Elective mapping and surgical division of the bundle of Kent in a patient with Ebstein's anomaly who required tricuspid valve replacement

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.

Ebstein's anomaly: a long-term study of survival

This study examines data regarding the survival of patients with Ebstein's malformation. Of 61 patients studied at the University of Minnesota, 31 are currently alive, with the average survival being 15 years. Several factors adversely affected survival: NYHA functional classification, hemoglobin level, right atrial pressure, symptoms during the neonatal period, and cardiac surgery. Data from a multi-institutional study collected during the past decade adds information regarding survival. Of 18,281 patients in the study, 71 (0.4%) had Ebstein's malformation. Sixteen of these were among 7235 infants, and of these seven died during the first year of life. In contrast, among 55 patients over the age of 1 year, four died, each after cardiac surgery. The data help our understanding of the course of patients with Ebstein's malformation and decisions regarding surgical treatment.

Surgical treatment of pediatric cardiac arrhythmia

The combination of improved diagnostic techniques, new and potent antiarrhythmia agents, and progress in antiarrhythmia surgical procedures has resulted in successful management of complex cardiac arrhythmia in children. The kinds of arrhythmia that can be considered for possible surgical intervention share several features. Each produces symptoms and usually is hemodynamically compromising. Each requires extensive preoperative and intraoperative electrophysiologic evaluation to establish the mechanism, response to drugs, and suitability for surgery. Although reports of surgical arrhythmia treatment have been limited in children, with increasing success the indications for such treatment may become less stringent. Our recommendations are shown in the Table. In general, patients intolerant of or unresponsive to medical treatment for symptomatic arrhythmia (tachycardia or bradycardia), should be considered candidates for surgical antiarrhythmia procedures. These patients should be referred for testing to cardiac centers staffed by pediatric cardiac electrophysiologists and surgeons experienced in arrhythmia diagnosis and ablation. Careful evaluation can identify those patients in whom surgical approaches are most appropriate. At present, surgical operations for selected, serious pediatric cardiac arrhythmias offer definitive and possibly curative treatment, and may be preferable to inadequate, poorly tolerated, or long-term medical therapy.

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.

Surgical management of refractory supraventricular tachycardia in infants and children

Sixty-seven children underwent attempted surgical correction of refractory supraventricular arrhythmias using a combination of intraoperative electrophysiologic mapping followed by surgical division or cryoablation of an aberrant conduction pathway or atrial ectopic focus. The patients ranged in age from 4 months to 18 years (mean 11.4 years). Fifty-five patients (82%) had an abnormal conduction pathway crossing the atrioventricular junction (Kent bundle). Thirty-six (65%) of these 55 patients had classic Wolff-Parkinson-White syndrome with a delta wave of pre-excitation on the surface electrocardiogram. Nineteen (35%), however, demonstrated only retrograde conduction across the Kent bundle and had a normal surface electrocardiogram when tachycardia was not present. Kent bundles were isolated to the following locations: right anterior or lateral in 19 (34.5%), left posterior or lateral in 22 (40%), posteroseptal in 10 (18%), anteroseptal in 2 (4%) and both right and left in 2 (4%). Follow-up evaluation of as long as 8 years (mean 34.9 months) has shown seven immediate failures and one late recurrence of arrhythmia (14.5%). Recent refinements in technique and the use of cryoablation for septal aberrant pathways have improved these results. There have been two failures (8%) in the last 25 attempts. Twelve patients underwent surgery for an atrial ectopic focus by the following techniques: cryoablation in seven patients, excision in one patient and both excision and cryoablation in four patients. At a mean follow-up of 16.6 months, there was one late recurrence in the group with an atrial ectopic focus.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Successful surgical treatment of atrial, junctional, and ventricular tachycardia unassociated with accessory connections in infants and children

Five children with severe, life-threatening tachydysrhythmias were treated successfully with surgery. Three had atrial ectopic automatic tachycardia (AET), one had AV junctional (his bundle) automatic ectopic tachycardia (JET), and one had ventricular reentry tachycardia (VT). The mechanism and site of the tachycardia were diagnosed preoperatively using intracardiac electrophysiologic studies (EPS). Medical management with all available drugs failed to control the tachycardia in each patient. The two patients with left atrial AET underwent cryoablation of the focus using cardiopulmonary bypass. The patient with right atrial AET had removal of the anterior one third of the right atrial appendage and cryoablation of the edges. The patient with AV JET first had incision and suture ligation of the bundle of His and implantation of a ventricular pacemaker, but the tachycardia recurred 2 weeks later. Cryoablation of the bundle of His prevented further recurrences. Tachycardia stopped in the patient with VT during incision of a tumor in the apex of the left ventricle. No patient had tachycardia after surgery and none has required medical treatment.

