PEDIATRIC CARDIOLOGY and CARDIAC SURGERY VOL. 24 NO. 5 (620 627) Electrophysiological Studies and Radiofrequency Catheter Ablation before Total Cavo-pulmonary Connection in Patients with Complex Congenital Heart Disease Keiko Toyohara, Yo Kajiyama, Jun Yoshimoto, Hitoo Fukuhara, and Yoshihide Nakamura Department of Pediatric Cardiology, Japanese Red Cross Society, Wakayama Medical Center, Wakayama, Japan Objectives: We characterized the mechanism of supraventricular tachycardia (SVT) in patients scheduled for total cavo-pulmonary connection (TCPC) and evaluated the outcome of preoperative electrophysiological studies (EPS) and radiofrequency catheter ablation (RFCA). Patients and methods: We performed EPS in 16 patients who had a history of SVT and were suspected of having an anatomic arrhythmogenic substrate (i.e., an anatomical anomaly causing tachycardia). Results: We were unable to induce supraventricular tachycardia in four patients. In 11 of 12 other patients ablation was successful; five patients had reciprocating tachycardia and twin atrioventricular nodes (twin AVNs), four had WPW syndrome, two had atrial tachycardia (AT), and atrial flutter (AFL) developed in one. Junctional tachycardia (JT) was documented clinically or during surgery in three cases with right isomerism. In 11 patients with RFCA, five patients underwent TCPC. In five patients, four did not have SVT during or after TCPC. Conclusion: EPS are essential for complete arrhythmic evaluation before TCPC. After successful RFCA, patients, especially those with right isomerism, may still develop JT during and after the TCPC procedure. Total cavo-pulmonary connection TCPC EPSRFCA TCPC 16 4 EPS EPS12 2 twin AVNs 5 WPW 4 AT 2 1 AT 1 11 RFCA 12 3 25 JT 3 RFCA 11 TCPC 5 4 TCPC EPS RFCA JT TCPC 1 2 5 5 6 TCPC 19 9 19 20 5 27 640-8558 4-20 34 24 5
621 2004 1 2007 5 TCPC 14 2 16 EPS Table 1 9 17 366.0 46.8kg12kg heterotaxy syndrome heterotaxy 10 atrioventricular discordance AVD 4 7 7 2 atrio-pulmonary connection APCTCPC conversion 7 APC TCPC EPS16 Fig. 1 4 heterotaxy 3 AVD 1 EPS2 case 1 2 WPW Fig. 2 case 1 His fasciculo-ventricular-fiber FVF 2 case 3 4 case 3 case 4 overdrive EPS RFCA 2 5 heterotaxy 4 AVD 1 2 His 2 sling 2 sling 4 case 5 8 3 case 5 7 1 case 8 RFCA 3 3 case 5 7 2 250msec 1 case 8 340msec 200msec RFCA 4 RFCA sling 1 case 9 heterotaxy RFCA Fig. 3 heterotaxy 4 AVD Fig. 1 5 TCPC 3 heterotaxy 1 AVD 1 TCPC heterotaxy 1 case 5 TCPC JT JT RFCA JTTCPC 2 heterotaxy 1 case 6 100 120/ JT Fig. 4 WPW 4 2 AVD 3 1 2 TCPC 2 AT 2 1 heterotaxy case 14 ATP 0.1mg/kg Fig. 5 2 His 4 His RFCA bidirectional cavo-pulmonary shunt BCPS EPS AT BCPS 140 JT 1 AT EPS AT EPS RFCA 20 9 1 35
622 Table 1 Patient characteristics case tachycardia age (months) weight (kg) morphology RFCA target of RFCA palliation condition JT 1 - none (FVF) 15 8.9 RI, {A,L,D}, MA, DORV - - - TCPC - 2 - none (FVF) 24 7.7 RI, {A,X,X}, SV, SA, CAVC, PA - - bil.bts + UF TCPC - 3 P none 58 17.1 {S,X,A}, DILV, PS - - PAB pre BCPS - 4 P none 17 11.8 {S,L,L}, DORV, PS - - BCPS pre TCPC - 5 P AVRT (twin AVNs) 42 12.3 RI, {A,L,L},CAVC, DORV, PS, TAPVC + ant.avn BCPS TCPC + 6 C AVRT (twin AVNs) 71 16.7 RI, {A,L,L}, CAVC, PA + ant.avn BCPS pre TCPC + 7 P AVRT (twin AVNs) 35 13.4 {I,D,D}, VSD, PS + ant.avn BCPS TCPC - 8 P AVRT (twin AVNs) 52 16.2 LI, {I,D,D}, CAVC, PA + ant.avn BCPS TCPC - 9 P AVNRT (twin AVNs) 22 9.9 RI, {A,L,L}, CAVC + post.avn BCPS pre TCPC - 10 C WPW 17 8.8 {S,L,L}, DORV, PS + AP (LL) lt.bt TCPC - 11 C WPW 26 10.3 {S,L,X}, DORV, PS + AP (LP) bil.bts TCPC - 12 C WPW 9 6.0 {S,D,D}, DIRV, PS + AP (LP) CS pre TCPC - 13 C WPW 17y* 46.8 {S,D,D}, DORV, straddling TV + AP (LA) BCPS, TVP pre TCPC - 14 P AT 38 13.9 RI, {A,L,L}, CAVC, PA, TAPVC + CAVC LL bil.bts + TAPVC repair pre TCPC + 15 C AT 47 12.4 RI, {A,X,X}, SV, SA, CAVC, PA + ** - bil.bts pre BCPS - 16 C AFL 70 10.8 RI, {A,X,D}, SV, SA, CAVC, PS + IVC-TV isthmus BCPS pre TCPC - JT: junctional tachycardia, FVF: fasciculo-ventricular-fiber, AVRT: atrioventricular reentrant tachycardia, AVNRT: atrioventricular nodal reentrant