Low-Energy DC Catheter Ablation of Left Atrial Ectopic Tachycardia That Had Resulted in Reversible Cardiomyopathy

Catheter ablation of automatic atrial tachycardia has been previously reported in a small number of adult cases in which the ectopic focus was predominantly located in the right atrium. We report on a patient with atrial automatic tachycardia originating in the left atrium, in whom successful low-energy DC catheter ablation was performed via a transseptal puncture. The patient presented wth severe congestive cardiac failure that resolved following the procedure. Catheter ablation in such cases is feasible, it can reverse tachycardia induced ventricular function impairment, and should be attempted before resorting to open heart surgical ablation.     

Persistent tachycardia originating from the superior vena cava as a driver for atrial fibrillation

We describe a patient with drug-resistant paroxysmal atrial fibrillation who underwent radiofrequency catheter ablation of tachycardia originating from the superior vena cava (SVC). A continuous and rapid tachycardia conducted to the atrium with evidence of exit block and drove atrial fibrillation (AF) and atrial tachycardia. Neither AF nor atrial tachycardia could be induced after SVC isolation, and nor were they observed during follow-up. We conclude that continuous and rapid tachycardia originating from the SVC can act as a driver as well as an initiator of AF.     

Novel Form of Atrial Tachycardia Originating at the Atrioventricular Annulus

We report two patients with reentrant atrial tachycardia that originated at the AV annulus. Atrial tachycardia originated in the posterior portion of mitral annulus in one patient (case 1) and the posterolateral portion of tricuspid annulus in one patient (case 2). Tachycardia was successfully eliminated by RF catheter ablation in both patients, with the catheter placed underneath the mitral valve in case 1 and on the tricuspid annulus in case 2. Spiky potentials were recorded in the diastolic phase of the atrium during tachycardia at the sites of successful ablation. Spiky potentials were also recorded after atrial electrogram during sinus rhythm, and showed decremental properties during atrial pacing. An accelerated atrial rhythm was observed during RF application, and tachycardia could not be induced after ablation in either patient. Tachycardia in these patients seemed to be due to reentrant tachycardia originating in the accessory AV node (Mahaim fiber) without ventricular connection.     

Successful radiofrequency ablation of a slow atrioventricular nodal pathway on the left posterior atrial septum

RF catheter ablation is highly effective in eliminating atrioventricular nodal reentrant tachycardia by targeting the slow pathway in the posteroinferior part of Koch's triangle in the right atrium. We report here a patient in whom "slow-fast" atrioventricular nodal reentrant tachycardia was eliminated only by ablation of the slow pathway in the left atrial posteroseptal region at the level of the mitral annulus after unsuccessful attempts at the traditional site on the right side.     

Atrial Tachycardia Successfully Treated by Electrical Isolation of the Superior Vena Cava

GERSTENFELD, E.P., et al .: Atrial Tachycardia Successfully Treated by Electrical Isolation of the Superior Vena Cava. This case report describes a patient with an atrial tachycardia that was difficult to induce and that originated from the superior vena cava. Although the patient had frequent episodes of tachycardia, the tachycardia induced in the electrophysiological laboratory was nonsustained and could not be adequately localized for focal ablation. A circumferential mapping catheter was used to guide electrical isolation of the superior vena cava from the right atrium, curing the tachycardia. Electroanatomic mapping and intracardiac echocardiography were used to monitor the ablation and document patency of the superior vena cava throughout the ablation. (PACE 2003; 26[Pt. I]:906–910)     

Radiofrequency Catheter Ablation of Atrial Tachycardia with Unusual Left Atrial Sites of Origin: Report of Two Cases

Two cases of successful radiofrequency catheter ablation of adult-onset atrial tachycardia originating from the left atrium adjacent to the mitral annulus are presented. Endocardial catheter activation mapping performed by retrograde or atrial transseptal approach revealed presystolic activation at the successful ablation site in both patients, and fractionation during sinus rhythm and tachycardia in one. The 12 lead electrocardiogrnphic P wave appearance was suggestive of a left atrial tachycardia origin in both cases.     

