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Radiofrequency Catheter Ablation Of Atrioventricular Nodal Reentrant Tachycardia Associated With Anomalous Drainage Of Both Superior Vena Cava Into Coronary Sinus
Rakesh Yadav,Sharad Chandra,Nitish Naik,Rajnish Juneja
Indian Pacing and Electrophysiology Journal , 2009,
Abstract: Total upper body drainage via left superior vena cava into coronary sinus (i.e. absent right superior vena cava) is a rare anomaly and distorts the anatomy of coronary sinus and triangle of Koch. Herewith we are reporting the first report of ablation in a patient with superior vena cava draining into coronary sinus totally. This patient with atrioventricular nodal re-entrant tachycardia, baseline left bundle branch block, transient complete heart block during electrophysiological study and total upper body venous drainage into coronary sinus had successful slow pathway ablation using anatomical approach.
Catheter Ablation of Fascicular Ventricular Tachycardia  [cached]
Ramprakash B,Jaishankar S,Hygriv B. Rao,Narasimhan C
Indian Pacing and Electrophysiology Journal , 2008,
Abstract: Fascicular ventricular tachycardia (VT) is an idiopathic VT with right bundle branch block morphology and left-axis deviation occuring predominantly in young males. Fascicular tachycardia has been classified into three subtypes namely, left posterior fascicular VT, left anterior fascicular VT and upper septal fascicular VT. The mechanism of this tachycardia is believed to be localized reentry close to the fascicle of the left bundle branch. The reentrant circuit is composed of a verapamil sensitive zone, activated antegradely during tachycardia and the fast conduction Purkinje fibers activated retrogradely during tachycardia recorded as the pre Purkinje and the Purkinje potentials respectively. Catheter ablation is the preferred choice of therapy in patients with fascicular VT. Ablation is carried out during tachycardia, using conventional mapping techniques in majority of the patients, while three dimensional mapping and sinus rhythm ablation is reserved for patients with nonmappable tachycardia.
Bundle Branch Reentrant Ventricular Tachycardia  [cached]
Alexander Mazur,Jairo Kusniec,Boris Strasberg
Indian Pacing and Electrophysiology Journal , 2005,
Abstract: Bundle branch reentrant (BBR) tachycardia is an uncommon form of ventricular tachycardia (VT) incorporating both bundle branches into the reentry circuit. The arrhythmia is usually seen in patients with an acquired heart disease and significant conduction system impairment, although patients with structurally normal heart have been described. Surface ECG in sinus rhythm (SR) characteristically shows intraventricular conduction defects. Patients typically present with presyncope, syncope or sudden death because of VT with fast rates frequently above 200 beats per minute. The QRS morphology during VT is a typical bundle branch block pattern, usually left bundle branch block, and may be identical to that in SR. Prolonged His-ventricular (H-V) interval in SR is found in the majority of patients with BBR VT, although some patients may have the H-V interval within normal limits. The diagnosis of BBR VT is based on electrophysiological findings and pacing maneuvers that prove participation of the His- Purkinje system in the tachycardia mechanism. Radiofrequency catheter ablation of a bundle branch can cure BBR VT and is currently regarded as the first line therapy. The technique of choice is ablation of the right bundle. The reported incidence of clinically significant conduction system impairment requiring implantation of a permanent pacemaker varies from 0% to 30%. Long-term outcome depends on the underlying cardiac disease. Patients with poor systolic left ventricular function are at risk of sudden death or death from progressive heart failure despite successful BBR VT ablation and should be considered for an implantable cardiovertor-defibrillator.
