Left Lateral Accessory Pathway Research Articles

A left lateral accessory pathway unmasked by rivastigmine

A 75-year-old woman was referred for advice regarding surface electrocardiographic modifications after the initiation of rivastigmine. In our patient, the baseline ECGs appeared perfectly normal. However, the initiation of a cholinesterase inhibitor unmasked a left lateral accessory pathway that had never been diagnosed before. Although cholinesterase inhibitors are known to increase vagal tone, the PR interval was shortened after rivastigmine administration, thus excluding this hypothesis to explain the appearance of the accessory pathway. Therefore, we hypothesized that cholinesterase inhibitors may have increased conduction velocity in the accessory pathway or in the atria.

MITRAL ISTHMUS BLOCK VERIFICATION USING A SINGLE CATHETER

The report describes the case of electrophysiological study and catheter ablation of right atrial flutter in patient undergone left lateral accessory pathway ablation. The technique of mitral isthmus block verification using a single catheter is described. This technique allows refusing unnecessary transseptal puncture, additional central vein catherization and use of extra catheter.

Ventriculoatrial Intervals ≤70 ms in Orthodromic Atrioventricular Reciprocating Tachycardia.

Although a ventriculoatrial interval (VAI) of ≤70 ms is used to distinguish atrioventricular nodal reentrant tachycardia from orthodromic atrioventricular reciprocating tachycardia (AVRT), a VAI of ≤70 ms is sometimes observed in cases of AVRT. The study aimed to evaluate the short VAI that is seen in AVRT and to understand its underlying mechanism. Electrophysiologic studies of 46 consecutive patients with AVRT involving an accessory pathway (AP) were examined retrospectively. AP was right sided in seven patients and left sided in 39. A VAI (interval from QRS onset to the earliest intracardiac atrial electrogram recorded by any mapping catheter during AVRT) ≤70 ms during AVRT (short VAI) was observed in eight patients: six with a left lateral AP and two with a left posteroseptal AP. During AVRT involving a left-sided AP, the QRS-V interval (from the earliest QRS onset to the local ventricular electrogram at a site which showed earliest atrial electrogram recorded from the coronary sinus catheter) was significantly shorter (37 ± 7 ms vs 54 ± 13 ms, P = 0.001) and supernormal conduction (QRS duration or the QRS-V interval shortening by ≥10 ms during AVRT) was more frequently seen (63% vs 6%, P = 0.02) in the short VAI group than in the normal VAI group. Furthermore, these parameters were shown to be determinants for short VAI. A short VAI is sometimes observed during AVRT involving a left-sided AP. The short VAI may be caused by rapid propagation or supernormal conduction between the proximal Purkinje-muscle junction and basal left ventricular myocardium.

96-27: Dual decremental limbs in a reciprocating tachycardia- an electrophysiological problem or the lack of it?

Introduction: Characterization of multiple decremental accessory pathways (AP) can be challenging. Methods: N/A Results: A 29-year old male with minimal electrocardiographic preexcitation and normal heart was evaluated for palpitations without a known tachycardia. Baseline HV interval was 13ms and ventricular activation in the para-Hisian region preceded the delta wave. Programmed atrial stimulation subtly but progressively increased preexcitation, as evidenced by loss of physiologic septal activation (loss of r-wave in V1 and q-waves in I, aVL), with short AVERP (<220ms). AV prolongation associated with a negative HV interval during increased pre-excitation and presence of junctional preexcited beats established the diagnosis of a nodoventricular (NV) pathway. Retrograde conduction was evidently through a left lateral AP with slow decremental conduction and long VAERP (340ms). Depending on the decrement in retrograde AP conduction, reciprocating ventricular echo-beats were reproducible during fixed ventricular pacing. A non-sustained tachycardia (CL 310ms-345ms) was induced with ventricular pacing soon after recovery of VA block following adenosine. The QRS morphology of the echo- beats and tachycardia represented fused NV and AV-nodal conduction decided by preceding coupling interval. Catheter ablation of the concealed left AP was successfully performed with resultant VA dissociation. No further ventricular echo-beats or tachycardias were observed. Ablation of the NV pathway was not attempted.