tachycardia, AT: atrial tachycardia, AFL: atrial flutter, P: tachycardia in early post-palliative operation and/or during catheter examination, C: clinical tachycardia, y*: years, + **: failure RI: right isomerism, MA: mitral atresia, DORV: double-outlet right ventricle, SV: single ventricle, SA: single atrium, CAVC: common atrio-ventricular canal, PA: pulmonary atresia, DILV: double-inlet left ventricle, PS: pulmonary stenosis, LI: left isomerism, TAPVC: total anomalous pulmonary venous connection, TV: tricuspid valve, ant.avn: anterior atrioventricular node, post.avn: posterior atrioventricular node, AP: accessory pathway, LL: left lateral, LP: left posterior, LA: left anterior, IVC: inferior vena cava, BT: Blalock-Taussig shunt, UF: unifocalization, PAB: pulmonary artery banding, BCPS: bidirectional cavo-pulmonary shunt 36 24 5
623 twin AVNs 5 (heterotaxy 4, AVD 1) WPW 4 (AVD 2) AT 2 (heterotaxy 2) AFL 1 (heterotaxy 1) EPS 4 (heterotaxy 3, AVD 1) C = 1 P = 4 C = 4 RFCA (+) 1 RFCA ( ) 1 RFCA FVF 2 JT 2 heterotaxy 2 (heterotaxy 1, AVD 1) RFCA 5 RFCA 4 EPS before BCPS No recurrence pre TCPC pre TCPC TCPC 2 pre TCPC 2 No recurrence No recurrence TCPC 3 JT (+) 1 ( ) 2 pre TCPC 2 JT (+) 1 ( ) 1 TCPC 2 pre TCPC 2 JT at BCPS pre TCPC Fig. 1 Clinical course in each case. P: tachycardia in early post-palliative operation and/or during catheter examination, C: clinical tachycardia A B Fig. 2 Two ECGs in case 1. A: sinus rhythm, B: HRA overdrive: delta waves were unchanged. ECG: electrocardiogram 1 heterotaxyrfca RFCA 11 TCPC 5 4 2 1 case 5 JT JT TCPCTCPC 20 9 1 37
624 case 5 case 6 case 7 A P RAO 55 RVG A P LVG A P case 8 case 9 A P case 5-8: twin AVNs with sling case 9: AVNRT in post.avn AVN targeted for RFCA case 5, 7, 8, 9: CAVC Fig. 3 Schema of re-entrant pathway of tachycardia in each case with twin AVNs. Asterisks represent AVNs, i.e., His potential recording sites. Dotted circles show common atrioventricular annulus. Dotted lines represent slings between two AVNs. White arrows act as anterograde limbs, black arrows act as retrograde limbs in AVRT. The curved arrows and black asterisk in case 9 show AVNRT. We targeted the AVNs shown with black asterisks. In patients with heterotaxy and a common AV valve, anterior and posterior AVNs exist either on the anterior and posterior sides or on the lateral and posterior sides of the common AV valve. In a patient with AV discordance (I,D,D), an anterior AVN existed on the anterior side by the mitral valve, and a posterior AVN existed on the posterior side by the tricuspid valve. heterotaxy 1 2 5 heterotaxy AVD twin AVNs 2 5 6 TCPC TCPC EPS 4 heterotaxy 3 AVD 1 FVF heterotaxy 2 TCPC EPS 2 TCPC WPWAVD heterotaxy WPWEbstein AVDheterotaxy 8 WPW RFCA TCPC 2 heterotaxytwin AVNs 5 1 4 twin AVNs TCPC heterotaxy AVD twin AVNs 2 5 2 QRS TCPC EPS heterotaxy sling twin AVNs l-loop twin AVNs 9 twin AVNs EPS Bae Fontan 52 EPS 4 52 38 24 5
625 A B C D E F G Fig. 4 A-C: Three ECGs in case 6. E-G: Schema of conduction from AVN (asterisk) to ventricle in relation to each ECG. A, B: Baseline ECGs showing two different QRS complexes, QS pattern (A), RS pattern (B). C: ECG during induced supraventricular tachycardia with the same QRS complex as demonstrated in panel A. We targeted the anterior AVN (the black asterisk) as the retrograde limb in the tachycardia. D: ECG during clinical JT with VA dissociation (arrows represent P waves) after RFCA with the same QRS complex as demonstrated in panel A, and C. 10 2 QRS 2 10 6 sling 2 52 9 JT 7 2 Bae Fontan 20 9 1 39
626 His RFCA His A B C Fig. 5 A: ECG during induced atrial tachycardia in case 14. B: Activation map during AT and successful ablation. C: Intracardiac electrogram. Dotted circle shows successful ablation site with the earliest fragmentation potential. atypical JT 10 III heterotaxy twin AVNs JT His 11 twin AVNs 5 2 JT RFCA RFCA 1 TCPC 1 JT JT sling 2 AVRT JT JT RFCA modification 12 RFCA RFCA RFCA AVRT JT twin AVNs RFCA AT 1 RFCA BCPS EPS BCPS JT sling twin AVNsJT 40 24 5
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