Atrioventricular Nodal Tachycardia Research Articles

Paradigm shift of catheter ablation of atypical atrioventricular nodal tachycardia: 3D mapping-based ablation of exits of slow pathway

Abstract Background In current practice, the ablation target of atypical atrioventricular nodal tachycardia (AVNRT) is the earliest atrial activation site in the coronary sinus (CS) or conventional slow pathway (SP) region. Objectives The purpose of this study was to map the site of earliest retrograde atrial activation using electroanatomic 3D mapping during atypical AVNRT and to evaluate successful ablation sites. Methods Forty-two patients with a total of 49 AVNRTs (slow/fast 30; fast/slow 15; slow/slow 4) underwent EP study and ablation. Among them there were 14 patients (10 women, 60±19 y/o) in whom 19 atypical AVNRT (fast/slow 15; slow/slow 4) were induced. Results The intracardiac electrocardiograms or 3D mapping of the exit site during tachycardia revealed that 7 patients had exit sites solely inside the CS (left inferior extension=LIE), 3 solely in the right postero-septal tricuspid annulus (TA) (right inferior extension=RIE), and 4 had both LIE and RIE exits. The distance from the CS ostium to LIE exits was 14±6 mm. RIE exits were located on the TA posterior to the CS ostium (between 5 and 6 o’clock in the LAO projection). Ablation targeting these exits or traditional SP succeeded in long term elimination of AVNRT in 13 of the 14 patients (93%). There were no complications. Conclusions Catheter ablation targeting the exit sites of LIE or RIE mapped at the CS or TA holds promise as an effective and safe alternative approach to the current targets of ablation for atypical AVNRT cases.Distribution of exit sites during atypicthe circuit of atypical AVNRT：the exit s

Nonreentrant atrioventricular nodal tachycardia: The great simulator

We present the case of a healthy 12-year-old boy without structural heart disease who was followed for several years for an arrhythmia with diverse and incorrect initial diagnoses, refractory to flecainide, metoprolol and verapamil. Thorough reevaluation of the electrocardiographic recordings led to a presumptive diagnosis of a non-reentrant atrioventricular nodal tachycardia, subsequently confirmed with electrophysiology study. Radiofrequency ablation was performed during the procedure and the arrhythmia resolved. Double conduction through the atrioventricular node often simulates other arrhythmias, leading to misdiagnosis.

Dual AV nodal non-reentrant tachycardia-induced cardiomyopathy

Dual atrioventricular (AV) nodal non-reentrant tachycardia (DAVNNT) is rare phenomenon where dual AV nodal physiology allows a single P wave to conduct down both the slow and fast AV node extensions resulting in two ventricular beats. We present a case of DAVNNT manifest as incessant ventricular triplets resulting in tachycardia-inducted cardiomyopathy. We discuss the underlying electrophysiology for this rare phenomenon, how to diagnose this condition and the appropriate treatment for this syndrome.

Remote magnetic navigation shows superior long-term outcomes in pediatric atrioventricular (nodal) tachycardia ablation compared to manual radiofrequency and cryoablation.

BackgroundCatheter ablation (CA) is the first-choice treatment for tachyarrhythmia in children. Currently available CA techniques differ in mechanism of catheter navigation and energy sources. There are no large studies comparing long-term outcomes between available CA techniques in a pediatric population with atrioventricular reentry tachycardia (AVRT) or atrioventricular nodal reentry tachycardia (AVNRT) mechanisms.ObjectiveThis study aimed to compare procedural and long-term outcomes of remote magnetic navigation-guided radiofrequency (RF) ablation (RMN), manual-guided RF ablation (MAN) and manual-guided cryoablation (CRYO).MethodsThis single-center, retrospective study included all first consecutive CA procedures for AVRT or AVNRT performed in children without structural heart disease from 2008 to 2019. Three study groups were defined by the ablation technique used: RMN, MAN or CRYO. Primary outcome was long-term recurrence of tachyarrhythmia.ResultsIn total, we included 223 patients, aged 14 (IQR 12–16) years; weighting 56 (IQR 47–65) kilograms. In total, 108 procedures were performed using RMN, 76 using MAN and 39 using CRYO. RMN had significantly lower recurrence rates compared to MAN and CRYO at mean follow-up of 5.5 ± 2.9 years (AVRT: 4.3% versus 15.6% versus 54.5%, P < 0.001; AVNRT: 7.7% versus 8.3% versus 35.7%, P = 0.008; for RMN versus MAN versus CRYO respectively). In AVNRT ablation, RMN had significantly lower fluoroscopy doses compared to CRYO [30 (IQR 20–41) versus 45 (IQR 29–65) mGy, P = 0.040).ConclusionIn pediatric patients without structural heart disease who underwent their first AV(N)RT ablation, RMN has superior long-term outcomes compared to MAN and CRYO, in addition to favorable fluoroscopy doses.

