Surgical treatment of tachyarrhythmias in patients with both an Ebstein anomaly and a Kent bundle

Surgical aspects of atrial arrhythmia : Right atrial ablation and anti-arrhythmic surgery in congenital heart disease

BACKGROUND

Atrial arrhythmias are frequently described in congenital heart disease.

OBJECTIVES

To provide a surgical perspective of anti-arrhythmic procedures and strategic approaches.

METHODS

Discussion of the history of anti-arrhythmic treatments in congenital heart disease.

RESULTS

Before the advent of the Maze procedure (first published in 1991), surgery mainly focused on patients with Wolff-Parkinson-White syndrome and also on arrhythmias in Ebstein's malformation. Atrial septal defects (ASD) subsequently received more attention, i.e., in terms of atrial arrhythmia in the natural prognosis and the surgically modified course and in terms of surgical versus transcatheter approaches. Based on the background of various atrial arrhythmia mechanisms of ASD, several surgical procedures have been reported, ranging from the bilateral full Maze procedure to simple modification of right atriotomy. The so-called right atrial Maze procedure occupies a special position from the viewpoint of cardiology in acquired heart disease, especially in cases of frequently occurring right heart failure. In hearts with more complex structural abnormalities, a detailed understanding of the conditions to improve overall surgical outcome and develop future "anti-arrhythmic" strategies is necessary.

CONCLUSIONS

It is important to precisely specify factors in the individual cases, not only morphological diversity but also technical and strategic variations and their consequences. A variety of anti-arrhythmic surgical procedures are currently available. How and when to use which procedure requires professional insight and cautious clinical decision-making.

Ebstein's anomaly: the Broussais approach

Ebstein's anomaly is rare, but it is the most frequent cause of congenital tricuspid valve anomaly. For many years valve replacement was performed. Conservative techniques are now preferred due to improvement of the results. The goals of surgery are to restore a normal tricuspid valve function, to preserve the right ventricular contractility and to decrease the risk of rhythm disturbances. Basically, the technique is based on mobilization of the anterior leaflet and longitudinal plication of the right ventricle. A bidirectional cavo pulmonary shunt is used in severe cases. Results are correlated with the severity of the disease, the expertise of the surgical team and also with the perioperative management.

Cardiac arrhythmia in patients undergoing surgical repair of Ebstein's anomaly

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 33 +/- 15 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 57 +/- 50 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.

Surgical treatment of Wolf-Parkinson-White syndrome during plastic operations in patients with Ebstein's anomaly

OBJECTIVE

Ebstein's anomaly is the most common pathology associated with the accessory conduction pathways.

METHODS

From January 1990 to August 1999 48 patients underwent surgical repair of Ebstein's anomaly by various plastic techniques. The pathways were identified and characterized at preoperative electrophysiologic mapping in 17 (34.5%) patients. There were seven males and ten females. The patients age ranged 6-35 years (mean 12.7+/-2.1 years). Five patients were in NYHA class II and were in 12 in NYHA class III. The cardiothoracic ratio ranged from 0.59 to 0.69 (mean 0.65+/-0.08). Tachycardia was present in 15 patients with Wolf-Parkinson-White (WPW) syndrome. Atrial septal defect was present in 12 patients (70. 6%). Accessory conduction pathways were in the right posterior septal area in seven patients, in right posterior septal area and free wall in seven patients and in right free wall in three. The pathways were successfully ablated in all patients during cardiopulmonary bypass.

RESULTS

There were no deaths, no relapses. Follow-up ranged from 4 months to 7 years (mean 4.7+/-1.1 years). There were no late deaths, but one patient required successful tricuspid valve replacement because of severe tricuspid insufficiency. At follow-up 57.8% of patients were in NYHA class I.

CONCLUSIONS

Preoperative electrophysiologic study allows to identify the accessory conduction pathways in patients with Ebstein's anomaly. The combined approach of tricuspid valve repair and surgical ablation of accessory atrioventricular connections has been proved safe and effective. This operative procedure allows to improve functional results in patients with Ebstein's malformation and concomitant accessory conduction pathways.

