Ebstein s anomaly is a congenital cardiac malformation

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1 Cardiac Arrhythmia in Patients Undergoing Surgical Repair of Ebstein s Anomaly Sylvain M. Chauvaud, MD, Gianluca Brancaccio, MD, and Alain F. Carpentier, MD, PhD Department of Cardiovascular Surgery, Hôpital Européen Georges Pompidou, Paris, France Background. Arrhythmias remain an unsolved problem in Ebstein s anomaly. The aim of this study was to investigate the evolution of arrhythmias after surgical repair. Methods. Forty-five patients with Ebstein s anomaly and arrhythmias were studied. Mean age was years. Twenty-four patients (53%) had paroxysmal supraventricular tachycardia, 12 (27%) had atrial fibrillation or flutter, 8 (18%) had ventricular preexcitation (Wolff- Parkinson-White syndrome), and 1 (2%) had a nonsustained ventricular tachycardia. Surgical technique included detachment of the tricuspid anterior leaflet and suture on the atrioventricular annulus associated with right ventricular longitudinal plication. Results. There were four hospital deaths (9%). A pacemaker was implanted early after operation in 5 patients (11%). During a mean follow-up of months (range, 4 to 226 months), there were six additional deaths, three of which were sudden. Two patients were lost to follow-up. Of the 33 surviving patients, 8 (24%) continued to have symptomatic arrhythmias, and 15 (45%) were in permanent sinus rhythm. Of the 24 patients with preoperative paroxysmal supraventricular tachycardia and the 12 with atrial fibrillation or flutter preoperatively, 9 and 2 of the survivors, respectively, have had no further episodes of arrhythmia. The incidence of arrhythmia with or without symptoms was reduced to 39% (13/33) of the surviving patients. Conclusions. Arrhythmia is not totally abolished after operation. However, patients with Ebstein s anomaly and arrhythmia show substantial improvement after conservative surgical intervention. (Ann Thorac Surg 2001;71: ) 2001 by The Society of Thoracic Surgeons Ebstein s anomaly is a congenital cardiac malformation in which the tricuspid septal and posterior leaflets attach below the valve annulus. The effective tricuspid valve orifice is displaced downward into the right ventricle at the junction of the inlet and trabecular components of the ventricle. [1] It was first described in 1866 by Wilhelm Ebstein in a 19-year-old laborer who died of tricuspid regurgitation caused by severe malformation of the tricuspid valve [2]. The incidence of Ebstein s anomaly is reported to be approximately 1 in 20,000 live births and is 0.5% or less among patients with congenital heart disease. Ebstein s anomaly is often associated with paroxysmal supraventricular tachycardia. The incidence of arrhythmias ranges between 22% and 42% of patients, 5% to 10% of whom have Wolff- Parkinson-White (WPW) syndrome [3]. These arrhythmias have an important impact on the quality of life of the patient and on midterm and long-term survival [4]. Different surgical techniques have been used to repair the anomaly, but the results in regard to arrhythmias are uncertain [5 9]. The present study reports our experience in a consecutive series of patients referred for surgical repair of Ebstein s anomaly, with particular emphasis on patients with documented preoperative arrhythmias. The Accepted for publication Jan 19, Address reprint requests to Dr Chauvaud, Département de Chirurgie Cardio-Vasculaire, Hôpital Européen Georges Pompidou, 20, rue Leblanc, Paris, France; sylvain.chauvaud@egp.ap-hop-paris.fr. purpose of the study was to evaluate whether the technique of Carpentier and associates [10] not only improves the underlying structural and hemodynamics problems but also reduces the incidence of cardiac arrhythmias. Material and Methods Between January 1980 and July 1999, 98 patients underwent operation to correct Ebstein s anomaly at Hôpital Broussais. Early in this experience, the diagnosis and the assessment of tricuspid valve insufficiency in each patient were performed with invasive methods, catheterization and angiography. Since 1985, echocardiography and Doppler echocardiography only have been used. Before operation, 45 (46%) of the 98 patients had documented arrhythmias. Arrhythmias and atrioventricular (AV) conduction before operation were assessed by routine 12-lead electrocardiograms in all patients and by electrophysiologic study, 24-hour ambulatory electrocardiographic monitoring, and treadmill exercise testing when clinically indicated. All patients were monitored by electrocardiograms intraoperatively and for 3 to 7 days postoperatively. Preoperative electrophysiologic assessment was carried out in only 12 patients. Indications were palpitations or electrocardiographic evidence of ventricular preexcitation. At the time of electrophysiologic study, inducible orthodromic reciprocating tachycardia was found in by The Society of Thoracic Surgeons /01/$20.00 Published by Elsevier Science Inc PII S (01)02464-X