Slow pathway elimination using antegrade conduction improvement with fast atrial pacing during AVNRT radiofrequency ablation: a proof-of-concept study

Background Radiofrequency (RF) ablation of slow pathway (SP) is usually performed in sinus rhythm while monitoring the occurrence of a slow junctional rhythm (JR). JR although sensitive, is not specific for elimination of SP conduction. Our objective was to prospectively evaluate feasibility and safety of SP elimination using fast atrial rate pacing (FAP) during RF delivery. Methods Consecutive patients admitted for atrioventricular nodal re-rentrant tachycardia (AVNRT) ablation were included. The rate of proximal coronary sinus (CS) pacing was set to a value constantly yielding antegrade SP conduction, while carefully monitoring the AH interval. RF delivery (at the lower part of Koch’s triangle) was considered successful if the AH shortened ≥ 14 ms or if transition from Wenckebach (WK) periods to a 1:1 conduction occurred. Results 24 patients were included (54 ± 20 y). Typical AVNRT was induced in all (cycle length 349 ± 83 ms). RF delivery during CS pacing (335 ± 73 ms) led to AH shortening by 51 ± 25 ms in 13 patients. In 10 patients, a transition from 3:2 or 4:3 WK periods to 1:1 conduction occurred during the successful pulse. In one patient, atrial fibrillation was systematically induced during FAP, requiring conventional ablation. Non-inducibility, and SP conduction disappearance was obtained in all patients. No patient developed AV block. After a follow-up of 12 ± 3 months, no recurrences were observed. Conclusion SP ablation using FAP during RF delivery allows direct visualisation of its disappearance. In our cohort of patients, this technique was feasible without safety compromise.

Atypical twin atrioventricular nodal re-entrant tachycardia in a congenitally corrected transposition of the great arteries patient with a surgical repair of a ventricular septal defect: a case report

BackgroundTwin atrioventricular (AV) nodal tachycardia is a rare mechanism of supraventricular arrhythmia, only seen in some specific congenital heart defects (CHD). It consists of a re-entrant circuit between two distinct AV nodes (anterior and inferior). Since both nodes have antegrade and retrograde conduction, there is usually two QRS morphologies in sinus rhythm.Case summaryThis case is about an atypical twin AV nodal tachycardia in a 15 years old patient with congenitally corrected transposition of the great arteries and previous history of a ventricular septal defect repair. The surgical closure was probably responsible of a poor antegrade conduction over the inferior AV node, which was responsible for a unique QRS morphology. He finally received a catheter ablation of the inferior AV node. He remained asymptomatic without anti-arrhythmic drugs at 8-months post-ablation.DiscussionTwin AV nodal re-entrant tachycardia is a rare phenomenon. The presentation and electrophysiological study can be both atypical due to previous surgical repair. The operator should be aware of specific CHD where twin AV nodal re-entrant tachycardias are expected.

