Sotalol for Atrial Tachycardias After Surgery for Congenital Heart Disease

Atrial tachycardias, in particular atrial flutter after surgery for congenital heart disease, is associated with a high mortality. Treatment with various antiarrhythmic drugs and/or antitachycardia pacemakers is not very successful. Sotalol, a Class III drug, has shown to be a promising drug in adults with atrial tachycardias. However, the experience with sotalol in children after surgery for congenital heart disease is limited. Therefore, we describe our results here. Between December 1990 and February 1997, 26 children with atrial tachycardias, most of them with atrial flutter or fibrillation (n = 20), after surgery for congenital heart disease were treated with sotalol orally. The age of the children at the start of treatment was 7.5 ± 5.8 years (mean ± SD). The time interval between surgery and the start of atrial tachycardia ranged from 1 day to 14.3 years (3.8 ± 3.8 years). Conversion to sinus rhythm was achieved in 16 out of 22 hemodynamically stable children with a dosage of 4.0 ±1.6 mg/kg per day. The six children without sinus rhythm on sotalol and four hemodynamically unstable patients were treated prophylactically with sotalol after DC cardioversion for their tachycardias. Two children complained of mild transient fatigue. Heart rate decreased during therapy (95 ± 33 vs 81 ± 21 beats/min; P = 0.01). QT_c-intervals did not change. Proarrhythmias such as torsades de pointes were not encountered. Two children with a preexis-tent sick sinus syndrome showed aggravation of bradycardia and needed pacemaker implantation. The percentage of children with a recurrence-free interval of 1 and 2 years was 96% and 81 %, respectively, for all atrial tachycardias, and 92% and 66% for atrial flutter. The recurrences of atrial tachycardias during the follow-up period, which ranged from 0.1-6.1 years (2.5 ± 1.8 years) could be treated with only an increase of the dosage of sotalol in all but one patient. We conclude that sotalol is an effective drug for the treatment and prevention of atrial tachycardia in children afler surgery for congenital heart disease.     

Intraoperative Mapping and Radiofrequency Ablation of the His Bundle in a Patient with Complex Congenital Heart Disease and Intractable Atrial Arrhythmias Following the Fontan Operation

Intraoperative mapping and radiofrequency ablation of the His bundie (with epicardial ventriculor pacing) were performed in an 18-year-old woman with complex congenital heart disease and inlractable chronic atrial arrhythmias following the Fontan operation. The presence of complex intracardiac anafomy as well as the exclusion of tbe atrioventricular conduction tissue from the systemic venous circulation strongly influenced the technical approach.     

Three-Dimensional Distribution of Bipolar Atrial Electrogram Voltages in Patients with Congenital Heart Disease

DE GROOT, N.M.S., et al. : Three‐Dimensional Distribution of Bipolar Atrial Electrogram Voltages in Pa‐tients with Congenital Heart Disease. Voltage differences might be used to distinguish normal atrial tissue from abnormal atrial tissue. This study was aimed at identifying lowest voltage areas in patients with atrial tachycardia after surgical correction of congenital heart disease and to evaluate if identification of these areas in diseased hearts facilitates selection of critical conduction pathways in reentrant circuits as target sites for catheter ablation. Ten patients (four men, age 39 ± 15 years ) with normal sized atria and atrioventricular reciprocating tachycardia (control group) and ten patients (5 men, 32 ± 7 years ) with congenital heart disease and postoperative atrial tachycardia (CL 281 ± 79 ms ) referred for radiofrequency catheter ablation were studied. Mapping and ablation was guided by a three‐dimensional electroanatomic mapping system (CARTO) in all patients. In the control group, voltage maps were constructed during sinus rhythm and during tachycardia to evaluate the voltage distribution. The amplitude of bipolar signals was 1.90 ± 1.45 mV (0.11–8.12 mV, n = 660 ) during sinus rhythm and 1.45 ± 1.66 mV (0.12–5.83 mV, n = 440, P < 0.05 ) during atrioventricular reciprocating tachycardia. In the study group, the amplitude of 1,962 bipolar signals during tachycardia was 1.01 ± 1.19 mV (0.04–9.40 mV ), which differed significantly from the control group during tachycardia (P < 0.0001). No significant difference in the tachycardia cycle length was found (P < 0.05) between the control and study groups. As the lowest voltage measured in normal hearts was 0.1 mV, this value was used as the upper limit of the lowest voltage areas in the patients with congenital heart disease. These areas were identified by detailed voltage mapping and represented by a gray color. Activation and propagation maps were then used to select critical conduction pathways as target sites for ablation. These sites were characterized by fragmented signals in all patients. Ablation resulted in termination of the tachycardia in eight (80%) of ten patients. Complications were not observed. Identification of the lowest voltage areas using a cut‐off value of 0.1 mV in congenital heart disease patients with postoperative atrial reentrant tachycardia facilitated the selection of critical conduction pathways as target sites for ablation.     