2 1548 CHAUVAUD ET AL Ann Thorac Surg REPAIR OF EBSTEIN S ANOMALY WITH ARRHYTHMIA 2001;71: Table 1. Characteristics of Patients With and Without Arrhythmias a Variable With Arrhythmias (n 45) Without Arrhythmias (n 53) P value Age (y) Sex Female Male NYHA class I 1 (2) 2 (4) II 13 (29) 15 (28) III 21 (47) 31 (59) IV 10 (22) 5 (9) Cyanosis 21 (47) 25 (47) Cardiothoracic ratio Tricuspid insufficiency I 0 0 II 4 (9) 5 (9) III 20 (44) 22 (42) IV 21 (47) 26 (49) Atrial septal defect 21 (47) 24 (45) Functional types b A 2 (4) 3 (6) B 18 (40) 16 (30) C 23 (51) 25 (47) D 2 (4) 9 (17) a Numbers in parentheses are percentages. b See Carpentier et al. [10]. not significant; NYHA New York Heart Association. patients, 2 of whom had inducible sustained atrial flutter or fibrillation. The accessory AV connections were located in the right posteroseptal or lateral free wall in all 12 patients. One patient (patient 2) had radiofrequency ablation preoperatively. The arrhythmias documented preoperatively in the 45 patients were as follows: paroxysmal supraventricular tachycardia in 24, permanent atrial fibrillation or flutter in 12, ventricular preexcitation (WPW syndrome) in 8, and nonsustained monomorphic ventricular tachycardia in 1. The 45 patients with a cardiac arrhythmia were significantly older than the 53 patients who did not have symptoms or a documented arrhythmia (mean age, 33 years versus 21 years; p 0.01). There were no other significant differences in preoperative functional or hemodynamic data between patients with and patients without symptoms of preoperative arrhythmia (Table 1). The tricuspid valve lesions were classified using a functional approach, which includes assessment of the motion of the anterosuperior leaflet and the size and contractility of the atrialized chamber [10]. Eleven patients had severe dysplasia of the leaflets with muscularization of the tensile apparatus and attachment of the anterosuperior leaflet to the right ventricular wall by abnormal chordae. In these patients, there was a muscular continuity between the right atrial wall, the tricuspid anterior leaflet, and the ventricular wall. The indications for operation were cyanosis, severe symptoms, severe tricuspid regurgitation, or arrhythmias. Four patients who had mild tricuspid regurgitation and were in New York Heart Association functional class I or II underwent surgical repair for symptoms of arrhythmia associated with cyanosis (3 patients) or after an unsuccessful noninvasive attempt to oblate the accessory pathways (1 patient). Operative Technique The operative technique has been described in detail [10, 11]. Operation was undertaken using cardiopulmonary bypass at 28 C. The tricuspid valve was approached through a right atriotomy. The corrective procedure as used at Hôpital Broussais has four basic steps, and the goals are to restore normal function to the tricuspid valve and to incorporate the inlet of the right ventricle in the repair. The anterosuperior leaflet is temporarily detached, and the restrictive trabeculations and cords are divided to restore normal motion (Fig 1). The anterolateral papillary muscle is fully mobilized by detaching the muscular bands, which were inserted into the lateral wall of the right ventricle. The atrialized right ventricle is plicated longitudinally, a measure achieving a reduction in the diameter of the tricuspid annulus. The anterosuperior leaflet is rotated in a clockwise direction and reattached to the newly reduced annulus. In adult patients, the annulus is reinforced with a Carpentier prosthetic ring. Valve repair was accomplished in 96% of patients and valve replacement with a bioprosthesis, in 4% (2/45). Longitudinal plication of the right ventricular chamber was required in 41 patients (91%). Annuloplasty using a prosthetic Carpentier ring was performed in 78% (35 patients). A bidirectional cavopulmonary shunt was added in 12 patients at high risk of early right ventricular failure [12]. Closure of an associated atrial septal defect or patent foramen ovale was performed in 21 patients. Cryoablation of an accessory pathway was performed perioperatively in 2 patients (patients 1 and 24) early in our experience. Follow-up data were collected at consultations every 6 months, and a 12-lead electrocardiogram was obtained. When clinical symptoms were present or when electrocardiographic abnormalities