Inadvertent isolation of a focal tachycardia within the superior vena cava  [PDF]
Milko K. Stoyanov, Tchavdar N. Shalganov
World Journal of Cardiovascular Diseases (WJCD) , 2012, DOI: 10.4236/wjcd.2012.24050
Abstract: The superior vena cava (SVC) is known to be a potential source of focal atrial tachycardias. Not uncommonly these tachycardias trigger atrial fibrillation or flutter. Focal ablation is safe and effective in eliminating arrhythmogenic foci within the SVC. We present the case of a patient with focal atrial tachycardia arising from the SVC. During presumably focal ablation inadvertent electrical isolation of the SVC from the right atrium was achieved, with restoration of sinus rhythm in the atria and persistence of the tachycardia within the SVC.
Incidence of Dual AV Node Physiology Following Termination of AV Nodal Reentrant Tachycardia by Adenosine-5'-Triphosphate: A Comparison with Drug Administration in Sinus Rhythm  [cached]
Bernard Belhassen,Roman Fish,Sami Viskin,Aharon Glick
Indian Pacing and Electrophysiology Journal , 2003,
Abstract: Administration of adenosine triphosphate (ATP) in sinus rhythm identifies dual atrioventricular node physiology (DAVNP) in 75% of patients with inducible slow / fast AV nodal reentrant tachycardia (AVNRT). The incidence of DAVNP following termination of AVNRT with ATP is unknown. Incremental doses of ATP (10-60mg) were administered, first in sinus rhythm and then during tachycardia induced at electrophysiologic study, to 84 patients with inducible AVNRT and to 18 control patients with inducible AV reentrant tachycardia (AVRT) and no electrophysiologic evidence of DAVNP. Study end-points were the occurrence of DAVNP or > 2nd degree AV block following administration of ATP in sinus rhythm and tachycardia termination following administration of ATP during tachycardia. Of the 82 patients with AVNRT who completed the study, 62 (75.6%) exhibited DAVNP following administration of 17.1 + 9.4 mg ATP in sinus rhythm, while 30 (36.5%) exhibited DAVNP at the termination of AVNRT following administration of 10.6 + 2.4 mg ATP. The occurrence of DAVNP following the administration of 10 mg ATP in sinus rhythm.was a good predictor (62%) of its occurrence after termination of AVNRT with ATP. The dose of ATP had a strong correlation between the presence of DAVNP following AVNRT termination and the ATP doses needed for tachycardia termination. Of the 18 control patients, none had DAVNP at ATP test during sinus rhythm but 1 (5.5%) showed slight (60 msec) PR jump after termination of AVRT with ATP. In conclusion, DAVNP is present in a relatively high proportion (36.5%) of patients following termination of AVNRT with ATP but is much less frequent (5.5%) in control patients. Thus, findings at termination of tachycardia by ATP may be useful in the noninvasive diagnosis of the mechanism of a paroxysmal supraventricular tachycardia.
Influence of Atrioventricular Nodal Reentrant Tachycardia Ablation on Right to Left Inter-atrial Conduction  [cached]
Abdurrahman Eksik,Ahmet Akyol,Tugrul Norgaz,Izzet Erdinler
Indian Pacing and Electrophysiology Journal , 2005,
Abstract: Background: Radiofrequency (RF) catheter ablation is the procedure of choice for the potential cure of atrioventricular nodal reentrant tachycardia (AVNRT) with high success rates. We hypothesed that as a result of the close proximity of Koch’s triangle and low inter-atrial septal fibers, the RF ablation applied at this region may result in prolongation of inter-atrial conduction time (IACT). Methods: RF ablation of AVNRT was performed by conventional technique. IACT was measured before and 20 minutes after RF ablation during sinus rhythm. Number of ablations given and duration of ablation were noted. Results: The study group was consisted of 48 patients (36 [75%] female, 12 [25%] male, mean age 43.4 ± 14. 5 years). RF ablation was successful in all patients. Mean RF time was 4. 0 ± 3. 3 minutes and mean number of RF was 11. 9 ± 9, 8. The mean IACT was 70.1 ± 9.0 ms before ablation and 84.9 ± 12.7 ms after ablation, which demonstrated a significant prolongation (p<0.001). The prolongation of IACT was very well correlated with the number of (r=0.897, p<0.001) and duration of RF (r=0.779; p<0.001). Conclusions: RF ablation of AVNRT results in prolongation of IACT. The degree of prolongation is associated with the duration and number of RF ablations given. The relationship between this conduction delay and late arrhythmogenesis need to be evaluated.