Radiofrequency ablation of tachyarrhythmias in patients with Ebstein's anomaly

We performed radiofrequency catheter ablation in five patients associated with Ebstein's anomaly to cure their refractory tachyarrhythmias. The presenting arrhythmias were four cases of orthodromic circus movement tachycardia using accessory pathways as a requisite limb, including one case of a Mahaim fiber and one of atrial flutter of common variety. All accessory pathways, including the Mahaim fiber, were ablated by RF energy delivered through the catheter placed at the AV annulus rather than the displaced anatomical AV groove. Interestingly, the antegrade or retrograde conduction interval over these accessory pathways was relatively longer than that of usual accessory pathways, and the accessory pathway potential was fractionated in some cases. The location of the atrioventricular node was displaced from the usual position to the postero-inferior area of Koch's triangle in one case. The configuration of the flutter wave was larger than usual in height as well as in width. All tachyarrhythmias were cured by RF catheter ablation. In the case of RF catheter ablation for patients with Ebstein's anomaly, close attention is indispensable in order to accomplish it safely and successfully, because of the anatomical and functional differences peculiar to Ebstein's anomaly.

Surgical treatment of patients with Wolff-Parkinson-White syndrome and associated Ebstein's anomaly

Ebstein"s anomaly is the most common congenital heart disease associated with the Wolf-Parkinson-White syndrome. Between November 1973 and March 1993, we surgically treated 42 patients with Wolff-Parkinson-White syndrome and Ebstein's anomaly. The patient's ages ranged from 5 months to 59 years (mean 35.3 +/- 14.0 years). There were a total of 52 accessory pathways, 48 of which were located in the right (65%) or posteroseptal (29%) area. A left-sided accessory pathway was seen in only two patients (3.8%). Division of all right-sided accessory pathways was done during normothermic cardiopulmonary bypass with the heart beating; cryocoagulation was applied together with scalpel dissection of the atrioventricular groove. Division of the left-sided accessory pathways was done with the use cold potassium cardioplegic arrest. Thirty-five of these patients underwent tricuspid valve operation for Ebstein's anomaly and 11 of them underwent tricuspid valve replacement with a bioprosthesis. All 52 accessory pathways were successfully divided, although two patients required reoperation because of tachycardia caused by accessory pathways in different positions. Three hospital deaths (7.1%) occurred. There were no late deaths during the follow-up period (mean 94.3 +/- 52.4 months), but two patients required repeat tricuspid operation because of progression of the tricuspid regurgitation. Because no repeat operations were required during long-term follow-up patients who underwent valve repair or valve replacement, correction should be indicated in some patients.

Surgical treatment of atrioventricular atresia combined with Wolff-Parkinson-White syndrome

BACKGROUND

Tachyarrhythmia has been thought to be an absolute contraindication for the Fontan operation.

PATIENTS AND METHODS

Three patients, 22, 9, and 11 years of age, diagnosed as having atrioventricular atresia combined with the Wolff-Parkinson-White syndrome underwent surgical treatment. Each had drug-resistant atrioventricular tachycardia that required direct cardioversion. Two patients with tricuspid atresia had an intermittent right-sided accessory pathway (ACP), and one with mitral atresia had a concealed left-sided ACP. The ACP was divided using an epicardial approach in two patients and an endocardial approach in one. Simultaneously, the Fontan operation was performed with atrioventricular connection (modified Fontan operation) in one patient, and a total cavopulmonary connection performed in another patient. In the remaining patient, ACP division was performed 3 years after the Fontan operation.

RESULTS

There was no early death or other fatal complication, and the hemodynamic results were excellent. During the mean follow-up period of 68 months (range, 5 to 127 months), there has been no late death or recurrence of tachyarrhythmia.

CONCLUSION

Tachyarrhythmias caused by ACPs are not contraindications for the Fontan operation. Concomitant surgery is advocated, as excellent short- and long-term results may be expected in these patients.