persisted, a 24-hour recording was made (Holter monitoring). Statistical Analysis Data are expressed as the mean the standard deviation. Differences between preoperative and postoperative data were analyzed using 2 contingency tables for discrete variables and Student s t test for continuous variables. The Kaplan-Meier method was used to calculate actuarial survival. A p value of less than 0.05 was considered significant. Results The hospital mortality rate for the 45 patients with preoperative arrhythmias was 9% (4 patients). The causes of death were right ventricular failure in 3 patients and postoperative hyperthermia in the other. All 4 had severe disease (type C) and an atrialized right chamber. In a

3 Ann Thorac Surg CHAUVAUD ET AL 2001;71: REPAIR OF EBSTEIN S ANOMALY WITH ARRHYTHMIA 1549 previous study [12] we defined patients to be at high risk when one or more of the following elements were present: massive tricuspid insufficiency, a long history of tricuspid valve disease, New York Heart Association functional class IV, or permanent atrial fibrillation. Reoperation for residual tricuspid insufficiency was performed in 3 patients with a second repair in 2 and valve replacement in the other. Postoperative Arrhythmias In the early postoperative period, 42% (17 of 41) of the patients were in permanent sinus rhythm, and only 7 patients (17%) had supraventricular tachyarrhythmia (Table 2). Atrial fibrillation was seen in 8 patients (19.5%). Implantation of a pacemaker to treat AV dissociation was necessary in 5 patients (12%). The other 3 patients with junctional rhythm immediately after operation regained sinus rhythm with normal AV conduction during the hospital stay. The surgical procedure significantly reduced the incidence of early postoperative arrhythmias: sinus rhythm was present in 17 of the 41 early survivors. Fig 1. (A) Detachment of the anterior leaflet and section of the muscular bands in order to individualize the lateral papillary muscle. Dashed lines indicate the limits of the atrialized chamber. (B) Longitudinal plication of the atrialized chamber from the apex of the right ventricle to the tricuspid annulus. Subsequently, the tricuspid annulus is reduced. (C) Reattachment of the anterior leaflet on the true annulus with a clockwise rotation. Follow-up Follow-up assessment was available for 39 of the 41 patients who survived the operation and the perioperative period (Table 3). The mean follow-up was months (range, 4 to 226 months). During this period, there were six deaths. Three patients died suddenly, 2 died of right ventricular failure, and 1 patient died of pulmonary infection. Actuarial survival was 88% 5% at 1 year and 76% 8% at 5 years and 10 years (Fig 2). Functional status was assessed using the New York Heart Association classification; 38% were in class I, 55% in class II, 5% in class III, and 2% in class IV. Twelve of the surviving 33 patients continued to have arrhythmias (4 had paroxysmal supraventricular tachycardia, 5 had atrial fibrillation, and 3 had WPW), but 15 (45%) patients reported no arrhythmia (see Table 3). Nineteen of the 24 patients with documented preoperative paroxysmal supraventricular tachycardia were followed up for a mean of months. Four died in the hospital, and 1 was lost to follow-up. Nine had no further episodes of palpitation, syncope or near syncope, or electrocardiographic signs of arrhythmia. Two patients died suddenly at a mean months after operation (patients 18 and 34) while still receiving flecainide acetate therapy for symptomatic tachycardias. Four patients continued to have symptomatic tachycardia, and 2 (patients 19 and 39) had development of atrial fibrillation, and 2 others had permanent pacemaker implantation, 1 of whom (patient 35) had complete AV block. The 12 patients with preoperative atrial fibrillation were followed up for a mean months. There were no hospital deaths in this group, and 1 patient was lost to follow-up. When last seen, 3 were in permanent sinus rhythm. Of the remaining 8 patients, 3 died while on a regimen of digoxin therapy (patients 26, 32, and 43), 1 had development of AV block with subsequent pacemaker implantation, and 3 continued to have chronic atrial