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.     

Atrial Tachycardia Originating from the Atrial Septum in a Patient with Dextrocardia and Complex Structural Heart Disease

We report a case with dextrocardia, corrected transposition of the great arteries. He also had an atrial septum defect (ASD) with patch repair. Activation map showed a centrifugal activation from a focal origin on the systemic lower left atrial ASD patch. Ablation of the origin can terminate the atrial tachycardia. (PACE 2012; 35:e306–e308)     

Acceleration of Atrial Ectopic Tachycardia as a Guide to Successful Radiofrequency Ablation

Three chiidren with atrial ectopic tachycardia (AET), ages 7–10 years, underwent radiofrequency ablation (RFA). Two had AET localized to the inferolateral orifice of the right atrial appendage, one had AET at the posteroinferior orifice of the left atrial appendage. Each patient received RFA at 15–16 watts for 30 seconds per application. Acceleration of AET rate was observed only during successful RFA application in each palienf. occurring within 5 seconds and Jasfing 2–4 seconds. All unsuccessful applications failed to show this phenomenon. Observation of acceleration of AET rate during RFA was a useful predictor of successful procedure, possibly indicating destruction of abnormally automatic substrates.     

Permanent Overdrive Atrial Pacing in the Chronic Management of Recurrent Postoperative Atrial Reentrant Tachycardia in Patients with Complex Congenital Heart Disease

This study investigated the value of permanent atrial pacing as an adjunct to the current therapy in the chronic management of recurrent postoperative atrial reentrant tachycardia in patients with complex congenital heart disease. We studied the postpacing clinical course in 18 patients with recurrent atrial reentrant tachycardias unresponsive to conventional therapy who had an implanted atrial pacemaker. The pacemaker was programmed at a lower pacing rate 20% faster than the spontaneous mean daily rate previously determined with 24-hour Holter monitoring. Serial Holter recordings and pacemaker programming sessions were subsequently performed trying to mantain a paced atrial rhythm overdriving the spontaneous rhythm as long as possible. Twenty-four hour Holter monitoring documented a prevalent (> 80%) paced rhythm during the daily hours in all patients during the follow-up; all patients, however, required at least once a variation In programmed mode and pacing rate. Antiarrhythmic medications were discontinued after 6 months if the patient remained arrhythmia free while on pacing. Recurrences of atrial reentrant tachycardia occurred in five patients (29%) during the initial 6 months interval after the pacemaker implantation, while late recurrences occurred in only two patients (11 %). One patient died suddenly 10 months after the pacemaker implant. At the end of the follow-up, 15 patients (83%) were arrhythmia-free and only 2 of them were still on antiarrhythmic drugs. We conclude that permanent atrial overdrive pacing can be an important tool in the management of patients with atrial reentrant tachycardia following repair of congenital heart disease.     

Radiofrequency Ablation of Intraatrial Reentrant Tachycardia after Surgery for Congenital Heart Disease

Intraatrial reentry tachycardia is a common cause of both morbidity and mortality after surgery for a variety of congenital heart defects. Despite an armamentarium of arrhythmia management tools, including drug therapy, antibradycardia, and antitachycardia pacing, and catheter ablation, management of these arrhythmias remains a challenge. This report briefly reviews the problem, assesses the current successes and failures of radiofrequency catheter ablation for treating it, and discusses a number of ongoing developments that may improve both early and late outcome.     

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.     