Will C. Sealy, MD: the father of arrhythmia surgery--the story of the fisherman with a fast pulse

The development of clinical electrophysiology and arrhythmia surgery has a long and interesting history. On May 2, 1968, Dr. Will C. Sealy, with the electrophysiologists at Duke University, performed the first successful ablation of a pathway in a patient with Wolff-Parkinson-White syndrome using an epicardial approach. Thereafter, he and his colleagues developed improved endocardial techniques to ensure ablation of even multiple and complex anatomic pathways. From this work the impulse to perform these procedures spread worldwide, and a school of arrhythmia surgeons sprouted. For these and other accomplishments, Dr. Sealy clearly became the Father of Arrhythmia Surgery. The story is told herein.

Surgical anatomy of accessory connections of atrioventricular conduction

Forty-nine descriptions of accessory pathways of atrioventricular (AV) conduction have been analyzed in the search for reasons for an occasional failure of interruption by operation. The validity of the steps now used for open interruption of connections was confirmed. Several possible but highly speculative reasons were found for failure. A pathway might remain intact after operation because atrial muscle on the AV valve may act as a pathway route after an atriotomy made just above the annulus. In another situation, the AV valve myocardium might be continuous with a papillary muscle directly attached to the valve. The small, middle, and great coronary veins, when budding from the coronary sinus, might carry with them an AV connection that escaped the invasion of the primitive AV junction by sulcus tissue. Final proof of these conjectures awaits more studies of hearts with accessory pathways of AV conduction.

Two unusual complications after surgical interruption of an accessory pathway

In a patient with the Wolff-Parkinson-White syndrome, Ebstein's anomaly of the tricuspid valve, a right atrial Chiari net and a patent foramen ovale two unusual complications developed after surgical epicardial dissection combined with cryoablation of the anomalous pathway. The first complication was that ablation of the right atrial wall led to changes in interatrial pressure gradients and the development of a right to left shunt necessitating surgical closure of the atrial septal defect. The second complication was the development of a thrombotic mass in the Chiari net simulating on intracavity tumour, which also had to be removed surgically.

Effect of Ebstein's anomaly on short- and long-term outcome of surgically treated patients with Wolff-Parkinson-White syndrome

BACKGROUND

Ebstein's anomaly is the most commonly occurring congenital abnormality associated with the Wolff-Parkinson-White (WPW) syndrome. However, the effects of Ebstein's anomaly on the risks and benefits of surgical ablation of accessory pathways in patients with WPW syndrome are unknown.

METHODS AND RESULTS

This study compared the long-term outcome of 38 WPW patients with Ebstein's anomaly undergoing accessory pathway ablation to a reference population of 384 similarly treated patients without the anomaly. Ebstein's anomaly was mild in 21 patients (55%) and moderate-to-severe in 17 patients (45%). Sixteen patients (42%) required tricuspid valve surgery, and 23 (61%) had an atrial septal defect or patent foramen ovale repaired. Baseline clinical characteristics and preoperative clinical arrhythmias were similar in both groups. Ten-year survival was 92.4% and 91.2% for patients with and without Ebstein's anomaly, respectively (p = NS). During a mean follow-up of 6.2 +/- 3.8 and 5.3 +/- 3.6 years, 82% of patients with and 90% without Ebstein's anomaly had either clinically insignificant or no arrhythmias, and 18% versus 10% reported symptoms suggesting arrhythmias lasting longer than 1 minute, respectively. Atrial fibrillation was reduced postoperatively to 9% (p less than 0.001) in patients with and to 4% (p less than 0.001) in those without the anomaly. Fewer hospitalizations were reported postoperatively by 90% versus 96% of patients with and without Ebstein's anomaly; 9.4% versus 6.0% of patients were disabled at follow-up, respectively (p = NS).

CONCLUSIONS

Patients with Ebstein's anomaly are improved significantly after accessory pathway ablation. The presence of this anomaly should not preclude accessory pathway ablation in these patients.