4 1550 CHAUVAUD ET AL Ann Thorac Surg REPAIR OF EBSTEIN S ANOMALY WITH ARRHYTHMIA 2001;71: Table 2. Clinical Features and Follow-up Data on 45 Patients With Preoperative Arrhythmias a Patient No. Age (y) Sex Rhythm Preop Early Postop Status Follow-up Duration (months) 1 9 F WPW Pacemaker Pacemaker F WPW Pacemaker Pacemaker F WPW SR Death F AF PSVT Asymptomatic F PSVT Bradycardia Asymptomatic F PSVT SR PSVT F WPW SR Asymptomatic M WPW WPW WPW M PSVT PSVT Asymptomatic M PSVT PSVT Asymptomatic M PSVT SR Asymptomatic F AF AF AF F PSVT SR Not available F PSVT SR Asymptomatic M PSVT Death M PSVT Pacemaker Pacemaker M PSVT SR Asymptomatic M PSVT PSVT Sudden death F PSVT AF/VF AF F PSVT SR Asymptomatic M PSVT Death F PSVT SR Asymptomatic F WPW SR Asymptomatic M WPW WPW Asymptomatic F AF AF AF M AF AF Sudden death M PSVT Death F PSVT PSVT Asymptomatic M AF SR AF M PSVT SR Asymptomatic F WPW WPW Asymptomatic F AF AF Death M AF AF Pacemaker F PSVT PSVT Death F PSVT PSVT Pacemaker M AF SR Asymptomatic M PSVT SR Asymptomatic F VT SR Asymptomatic M PSVT AF AF F AF AF Not available F AF SR Asymptomatic F AF Pacemaker Pacemaker F AF Pacemaker Sudden death M PSVT Death M PSVT SR Asymptomatic 4 a In the follow-up, patients presenting with persistent rhythm disturbance without any symptoms were classified as asymptomatic. F atrial fibrillation; PSVT paroxysmal supraventricular tachycardia; SR sinus rhythm; VT ventricular tachycardia; WPW Wolff-Parkinson-White syndrome. fibrillation. One patient had had a pacemaker implanted early postoperatively. The 8 patients with Wolff-Parkinson-White syndrome were followed up for a mean of months. 2 were in sinus rhythm. Of the remaining 6 patients, 1 died 56 months after operation (patient 3), 2 had development of AV block immediately after operation and had a pacemaker implanted (patients 24 and 31), and 3 continued to have WPW, but only 1 has symptoms requiring medications. The patient with preoperative ventricular arrhyth-

5 Ann Thorac Surg CHAUVAUD ET AL 2001;71: REPAIR OF EBSTEIN S ANOMALY WITH ARRHYTHMIA 1551 Table 3. Baseline Data for 45 Patients in Preoperative and Follow-up Period Late Postoperative Period Preoperative Period Sinus Rhythm Bradycardia AF Pacemaker PSVT WPW Hospital Death Late Death Lost to Follow-up PSVT (n 24) AF (n 12) a 1 WPW (n 8) Sinus VT (n 1) Total a Included here is patient 43, who received a pacemaker early postoperatively and died suddenly at 35 months of follow-up. AT atrial fibrillation; PSVT paroxysmal supraventricular tachycardia; VT ventricular tachycardia; WPW Wolff-Parkinson-White syndrome. mias was free from symptomatic tachycardia at 99 months of follow-up (patient 38). Quality of Life The number of patients on a regimen of antiarrhythmic therapy decreased significantly from 100% (45 patients) preoperatively to 44% (18 of 41 patients) postoperatively and to 24% (8 of 33 patients) during follow-up (p 0.01). Seven patients underwent treatment, 2 with SVT, 4 with AF, and 1 with WPW. Two patients with persistent paroxysmal supraventricular tachycardias were on a regimen of propranolol hydrochloride, and 4 patients in atrial fibrillation continued therapy with digoxin and an anticoagulant. The patient with WPW (patient 8) who continued to experience paroxysmal tachycardia was considerably less symptomatic than preoperatively on a regimen of propafenone hydrochloride therapy. New York Heart Association functional status improved significantly during follow-up. In conclusion, of 45 patients with preoperative documented arrhythmias, only 13 patients (39% of the 33 patients available for follow-up) had persisting arrhythmia. Comment Patients with Ebstein s anomaly frequently have troublesome and occasionally fatal cardiac arrhythmias. This anomaly is the most common congenital cardiac defect Fig 2. Actuarial survival curve at 1 year, 5 years, and 10 years. associated with WPW syndrome. Some arrhythmias such as paroxysmal supraventricular tachycardia with WPW syndrome are explained by the presence of accessory pathways, whereas atrial fibrillation is related to right atrial enlargement caused by tricuspid insufficiency. This finding is consistent with the hypothesis that Ebstein s anomaly originates from the incomplete separation of the right atrium and the right ventricle [13]. Therefore it is possible that any part of the atrialized ventricle can be connected to the right atrium across the annulus. The accessory AV connections usually are located on the same side as the malformed valve, and in more than 50% of patients, multiple accessory pathways have been found [14 16]. Pressley and coworkers [17] reported that 50% of 38 patients with Ebstein s anomaly and WPW syndrome had multiple pathways. Cappato and associates [14] described an adult population undergoing radiofrequency ablation for Ebstein s associated arrhythmia and found 62% of patients had multiple accessory pathways. The preponderance of right posterior and right posteroseptal accessory pathways [14, 16 19] and the morphological abnormalities of the atrialized ventricle [13] could explain the arrhythmogenic role of this chamber. Thus, we suggest that plication of