surgical management of refractory supraventricular tachycardia in infants management of refractory...
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124 JACC Vol. 5, No. 1January 1985:124-9
Surgical Management of Refractory Supraventricular Tachycardia inInfants and Children
DAVID A. OTT, MD, FACC, PAUL C. GILLETTE, MD, FACC, ARTHUR (lARSON, JR., MD, FACC,
DENTON A. COOLEY, MD, FACC, GEORGE J. REUL, MD, FACC,
DAN G. McNAMARA, MD, FACC
Sixty-seven children underwent attempted surgical cor-rection of refractory supraventricular arrhythmias usinga combination of intraoperative electrophysiologicmap-ping followed by surgical division or cryoablation of anaberrant conduction pathway or atrial ectopic focus. Thepatients ranged in age from 4 months to 18 years (mean11.4 years).
Fifty-fivepatients (82%) had an abnormal conductionpathway crossing the atrioventricular junction (Kentbundle). Thirty-six (65%) of these 55 patients had classicWolff-Parkinson-White syndrome with a delta wave ofpre-excitation on the surface electrocardiogram. Nine-teen (35%), however, demonstrated only retrogradeconduction across the Kent bundle and had a normalsurface electrocardiogram when tachycardia was notpresent. Kent bundles were isolated to the following lo-cations: right anterior or lateral in 19 (34.5%), left pos-terior 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
The surgical treatment of supraventricular tachycardia queto the presence of an accessory conduction bundle (Kent)has been adequately described in adults and its efficacyaccepted (1-3). The diagnostic evaluation and surgical man-agement of these pre-excitation syndromes in children aswell as those due to an atrial ectopic focus have only recentlybeen documented (4-6). We have described the electro-physiologic evaluation and medical management of supra-ventricular and ventricular tachycardias in infants and chil-dren, and since 1976 we have applied these principles to
From the Divisions of Surgery and Pediatric Cardiology of the TexasHeart Institute and Texas Children's Hospital, Houston, Texas. This studywas presented in part at the 33rd Annual Scientific Session of the AmericanCollege of Cardiology, March [984, Dallas, Texas. Manuscript receivedApril 2, 1984; revised manuscript received July 2, 1984, accepted July18.1984.
Address for reprints: David A. Ott, MD, Texas Heart Institute. P. O.Box 20345, Houston. Texas 77225.
1985 by the American College of Cardiology
months) has shown seven immediate failures and onelate recurrence of arrhythmia (14.5%). Recent refine-ments in technique and the use of cryoablation for septalaberrant pathways have improved these results. Therehave been two failures (8%) in the last 25 attempts.Twelve patients underwent surgery for an atrial ectopicfocus by the following techniques: cryoablation in sevenpatients, excision in one patient and both excision andcryoablation in four patients. At a mean follow-up "f16.6 months, there was one late recurrence in the groupwith an atrial ectopic focus.
Children with refractory supraventricular tachycar-dia, even in the absence of pre-excitation on the elec-trocardiogram should undergo complete electrophysio-logic study to elucidate the mechanism of tachycardia.Surgery for supraventricular tachycardia can be per-formed safely in infants and children and offers pre-dictable results and the opportunity to cure the tachy-cardia syndrome.
(J Am Coli Cardiol 1985;5:124-9)
the surgical resolution of the tachycardia in a series of 67patients (7-20). This report documents the evaluation, re-sults and current approach to the surgical treatment of supra-ventricular tachycardia in children.
MethodsPatients. From March 1976 to September 1983, 67 chil-
dren were referred for surgery for incapacitating, refractoryor life-threatening supraventricular tachycardia after com-plete electrophysiologic evaluation including intracardiaccatheterization. After this evaluation, operative ablation ofthe accessory conduction bundle was attempted, using eithersurgical division, cryoablation or a combination of bothtechniques with or without the use of temporary total car-diopulmonary bypass. Fifty percent of the patients wereoperated on in the most recent 2 years of the study (Sep-tember 1981 to September 1983).
