Wolff-Parkinson-White Syndrome Presenting as the Permanent Form of Junctional Reciprocating Tachycardia

Permanent Reciprocating Tachycardia and Preexcitation. The substrate of the permanent form of junctional reciprocating tachycardia is an accessory pathway with no spontaneous anterograde conduction, usually located in the posteroseptal area. We report a case of this type of tachycardia with overt anterograde ventricular preexcitation. Electrophysiologic study confirmed that tachycardia was due to an accessory pathway with long retrograde conduction time; electrophysiologic findings suggested longitudinal dissociation of the accessory pathway. Radiofrequency application at the coronary sinus os resulted in disappearance of preexcitation and cure of the tachycardia.     

A Rare Case of Permanent Junctional Reciprocating Tachycardia Ablated on the Roof of the Left Atrium

A Rare Case of Permanent Junctional Reciprocating Tachycardia. Left‐sided anteroseptal accessory pathways that course through the aortomitral fibrous continuity are some of the rarest types of accessory pathways. At this region the atrium and ventricle are separated by their greatest distance because of the intervening aortic valve. These pathways often have a long circuitous course that may involve the root and cusps of the aortic valve. Prior reports have demonstrated the feasibility of ablating these pathways along the anteroseptal mitral annulus, the left ventricular outflow tract, or in the left or noncoronary cusps of the aortic valve. We describe a case of a concealed decremental anteroseptal accessory pathway that was ablated on the roof of the left atrium remote from the mitral or aortic valve annuli. This report indicates that when an appropriate site for ablation of a left‐sided anteroseptal accessory pathway is not found close to a valve annulus, these pathways may be amenable to ablation by targeting their atrial insertion site. (J Cardiovasc Electrophysiol, Vol. 24, pp. 464‐467, April 2013)     

New Diagnostic Finding to Assess Para-Hisian Pacing Observed in a Patient with a Permanent Form of Junctional Reciprocating Tachycardia

Morphologic Change During Para-Hisian Pacing. Para-Hisian pacing, a useful method to differentiate conduction over an accessory pathway from conduction over the AV node, is assessed essentially by comparing the timing of local atrial electrograms between Hisbundle captured heats and His-bundle noncaptured heats. We describe the case of a patient with a permanent form of junctional reciprocating tachycardia, in whom an atrial double potential was recorded only during the tachycardia at the right posterior septum. During para-Hisian pacing, a morphologic change in the atrial electrogram at the posterior septum was also identified, as well as a change in the retrograde atrial sequence. Since the morphologic change of atrial electrograms during para-Hisian pacing cannot be demonstrated in a patient without an accessory pathway, this new finding could he considered a new additional diagnostic criterion suggesting the presence of an accessory pathway.     

导管射频消融术治疗持续性交界区反复性心动过速2例报告

本文报告两例持续性交界区反复性心动过速(PJRT)患者,应用导管射频消融术治疗,成功地阻断了位于后间隔具有递减传导特性的稳若旁路.随访7～10个月.病人无心动过速发作,提示导管射频消融术是治疗PJRT的有效方法.     

Neonatal Radiofrequency Catheter Ablation of Junctional Tachycardias

Junctional tachycardias comprise several arrhythmia types with differing mechanisms, principally involving the region of the atrioventricular (A-V) junction. Neonatal radiofrequency catheter ablation has typically been reserved for life-threatening, drug-refractory cases due to the unique concerns regarding patient size and development. We performed radiofrequency catheter ablation on two neonates with incessant, rapid junctional tachycardias and hemodynamic compromise after failing conventional medical therapy. This report describes 2 neonates who underwent emergent radiofrequency catheter ablation, and compares these two patients to a larger pediatric catheter ablation patient cohort. Both neonates had an acutely successful outcome and were able to be discharged within a week of the ablation procedure. Fluoroscopy time and total procedure time were shorter in these two patients than in the course of the average pediatric catheter ablation. Though long-term developmental consequences of neonatal catheter ablation are yet unknown, in unique extreme situations, radiofrequency catheter ablation can be performed in neonates, as in older children and adults, without excessive acute morbidity.     

