Surgical management of Wolff-Parkinson-White syndrome in infants and small children

Beyond Fontan conversion: Surgical therapy of arrhythmias including patients with associated complex congenital heart disease

BACKGROUND

Arrhythmia operations may be extended to patients with failed ablation procedures or associated structural defects requiring surgical intervention. The purpose of this study is to review our experience with arrhythmia operations in 29 patients who did not have Fontan conversions after the introduction of catheter ablation.

METHODS

Between July 1992 and January 2002, 29 patients had operations for refractory atrial (n = 24) or ventricular (n = 5) arrhythmias. Mechanisms of arrhythmia included atrial reentry (n = 11), atrial fibrillation (n = 5), automatic atrial (n = 3), accessory connections (n = 6), atrioventricular nodal reentry (n = 2), and ventricular tachycardia (n = 5). Median age at operation was 12.3 years (range, 6 days to 45 years). Two patients had structurally normal hearts; the remaining 27 patients underwent concomitant repair of structural heart disease, including atrioventricular valve replacement or repair (n = 8), anatomy-specific repair of Ebstein's anomaly (n = 4), tetralogy of Fallot repair or revision (n = 4), atrial septal defect closure (n = 3), ventricular septal defect repair (n = 2), Mustard takedown with arterial switch (n = 2), initial Fontan (n = 2), right ventricle-to-pulmonary artery conduit revision (n = 2), Norwood procedure (n = 1), 1 ventricular repair for Uhl's anomaly (n = 1), Mustard baffle revision (n = 1), pulmonary valve replacement with aneurysm resection (n = 1), and aortic valve replacement with complex repair (n = 1).

RESULTS

No patient developed heart block, and the surgical mortality rate was 7%. One patient died after Mustard takedown and arterial switch operation, and 1 neonate died after repair of severe Ebstein's anomaly. There was one late death after arterial switch conversion at another institution. Recurrent clinical supraventricular tachycardia was present in 2 patients (2 of 27, 7.4%) and 2 patients had new-onset tachycardias with different underlying mechanisms of arrhythmia at late follow-up (median follow-up 47 months).

CONCLUSIONS

Successful surgical therapy of arrhythmias can be performed safely at the time of repair of complex congenital heart disease or in patients with failed catheter ablation procedures. Early consideration for single-stage therapy of arrhythmia and structural heart disease is indicated.

Surgical treatment of cardiac dysrhythmias in infants and children

A variety of cardiac rhythm disturbances that occur in infants and children may be refractory to medical or catheter ablation therapy, or both, and thus require surgical ablation. These dysrhythmias include Wolff-Parkinson-White syndrome, atrial automatic tachycardia, atrioventricular node reentry tachycardia, and ventricular tachycardia. The surgical technique originally used in adults may be equally well applied in infants and small children. In the interval from July 1, 1984, through December 31, 1993, a total of 130 infants and children (< or = 16 years old) underwent surgical treatment for various forms of dysrhythmias (96 with Wolff-Parkinson-White syndrome, 8 with atrioventricular node reentry, 11 with atrial automatic tachycardia, and 15 with ventricular tachycardia). The success rate for completely abolishing these arrhythmias has been 92% for the Wolff-Parkinson-White syndrome, 100% for atrioventricular node reentry, and 64% for atrial automatic tachycardia. In infants younger than 2 years, the success rate for the surgical treatment of ventricular tachycardia is 100%, but the long-term success in older children has been poor. One patient sustained a severe intraoperative neurologic event that resulted in her death (operative mortality, 0.7%). Ventricular function returned to normal in all patients in whom it was abnormal preoperatively. These data suggest that the surgical treatment of these dysrhythmias remains a viable alternative in those patients whose dysrhythmias are refractory to medical therapy, those in whom catheter ablation has been unsuccessful, or those in whom both situations apply.