Remote magnetic navigation shows superior long-term outcomes in pediatric atrioventricular (nodal) tachycardia ablation compared to manual radiofrequency and cryoablation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction – Catheter ablation (CA) is a first-choice treatment for tachyarrhythmia in pediatric patients. The currently available CA techniques differ in manner of catheter steering technique and energy sources. There are no large studies comparing long-term outcomes between the available CA techniques in pediatric patients with atrioventricular reentry (also known as accessory pathway mediated) tachycardia (AVRT) or atrioventricular nodal reentry tachycardia (AVNRT) mechanisms. Objective – The aim of this study was to compare procedural parameters and outcomes of remote magnetic navigation-guided radiofrequency (RF) ablation (RMN), manual-guided RF ablation (MAN) and manual-guided cryoablation (CRYO). Methods – This single-center, retrospective study included all first consecutive CA procedures for AVRT or AVNRT mechanisms performed in pediatric patients with no structural heart disease from January 2008 until June 2019. Three study groups were defined by the ablation technique used: RMN, MAN or CRYO. Primary outcome was recurrence of tachyarrhythmia and/or pre-excitation on ECG. Baseline clinical parameters, procedure times and complication rates were also evaluated. Results – In total, we included 223 patients, aged 13.8 ± 2.8 years, with a mean weight of 55.6 ± 14 kilograms. In total, 108 procedures were performed using RMN, 76 using MAN and 39 using Cryo. RMN had the lowest recurrence rates at a mean follow-up of 5.5 ± 2.9 years (AVRT ablation: 4% vs. 16% vs. 55%, P &amp;lt; 0.001; AVNRT ablation: 8% vs. 8% vs. 36%, P = 0.008; for RMN vs. MAN vs. CRYO respectively). In AVRT ablation, procedure and fluor times were comparable between groups. However, in AVNRT ablation, RMN and MAN had significantly lower fluoroscopy times compared to Cryo (10 (IQR 7-14) vs. 9 (IQR 6-26) vs. 15 (IQR 10-22) minutes respectively, P = 0.040). Moreover, procedure times were shortest in MAN and second in RMN ablation (101 (IQR 87-121) vs. 88 (IQR 62-99) vs. 120 (IQR 88-143) minutes respectively, P = 0.018). We observed minor complications in 3 patients (1%), which were comparable between groups and no major complications. Conclusion – In pediatric patients with no structural heart disease who underwent their first AV(N)RT ablation, RMN has the most favorable long-term outcomes, in addition to favorable fluoroscopy and procedure times. Abstract Figure. AVRT and AVNRT ablation recurrence rates

Arrhythmia Mechanisms and Outcomes of Ablation in Pediatric Patients With Congenital Heart Disease.

In contrast to the adult population with congenital heart disease (CHD), arrhythmia mechanisms and outcomes of ablation in pediatric patients with CHD in recent era have not been studied in detail. Aims of this study were to determine arrhythmia mechanisms and to evaluate procedural and long-term outcomes in pediatric patients with CHD undergoing catheter ablation. Consecutive patients <18 years of age with CHD undergoing catheter ablation over an 11-year period (2007-2018) were included. Procedural outcome included complete or partial success, failure or empirical ablation. Long-term outcome included arrhythmia recurrence and burden according to a 12-point clinical arrhythmia severity score. The study population consisted of 232 patients (11.7 years [0.01-17.8], 33.5 kg [2.2-130.1]). The most common diagnoses were Ebstein's anomaly (n=44), septal defects (n=39), and single ventricle (n=36). Arrhythmia mechanisms included atrioventricular reentry tachycardia (n=104, 90 patients), atrioventricular nodal reentry tachycardia (n=33, 29 patients), twin atrioventricular nodal tachycardia (n=3, 2 patients), macroreentrant atrial tachycardia (n=59, 56 patients), focal atrial tachycardia (n=33, 25 patients), ventricular ectopy (n=10, 8 patients), and ventricular tachycardia (n=15, 13 patients). Fifty-six arrhythmias (39 patients) were undefined. Outcomes included complete success (n=189, 81%), partial success (n=7, 3%), failure (n=16, 7%), or empirical ablation (n=20, 9%). Over 3.6 years (0.3-10.7) arrhythmia recurred in 49%. Independent of arrhythmia recurrence, arrhythmia scores decreased from 4 (0-10) at baseline to 0.5 (0-8) at 4 years follow-up (P<0.001). In 23/51 repeat procedures (45%), a different arrhythmia substrate was found. Overall adverse event rate was 9.4%, although only 1.6% (n=4) were of major severity and 0.8% (n=2) of moderate severity. Pediatric patients with CHD demonstrate a broad spectrum of arrhythmia mechanisms. Despite recurrence and emergence of novel mechanisms after a successful procedure, ablation can be performed safely and successfully resulting in decreased arrhythmia burden.