"Atypical" posteroseptal accessory pathway in Wolff-Parkinson-White syndrome

The posteroseptal accessory pathway in the Wolff-Parkinson-White syndrome is associated with a delta wave that is negative in the inferior electrocardiographic (ECG) leads and the occurrence of the earliest retrograde atrial activation near the orifice of the coronary sinus during atrioventricular (AV) reentrant tachycardia. Seventy-two patients with a posteroseptal accessory pathway underwent epicardial mapping before operative ablation. The earliest epicardial activation occurred at the posterosuperior process of the left ventricle in all patients. Dissection of the posteroseptal region (right atrial-left ventricular sulcus) resulted in permanent loss of preexcitation in 69 patients and failure to abolish preexcitation permanently in 3. At reoperation in two patients, preexcitation was abolished by discrete cryoablation of the left side of the interatrial septum near the AV node approached through the atrial septum in the normothermic beating heart. At reoperation, one patient had extensive AV node dissection. All patients have had permanent loss of preexcitation. The vast majority of posteroseptal accessory pathways ("typical") are epicardial and ablated by dissection of the posteroseptal region. Rarely, posteroseptal accessory pathways are "atypical" in that they are intraseptally located near the AV node on the left atrial endocardial surface.

The long R-P' tachycardias

The family of tachycardias that are called long R-P' tachycardias represent a unique group of tachycardias which have been notably refractory to pharmacologic therapy in the past. On the surface electrocardiogram, the rhythms may be indistinguishable. It is only with careful electrophysiological evaluation in many cases that these rhythms can be sorted out. The differential diagnosis in these rhythms is important because with incessant tachycardia, ventricular dysfunction may be produced. In many of the instances of long R-P' tachycardias definitive and directed ablation of the tachycardia can be accomplished. New techniques involving catheter ablation and super-selective surgical dissection are now present which makes ablation of these tachycardias possible.

Ebstein's anomaly: sixteen years' experience with valve replacement without plication of the right ventricle

From June 1967 to February 1983 10 patients aged from 13 to 51 years underwent surgery for Ebstein's anomaly. Nine patients were in class III according to the New York Heart Association (NYHA) classification and one was in class IV. The interatrial communication was closed in all patients; the tricuspid valve was repaired in one patient and replaced in the other nine patients. There were no deaths in hospital but there were two late deaths. One patient died when the tricuspid prosthesis clotted seven years after its insertion. The other patient committed suicide 11 years after surgery. The remaining eight patients have been followed up for periods ranging from six months to 16 years (mean 10 years). Seven of the eight survivors are well and in NYHA class I, the eighth being in class II. Cardiac arrhythmias have been a problem in only one patient. Tricuspid valve replacement combined with closure of interatrial communication without right ventricular plication has given satisfactory clinical results and has improved the quality of life.

Direct endocardial recording from an accessory atrioventricular pathway: localization of the site of block, effect of antiarrhythmic drugs, and attempt at nonsurgical ablation

We recorded a discrete 0.95 mV potential consistent with accessory atrioventricular pathway (AP) activation during serial electrophysiologic studies in a patient with Ebstein's anomaly and Wolff-Parkinson-White syndrome. Bipolar pacing from the catheter electrode in which the AP potential was recorded resulted in a stimulus-ventricle interval identical to the AP-ventricle interval during antegrade conduction, and a stimulus-atrium interval identical to the AP-atrium interval during retrograde conduction. With the patient in the drug-free state, antegrade AP block during atrial pacing and retrograde AP block during ventricular pacing occurred distal to the AP potential (AP-ventricle junction and AP-atrium junction, respectively), supporting the "impedance mismatch" hypothesis. Procainamide and disopyramide each lengthened the antegrade AP effective refractory period by affecting the AP-ventricle junction (possibly by decreasing the current generated by the AP). Both drugs also lengthened the retrograde AP effective refractory period but produced a greater effect on the ventricle-AP junction than on the AP-atrium junction, suggesting marginal geometry of the former. R wave synchronous shocks of 160 and 320 W-sec delivered between the catheter electrode recording the largest unipolar AP potential and a skin electrode produced transient, complete, antegrade block over the AP, suggesting the feasibility of this new nonsurgical technique for AP ablation.