Clinical experience with electroanatomic mapping of ectopic atrial tachycardia

The aim of this study was to evaluate the clinical use of a new three-dimensional mapping system as a guide for catheter ablation of ectopic atrial tachycardia. A series of 42 consecutive patients with drug refractory ectopic atrial tachycardia was studied in a prospective observational trial with the electroanatomic mapping system CARTO. The arrhythmogenic focus was found in the right atrium in 30 patients and in the left atrium in 12 patients. The construction of a complete electroanatomic map of the right or left atrium was possible in 37 of 42 consecutive patients with ectopic atrial tachycardia. Mean activation time of the right atrium, including the proximal coronary sinus, was 94 +/- 25 ms for right atrial tachycardias; left atrial activation time during left atrial tachycardias was 86 +/- 17 ms. Average mapping time was 30 minutes for right atrial tachycardias and 22 minutes for left atrial tachycardias, allowing the collection of 86 +/- 50 and 65 +/- 28 catheter positions, respectively. The size of the area of earliest atrial activation calculated from the electroanatomic map amounted to 0.6 +/- 0.4 cm2 in right atrial tachycardias and 1.0 +/- 0.9 cm2 in left atrial tachycardias. In the right atrium the most common locations of the 33 arrhythmogenic foci in 30 patients were the high or mid-lateral right atrium (n = 10) and the inferoparaseptal region near the coronary sinus ostium (n = 7). Ectopic left atrial foci were most commonly located in an inferior position near the mitral annulus (n = 5) and in proximity to the ostium of the pulmonary veins (n = 4). Biatrial electroanatomic mapping allowed visualization of earliest right atrial activation during left atrial tachycardia at the high interatrial septum or near the coronary sinus ostium. Catheter ablation was successful in 85% of right atrial tachycardias and 82% of left atrial tachycardias. In patients with ectopic atrial tachycardia electroanatomic mapping is a safe and feasible technique that allows three-dimensional visualization of the automatic focus in a precise anatomic reconstruction of the atria. This novel mapping technology facilitates catheter ablation of complex ectopic atrial tachycardia.     

Deglutition induced atrial tachycardia and atrial fibrillation

Deglutition induced supraventricular tachycardia is an uncommon condition postulated to be a vagally mediated phenomenon due to mechanical stimulation. Patients usually present with mild symptoms or may have severe debilitating symptoms. Treatment with Class I agents, beta blockers, calcium channel blockers, amiodarone and radiofrquency catheter ablation has shown to be successful in the majority of reported cases. We report the case of a 46-year-old healthy woman presenting with palpitations on swallowing that was documented to be transient atrial tachycardia with aberrant ventricular conduction as well as transient atrial fibrillation. She was successfully treated with propafenone with no induction of swallowing-induced tachycardia after treatment. This is also the first case to show swallowing-induced atrial tachycardia and atrial fibrillation in the same patient.     

Basket catheter localization of the origin of atrial tachycardia with atypical morphology after atrial flutter ablation

Atrial activation from a site in the low lateral right atrium will typically proceed in a superior direction. We present a case of a low lateral right atrial tachycardia with a surface electrocardiographic P wave morphology that appeared to have an inferiorly directed axis. The tachycardia occurred 2 years after successful atrial flutter ablation. The use of a multipolar basket catheter allowed confirmation of the focal origin of the tachycardia, permitted its rapid localization, facilitated catheter ablation, and provided clues to atrial activation that helped describe the appearance of the P wave.     

Radiofrequency catheter ablation therapy of swallowing-induced atrioventricular nodal reentrant tachycardia: report of two cases

We describe two patients who presented with a history of recurrent palpitations on swallowing of solid food. The event-recorder and Holter monitoring documented episodic supraventricular tachycardia (SVT) initiated by atrial premature contractions (APCs). During electrophysiological study (EPS), swallowing of solid food consistently induced APCs and their activation sequence, morphology of P wave were suggestive of their right atrial origin in them. Drug challenge did not affect the APC onset during the swallowing. During EPS, slow-fast variety of atrioventricular nodal reentrant tachycardia (AVNRT) was induced and successful radiofrequency (RF) catheter ablation of slow pathway resulted in total relief of their symptoms.     

Electrophysiological demonstration of dissociation of pulmonary vein potentials through electroanatomically guided circumferential ablation

A 57-year-old woman with frequent isolated and repetitive premature atrial contractions initiating paroxysmal atrial fibrillation, underwent electrophysiological study and catheter ablation. A real-time three-dimensional map of the left atrium was reconstructed using a nonfluoroscopic navigation system. By means of a deflectable decapolar catheter, the left superior pulmonary vein (PV) was identified as the arrhythmogenic vein, and PV potentials were found in the left inferior and right superior veins. Ablation was performed under electroanatomic guidance. After circumferential ablation outside the PV ostia, dissociation of PV potentials was obtained in the left superior vein, and PV potentials were eliminated in the other two veins.     