JACC Vol. 5. No.1January 1985:124-9
OTT ET AL.SURGERY FOR REFRACTORY SUPRAVENTRICULAR TACHYCARDIA
Table 1. Congenital Cardiac Defects Associated WithSupraventricular Tachyarrhythmias
Intraoperative mapping. Patients considered to be can-didates for surgical ablation were operated on through amedian sternotomy incision. Care was taken to maintainnormothermic conditions during electrophysiologic mappingbecause we have found that arrhythmias in children are
The study was limited to patients J8 years of age oryounger (mean JJ) at the time of surgery. The diagnosis ofabnormal tachycardia was made in utero in the youngestpatient, who required surgical treatment at 4 months of age.All patients had refractory, incessant or recurrent tachycar-dia, and three children (all with Wolff-Parkinson-White syn-drome) had had documented episodes of ventricular fibril-lation from which they were successfully resuscitated beforeevaluation. Various associated congenital cardiac defectswere noted (Table 1) (21).
The patients were managed medically initially unless theirarrhythmia wds considered life-threatening. The latter groupincluded those patients with a documented history of car-diovascular collapse or ventricular fibrillation, as well asthose who had an anterograde effective refractory period ofthe Kent bundle of less than 230 ms (22). This group ofpatients at high risk of sudden death was referred for surgicaltreatment initially whether or not the arrhythmia wasincapacitating.
Medical attempts to control the tachycardia consisted ofadministration of the usual medications for supraventriculartachycardia, including digitalis, propranolol, quinidine andverapamil. Amiodarone was used in two cases without suc-cess. Failure of drug treatment was considered an indicationfor surgical intervention. In the later period of the study,confidence in the success and predictability of surgical man-agement resulted in more frequent consideration of the sur-gical approach as the initial method of management in pa-tients with refractory arrhythmias.
Electrophysiologic evaluation. All patients in whomthe diagnosis of refractory tachycardia was made or stronglysuspected underwent complete electrophysiologic, hemo-dynamic and angiographic evaluation. The methods for elec-trophysiologic investigation of supraventricular tachycardiahave been detailed elsewhere (8,9,16,17).
especially sensitive to body temperature changes. Chrono-tropic anesthetic agents were avoided for similar reasons.Wires for ventricular pacing were placed on the right ven-tricular wall, and a removable clip-on lead was used toestablish atrial pacing or to act as a bipolar atrial referenceelectrogram (3-5). Various types of sensing probes wereused in searching for the point of earliest retrograde con-duction to the atrium during ventricular pacing or sustainedsupraventricular tachycardia using a simplified map of theepicardial surface of the heart. In patients with anterogradeconduction across the accessory bundle, the earliest pointof activation on the ventricular side of the anulus was mappedas needed. In patients with atrial ectopic tachycardia, map-ping was done to localize the point of earliest activation ina similar fashion. ,
Methods for division or cryoablation of accessorypathways. The surgical approach to left-sided accessoryconnections was similar to that previously described by Sealyand Gallagher (23). The left atrium was opened as for amitral valve procedure from the right lateral approach duringa period of induced cold cardioplegic arrest. A suture wasplaced through the atrial wall above the coronary sinus fromthe epicardial surface at the site of earliest activation. Withthis point as the center, a wide endocardial incision wasmade just above the mitral valve anulus, dissecting deeplyand caudally until ventricular myocardium was clearly ex-posed, but without breaking the epicardial surface (Fig. I).In two patients operated on for recurrence of a left-sidedconnection after this technique, we added an epicardial in-
Figure 1. Surgeon's view of endocardial dissection for divisionof a left-sided Kent bundle. The posterior mitral leaflet and chordaeare elevated by the clamp.
Ebstein's anomalyEndocardial cushion defectMultiple atrial septal defectsVentricular inversionTransposition of great vesselsMitral stenosisMitral regurgitation
126 orr ET AL.SURGERY FOR REFRACTORY SUPRAVENTRICULAR TACHYCARDIA
JACC Vol. 5. No. IJanuary 1985:124--9
cision beginning at the left atrial appendage and extendingto the inferior vena cava immediately above the coronarysinus (Fig. 2). This incision was carried deep behind thecoronary sinus by retracting it and the left circumflex coro-nary artery toward the apex of the heart. We now routinelymake both an endocardial and epicardial dissection at theinitial procedure in an effort to preclude recurrence. Cryoab-lation was not used on left-sided accessory pathways forfear of injury to the circumflex artery.
Right-sided and septal accessory pathways were ap-proached through a right atriotomy incision with the heartbeating. After closure of a septal defect or patent foramenovale, endocardial mapping was performed to confirm theepicardial map and localize the His bundle spike. Anteriorand lateral accessory bundles were divided using a deependocardial incision extending to the epicardial surface ofthe heart near the right coronary artery. Localization of theKent bundle was mo