P5361Pregnancy in patients with cardiac arrhythmias

Abstract Introduction Negative trends in the state of somatic and reproductive health of the female population are observed in the last decades all over the world. On the background of declining birth rates, the problems of managing pregnancy in women with extragenital pathology become relevant. Aim To study the effects of cardiac arrhythmias and antiarrhythmic treatment on the course and outcomes of pregnancy. Material and methods A total of 55 case histories of pregnant women hospitalized in the Department of Interventional Arrhythmology. All patients signed informed consent to be enrolled in the study. The age of patients ranged from 17 to 41 years (mean age of 30.2±4.0 years). Patients were hospitalized on average at 28.0±6.4 weeks of gestation (from 12 to 37 weeks) and had some form of cardiac arrhythmia. Results Cardiac arrhythmias were idiopathic in 65% of cases; the rest of patients had verified cardiovascular diseases. Cardiac arrhythmias were registered in 41 (74%) of women prior to pregnancy and their arrhythmological history lasted for 7.9±1.1 years. Extrasystolic arrhythmia was the most common type of cardiac arrhythmias: ventricular premature beats occurred in 23 pregnant women (42%) including supraventricular premature beats in 8 patients (14%), supraventricular tachycardia in 12 patients (22%), and ventricular tachycardia (VT) in 5 women (9%). In three cases, VTs were hemodynamically significant. Radiofrequency ablation (RFA) of VT was performed in pregnant women at 26, 27, and 32 weeks of gestation. Five patients with gestational ages of 27–34 weeks received RFA for atrial tachycardia and atrioventricular (AV) reciprocal tachycardia to treat symptomatic intracardiac tachycardia (n=4) and continuous recurrent AV nodal tachycardia (n=1), paroxysms of which were accompanied by destabilization of hemodynamics. AV block was registered in 4 pregnant women (9%); sick sinus syndrome was diagnosed in 1 patient (2%). Implantation of pacemaker was required in 1 case for a second-degree AV block type II (Mobitz type II) at 24 weeks of pregnancy. RFA and pacemaker implantation were carried out with minimal or zero fluoroscopy and only after the 22nd week of pregnancy, that is, without or with reduced radiation risk to the fetus. 16 patients (29%) had cesarean section; the rest of patients had spontaneous vaginal delivery. The average Apgar scores were 8.64 immediately after birth and 9.35 five minutes after birth. Preterm births (n=2) were due to obstetric pathology and were not associated with cardiac arrhythmias. Cardiac arrhythmias were not observed in any patient in childbirth. Conclusions Cardiac arrhythmias, observed in patients, did not require termination of pregnancy. Catheter ablation for symptomatic, hemodynamically significant, and life-threatening cardiac arrhythmias made it possible to effectively guide pregnant women to delivery with a close follow-up.

Clinical Significance of the Forsaken aVR in Evaluation of Tachyarrhythmias: A Reminder.

Mechanism of a regular, monomorphic Wide QRS Complex Tachycardia (WCT) is an important diagnostic challenge in day to day practice for the clinicians and affects further management and prognosis. Many of the WCT and Narrow Complex Tachycardia (NCT) produce certain characteristic changes in lead aVR by which we can differentiate between them. The present study was aimed to evaluate tachyarrhythmias in relation to lead aVR and to highlight the clinical significance of lead aVR, "The Neglected Lead". This is prospective study in which 55 consecutive cases of tachyarrhythmias excluding sinus tachycardia, atrial fibrillation and atrial flutter were taken for the study admitted in from ICCU of Department of Medicine at S.S. Medical College and S.G.M. Hospital Rewa (M.P.), India, during July 2014 to September 2015, fulfilling the required study protocol. The data was collected regarding detailed history, physical examination; necessary investigations (including ECG and echocardiography) were done. Among 55 patients, 30 were of WCT and 25 were of NCT. The most common cause of WCT was Ventricular Tachycardia (VT) (83.3%) and rest were Supra Ventricular Tachycardia (SVT) with aberrancy (16.7%). The most common cause of NCT was Atrioventricular Nodal Tachycardia (AVNRT) (84%) followed by Atrioventricular Reciprocating Tachycardia (AVRT) (16%). The present study observed that 38.1% of the AVNRT cases and 50% of AVRT cases showed positive 'p' wave in lead aVR. The present study observed that 75% cases of AVRT showed ST segment elevation in lead aVR while only 33.3% cases of AVNRT showed ST elevation. In the present study 80% of the patients with WCT were diagnosed to have VT using Brugada algorithm while using Vereckei's new aVR algorithm, 83.3% were diagnosed to have VT. Lead aVR, one of the most neglected leads on 12 lead ECG, is a very important diagnostic tool for identification and categorization of different type of tachyarrhythmias. The presence of ST elevation in lead aVR on ECG showing NCT is relatively sensitive for diagnosing AVRT. New aVR algorithm by Vereckei is more sensitive for differential diagnosis of WCT. One should pay careful attention to lead aVR which provides essential diagnostic information.