Successful Radiofrequency Catheter Ablation of Automatic Atrial Tachycardia with Regression of the Cardiomyopathy Picture

Ectopic atrial tachycardia (EAT) is often refractory to pharmacological suppression, and if uncontrolled, it can lead to cardiomyopathy. Although RF current catheter ablation therapy has been effective in eliminating the arrhythmia, there is limited information. particularly in adult patients with regard to the reversal of the tachycardia induced cardiomyopathy. Four adult patients, 20–56 years of age, and a 6-year-old boy, were referred with refractory EAT. Four patients had heart failure and three had depressed LV function by echocardiographic criteria. AH patients underwent electrophysiological study, and RF ablation was successful in abolishing the arrhythmogenic foci. Of these, four were located in the right atrium and one in the left atrium, and were identified by recording of the earliest atrial activation. No complications occurred. Termination of the EAT resulted in symptomatic improvement. Serial echocardiographic assessment of LV function indicated a significant reversal of the cardiomyopathy picture with reduction in chamber size and recovery in systolic function; indices of diastolic dysfunction persisted in one patient. Chronic, uncontrolled EAT can cause tachycardia induced cardiomyopathy. The picture of the cardiomyopathy resolves after elimination of the focus. RF ablation is both effective and safe, and may be considered as early therapy, particularly in patients with incessant EAT and ventricular dysfunction.     

Atrio-ventricular block during left atrial flutter ablation

We present a case of a patient treated with catheter ablation for atrial fibrillation aiming to pulmonary veins isolation. During ablation, atrial fibrillation organized into a left atrial flutter. Electroanatomic and electrophysiologic mapping revealed the anterior left atrium area between the mitral annulus and left atrium septum as a critical region for flutter ablation. After a few pulses of radiofrequency, complete atrio-ventricular block appeared. Finally, we propose pace mapping of the mitral annulus to detect left dislodgment of the compact atrio-ventricular node.     

Thoracoscopic Epicardial Radiofrequency Ablation for Vagal Atrial Fibrillation in Dogs

Epicardial radiofrequency catheter ablation of the atria in the open-chest dog has been shown to reduce inducibility of atrial fibrillation. Video-assisted endoscopic techniques decrease the operative trauma in adult thoracic surgery. We report our results of video-assisted thoracoscopic radiofrequency catheter ablation of the atria for the prevention of atrial fibrillation induction in canines. In 12 consecutive anesthetized dogs, induction of sustained atrial fibrillation was reproducibly obtained by burst pacing and cervical vagal stimulation. In six dogs, biatrial ablation was performed through right and left minithoracotomies and guided by video-assisted endoscopic techniques. The remaining six dogs underwent a video-guided left atrial procedure. Long continuous and transmural lesions were produced using epicardial temperature controlled radiofrequency energy delivered according to a simplified maze approach. Transmural lesions were demonstrated at the end of the study by examination of the heart. Sustained atrial fibrillation was still inducible after the right atrial ablation but sustained atrial fibrillation could not be induced following left atrial ablation. In acute canine studies: (1) epicardial radiofrequency catheter ablation of the atria is feasible using video-assisted endoscopic techniques; (2) ablation extended or confined to the left atrium appears to be effective in preventing the inducibility of sustained vagal atrial fibrillation; and (3) ablation of the right atrium alone had no antiarrhythmic effect .     

A simple method of mapping atrial premature depolarizations triggering atrial fibrillation

Atrial premature depolarizations (APDs) originating from focal sites, particularly the pulmonary veins (PV), may become triggers of atrial fibrillation (AF). Accurate mapping of APDs with conventional methods may be time consuming and expose the patient to unnecessary instrumentation of the left atrium. We hypothesized that the atrial activation sequence recorded using a simple system that includes an esophageal catheter and a custom-made 16-electrode catheter with two sets of floating electrodes eight in the coronary sinus and eight in the high right atrium) could be sufficient to localize the APDs. The study included 29 patients with frequent APDs and AF refractory to antiarrhythmic medications. The APD site of origin was confirmed with single-point sequential mapping techniques using the CARTO system ten patients) or by placement of multielectrode catheters in the right and left PV (19 patients). Of the 29 patients, 20 patients had a single APD focus; 8 patients had two different APD morphologies; and 1 patient had three APD foci. Mapping for ablation of the APD foci showed earliest activation in the left superior PV in 12 patients, right superior PV in 15 patients, right middle PV in 4 patients, right inferior PV in 1 patient, the lingular branch of the left superior PV in 2 patients, left inferior PV in 2 patients, and right atrium along the crista terminalis in 3 patients. The activation sequence and relative timing of the recordings obtained with our catheter configuration was highly predictive of right and left atrial origin and, more importantly, of right and left PV foci.     