Ebstein's anomaly: editorial comments and personal observations

Renewed interest in the natural history of Ebstein's anomaly has been created by recent surgical innovations in its management. Tricuspid valve replacement and various types of plastic reconstruction are the two methods of treating Ebstein's anomaly. Replacement of the tricuspid valve has been more successful in older children and adults than in infants, but overall, less successful than procedures involving mitral or aortic valve prosthesis. At the Mayo Clinic, 42 patients with Ebstein's anomaly, aged 11 months to 62 years, underwent surgical repair. Plastic repair was accomplished in 34 of these patients, and right ventricular plication and valve replacement in 6 others. Two patients had valves that could not be reconstructed, and underwent a Fontan procedure instead. Three hospital deaths and two late deaths occurred. There have been no deaths in the 25 patients seen last in the series. Long-term follow-up was obtained in the first 22 survivors. The majority were in New York Heart Association (NYHA) Class III or IV preoperatively; all but 3 had improved to NYHA Class I or II at follow-up. Because of the low mortality rate and good long-term results as well as the fact that the majority of patients can be repaired with a plastic procedure, the operation is advisable for patients who have deteriorated into NYHA Class III or IV. Those patients with moderate to severe cyanosis, paradoxical emboli, or progressive increase in cardiac size are also candidates for operation.

Surgical treatment in Ebstein's malformation

Between January, 1967, and July, 1981, 24 patients with Ebstein's malformation underwent surgical repair. Sixteen had tricuspid valve replacement; 8 did not. All interatrial communications were closed. Two patients had plication of atrialized ventricle. Twenty had dysrhythmias; these were surgically treated in 4. Four patients (17%), each with valve replacement, died in the hospital (70% confidence limits, 9-28%); 3 of these were among the 6 patients who were preoperatively in New York Heart Association Functional Class IV. There were 3 late deaths, 1 from noncardiac causes and 2 from persistent tricuspid regurgitation in patients without valve replacement. No late deaths or valve-related complications occurred in the valve replacement group. Dysrhythmias remain a problem, although most patients are symptomatically improved after operation. This experience suggests that good early and late results are obtained with replacement of incompetent tricuspid valves if this is done before advanced symptomatic deterioration, that plication rarely is necessary, and that rhythm disturbances should be recognized and appropriately managed.

The electrophysiologic basis and management of symptomatic recurrent tachycardia in patients with Ebstein's anomaly of the tricuspid valve

Twenty-two patients with Ebstein's anomaly were evaluated because of recurrent tachycardia. A total of 30 accessory pathways were present in 21 of the 22 patients. Twenty-six accessory pathways were of the atrioventricular (A-V) type while four were Mahaim fibers. Multiple accessory pathways were present in eight patients. Twenty-five of the 26 accessory A-V pathways were right-sided, either in the posterior septum (12 pathways) or the posterolateral free wall (13 pathways); one patient with corrected transposition of the great arteries had a left-sided accessory A-V pathway in a lateral free wall location. Patients with accessory A-V pathways had a long minimal ventriculoatrial (V-A) conduction time during reciprocating tachycardia (192 +/- 47 ms) and usually showed a persistent complete or incomplete right bundle branch block morphology. At surgery, preexcitation was invariably localized to the atrialized ventricle. The long V-A conduction time during reciprocating tachycardia appeared to consist of late activation of the local ventricle in the region of the accessory pathway with a further delay occurring before excitation of adjacent atrium presumably due to conduction over the accessory pathway. Accessory A-V pathways were successfully sectioned with no deaths in 13 of 15 patients. On the basis of these data, certain electrocardiographic findings encountered in the study of patients with recurrent tachycardia should point to the possibility of associated Ebstein's anomaly: morphology of the surface electrocardiogram suggesting preexcitation of the right posterior septum or right posterolateral free wall as well as the combination during reciprocating tachycardia of a long V-A interval and right bundle branch block.