Radiofrequency Catheter Ablation of Atrioventricular Nodal Reentrant Tachycardia: Success Rates and Complications during 14 Years of Experience
Ahmad Yaminisharif,Gholamreza Davoodi,Ali Kasemisaeid,Ali Vasheghani Farahani
Journal of Tehran University Heart Center , 2010,
Abstract: Background: Radiofrequency catheter ablation (RFCA) has been introduced as the treatment of choice for supraventricular tachycardia. The aim of this study was to evaluate the success rate as well as procedural and in-hospital complications of RFCA for the treatment of atrioventricular nodal reentrant tachycardia (AVNRT).Methods: Between March 1995 and February 2009, 544 patients (75.9% female, age: 48.89 ± 13.19 years) underwent 548 RFCAs for AVNRT in two large university hospitals. Echocardiography was performed for all the patients before and after the procedure. Electrocardiograms were recorded on digital multichannel systems (EP-Med) or Bard EP system. Anticoagulation was initiated during the procedure.Results: From the 548 patients, 36 had associated arrhythmias, atrial flutter (4%), atrial fibrillation (0.7%), concurrent atrial fibrillation and atrial flutter (0.7%), and concealed atrioventricular pathway (0.4%). The overall success rate was 99.6%. There were 21 (3.9%) transient III-degree AV blocks (up to a few seconds) and 4 (0.7%) prolonged II- or III-degree AV blocks, 2 (0.25%) of which required permanent pacemaker insertion, 3(0.5%) deep vein thrombosis, and one (0.2%) arteriovenous fistula following the procedure. No difference was observed in the echocardiography parameters before and after the ablation.Conclusion: RFCA had a high success rate. The complication rate was generally low and in the above-mentioned centers it was similar to those in other large centers worldwide. Echocardiography showed no difference before and after the ablation. The results from this study showed that the risk of permanent II or III-degree AV block in patients undergoing RFCA was low and deep vein thrombosis was the second important complication. There was no risk of life-threatening complications.
Modeling Excitable Systems: Reentrant Tachycardia  [PDF]
Jarrett L. Lancaster,Esther M. Leise,Edward H. Hellen
Physics , 2008, DOI: 10.1119/1.3246868
Abstract: Excitable membranes are an important type of nonlinear dynamical system and their study can be used to provide a connection between physical and biological circuits. We discuss two models of excitable membranes important in cardiac and neural tissues. One model is based on the Fitzhugh-Nagumo equations and the other is based on a three-transistor excitable circuit. We construct a circuit that simulates reentrant tachycardia and its treatment by surgical ablation. This project is appropriate for advanced undergraduates as a laboratory capstone project, or as a senior thesis or honors project, and can also be a collaborative project, with one student responsible for the computational predictions and another for the circuit construction and measurements.