216-33: High resolution mapping and ablation of a recurrent left lateral accessory pathway conduction

216-33: High resolution mapping and ablation of a recurrent left lateral accessory pathway conduction

Percutaneous Retrieval of an Entrapped Ablation Catheter during a Retrograde Approach for a Left Free Wall Accessory Pathway

A 25-year-old man suffered from repeated attacks of orthodromic atrioventricular reciprocating tachycardia utilizing a left lateral accessory pathway (AP) for retrograde conduction. The catheter was approached through the aorta to map the AP and was entrapped in the mitral valve apparatus, and it had a broken internal wire. A snareassisted technique was successfully utilized to retrieve the catheter.

Percutaneous Retrieval of an Entrapped Ablation Catheter during a Retrograde Approach for a Left Free Wall Accessory Pathwa

A 25-year-old man suffered from repeated attacks of orthodromic atrioventricular reciprocating tachycardia utilizing a left lateral accessory pathway (AP) for retrograde conduction. The catheter was approached through the aorta to map the AP and was entrapped in the mitral valve apparatus, and it had a broken internal wire. A snareassisted technique was successfully utilized to retrieve the catheter.

0329: Zero-fluoroscopy ablation for young patients: about 2 cases

Radiofrequency catheter ablation (RFA) is the mainstay of therapy for supraventricular arrhythmias. Conventional radiofrequency catheter ablation requires the use of fluoroscopy, exposing patients to ionising radiation. The feasibility and safety of non-fluoroscopic ablation has already been reported using three-dimensional mapping systems. We are reporting 2 cases of young patients, for whom a RFA was performed without using Fluoroscopy. 1 rt Case: A 20-year old patient, presenting dyspnea and palpitation. Physical examination was normal. On ECG, a supraventricular tachycardia (SVT) with long RP and negative P waves in inferior leads was noted. RF ablation was indicated. Catheters were placed in the right atrium without the need to use fluoroscopy, guided by Carto 3D system mapping. The electrophysiology study made the diagnosis of atrial tachycardie arising from the coronary sinus ostium. The foci was successfully ablated. 2 nd Case: A 16-year old patient, consulting for orthodromic reciproting tachycardia. Physical exmination and transthoracic echocardiography were unremarkable. Catheters were placed in the right atrium without the need to use fluoroscopy, guided by Carto 3 D system mapping. Tachycardia was initiated via atrial pacing. An anterograd left lateral accessory pathway was diagnosed. Left atrium was mapped with Carto 3D system through a permeable foramen ovale. The pathway was ablated. Ablation of SVT without use of fluoroscopy has a high acute procedural success rate with low incidence of procedural complication. Use of this technique completely relieves the patient and healthcare of radiation exposure.

Five tachycardia mechanisms in a structurally normal heart

A 22 year old man with WPW syndrome and a structurally normal heart was admitted for the treatment of recurrent paroxysmal tachycardia. Induction protocols gave interesting clues for existence of more than one tachycardia mechanism. Five different tachycardia were demonstrated, the substrates being a right free wall accessory pathway (AP), a left lateral AP and dual AV nodal physiology. Successful ablation at 3 sites (lateral tricuspid annulus, lateral mitral annulus and slow pathway) in the same session led to complete elimination of these tachycardia mechanisms. Key words: AVRT, His refractory, Outflow VT, Fascicular VT, Slow pathway.