The inferior displacement of the His bundle and fast pathway in a patient with common type atrioventricular nodal tachycardia: Three-dimensional computed tomography analysis

A 66-year-old woman with palpitations was referred to our center for catheter ablation due to drug-refractory, common type atrioventricular nodal tachycardia (AVNRT). A selective slow pathway ablation was attempted. A fast junctional rhythm with transient ventriculoatrial block followed by transient prolongation of the A–H interval occurred immediately after the radiofrequency (RF) application at the coronary sinus ostium (CSOS) level. To assess the location of the fast pathway and His bundle, we sought to visualize the anatomy of the triangle of Koch (TOK) by three-dimensional computed tomography (CT).

Evaluation using the Umea 22 questionnaire of quality of life among patients with atrioventricular nodal tachycardia undergoing successful radiofrequency ablation treatment

Atrioventricular nodal reentrant tachycardia (AVNRT) attacks is one of the common arrhythmias adversely affecting quality of life. The Umea 22 (U22) is a questionnaire developed for the assessment of symptoms associated with supraventricular tachycardia (SVT), and it is found to be effective in evaluation of quality of life after radiofrequency ablation. Using this questionnaire, the study aimed to assess quality of life among Turkish patients with ANRT before and after the successful RFA. The study was conducted between January 2011 and September 2013, and included 57 patients who had undergone RFA due to AVNRT. The U22 questionnaire was administered pre-procedure and at 6 months post-procedure. The participants were asked to report on their general well-being, arrhythmia effects on their wellbeing, and intensity of discomfort associated with episodes. They were asked to provide a score from 1 to 10 in order to determine to severity of discomfort, and the quantity of symptoms was then assessed according to the visual analogue scale (VAS). Patients' general wellbeing (7.5±2.3 vs. 8.7±1.8, p<0.001), the effects of arrhythmia episodes on general well-being (8.1±1.7 vs. 1.0±2.1, p<0.001), frequency of symptoms (2.8±0.8 vs. 0.4±0.9, p<0.001) and duration of symptoms were reduced significantly after RFA. The rate of drug use among patients also decreased after RFA (70% vs. 23%, p=0.017). Treatment success was high in patients undergoing RFA due to AVNRT according to the U22 quality of life questionnaire. General and arrhythmia-associated quality of life had improved significantly by the 6th month post-procedure.

Atrioventricular nodal block with atrioventricular nodal reentrant tachycardia ablation.

The initial model of atrioventricular nodal tachycardia (AVNRT) as a small circuit of reentry within the AV node precluded a catheter-based cure for this arrhythmia without the occurrence of AV conduction block. Landmark observations that the atria were part of the circuit of AVNRT1 and that the arrhythmia could be reset with paced beats placed at sites anatomically distant from the compact AV node2 set the stage for the present expectation of curative ablation without AV block. Despite this understanding of the AVNRT mechanism and the large accrued operator experience during the past 3 decades when ablating this arrhythmia, AV block still occurs in ≈1% to 2.3% as a complication of ablation.3 See Article p 739 In this installment of teaching rounds, Chen et al4 share with us what we can learn from a series of patients with permanent or transient AV block noted during and soon after radiofrequency energy delivery. The authors provide an honest, transparent, and instructive view of their 5 cases. The fact that we are successful ≈99% of the time without complication suggests that the present methods for maintaining safety, including monitoring junctional rhythm during ablation and relating catheter position to the fluoroscopic anatomic approximation of the AV node location are mostly successful. The student of electrophysiology must, however, be aware of how these precautions can fail us. Even closely spaced bipolar electrodes placed over the compact AV node are not able to record electrograms from the node itself. Because we cannot map the structure we need to avoid, we must estimate anatomically its location and correlate this information with our standard fluoroscopic views. ### Utility The compact AV node is located within Koch’s triangle, approximately in its mid and central position. Using the His bundle as a surrogate for the superior vertex and …