Surgical treatment of the Wolff-Parkinson-White syndrome in infants and children

Eleven pediatric Wolff-Parkinson-White (WPW) syndrome patients underwent surgery. Four had left, 5 right cardiac type and 2 had right septal type WPW syndrome. Two patients had 2 accessory conduction pathways (ACP). Ebstein's anomaly and secundum type atrial septal defect were the association congenital cardiac diseases in one patient each. Indications for surgery included repeated and/or long-lasting paroxysmal supraventricular tachycardia (PSVT), ineffective drug therapy, cardiac failure due to frequent tachycardia, short effective refractory period of the ACP, and simultaneous surgery for associated congenital cardiac diseases. Pre- and intra-operative examinations, including ECG, VCG, UCG, body surface mapping, intracavitary recording by catheter electrodes, computerized epicardial mapping, and endocardial mapping, were performed for the precise localization of the ACP. The surgical method was basically the same as is used for adults. Anterior median stermotomy was used primarily in right cardiac and right septal type and left anterior thoracotomy was used in 3 of 4 cases of the left cardiac type. Eight of 11 cases, two of which had 3 ACPs, were completely cured and in 3 there was evidence of postoperative pre-excitation. However, the PSVT attacks disappeared almost completely and drug therapy is not required at present.

Surgical treatment of supraventricular tachycardia in infants and children

The technique, indications and results of surgical division of accessory atrioventricular connections in 10 infants and children with drug-resistant supraventricular tachycardia are described. The patients ranged in age from 6 months to 15 years. Four patients had associated congenital heart disease. Division of accessory connections were performed on free wall pathways in nine patients (seven right atrial, two left atrial) and on a septal pathway in one patient. Four patients had both anterograde and retrograde conduction over the accessory connection (manifest Wolff-Parkinson-White conduction) whereas six had only retrograde conduction (concealed Wolff-Parkinson-White conduction). The manifst Wolff-Parkinson-White conduction was abolished by surgical division in all four patients. In 8 of the 10 patients the procedure stopped the attacks of paroxysmal supraventricular tachycardia for follow-up periods ranging from 9 months to 3 1/2 years; no patient receives medication to date.

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.

Accessory atrioventricular pathway in an infant: prediction of location with body surface maps and ablation with cryosurgery

A 10-month-old infant with multiple muscular ventricular septal defects, congestive heart failure, Wolff-Parkinson-White syndrome, and supraventricular tachycardia is presented. The site of ventricular pre-excitation was predicted by analysis of ST-T wave isopotential body surface maps to be in the posterior free wall of the right ventricle. The site was confirmed by epicardial mapping of the ventricles during surgery. The pathyway was cryoblated and the ventricular defects were closed. The patient has been free of pre-excitation and supraventricular tachycardia for over two years since surgery.

Wolff-Parkinson-White syndrome in children: electrophysiologic and pharmacologic characteristics

Intracardiac electrophysiologic studies were performed on 28 infants and children, ages 1 month to 18 years, with the Wolff-Parkinson-White syndrome to try to determine 1) the electrophysiologic characteristics of the accessory connection and 2) the mechanisms of associated supraventricular dysrhythmias. Although the antegrade refractory periods of the normal conduction system were shorter than those found in adults, those of the accessory connection were slightly longer. Reciprocating supraventricular tachycardia (SVT), which had been a clinical problem in 26 of 28, could be induced in the laboratory in all 26 subjects. The mechanism involved reentry with antegrade conduction through the atrioventricular (AV) node and retrograde through the accessory connection in 22. Eleven of these 22 had a wide QRS during tachycardia due to a bundle branch block. Three other subjects had wide QRS tachycardia, but the mechanism involved antegrade conduction through the accessory connection and retrograde through the AV node. The other patient had AV node reentry tachycardia. Two patients did not have clinical SVT, and in these two, SVT could not be induced. Neither patient had retrograde conduction through the accessory connection. The site of the accessory connection could be identified in 26 subjects by the sequence of retrograde activation of the atrium during SVT or ventricular pacing. Digitalis shortened the refractory period of the accessory connection in five of the eight patients studied.

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.

Ebstein's anomaly in association with anomalous nodoventricular conduction. Pre-operative and intra-operative electrophysiological studies

A 13 year old girl with Ebstein's anomaly was investigated for refractory paroxysmal tachycardias and ventricular pre-excitation. Intracardiac electrophysiological studies demonstrated that ventricular pre-excitation was due to conduction in an anomalous nodo-ventricular pathway. Tachycardia occurred as a result of re-entry within the A-V node with pre-excitation during tachycardia due to conduction in the nodo-ventricular pathway. These tachycardias were controlled initially by medical therapy but because of increasing frequency of attacks, occasionally requiring D.C. conversion, further electrophysiological studies and epicardial mapping were undertaken. The epicardial surface of the right ventricle and right atrium were mapped during tachycardia. The results of the studies confirmed that a direct anomalous atrio-ventricular pathway was not present and that re-entrant tachycardia did not involve an accessory pathway of this type. A rapid atrial pacing system was implanted and paroxysmal tachycardias have been successfully controlled.