322 A case of asymptomatic exercise and Wolff–Parkinson–White syndrome: Physio's be aware!

A cardiopulmonary exercise test (CPET) including ECG is performed to assess aerobic exercise capacity and monitor exercise induced limitations. ECG is not routinely performed at clinic or annual reviews in children with CF. Cardiac arrhythmias are reportedly rare in CF. Objectives This report highlights a previously undiagnosed abnormal ECG in a child with CF during CPET. Methods A 13-year old girl, genotype ΔF508/unknown, FEV 1 was 1.43 L (75% pred.) with pancreatic insufficiency, was recruited to participate in a CF trial assessing the effects of weekly exercise. She underwent baseline testing that included spirometry, CPET, 10 m modified shuttle walk and quality of life assessment. Results Resting ECG detected a delta wave associated with a short PR interval (SpO 2 95%, HR 110 bpm and BP 118/60). Throughout CPET the delta wave remained unresolved. Other CPET outcomes were unremarkable. Post-testing the cardiology team fitted a 24-hour Holter monitor. Wolff–Parkinson–White (WPW) syndrome was diagnosed, with a recommendation for further electrophysiological investigation. Interventional ablation of the left lateral accessory pathway was performed 2 months post-diagnosis and the girl was advised to return to full physical activity. Conclusion This patient was asymptomatic during exercise prior to testing, so WPW syndrome may have remained undiagnosed had she not undertaken CPET. This highlights a potential risk area in CF assessment. With increased emphasis on increasing exercise and physical activity in these patients, it is recommended that individuals with CF are assessed carefully and cardiac monitoring is considered alongside routine CF examinations.

Narrow complex tachycardia after ablation of the left lateral accessory pathway: What is the mechanism?

Narrow complex tachycardia after ablation of the left lateral accessory pathway: What is the mechanism?

Both atrioventricular nodal reentrant and atrioventricular reentrant tachycardias in one patient: a case report

E-mail: ivanzeljkov@gmail.com The two most common supraventricular tachycardias are typical (slow-fast) atrioventricular nodal reentrant tachycardia (AVNRT) and orthodromic atrioventricular reentrant tachycardia (AVRT) using accessory pathway (AP). Nowadays, a leading method in the treatment of supraventricular re-entrant tachycardias is radio-frequent (RF) catheter ablation during the electrophysiological (EP) study. We report the case of a 46-year old woman on whom an EP study was performed due to the presence of paroxysmal supraventricular tachycardia documented in 12-lead ECG. During the EP study, at baseline, supraventricular tachycardia was induced very easily and it corresponded to orthodromic AVRT (frequency of 190-200/min) using concealed, left lateral AP (PPI TCL = 100 ms; VAV pattern, preceding positive for AP). However, during the study, AVRT spontaneously converted to the typical slow-fast AVNRT (frequency 150/min) using the slow AV node pathway (PPI TCL >150 ms; VA < 30 ms; preceding negative for AP; jump noted at programmed pacing (500+280 ms) from right atrium as well as echo beat). During the EP study, a slow pathway was localized and then ablated using the RF catheter ablation. By performing the transseptal puncture of the interatrial septum, the left lateral wall AP was also successfully localized and then ablated using the RF catheter ablation. The patient remained asymptomatic for more than 6 months after the successful ablation procedures. To the authors' best knowledge, the coexistence of AVRT and AVNRT is not reported in the literature.

Radiofrequency ablation of a left lateral atrioventricular accessory pathway in a 13-year-old boy with a criss-cross heart guided by nonfluoroscopic imaging

We present the first description of successful radiofrequency (RF) ablation of a bidirectional atrioventricular accessory pathway (AP) guided by nonfluoroscopic mapping with use of three-dimensional magnetic resonance imaging integrated into the Nav-X system (MRI/Nav-X fusion) in a 13-year-old boy with remote surgical palliation for cyanotic criss-cross heart with atrioventricular discordance, double-outlet right ventricle, and a large ventricular septal defect. Due to complex anatomy, a unique finding was that the eliminated left lateral AP electrically connected the left atrium to the antero-superior morphologic right ventricle prior to ablation.