The Role of Concomitant Arrhythmia Surgery in Patients Undergoing Repair of Congenital Heart Disease

Long-term survival after repair of complex congenital heart lesions is associated with the late development of arrhythmias as well as residual hemodynamic abnormalities. Understanding arrhythmias as electromechanical problems provides the basis for surgical intervention to correct the arrhythmia as well as anatomical disturbances. Operative techniques are highly effective in treating atrial reentry tachycardia and atrial fibrillation. Surgery for ventricular tachycardia is less effective: the arrhythmia may be reduced by improving hemodynamics, but a defibrillator may be required. Integration of device therapy into surgery may improve outcomes by preventing bradycardia as a precursor to tachycardia, and optimizing ventricular synchrony.     

Electrophysiology of "Incisional" Reentrant Atrial Tachycardia Complicating Surgery for Congenital Heart Disease

Intraatrial reentrant tachycardia, which occurs frequently in patients who have undergone corrective surgery for congenital heart disease, presents a challenge to successful management. Because the surgical repair sites are invariably critical to the development and maintenance of reentrant atrial tachycardia, we use the term "incisional reentry" to describe these arrhythmias. An understanding of the electrophysiology of such "incisional reentry," and techniques to identify a critical isthmus, are essential for successful ablation of these circuits. A critical isthmus may be identified by the presence of entrainment with concealed fusion. Confirmation that the site is critical to the tachycardia circuit is obtained by an analysis of the relationship between the postpacing interval and the tachycardia cycle length. Advances in mapping from multiple simultaneous sites, along with the ability to create larger, deeper lesions will be needed in order to cure a larger number of these patients. Ultimately, in some cases one must consider each procedure palliative rather than curative, as the disease progresses and substrate evolves and more tachycardia circuits become active.     

经食管超声心动图在复杂性先天性心脏病Fontan术中的应用

应用双平面经食管小儿探头对13例患复杂性先天性心脏病儿童，于Fontan术中连续监测。提供了高清晰的二维及彩色多普勒血流图，右房一肺动脉连接的内径0.5～1.0cm与外科手术中直接测量结果基本一致，脉冲多普勒提供术中Fontan连接内血流信息，前向性血流平均峰值速度57±26cm／sec，逆向血流平均峰值速度43±25cm／sec。经胃扫查显示下腔簿脉至肺动脉隔的全貌。2例再手术患者均基于术中超声立即发现的异常;1例为过长的隔引起左房流出道阻塞，另1例为房间隔小孔过小。本文表明经食管超声心动图（TEE）是小儿Fontan术中、术后的重要诊断与监视技术。     

Atrial Dissociation After Atrial Compartment Operation for Chronic Atrial Fibrillation in Mitral Valve Disease

Atrial dissociation with segmental atrial arrhythmia is an interesting electrophysiological phenomenon. It was rarely reported before to be caused by anatomical exit block after cardiac surgery. We report the case of a 28-year-old patient who developed atrial dissociation after a surgical method for correcting atrial fibrillation—atrial compartment operation. The segmental atrial flutter was first found by Doppler echocardiography and proved later by detailed intracardiac mapping.     

Radiation Exposure During Radiofrequency Catheter Ablation for Atrial Fibrillation

MACLE, L., et al. : Radiation Exposure During Radiofrequency Catheter Ablation for Atrial Fibrillation. RF catheter ablation of paroxysmal atrial fibrillation (PAF) is associated with prolonged fluoroscopy. The procedural duration and fluoroscopic exposure to patients and medical staff were recorded and compared among 43 ablation procedures for PAF, 20 for common atrial flutter, and 16 for accessory pathways. Patient radiation exposure was measured by dosimeters placed over the xyphoid, while that of physicians and nurses was measured by dosimeters placed outside and inside the lead apron. The mean fluoroscopy time was   57 ± 30   minutes for PAF,   20 ± 10   minutes for common flutter, and   22 ± 21   minutes for accessory pathway ablation. The patient median radiation exposure was 1110μSv for PAF, compared with 500 μSv for common flutter and 560 μSv for accessory pathway ablation (P < 0.01). The median radiation exposure to physician and nurse inside the lead apron were, respectively, 2 μSv and 3 μSv for PAF, 1 μSv and 2 μSv for common flutter, and <0.5 μSv and 3 μSv for accessory pathway ablations. RF catheter ablation for PAF was associated with prolonged fluoroscopy times and a twofold higher radiation exposure to the patient and physician compared with other ablation procedures. Assuming 300 procedures/year, radiation exposure to the medical staff was below the upper recommended annual dose limit. (PACE 2003; 26[Pt. II]:288–291)     

