Definitive operation for refractory cardiac tachyarrhythmias in children

Abstract

A total of 114 children (age range 4 months to 18 years) underwent definitive operation for life-threatening or incessant tachydysrhythmias resulting from accessory conduction pathways (Kent bundle) (79), atrial ectopic foci (18), or ventricular ectopic foci (17). Of the patients with the accessory pathway type of supraventricular tachycardia, 63.3% (50/79) had classical Wolff-Parkinson-White syndrome whereas 36.7% (29/79) had retrograde conduction only across the pathway. Locations of the pathways were as follows: left posterior 48.1% (38/79), right anterior or lateral 27.8% (22/79), posterior septal 16.5% (13/79), anterior septal 3.8% (3/79), and both right and left 3.8% (3/79). With increasing experience, the success rate (cure of tachycardia) improved from 85% in the first 40 patients to 95% in the last 40 patients. One surgical death (1.3%) occurred secondary to a paradoxical air embolus. Atrial ectopic tachycardia was treated by cryoablation (nine), excision (one), combined excision and cryoablation (six), and atrial disconnection (two). The ectopic focus was located on the right atrial wall in 13 patients (72.2%) and cardiopulmonary bypass was required in eight (44.4%). The operation was successful in 89%; two patients with multiple ectopic foci continued to have uncontrolled tachycardia after the operation. Ventricular tachycardia presenting in the first 2 years of life was due to gross tumor in three cases (rhabdomyoma two, fibroma one) or microscopic hamartomatous change (Purkinje tumor) in five cases and was treated by excision alone or with adjuvant cryoablation. In four cases no tumor was found but the area of ectopic focus was successfully cryoablated. One child with diffuse endocardial tumor died of low cardiac output after the operation. Ventricular tachycardia in older children was localized to outflow patch aneurysms or other areas in the right ventricle following tetralogy of Fallot repair (three patients, treated by excision or cryoablation) and arrhythmogenic right ventricular dysplasia (two patients, treated by right ventricular disconnection). We conclude that mapping and operation for supraventricular tachycardia resulting from accessory pathways are predictable and curative in a high percentage of patients. Atrial ectopic tachycardias are more difficult to precisely localize but can be cured by a combination of excisional and cryoablative techniques. Ventricular tachycardia in infants is lethal and is commonly due to ectopic foci or microscopic tumors that may not be apparent on preoperative angiography or echocardiography. Electrophysiologically directed operations in these patients can be lifesaving.