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

Electrophysiologic features and surgical results were examined in 55 pediatric patients who underwent surgical accessory pathway division for Wolff-Parkinson-White syndrome. There were 31 male and 24 female patients ranging in age from 4 months to 15 years (mean age, 9.8 +/- 4.2 years; 25 patients were less than 10 years old; 4 patients were less than 12 months). Eleven of these patients had associated congenital heart disease and underwent concomitant surgical procedures to treat those conditions. Preoperative effective refractory period of antegrade accessory pathways, the right atrium, atrioventricular node, and cycle length during reentrant tachycardia were shorter in pediatric patients than in adult patients. Antegrade accessory pathways showed right predominance more frequently in the pediatric group than in the adult group. Surgical techniques included an endocardial approach (an epicardial approach was used in 1 patient) and concomitant operation for combined heart disease. The early mortality rate was 3.6%, whereas no late deaths occurred during the follow-up period of 96.8 +/- 54.9 months (maximum follow-up, 205 months). The absolute cure rate was 92%. There were no significant differences in early and late mortality between pediatric and adult patients. Surgical treatment of the Wolff-Parkinson-White syndrome in pediatric patients is as safe and effective as in adults. Considering the potential complications from prolonged fluoroscopic exposure during catheter ablation, surgical division of accessory pathways in children is a promising modality for the treatment of Wolff-Parkinson-White syndrome in selected cases.

Phase image analysis of anomalous ventricular activation in pediatric patients with preexcitation syndromes or ventricular tachycardia

This prospective study evaluated the accuracy of phase analysis of scintigraphic imaging in defining the site of earliest ventricular activation in pediatric patients with electrophysiologic disorders. Twenty patients (10.8 +/- 5.5 years) with preexcitation (n = 16) or ventricular tachycardia (VT) (n = 4) were independently evaluated by phase image analysis and endocardial catheter mapping. The earliest phase angle (contraction), which was common to three scintigraphic imaging planes during preexcited sinus rhythm or VT, was compared with the earliest retrograde atrial activation during reciprocating tachycardia or the origin of VT, as defined by catheter mapping. Phase analysis of earliest contraction was concordant with catheter mapping of electrical activation in all 13 free-wall accessory connections and in three of four patients with VT. Inconclusive definition of activation occurred only in paraseptal accessory connections or VT. In conclusion, phase analysis accurately defines anomalous ventricular activation that is due to free-wall accessory connections or VT. In patients with complex anatomy or small size, phase analysis allows noninvasive localization of the anatomic substrates of tachycardia.

Radiofrequency catheter ablation of incessant, medically resistant supraventricular tachycardia in infants and small children

OBJECTIVES

This study retrospectively evaluates initial experience with radiofrequency catheter ablation in a group of seven infants and small children with a history of incessant, medically resistant supraventricular tachycardia.

METHODS

Before attempted catheter ablation, all patients had had unsuccessful conventional medical therapy (with digoxin or propranolol, or both) and, in addition, each continued to have daily episodes of supraventricular tachycardia while taking amiodarone or a class IC antiarrhythmic agent alone or in combination. The average patient age was 10 months (range 1 to 27) and the average patient weight was 6 kg (range 3 to 13). Electrophysiologic diagnosis included reentrant supraventricular tachycardia in six patients and atrial ectopic tachycardia in one patient.

RESULTS

These seven patients underwent a total of nine catheter ablation procedures. The atrial approach to ablation was employed in eight of the nine procedures. Overall, radiofrequency catheter ablation was totally successful in five of the seven patients, partially successful in one patient and unsuccessful in the remaining patient. The combination of radiofrequency catheter ablation and surgical ablation was successful in controlling tachycardia in all patients; with at least 5 months of follow-up study, no patient has had a recurrence of supraventricular tachycardia or reappearance of a delta wave.

CONCLUSIONS

Surgical ablation of arrhythmogenic substrates in the pediatric age group, although rarely indicated, has been found in the past to be safe and effective. Our initial experience with radiofrequency catheter ablation in infants and small children demonstrates that this procedure is a promising nonpharmacologic therapeutic alternative to surgical ablation.