Corrected transposition with severe intracardiac deformities with Wolff-Parkinson-White syndrome in a child. Electrophysiologic investigation and surgical correction

This is a report of a 10-year-old child who underwent surgery for complex congenital heart disease consisting of corrected transposition of the great vessels, ventricular septal defect, patent ductus arterisus, severe left-sided atrioventricular (AV) valve insuffieicney (Ebstein's deformity) and Wolff-Parkinson-White syndrome. The site of his accessory AV connection was localized preoperatively at a left anterolateral site by isopotential body surface maps and by intracardiac electrophysiologic studies. He successfully underwent surgery for closure of the ventricular septal defect, ligation of the patent ductus arteriosus, replacement of the left-sided AV valve, and interruption of the accessory AV pathway. Unavoidable complete AV block acquired at surgery required subsequent permanent pacemaker therapy.

The cause of the hemodynamic disturbances in Ebstein's anomaly based on observations at operation

Ten adult patients with Ebstein's anomaly had open-heart operation for interruption of a Kent bundle. The 4 patients in Group 1 had arrhythmias. One patient had a patent foramen ovale, which was closed. In 3 patients the Kent pathway was identified and interrupted, but in the other only the pathway's anterograde function was interrupted, leaving the patient subject to supraventricular tachycardia (SVT). The 3 patients in Group 2 had mild to moderate cyanosis and dyspnea during SVT as well as mild impairment during strenuous physical activity. Only interruption of their Kent bundles and closure of the patent foramen ovale were done. The 3 patients in Group 3 had dyspnea and cyanosis on exertion, and 1 had overt right heart failure. In each patient, obstruction between the atrialized right ventricle (RV) and functioning RV by the displaced tricuspid valve (TV) was relieved by valve excision and replacement. Interruption of the Kent bundle was successful in 2 of the 3 patients. Operation for Ebstein's anomaly is indicated when any of the following conditions are present: arrhythmias due to Kent bundles that are refractory to medical management; a defect in the atrial septum that must be closed because of a history of cyanosis or paradoxical emboli, or an arrhythmia that must be corrected by right atriotomy; and obstruction between the atrialized and functioning RV or a small functioning RV, both of which can be corrected by TV replacement.

Surgical treatment of Ebstein's anomaly. Early and late results in seven consecutive cases

The surgical treatment of Ebstein's anomaly is discussed on the basis of our experience with 7 patients who underwent operation at this clinic during the last ten years. The age of the patients (2 males, 5 females) ranged from 17 to 47 years (mean 27 years) at the time of operation. Two patients were in functional class II and five in classes III or IV (N.Y.H.A.). The Wolff-Parkinson-White syndrome was concomitant in 2/7 cases and patent foramen ovale or atrial septal defect (ASD) with right-to-left shunt was present in 6/7 cases. The valvular anomaly was typical in 5 patients and stenosis of displaced tricuspid leaflets into right ventricular outflow region was detected in two patients. Tricuspid valve replacement (TVR) with disc valve prosthesis was performed in 5 patients (Björk-Shiley model in 4 cases, Kay-Shiley model in one) and tricuspid valve commissurotomy in two patients. All six patients with interatrial communication underwent closure of this communication simultaneously. One patient had concomitant epicardial mapping and attempted division of the anomalous conduction pathways was unsuccessful. This patient died on the 14th postoperative day from ventricular fibrillation. No other early or late mortality was recorded. Life-long anticoagulation therapy was introduced in all 5 patients with TVR. Thrombotic malfunction of the prosthetic valves necessitated re-operation and new prosthetic valve replacement in two patients 15 and 16 months after the first TVR. One of these patients had recurrent prosthetic thrombosis twice which was successfully treated with streptokinase. The other patient's prosthesis is functioning well 18 months after re-operation. All 6 long-term survivors were improved and remained in good condition, in functional class I, 1, 3, 3, 8, 9, and 10 years, respectively, after operation.