ECG Response: November 26, 2013

HomeCirculationVol. 128, No. 22ECG Response: November 26, 2013 Free AccessResearch ArticlePDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessResearch ArticlePDF/EPUBECG Response: November 26, 2013 Originally published26 Nov 2013https://doi.org/10.1161/CIRCULATIONAHA.113.007077Circulation. 2013;128:2419IntroductionECG Challenge: A 22-year-old graduate student presents to student health because of palpitations that have been present for ≈2 hours. They occurred after she was jogging. She states that she has had similar palpitations in the past, but they were usually of a briefer duration. An ECG (ECG A) is obtained during the palpitations. Adenosine is administered, and this terminates the arrhythmia. A second ECG (ECG B) is obtained thereafter.Download figureDownload PowerPointECG A: The rhythm is regular at a rate of 190 bpm. The QRS-complex duration is normal (0.08 s), and there is a normal morphology and axis between 0° and +90° (positive QRS complex in leads I and aVF). The QRS amplitude is increased, with an S wave in lead V2 that is 20 mm (]) and an R wave in lead V6 that is 30 mm ([) (total=50 mm). Although this meets 1 of the criteria for left ventricular hypertrophy (ie, SV2+RV6≥45 mm in a subject <45 years of age), the QRS-complex amplitude or voltage is likely normal in this young healthy woman who is likely thin and has no lung disease. ST-segment depression is noted in leads II, aVF, and V3 to V6 (^). These are likely related to the rapid rate, although subendocardial ischemia should be considered. The QT/QTc intervals are normal (240/430 ms). There are no obvious P waves seen before or after any of the QRS complexes. However, there is notching (that appears to be negative) of the ST segment, seen best in leads III, aVF, and V6 (). There is also a positive waveform at the end of the QRS complex in lead aVL (). These notches are P waves and therefore this is a short RP tachycardia. Causes for a short RP tachycardia include sinus tachycardia, atrial tachycardia, ectopic junctional tachycardia, atrial flutter, typical atrioventricular nodal tachycardia, or an atrioventricular tachycardia. However, the cause for this tachycardia cannot be definitively established.ECG B: After the tachycardia has been terminated by adenosine, there is a regular rhythm at a rate of 76 bpm. The QRS-complex duration is increased (0.14 s), and the morphology does not resemble either a typical right or left bundle-branch block. Indeed, the upstroke of the QRS complex is slurred (), and there is positive concordance (ie, tall R wave) across the precordium (→). This is abnormal and is not seen with normal conduction through the His-Purkinje system, but rather reflects direct myocardial activation, as seen with a paced complex, ventricular complex, or preexcited complex. There is a P wave before each QRS complex (+), and the P wave is positive in leads I, II, aVF, and V4 to V6. Hence, there is an underlying normal sinus rhythm. The PR interval is constant; however, it is short (0.12 s). The short PR interval and the widened QRS complex are characteristic of a Wolff-Parkinson-White pattern. The slurred upstroke is known as a delta wave. There are diffuse ST-T–wave abnormalities (^). However, because initial myocardial activation occurs via the accessory pathway and not the normal His-Purkinje system, abnormalities of the left ventricle cannot be reliably established on the ECG. Therefore, the ST-T–wave changes are related to preexcitation and not a primary problem of the myocardium. Because this patient has Wolff-Parkinson-White, the narrow QRS complex tachycardia seen in ECG 11A is termed orthodromic atrioventricular reentrant tachycardia. In this situation, antegrade activation of the ventricles is via the normal AV node His-Purkinje system, whereas the retrograde conduction back to the atria is via the accessory pathway.FootnotesCorrespondence to Philip J. Podrid, MD, West Roxbury VA Hospital, Section of Cardiology, 1400 VFW Pkwy, West Roxbury, MA 02132. E-mail [email protected] Previous Back to top Next FiguresReferencesRelatedDetailsCited By Reyes M Opening Borders: African Americans and Latinos Through the Lens of Immigration, SSRN Electronic Journal, 10.2139/ssrn.2477900 November 26, 2013Vol 128, Issue 22 Advertisement Article InformationMetrics © 2013 American Heart Association, Inc.https://doi.org/10.1161/CIRCULATIONAHA.113.007077PMID: 24276877 Originally publishedNovember 26, 2013 PDF download Advertisement SubjectsElectrocardiology (ECG)

What is the next step after a failed standard radiofrequency ablation of atrioventricular nodal tachycardia?