A simple algorithm for localizing accessory pathways in patients with Wolff-Parkinson-White syndrome using only the R/S ratio

BackgroundSeveral algorithms for localizing accessory pathways (APs) are based on the delta wave morphology, R/S ratio, and QRS polarity. However, they are somewhat complicated, and an accurate determination of the delta wave morphology is occasionally difficult. The aims of this study were to develop a simple algorithm for localizing APs using only the R/S ratio, and to test the accuracy of the algorithm prospectively. MethodsWe studied 142 patients with a single anterogradely conducting AP on a 12-lead ECG. R/S ratios were analyzed in leads V1, V2, and aVF (R/S-V1, R/S-V2, and R/S-aVF). AP locations were divided into five regions based on fluoroscopic anatomy. ResultsA new algorithm was developed by correlating R/S-V1, R/S-V2, and R/S-aVF with successful ablation sites in 88 initial consecutive patients. All 55 patients with left free wall APs showed R/S-V1 ≥0.5, and 47 (98%) of 48 patients with left anterior or lateral APs showed R/S-aVF ≥1. In contrast, all seven patients with left posterolateral or posterior APs showed R/S-aVF <1. All nine patients with right-and-left midseptal or posteroseptal APs showed R/S-V1 <0.5 and R/S-V2 ≥0.5. Of 12 patients with right anterior, lateral or anteroseptal APs, 10 (83%) showed R/S-V1 <0.5, R/S-V2 <0.5 and R/S-aVF ≥1. Finally, nine (75%) of 12 patients with right posterolateral or posterior APs showed R/S-V1 <0.5, R/S-V2 <0.5, and R/S-aVF <1. Then this algorithm was tested prospectively in 54 patients. Overall, the sensitivity was 94%, and the specificity was 98%. ConclusionsThis ECG algorithm provides a simple and accurate way to identify the AP localization.

Epicardial mapping and ablation of arrhythmias: is magnetic navigation the answer we have been waiting for?

Epicardial mapping and ablation of arrhythmias: is magnetic navigation the answer we have been waiting for?

Mitral Valve Injury After Radiofrequency Ablation for Wolff-Parkinson-White Syndrome

A 39-year-old athletic female with symptomatic Wolff-Parkinson-White syndrome underwent an electrophysiological study and subsequent ablation of orthodromic reentrant tachycardias using left lateral, posterolateral, and posteroseptal accessory pathways. Ablation was performed with 7F medium- and large-curl Safire catheters using the retrograde aortic approach. Eighteen radiofrequency lesions were delivered at the mitral valve annulus (50 W, 60°, 10–60 seconds), and 8 were delivered in the coronary sinus, with weak persistence of antegrade conduction through the posteroseptal pathway. Two weeks later, she presented to the emergency room with a new episode of supraventricular tachycardia, She had been having dyspnea since the ablation procedure. A transthoracic echocardiogram revealed severe mitral regurgitation with a regurgitant volume of 66 ml and estimated regurgitant orifice of 39 mm2 (Figure [C, F, and G]); the left atrium was enlarged with a volume index of 36 ml/m2. Transesophageal echocardiogram revealed a ruptured chord to the anterior leaflet adjacent to the posteromedial commissure (Figure [E]). Given the symptoms and severity of the mitral valve regurgitation, the decision …

Impact of Transesophageal Electrophysiologic Study to Elucidate the Mechanism of Arrhythmia on Children With Supraventricular Tachycardia and No Preexcitation