Radiofrequency Catheter Ablation of Sinus Node Reentrant Tachycardia

Sinus node reentrant tachycardia is a relatively uncommon (5%-5%) form of recurrent paroxysmal supraventricular tachycardia (SVT). We describe a case of symptomatic sinus node reentrant tachycardia in a 67-year-old male with ischemic heart disease, congestive heart failure, and depressed ventricular function. Adenosine administered during an electrophysiology study caused prolongation of the tachycardia cycle length due to atrial cycle length prolongation (without atrio-His prolongation) prior to tachycardia termination. Right atrial mapping revealed the earliest site of atrial activation in the high lateral right atrium just below the superior vena cava. Low energy (10 and 20 W) radiofrequency lesions were applied ai this site with termination of the tachycardia within 3 seconds of radiofrequency energy delivery. Tachycardia could not be reinduced after delivery of the radiofrequency lesions. The sinus node function immediately and 6 weeks after radiofrequency catheter ablation remained normal and the patient was without clinical recurrence of SVT. Mapping of sinus node reentrant tachycardia and elimination of the reentrant circuit with radiofrequency catheter ablation is possible without causing sinus node dysfunction. Adenosine causes prolongation of the atrial cycle length followed by termination of sinus node reentrant tachycardia.     

导管射频消融治疗对心房纤颤患者左心房功能的影响

目的探讨心房纤颤射频消融术对患者左心房功能中远期的影响。方法选择2008年12月以来于我科接受房颤射频消融治疗的患者共20例,均于术前和术后6个月进行心脏超声检查,分别测定患者舒张末期左房容积、左房压和左心房射血力,比较手术前后各项指标的变化。结果与术前相比,接受房颤射频消融术后6个月,患者舒张末期左房容积显著减小(P<0.05),左房压无显著变化(P>0.05),而左心房射血力显著增加(P<0.05)。结论心房纤颤患者接受射频消融术后6个月,患者的左心房功能明显改善。     

三维电解剖标测系统指导下射频消融房性心动过速的临床研究

目的：探讨三维电解剖标测系统（CARTO）指导下进行房性心动过速射频消融的方法及效果。方法：对40例房性心动过速患者应用CARTO标测心房,构建三维电解剖图,分析房性心动过速的电生理机制。局灶性房速消融最早激动点,大折返性房速消融折返环的关键性峡部。选择利用常规方法行消融的28例患者作为对照组。比较两组消融的成功率、X线曝光时间。结果：38例患者CARTO三维标测系统标测提示为局灶性房性心动过速,最早激动点位于右心房35例,其中冠状静脉窦口8例（20%）、间隔部10例（25%）、侧壁8例（20%）、上腔静脉口附近4例（10%）、后壁4例（10%）,1例患者（2.5%）有3种类型房速（分别为间隔部、上腔静脉口的局灶房速和三尖瓣峡部依赖的大折返房速）。位于左心房的局灶房速3例,分别位于右上肺静脉口（2.5%）、左上肺静脉口（2.5%）及左心耳（2.5%）。2例患者为大折返房速（5%）,1例为三尖瓣峡部依赖性,1例为围绕界嵴的大折返房速。均消融成功（100%）,随访4～16个月,均无复发。常规消融组成功率为89.3%（P〈0.05）。CARTO组X线曝光时间比常规组明显缩短,分别为（13.8±5.5）min和（30.4±12.9）min,差异有统计学意义（P〈0.05）。结论：应用CARTO标测房性心动过速,对分析房性心动过速的机制准确快速,能有效指导射频消融。     

Radiofrequency Catheter Ablation of Left Atrial Tachycardia Originating Within the Pulmonary Vein in a Patient with Dextrocardia

A case is presented of a 38-year-old male with dextrocardia in whom radiofrequency current ablation of an incessant atrial tachycardia originating within the infero-lateral pulmonary vein was achieved. Activation mapping with detection of the earliest atrial activation was used for identification of the arrhythmogenic focus. In addition to fluoroscopy, trans- esophageal echocardiography was used for catheter guidance during the transseptal puncture. The present experience suggests that location of an arrhythmogenic focus within the pulmonary venous system should be considered whenever early atrial activation during ectopic atrial tachycardia is recorded at the junction between thfi left atrium and the pulmonary veins.     

Isolated Left Atrial Standstill Identified during Catheter Ablation

This report describes the incidental finding of complete left atrial standstill during successful ablation of a right‐sided atrial tachycardia in a patient with severe dilated cardiomyopathy and a history of extensive catheter ablation within the left atrium.