the right atrialized ventricle permits the interruption of accessory pathways across this region, and, on the other hand, excludes this chamber that causes arrhythmogenic circuits or foci [20]. Our hypothesis is that by means of muscular strands, accessory pathways cross the tricuspid annulus in the place where the anterosuperior leaflet is located. This leaflet, as reported by Anderson and coauthors [1], is always abnormal anatomically. Usually, it is large and has abnormal fibrous strands running through it. These strands sometimes become muscularized, and attach the leaflet at the right ventricle wall. In some hearts the attachment is by means of these abnormal muscularized chordae, whereas in others the attachment is continuous and can incorporate the anterolateral papillary muscle. The tricuspid valve is muscularized in Ebstein s anomaly, and in 11 of our patients during operation, it was noticed in the presence of continuous muscular bands. Therefore, detachment of the anterosuperior leaflet and incision of all the muscular trabeculations provide not only leaflet mobilization, but also interruption of accessory pathways.

6 1552 CHAUVAUD ET AL Ann Thorac Surg REPAIR OF EBSTEIN S ANOMALY WITH ARRHYTHMIA 2001;71: The goals of the various surgical procedures are to reduce the structural and functional anomaly. However, the major unsolved problem is the high incidence of atrial arrhythmias, which exist preoperatively and postoperatively [21]. In a study of cardiac arrhythmias in patients undergoing surgical repair of Ebstein s anomaly, Oh and associates [3] found that 33% of patients with preoperative arrhythmias continued to have symptomatic tachycardia after operation. For this reason, in patients with a wide complex, Danielson and co-workers [5] reported prophylactic intravenous administration of lidocaine hydrochloride 48 hours before operation and use of procainamide hydrochloride for 3 months postoperatively once oral intake has begun. In no patient in our series did we use the maze procedure because of the lack of published data favoring a reduction in atrial fibrillation in right-sided lesions. Map-directed ablation of accessory pathways is time-consuming, and according to the Mayo clinic experience [5], the incidence of recurrent rhythmic disturbances is still a problem with this procedure. With our technique, we were able to reestablish sinus rhythm in about 30% of patients with preoperative cardiac arrhythmias, and fewer than one sixth continued to have symptomatic tachycardias after operation. There was a more marked decrease in the occurrence of supraventricular tachycardia compared with atrial fibrillation. This suggests that the etiology of supraventricular tachycardia in many of these patients may be related more to the presence of the accessory pathways than to primary or secondary myocardial abnormalities seen with Ebstein s anomaly. These observations correlate with those in previous reports [17, 22] in which the authors observed that patients in atrial fibrillation with surgical ablation of the accessory pathways in Ebstein s anomaly had a twofold to threefold increased risk of a new atrial fibrillation developing postoperatively compared with patients without Ebstein s anomaly. This fact demonstrates that the etiology of atrial fibrillation in patients with Ebstein s anomaly is due overall to right atrial enlargement. In summary, interruption of accessory pathways, whatever the technique used, is not efficient when atrial fibrillation is present. On the basis of the good results of conservative surgical procedures, we advise discussion about an operation before the onset of atrial enlargement. The significant decreases in the frequency and severity of arrhythmias, in the need of antiarrhythmic drugs, and in activity limitations as demonstrated by a better New York Heart Association class after operation appear to have greatly improved the quality of life of patients with Ebstein s anomaly. Our study does have limitations. It is a retrospective study, and it was not possible to demonstrate electrophysiologically the presence of accessory pathways in the anterior leaflet of the tricuspid valve. Nevertheless, our study reveals that arrhythmia can be found in nearly 1 of every 2 Ebstein s patients referred for surgical correction. Detachment of the anterosuperior leaflet and plication of the right ventricular chamber reduce the incidence of postoperative arrhythmias. The technique is not as effective for arrhythmias secondary to atrial enlargement; therefore, we suggest the operation be performed earlier before atrial enlargement occurs. References 1. 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