A 37-year-old man with recurrent atrioventricular nodal reentrant tachycardia (AVNRT) came to our centre. He had a 14-year history of paroxysmal palpitations refractory to usual medications. Two previous ablation attempts with radiofrequency (RF) had been made. Programmed atrial stimulation induced typical AVNRT. …

Percutaneous transhepatic access for catheter ablation of cardiac arrhythmias

Femoral venous access may be limited in certain patients undergoing electrophysiology (EP) study and ablation. The purpose of this study is to review a series of patients undergoing percutaneous transhepatic access to allow for ablation of cardiac arrhythmias. Six patients with a variety of cardiac arrhythmias and venous abnormalities underwent percutaneous transhepatic access. Under fluoroscopic and ultrasound guidance, a percutaneous needle was advanced into a hepatic vein and exchanged for a vascular sheath over a wire. Electrophysiology study and radiofrequency ablation was then performed. All tachycardias, including atrial tachycardia, atrial flutter, atrioventricular nodal tachycardia, and atrial fibrillation, were ablated. Procedural times ranged from 227 to 418 min. Fluoroscopy times ranged from 32 to 95 min. There were no complications. All six patients have been arrhythmia-free in follow-up (5-49 months, mean 23.1 months). Percutaneous transhepatic access is safe and feasible in patients with limited venous access who are undergoing EP study and ablation for a range of cardiac arrhythmias.

Non-reentrant atrioventricular nodal tachycardia

Dual ventricular response to a single supraventricular impulse through dual atrioventricular (AV) nodal pathways is an interesting and uncommon phenomenon. Rarely, some patients can exhibit sustained one-to-two conduction producing a non-reentrant AV nodal tachycardia during sinus rhythm [1–6]. We report the case of a patient whose arrhythmia was caused by this mechanism. A 44-years-old male patient who had frequent irregular palpitations was admitted to hospital. He was misdiagnosed with atrial fibrillation and referred to our institute for consideration of pulmonary vein isolation. He did not have any significant disease in his medical history. Echocardiography was normal. The electrocardiogram showed an irregular narrow QRS complex tachycardia. Careful evaluation of the electrocardiograms revealed the presence of two ventricular activations for each atrial beat (Fig. 1). On some occasions, the wide QRS complexes with right bundle branch block (RBBB) morphology not preceded by P waves simulating premature ventricular complexes (PVCs) were observed. Electrophysiological study revealed regular 1:2 AV relationship. Each ventricular signal was preceded by a His deflection with a constant HV interval (46 ms) (Fig. 2a). The AH1 interval between the atrial wave and the first His deflection was 159 ms. The AH2 interval between the atrial wave and the second His deflection was 528 ms. Both AH1 and AH2 intervals were slightly variable. When AH2 interval was shorter than 520 ms, second ventricular responses were conducted by RBBB morphology (Fig. 2a). Because of sustained double responses, we could not perform programmed atrial extra stimulation to identify a jump in AH interval. After detailed electrophysiological examination, radiofrequency (RF) energy was delivered (40 W, 55 C, 66 s) in the posterior aspect of Koch’s triangle, where the typical ‘‘slow pathway potentials’’ were observed. After first RF application, 1:2 response disappeared (Fig. 2b). During post-ablation tests, we did not observe dual AV nodal conduction properties, and we could not induce any arrhythmia. On the 6 month follow-up, the patient was asymptomatic. Non-reentrant AV nodal tachycardia (1:2 tachycardia) is a rare manifestation of dual AV nodal physiology. Persistent simultaneous conduction of P waves over a fast and a slow nodal pathways may lead irregular supraventricular tachycardia. The two major electrophysiological properties of simultaneous anterograde fast and slow conduction during sinus rhythm are: (1) Absence of retrograde ventriculoatrial conduction via fast and slow pathways and (2) Critical conduction delay in slow pathway to allow sequential conduction of impulse from both pathways [1, 2]. Delay has to be longer than the effective refractory period of infranodal conduction system. A recently published review reported just 49 cases between dates of 1950 and 2011 [3]. Nevertheless, the prevalence of AV nodal non-reentrant tachycardia is likely to be underestimated because of difficulties in differential diagnosis. Sustained cycle length alternans is the characteristic for this arrhythmia [4]. However, changes in autonomic tone affecting conduction properties may lead irregular cycle length alternans and rate-dependent aberrancy. For these reasons, it can be erroneously diagnosed as atrial fibrillation, atrial flutter or atrial tachycardia with Wenckebach periodicity [3, 5, 7, 8]. These arrhythmias, E. E. Ozcan G. Szeplaki B. Merkely L. Geller (&) Heart Center, Semmelweis University, Gaal Jozsef street 9, Budapest 1122, Hungary e-mail: laszlo.geller@gmail.com