Surgical management of posteroseptal accessory atrioventricular pathways

From October 1988 through January 1991, 22 consecutive patients with Wolff-Parkinson-White syndrome underwent surgical ablation of symptomatic accessory posteroseptal atrioventricular pathways at our institution. As our experience with posteroseptal tracts accumulated, we found that surgical technique was logically dictated by the presence of free wall tracts and the exact location of the posteroseptal tract. Accordingly, we developed an operative approach that involves the selective use of endocardial, epicardial, and cryoablation techniques depending on the anatomic location of accessory tracts. This selective approach allows one to exploit the advantages of each technique while minimizing associated disadvantages. There were 14 men and 8 women with an average age of 25 years (range, 19 to 39 years). All patients had symptomatic tachyarrhythmias caused by accessory atrioventricular pathway(s). Most required several antiarrhythmic medications and 17 (77%) had poor arrhythmia control despite maximal medical therapy. Twelve patients had two accessory pathways and 3 also had dual atrioventricular nodal pathways. There were no early or late deaths. In 2 patients, a delta wave associated with a free wall tract reappeared 3 to 5 days after the initial operation, necessitating a second operation which successfully eliminated the accessory tract. All posteroseptal tracts were successfully eliminated during the initial operation. All patients were relieved of symptoms and are now free of medical therapy. Each patient has undergone a postoperative electrophysiologic study which confirms the absence of posteroseptal accessory conduction. The selective approach has been totally successful in our hands and should prove useful to those interested in optimizing the efficiency of surgical procedures for Wolff-Parkinson-White syndrome.

Surgical treatment of cardiac arrhythmias

This report describes 20 consecutive patients who underwent surgical procedures for treatment of cardiac arrhythmias. 16 patients have been operated for WPW syndrome, always using the epicardial approach, without extracorporeal circulation. Three patients underwent surgery for atrio-ventricular nodal reentrant tachycardia, using a discrete perinodal cryotreatment, during normothermic extracorporeal circulation. In one case we used cryoablation of the atrial myocardium below the coronary sinus to treat atrial flutter. This operation was performed under normothermic extracorporeal circulation. In our observations, there was no early or late death; postoperative complications developed in 1 patient (5%) due to pericarditis. Ablation of the AP was completely successful in all the cases (100%) operated for WPW as well as for AVNRT syndromes and atrial flutter.

Current treatment for Wolff-Parkinson-White syndrome: results and surgical implications

From July 1986 to January 1991, 123 patients with Wolff-Parkinson-White syndrome underwent operation for ablation of aberrant conduction pathways. There were 85 male and 38 female patients ranging in age from 11 months to 68 years. Associated anomalies included Ebstein's anomaly, sudden death syndrome, coronary artery disease, cardiomyopathy, abdominal aortic aneurysm, neurofibromatosis, other arrhythmias, or other complex congenital heart disease. Forty-one patients had multiple accessory pathways. Operative results showed a 7% initial failure rate, which dropped to 3% after reoperation. One patient had undergone previous operation for Wolff-Parkinson-White syndrome at another institution. Procedures performed concomitantly included mitral or tricuspid valve repair or replacement (6), right ventricular conduit replacement, subaortic resection, Fontan repair, corrected transposition repair, coronary artery bypass, and placement of an automatic internal cardioverter defibrillator. There was no operative mortality. Late follow-up is 27 +/- 16 months, and complications included mitral regurgitation and myocardial infarction. By comparison, in the last 12 months 124 patients with the Wolff-Parkinson-White syndrome underwent catheter ablation using radiofrequency current. There were 9 patients with multiple pathways. One hundred twelve patients (90%) had all accessory atrioventricular connections ablated and have remained free of symptomatic tachycardia. There have been 12 failures (10%), of which 5 have had operation and 7 are being treated medically. Mean follow-up is 7 +/- 5 months, and complications included circumflex coronary artery occlusion, excessive bleeding, valve perforation, and cerebral vascular accident.(ABSTRACT TRUNCATED AT 250 WORDS)

Supraventricular tachycardia: diagnosis and current acute management

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