An electrophysiologic study (EPS) of children and teenagers with paroxysmal supraventricular tachycardia (SVT) and normal electrocardiography (ECG) in sinus rhythm was evaluated. Generally, EPS is performed only before paroxysmal SVT ablation in these patients. In this study, 140 patients (mean age, 15 ± 3 years) with normal ECG in sinus rhythm were studied for SVT by a transesophageal route in baseline state and after isoproterenol. Idiopathic left or right ventricular tachycardia was diagnosed in four patients (3 %). Anterograde conduction over an atrioventricular (AV) left lateral (n = 10) or septal (n = 9) accessory pathway (AP) was noted in 19 patients (13.5 %) at atrial pacing. Orthodromic AV reentrant tachycardia (AVRT) was induced in these children. Five of the patients had a high rate conducted over AP (>240 bpm in baseline state or >290 bpm after isoproterenol). Two of the patients (a 10-year-old girl with well-tolerated SVT and a 17-year-old with syncope-related SVT) had the criteria for a malignant form with the induction of atrial fibrillation conducted over AP at a rate exceeding 290 bpm in baseline state. Of the 140 patients, 74 (53 %) had typical AV node reentrant tachycardia (AVNRT), nine had atypical AVNRT (6 %), 1 had atrial tachycardia (0.7 %), and 33 (23.5 %) had AVRT related to a concealed AP with only retrograde conduction. Electrophysiologic study is recommended for children with paroxysmal SVT and normal ECG in sinus rhythm. The data are helpful for guiding the treatment. Ventricular tachycardia or atrial tachycardia can be misdiagnosed. Masked preexcitation syndrome with anterograde conduction through AP was present in 13.5 % of the patients, and 1.4 % had a malignant preexcitation syndrome.

Multiple vascular anomalies in a patient with atrioventricular reentrant tachycardia

A 38year-old female patient was admitted to our clinic with the complaint of palpitation in spite of medical treatment. She had a history of hypertension and was using antihypertensive medications including metoprolol and valsartan for two years. Her blood pressure was 140/90mmHg without any significant difference between upper or lower extremities. An electrophysiological study (EPS) was performed because of documented supraventricular tachycardia. Since diagnostic EPS induced an atrioventricular re-entrant tachycardia (AVRT) associated with a concealed left lateral accessory pathway (AP) (Fig. 1A).

Successful Ablation of Resistant Left Lateral Accessory Pathway and Coexisting Atypical Atrioventricular Nodal Reentrant Tachycardia

A 41-year-old male was presented with drug-resistant supraventricular tachycardia. Electrophysiological study confirmed that the supraventricular tachycardia was caused by dual atrioventricular nodal pathways and a left lateral accessory pathway (AP). The left lateral AP was resistant to traditional endocardial ablation, but was successfully eliminated by radiofrequency ablation via the intracoronary sinus approach.

Incidence and prognostic significance of spontaneous and inducible antidromic tachycardia

Orthodromic atrioventricular reentrant tachycardia (ORT) is the most common arrhythmia at electrophysiological study (EPS) in patients with pre-excitation. The purpose of the study was to determine the clinical significance and the electrophysiological characteristics of patients with inducible antidromic tachycardia (ADT). Electrophysiological study was performed in 807 patients with a pre-excitation syndrome in control state and after isoproterenol. Antidromic tachycardia was induced in 63 patients (8%). Clinical and electrophysiological data were compared with those of 744 patients without ADT. Patients with and without ADT were similar in term of age (33 ± 18 vs. 34 ± 17), male gender (68 vs. 61%), clinical presentation with spontaneous atrioventricular reentrant tachycardia (AVRT) (35 vs. 42%), atrial fibrillation (AF) (3 vs. 3%), syncope (16 vs. 12%). In patients with induced ADT, asymptomatic patients were less frequent (24 vs. 37%; <0.04), spontaneous ADT and spontaneous malignant form more frequent (8 vs. 0.5%; <0.001) (16 vs. 6%; <0.002). Left lateral accessory pathway (AP) location was more frequent (51 vs. 36%; P < 0.022), septal location less frequent (40 vs. 56%; P < 0.01). And 1/1 conduction through AP was more rapid. Orthodromic AVRT induction was as frequent (55.5 vs. 55%), but AF induction (41 vs. 24%; P < 0.002) and electrophysiological malignant form were more frequent (22 vs. 12%; P < 0.02). The follow-up was similar; four deaths and three spontaneous malignant forms occurred in patients without ADT. When population was divided based on age (<20/≥20 years), the older group was less likely to have criteria for malignant form. Antidromic tachycardia induction is rare in pre-excitation syndrome and generally is associated with spontaneous or electrophysiological malignant form, but clinical outcome does not differ.