Decremental Accessory Pathway Conduction After Ablation and Antidromic Atrioventricular Reciprocating Tachycardia 8 Years After Successful Radiofrequency Ablation

Introduction: This is a rare case of antidromic reciprocating tachycardia developing 8 years after successful catheter ablation.
Result: A 15-year-old girl had recurrence of palpitations 8 years after the ablation of manifest right posteroseptal accessory pathway. Atrial burst pacing revealed Wenckebach atrioventricular conduction with preexcitation. Wide QRS tachycardia with identical morphology to sinus rhythm associated with retrograde His potential recorded immediately after the V-wave was induced by isoproterenol infusion. Atrial premature stimulus applied at the identical timing of His potential advanced the subsequent ventricular beat and His potential.
Conclusion: Catheter ablation may produce decremental accessory pathway conduction and rarely cause antidromic atrioventricular reciprocating tachycardia. This may be explained by a presence of "de novo" accessory pathway with decremental conduction properties that became manifest after the first ablation.     

Catheter Ablation for the Treatment of Paroxysmal Supraventricular Tachycardia

Catheter Ablation for PSVT. Radiofrequency catheter ablation has evolved into a front-line curative therapy for patients who have paroxysmal supraventricular tachycardia secondary to Wolff-Parkinson-White syndrome, AV nodal reentrant tachycardia, and atrial tachycardia. In patients with accessory pathways, cure rates exceed 90% in almost all anatomic locations. Equally high success rates are noted in patients with atriofascicular pathways and the permanent form of junctional reciprocating tachycardia. Complications secondary to catheter ablation of accessory pathways occur in 1% to 3% of patients and include cardiac perforation, tamponade, AV block, and stroke. In patients with AV nodal reentrant tachycardia, selective slow pathway ablation is curative in over 95% of patients with a very low risk of AV block. Atrial tachycardias originating in both the left and right atria can he successfully ablated in over 80% of patients. Given the overall effectiveness of this procedure, radiofrequency catheter ablation should be considered as front-line therapy in patients with recurrent or drug-refractory paroxysmal supraventricular tachycardia. Although an effective therapy, the risks and benefits of this procedure need to be assessed in all patients who are candidates for this procedure.     

Catheter Ablation of Idiopathic Ventricular Tachycardia Arising from the Aortic Root

Most idiopathic ventricular tachycardia (VT) arises from the area of the outflow tracts, and the most common left ventricular site is the aortic root, usually from the right and left sinuses of Valsalva. This site of origin is suggested by specific patterns on the electrocardiogram. Activation mapping and pace mapping are both useful strategies, and their relative benefits and limitations need to be appreciated. The mapping strategy for a VT of suspected aortic root origin is based on the consideration that multiple chambers may need to be mapped, and the temptation to ablate at suboptimal sites based on the justification that it was easy to get to should be resisted. The entire surface of each cusp needs to be sampled, as distinct activation times and pacemaps are obtained at each site. Standard radiofrequency energy is typically adequate and the precision of mapping rather than the amount of tissue ablated is tantamount to success. In my opinion, the indications for ablation of aortic root VT are similar to those for other idiopathic VT. Although I offer patients both pharmacologic and nonpharmacologic options, I feel that ablation is first line therapy for patients with sufficient symptoms to warrant therapy.     

Anterior Q-Wave Infarction Complicating Attempted Catheter Electrode Ablation of Ventricular Tachycardia

This report describes an attempt to treat recurrent ventricular tachycardia by catheter electrode ablation. The procedure failed to control the arrhythmia and resulted in a Q-wave anteroseptal myocardial infarction. The potential complications of catheter electrode ablation in the normal ventricle are emphasized.     

