulus and posteroseptal region of the tricuspid annulus for ablation of a left posterior accessory pathway and a right posteroseptal accessory pathway. This is the first angiographic documentation of coronary sinus stenosis as a late complication of electric ablation of accessory pathway. Cathet. Cardiovasc. Diagn. 42:70–72, 1997. © 1997 Wiley-Liss, Inc.

Echocardiographic demonstration of coronary sinus diverticula in patients with Wolff-Parkinson-White syndrome

Coronary sinus (CS) diverticula have been reported to be the anatomic basis of some posteroseptal accessory atrioventricular pathways. During 1 year, 53 patients with Wolff-Parkinson-White syndrome referred to our center for catheter ablation were found to have posteroseptal or left posterior accessory pathways. The accessory pathway was associated with an anomaly of the CS in seven patients (13%), including six diverticula of the CS or its branches and one aneurysmal CS. Four of the CS diverticula were visualized by transesophageal echocardiography. Diverticula appear as echolucent, contractile pouches on the epicardial surface of the posteroseptal or posterior left ventricle that connect to the CS by an isthmus. Previous reports have suggested that accessory pathways associated with CS aneurysms have rapid conduction times and may be associated with an increased risk of rapid ventricular response during atrial fibrillation and sudden death; five of our seven patients had a short preexcited R-R interval in the range of 172 to 225 msec during atrial fibrillation. In summary, many, if not the majority, of CS diverticula associated with preexcitation can be visualized by transesophageal echocardiography.

Concertina-like Phenomenon in Ventricular Preexcitation Due to Spontaneous Atrioventricular Nodal Wenckebach Periodicity

Electrophysiologic study and radiofrequency ablation therapy were performed in a 28-year-old male patient with the Wolff-Parkinson-White syndrome and electrocardiographic manifestation of concertina phenomenon. His bundle recordings showed a sinus cycle length of 720 = ms with a cyclic variation of QRS morphologies of every 3 beats and an antidromic atrial echo following the last fully preexcited QRS complex. After successful radiofrequency ablation of a left posterior accessory pathway, spontaneous 3:2 atrioventricular nodal Wenckebach periodicity was noted and the mechanism of the concertina phenomenon was unraveled.

Radiofrequency Ablation of Left‐Sided Accessory Atrioventricular Pathways in Patients with Unusual Coronary Sinus

Four patients with left-sided accessory pathways (APs) and unusual coronary sinus (CS) received radiofrequency ablation. Unusual CS included occlusion of CS (patient 1), acute angulation of proximal CS (patients 2 and 3), and narrowing of CS orifice and proximal segment (patient 4). CS catheterization and AP mapping along the CS could not be performed in the four patients. Radiofrequency ablation by left ventricular retrograde technique for the manifest left posteroseptal AP (patient 1), concealed left posterior AP (patient 2), and transseptal left atrial technique for the manifest left posteroseptal AP (patient 3) and manifest left posterior AP (patient 4) were performed successfully without CS catheter guidance. This study suggests that radiofrequency ablation of left-sided AP with unusual CS is feasible by some special techniques.

Two Accessory Pathways, Dual AV Nodal Conduction, and 1:2 Ventriculoatrial Conduction in a Patient with Multiple Supraventricular Tachycardias

Multiple supraventricular tachycardias were induced in a patient with two left posterior accessory pathways and dual atrioventricular nodal conduction. One of the accessory pathways conducts slowly and exhibits decremental conduction. A "double retrograde response" (2:1 ventriculoatrial conduction) due to simultaneous retrograde propagation of a single ventricular depolarization over two longitudinally dissociated pathways plays a role not only in tachycardia initiation, but in the maintenance of a unique, irregular tachycardia.