Double Tachycardia After Slow Pathway Ablation for Atrioventricular Nodal Tachycardia: What Is the Mechanism?

Double Tachycardia After Slow Pathway Ablation for Atrioventricular Nodal Tachycardia: What Is the Mechanism?

Dual Atrioventricular Nodal Nonreentrant Tachycardia with Alternating 1:1 and 1:2 AV Conduction: Mechanistic Hypotheses and Total Suppression Using Right Atrial Pacing

Dual atrioventricular (AV) nodal nonreentrant tachycardia is an uncommon arrhythmia with several pattern types. The primary therapy is ablation of the slow AV nodal pathway. A rare pattern type demonstrates alternating 1:2 and 1:1 AV ratios with longer PR intervals during 1:1 conduction. We report the second intracardiac study of this variant and the first case of using right atrial pacing as the ultimate therapy for any pattern type.

Long-term results of slow pathway ablation in patients with atrioventricular nodal reentrant tachycardia: simple approach

AimsThe aim of this study was to report the short- and long-term results of slow pathway radiofrequency (RF) ablation in patients with atrioventricular (AV) nodal reentrant tachycardia (AVNRT) using a simplified approach (2 catheters and short applications of RF). Materials and MethodsThis was a retrospective study that included consecutive patients with AVNRT. We used an anatomical approach with only 2 catheters. Decremental AV nodal conduction and atrial-His conduction interval jump were measured. To detect the onset of the QRS, we used surface lead II. During the stimulation protocol, we performed S2-QRS and S3-QRS measurements. An increase in the S3-QRS3 interval of 50 milliseconds or greater in response to a decrease in the S2-QRS2 coupling interval of 10 milliseconds was defined as a discontinuous AV nodal function curve and taken as evidence of dual antegrade AV pathways. Atrioventricular nodal reentrant tachycardia was demonstrated by the presence of dual AV nodal physiology, atrial echoes, and tachycardia induction with a 1:1 AV relationship and a VA interval of less than 70 milliseconds. Short RF applications (10-15 seconds) were delivered at an intermediate point between the posteroseptal and medioseptal regions of the Koch triangle. The applications were considered effective when junctional rhythm appeared. The end point was the demonstration of slow pathway modification without AVNRT induction. ResultsThree hundred forty-four patients (age, 49.22 ± 17.47 years; 254 were female) were included. Discontinuous AV nodal function curves were found in 271 patients (78.77%), and short-term success was achieved in all patients. The anterograde jump in AV nodal conduction was abolished after RF in 222 patients (81.91%), and discontinuous AV nodal conduction and single AV nodal echo beats persisted in 49 cases (18%). The mean number of RF application was 7.79 ± 2.23, the mean number of effective applications was 4.63 ± 0.62, and the mean RF application time was 54.92 ± 8.03 seconds. The total procedure and fluoroscopy time was 29.45 ± 9.6 and 10.87 ± 2.36 minutes, respectively. After the procedure, all patients were followed up for a mean of 46.44 ± 18.89 months, and 7 patients (2%) presented AVNRT recurrences. Complications were observed in 4 patients (1.16%); no permanent AV block was observed. ConclusionIn this study, slow pathway RF ablation using a simplified approach technique is an effective and safe approach for the treatment of AVNRT.