Surgery for Atrial Tachycardia

GUIRAUDON, G.M., ET AL.: Surgery for Atrial Tachycardia. Atrial flutter is associated with a macro-reentrant loop including an area of slow conduction cryoablation of which prevents atrial flutter to occur. Three patients underwent such intervention. Atrial fibrillation is associated with multiple reentrant circuits (leading circle of Allessie) that requires a critical surface area to perpetuate. We have designed an operation, the corridor operation, which isolate the sinus node and the AV node within a small segment of atrial tissue, to restore the chronotropic function of the sinus node. Nine patients underwent the corridor operation at our institution. There were eight men and one woman. Five had incessant atrial fibrillation and four paroxysmal. One patient had associated mitral valve stenosis and one cardiomyopathy. There were no perioperative complications. Six patients had normal sinus node function postoperatively including all the four patients with documented normal sinus node function preoperatively. Three patients required implantation of an AAI pacemaker. Two patients had recurrence of atrial fibrillation within the corridor. Our experience suggests that the corridor operation should be restricted to patients with documented good sinus node function and without structural heart disease. Our experience with five patients with paroxysmal sinus node tachycardia has been disappointing. Only one patient had long-term success although better series have been published.     

Significance of Late Recurrence of Atrial Fibrillation during Long-Term Follow-Up after Pulmonary Vein Isolation

Background and Study Objective : Patients with paroxysmal or persistent atrial fibrillation (AF) can be treated by pulmonary vein (PV) isolation. Although the recurrence rate after the procedure is relatively high, the long-term outcomes after initially recurrence-free procedures remains unclear. We examined the rates of recurrence of AF after PV isolation.
Methods: Our study included 278 consecutive patients with drug-refractory AF (mean age = 53 ± 11 years, 228 men). PV isolation was based on the disappearance of PV potentials recorded from a circumferential catheter after segmental ostium ablation. Cavo-tricuspid isthmus lines and additional atrial lines were performed in 124 and 28 patients, respectively. Patients were monitored for a mean of 26 ± 11 months (range 12–56). Recurrence was defined as ≥1 episodes of symptomatic or asymptomatic AF >1 month after the procedure.
Results: A total of 120 (34) patients had ≥1 recurrence of AF >1 month after the procedure, of whom 14 (4) had a first recurrence >6 months after the procedure. There was a significantly higher recurrence rate among patients with persistent AF.
Conclusions : A relatively high AF recurrence rate was observed after PV isolation. AF may recur late after the ablation procedure, though the majority of recurrences occurred within 6 months after the first procedure. There were no differences in incidence or time of occurrence of late recurrences between patients with paroxysmal versus persistent AF.     

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。     

Atrial Tachycardia as a Proarrhythmic Effect of Radiofrequency Catheter Ablation for Atrioventricular Nodal Reentrant Tachycardia

Radiofrequency catheter ablation is now the first line treatment for atrioventricular nodal reentrant tachycardia. The success rate is high with a low incidence of complications. However, a possible proarrhythmic effect of radiofrequency energy has been rarely reported and no study has demonstrated a direct correlation between the anatomic site of the radiofrequency application and the origin of a new post‐ablation arrhythmia. We present a case of a focal atrial tachycardia that occurred after slow pathway radiofrequency catheter ablation for atrial nodal reentrant tachycardia and originating close to the previous ablation site. This tachycardia was successfully treated with a second ablation session. (PACE 2011; 34:e33–e37)     

Radiofrequency Catheter Ablation of Ventricular Tachycardia Guided by Nonsurgical Epicardial Mapping in Chronic Chagasic Heart Disease

We report a case of a 63-year-old women with Chagas'disease and recurrent, syncopal VT treated by RF catheter ablation in whom endocardial application of RF energy was guided by nonsurgical epicardial mapping. The procedure was undertaken in the electrophysiology laboratory under deep anesthesia. VT was interrupted after 2.4 seconds of application and rendered noninducible afterwards. Two weeks after the procedure, a distinct morphology VT was induced by programmed ventricular stimulation, and the patient was started on amiodarone, remaining asymptomatic 12 months after the procedure.