Atrial Tachycardias Arising from Ablation of Atrial Fibrillation: A Proarrhythmic Bump or an Antiarrhythmic Turn?  [PDF]
Ashok J. Shah,Amir Jadidi,Xingpeng Liu,Shinsuke Miyazaki,Andrei Forclaz,Isabelle Nault,Lena Rivard,Nick Linton,Olivier Xhaet,Nicolas Derval,Frederic Sacher,Pierre Bordachar,Philippe Ritter,Meleze Hocini,Pierre Jais,Michel Haissaguerre
Cardiology Research and Practice , 2010, DOI: 10.4061/2010/950763
Abstract: The occurrence of atrial tachycardias (AT) is a direct function of the volume of atrial tissue ablated in the patients with atrial fibrillation (AF). Thus, the incidence of AT is highest in persistent AF patients undergoing stepwise ablation using the strategic combination of pulmonary vein isolation, electrogram based ablation and left atrial linear ablation. Using deductive mapping strategy, AT can be divided into three clinical categories viz. the macroreentry, the focal and the newly described localized reentry all of which are amenable to catheter ablation with success rate of 95%. Perimitral, roof dependent and cavotricuspid isthmus dependent AT involve large reentrant circuits which can be successfully ablated at the left mitral isthmus, left atrial roof and tricuspid isthmus respectively. Complete bidirectional block across the sites of linear ablation is a necessary endpoint. Focal and localized reentrant AT commonly originate from but are not limited to the septum, posteroinferior left atrium, venous ostia, base of the left atrial appendage and left mitral isthmus and they respond quickly to focal ablation. AT not only represents ablation-induced proarrhythmia but also forms a bridge between AF and sinus rhythm in longstanding AF patients treated successfully with catheter ablation. 1. Introduction Atrial fibrillation (AF) is no longer a formidable rhythm since ablationists challenged this notorious arrhythmia more than a decade ago in their unprecedented quest for sinus rhythm (SR) [1]. Ablation strategies are based on clinical types of AF but nevertheless, the volume of tissue ablated to treat AF is highest for any cardiac arrhythmia described so far. Paroxysmal AF is amenable to catheter ablation with minimum atrial tissue destruction such that electrical isolation of pulmonary veins (PVs) suffices for establishing cure [2]. Persistent and longer lasting forms of AF necessitate extensive atrial tissue ablation in addition to PV isolation to restore SR [3–7]. Besides having evolved as a therapeutic option in symptomatic AF, surgical ablation has become a routine adjunct to many valvular surgeries and may be employed with surgical coronary revascularization and also as a “standalone” procedure [8, 9]. Despite improvements in ablation strategies, relatively high volume of tissue ablation is performed in AF. Together with remodeling of atria, it provides a favourable substrate for the development of sustained atrial tachycardia(s) during and after AF ablation (ATp) [4]. 2. Magnitude of ATp Burden Based on our observation and also that of
Arrhythmogenicity of the Coronary Sinus  [cached]
Demosthenes G. Katritsis
Indian Pacing and Electrophysiology Journal , 2004,
Abstract: The coronary sinus (CS) is the cardiac venous system that begins at its ostium in the right atrium and ends at the origin of the great cardiac vein. The major tributaries of the CS include the great cardiac vein (anterior cardiac vein), the left obtuse marginal vein, the posterior (or inferior) left ventricular vein, the middle cardiac vein, and the right coronary vein. In addition, atrial veins and, notably, the vein of Marshall (or oblique left atrial vein) also enter the coronary sinus. From the perspective of electrophysiologists, the CS represents an anatomical structure of particular interest. First, it provides access to epicardial atrioventricular pathways and arrhythmogenic foci of both atrial6 and ventricular arrhythmia. Second, it represents by itself a potential source of atrial arrhythmia. The arrhythmogenic potential of the thoracic veins in general has been recognised since the 1970s. Atrial arrhythmias can originate in the pulmonary veins, the superior vena cava, and the CS. Indeed, biatrial flutter,left atrial tachycardia, and atrial fibrillation, involving the distal CS have been well described. There is now evidence that the CS apart from participating in arrhythmia circuits, such as in the slow-slow form of atrioventricular nodal reentrant tachycardia and atrioventricular reentrant tachycardia due to accessory pathways,may itself be a source of apparently atrial arrhythmia. In patients with paroxysmal atrial fibrillation apparently originating from the left superior or inferior pulmonary vein, detailed epicardial mapping through the distal coronary sinus might identify epicardial location of the arrhythmogenic focus. Therefore, the search for foci of abnormal automaticity within the CS should be part of the electrophysiologic evaluation of left atrial arrhythmias.
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