Ablation of Ventricular Tachycardia with a Saline-Cooled Radiofrequency Catheter:

INTRODUCTION: In animal models, active cooling of the electrode during radiofrequency (RF) ablation allows creation of larger lesions, presumably by increasing the power that can be delivered without coagulum formation. These RF lesions have not been characterized in human myocardium in regions of infarction and scarring. METHODS AND RESULTS: Cooled-tip RF catheter ablation of ventricular tachycardias (VTs) was performed in two patients who had severe congestive heart failure and subsequently underwent cardiac transplantation. The first patient had four different monomorphic VTs. RF applications along the inferoseptal margin of a scarred region abolished all inducible VTs. The second patient had sarcoidosis involving the myocardium and four different inducible VTs. RF current applied at an inferobasal VT exit and at the right and left septa failed to abolish the VTs. The explanted hearts were examined at the time of cardiac transplantation 18 and 21 days later, respectively. Lesions extended to depths up to 7 mm, reaching clusters of myocardial cells deep to regions of fibrosis. Microscopically, the ablation sites contained coagulation necrosis with hemorrhage, surrounded by a rim of granulation tissue. CONCLUSION: Saline-irrigated RF catheter ablation produces relatively large lesions capable of penetrating deep into scarred myocardium.     

Successful Radiofrequency Catheter Ablation of Sustained Ventricular Tachycardia Postmyocardial Infarction in Man Guided by a Multielectrode "Basket" Catheter

Multielectrode "Basket" Catheter. Currently, analysis of sustained ventricular tachycardia postmyocardial infarction in man is limited by the time required for single point activation mapping and the difficulty in obtaining information during hemodynamically unstable arrhythmias. To overcome these limitations, we developed a multielectrode "basket" catheter for endocardial recording and pacing. This report describes the first clinical use of such a catheter to guide successful radiofrequency ablation of incessant sustained ventricular tachycardia postmyocardial infarction. This system may significantly shorten the time required for VT analysis and improve the results of radiofrequency catheter ablation for VT postmyocardial infarction.     

Catheter ablation of an epicardial accessory pathway via the middle cardiac vein guided by monophasic action potential recordings.

This report describes a case of permanent junctional reciprocating tachycardia (PJRT) that was ablated via the middle cardiac vein, guided by monophasic action potential recording. The patient was a 63-year-old woman who had been suffering from palpitation for 10 years. ECG during palpitation showed a narrow QRS tachycardia with a long RP interval. Electrophysiological study revealed that this tachycardia was an orthodromic reciprocating tachycardia, via an accessory pathway with a decremental property and a long ventriculoatrial interval (130 ms): PJRT. The earliest atrial activation during tachycardia was detected at the junction of the middle cardiac vein with the coronary sinus. Monophasic action potentials were recorded to confirm that the ablation catheter was in contact with the epicardium.     

器质性心脏病室性心动过速的导管消融进展

器质性室性心动过速绝大多数是折返性机制。激动顺序、拖带和舒张期电位仍然有价值,而非接触式标测等新技术提供了较强大的标测手段。然而,消融的能量和效能仍然是制约成功率的主要因素。心外膜标测、盐水冲洗大头和冷凝消融具有潜在的价值。     

Radiofrequency Catheter Ablation Using Non-Contact Mapping for Inappropriate Sinus Tachycardia

INTRODUCTION: In this report we describe our experience using non-contact mapping for radiofrequency ablation in patients with inappropriate sinus tachycardia. METHODS AND RESULTS: Two female patients with persistent complaints of palpitations and documented inappropriate sinus tachycardia with failed medical management underwent radiofrequency ablation using non-contact mapping. Non-contact mapping provided a continuous determination of the site of earliest breakthrough, facilitating the delivery and the assessment of the results of each radiofrequency application. CONCLUSION: Non-contact mapping is an effective mapping modality in the interventional treatment of inappropriate sinus tachycardia.     

Radiofrequency Catheter Ablation of Sustained Monomorphic Ventricular Tachycardia in Hypertrophic Cardiomyopathy

Monomorphic VT in HCM. Introduction : Incessant monomorphic ventricular tachycardia (VT) with a right bundle branch block morphology and a northwest axis is a rare arrhythmic complication in a patient with hypertrophic cardiomyopathy and apical left ventricular aneurysm.
Methods and Results : The origin of this VT was localized using the following criteria: the presence of entrainment without fusion, equal internals from the stimulus to the beginning of the QRS complex and from the electrogram to the QRS complex during VT, and the first postpacing interval identical to the tachycardia cycle length. Radiofrequency energy applied to the septoapical part of the apical left ventricular aneurysm terminated the tachycardia within 2 seconds.
Conclusion : Using criteria to guide radiofrequency (RF) ablation of VT in patients with coronary artery disease, an incessant monomorphic VT in a patient with hypertrophic cardiomyopathy was successfully ablated.     

Radiofrequency Catheter Ablation of Idiopathic Left Ventricular Tachycardia:

Idiopathic Left Ventricular Tachycardia. Introduction: Idiopathic left ventricular tachycardia with a QRS pattern of right bundle branch block and left-axis deviation constitutes a rare but electrophysiologically distinct arrhythmia entity. The underlying mechanism of this tachycardia, however, is still a matter of controversy. This report describes findings in a 42-year-old man who underwent successful radiofrequency catheter ablation of idiopathic left ventricular tachycardia.
Methods and Results: On electrophysiologic study, the tachycardia was reproducibly induced and terminated with double ventricular extrastimuli. Intravenous verapamil terminated the tachycardia whereas adenosine did not. Detailed left ventricular catheter mapping during sinus rhythm revealed a fragmented delayed potential at the mid-apical region of the inferior site near the posterior fascicle of the left bundle branch. At the same site, continuous electrical activity throughout the entire cardiac cycle was recorded during ventricular tachycardia. Repeated spontaneous termination of this continuous electrical activity in late diastole was followed immediately by termination of the tachycardia. Single application of radiofrequency current for 20 seconds at this site completely abolished inducibility of the tachycardia. After catheter ablation, at the identical site of preablation recording of the fractionated potential during sinus rhythm, no fragmented delayed activity could be recorded. There was no complication from the ablation procedure.
Conclusion: The preablation recordings of fragmented delayed potentials during sinus rhythm and continuous diastolic electrical activity during tachycardia, together with ablation characteristics and previously reported electrophysiologic properties of this arrhythmia, may further support microreentry as the underlying mechanism in idiopathic left ventricular tachycardia.     

器质性心脏病室性心动过速导管消融治疗进展

器质性心脏病瘢痕相关性室性心动过速（室速）的发生主要是折返机制,目前多采用心脏三维标测系统指引下对耐受性好、血流动力学稳定的室速激动标测消融,对于血流动力学不稳定的室速,窦性心律下基质标测、电压图判断室速的解剖基质,结合起搏标测和拖带标测技术识别室速的折返环,盐水灌注导管消融治疗;近年来不断积累有关临床循证证据、适应证进一步拓展、新的标测消融和辅助技术临床上应用,取得了新的进展。     

Transient QT prolongation with torsades de pointes tachycardia after ablation of permanent junctional reciprocating tachycardia

INTRODUCTION: Catheter ablation with radiofrequency energy is a curative therapy in patients with permanent junctional reciprocating tachycardia (PJRT). METHODS AND RESULTS: For the first time, we report a case of transient QT prolongation with torsades de pointes tachycardia 18 hours after successful radiofrequency energy ablation of PJRT in a 25-year-old woman with tachycardia-induced cardiomyopathy. Of note, the torsades de pointes occurred in the absence of bradycardia, electrolyte disturbances, or QT-prolonging drugs. This patient initially was thought to have a hereditary long QT syndrome that was unmasked by PJRT ablation. Therefore, the patient received an implantable defibrillator in addition to beta-blocker therapy, which was discontinued 6 months later. Surprisingly, the QT interval completely normalized within 1 week after PJRT ablation, and the patient remained free of arrhythmias during a follow-up period of 4.5 years. CONCLUSION: Patients with incessant tachyarrhythmias should undergo ECG monitoring for at least 24 hours following successful radiofrequency catheter ablation because transient QT prolongation with torsades de pointes may occur even in the absence of bradycardia, QT-prolonging drugs, or electrolyte disturbances.     

心房颤动导管消融术后快速性房性心律失常的机制和治疗

随着心房颤动导管消融治疗的日益广泛开展,导管消融术后快速性房性心律失常（即继发性房性心律失常,包括房性心动过速和心房扑动）逐渐成为临床心律失常治疗的关注热点,其机制在不同患者中不尽相同,甚至同一患者亦可涉及多种机制,因此这种心律失常的处理可能较心房颤动本身更为棘手。现就心房颤动导管消融术后发生快速性房性心律失常的可能机制及其防治策略作一综述。