Wolff-Parkinson-White syndrome in a criss-cross heart with a rare left atrial appendage accessory pathway

A 13-year-old boy with complex cyanotic congenital heart disease with criss-cross atrio-ventricular connection presented with Wolff-Parkinson-White (WPW) syndrome and recurrent orthodromic re-entrant tachycardia. During electrophysiological study, the accessory pathway was mapped along the left atrioventricular annulus initially but was successfully ablated through the left atrial appendage. The case describes the challenges and the intricacies while ablating an atypical accessory pathway connection in the setting of complex congenital heart disease.

Radiofrequency ablation of accessory pathways in the setting of complex congenital heart diseases pose several challenges for the electrophysiologists. Localization of conduction system and the annulus may pose a significant challenge. In addition, abnormal course of the accessory pathway may add to the challenges. We describe such a case of accessory pathway in a crisscross heart and the challenges and learning points are then discussed. Case Report A 13-year-old boy presented with recurrent paroxysmal palpitations and an adenosine responsive regular narrow complex tachycardia (Figure 1a) which was not suppressed by regular use of betablockers and amiodarone. Baseline ECG revealed Wolff Parkinson White (WPW) ECG with (Figure 1b) delta wave negative in leads I and aVL; and positive in inferior leads as well as V1- V6 suggesting a left sided accessory pathway. On examination, the child was cyanosed. Echocardiography and CT angiography revealed situs solitus, levocardia, criss cross atrio-ventricular connections (right atrium connected to levoposed morphological right ventricle, and left atrium connected to dextroposed morphological left ventricle), large ventricular septal defect, double outlet right ventricle, d-posed aorta, severe pulmonary stenosis. He was planned for palliative surgery with bilateral bidirectional Glenn shunt and atrial septectomy. In view of recurrent palpitations, a presurgical electrophysiological study was advised and done without 3D system due to cost constraints. The weight of the child was 35 kg and bilateral femoral venous accesses (2 on the right side and 1 on the left side were taken). A venogram was done to delineate the inferior vena cava and the anatomy of the right atrium and the atrioventricular valves. Decapolar catheter could be placed in the coronary sinus. The His signal could not be located along the right sided atrioventricular valve annulus. The quadripolar catheter was placed in the ventricle. Regular narrow QRS tachycardia was easily inducible with atrial extrastimuli and was proven to be orthodromic re-entrant tachycardia (ORT) by demonstrating response to ventricular overdrive pacing manoeuvre and reset with fusion (late coupled) ventricular extrastimuli. The ORT was incessant during the procedure with an eccentric atrial activation, earliest at the distal decapolar catheter placed inside the coronary sinus. For mapping inside the left atrium, the ablation catheter using a Shwartz Right – 0 (Abbott) sheath could be passed through the patent foramen ovale into the left atrium. Earliest atrial activation site along the left sided atrio-ventricular valve annulus was mapped at the 12 o’ clock region of the annulus but ablation at the earliest annular site did not terminate the tachycardia (intracardiac electrograms in Figure 2a) but did slow down the tachycardia and caused a change in the QRS morphology due to loss of aberrancy and a change in local activation signals. While mapping was being done away from the annulus during the ongoing ORT, earliest atrial signals were obtained around 2 cm superior from the annular signals which was 10 msec early than the earliest annular signal where the ablation was attempted prior. Ablation at this atrial site, with no significant ventricular electrogram, (intracardiac electrograms in Figure 2b) terminated the tachycardia immediately and rendered the tachycardia non-inducible but the preexcitation persisted. Consolidation ablation energies were delivered around this region during sinus rhythm which eliminated the pre-excitation also (Figure 2c). An angiogram done through the SR-0 sheath confirmed the site of ablation to be inside left atrial appendage (Figure 3 a, b). The procedure was successful with no tachycardia or preexcitation noted at the end of the procedure and at 3 months of follow up. Patient was advised palliative surgery which is awaited.

Radiofrequency ablation is the treatment of choice for management of accessory pathway related supraventricular tachycardia. 1 EP study and ablation in with complex congenital heart diseases presents a challenge to access the heart, place catheters at appropriate anatomical landmarks and map the arrhythmia. Criss cross heart is an extremely rare condition constituting less than 0.1% of the congenital heart disease patients. 2 The knowledge of supraventricular tachycardia, which underwent successful radiofrequency ablation in these cases is limited to rare case reports. 3-5 In our case the pre-excitation pattern on baseline ECG suggested an accessory pathway related to the left atrioventricular valve annulus. Though we could not localize the His signals, we could enter the left atrium with ease through a patent foramen ovale. Trans-septal puncture to enter left atrium in complex congenital heart disease would have additionally required imaging guidance in the form of an intracardiac or trans-esophageal echocardiography. Retroaortic approach and mapping the annulus would have been an alternative but localization of earliest A signal more atrially would have been very difficult. After mapping and ablating the earliest atrial activation during ORT along the annulus, we could not get rid of the accessory pathway though some modification was done in view of the change in CL and in the local activation suggesting possibly elimination of the endocardial limb of the pathway. Although left sided accessory pathways have the highest success rates of ablation with lowest recurrence, in some patients, ablation along the mitral annulus may not be effective as the accessory pathway is crossing the annulus epicardially and inserting away from the annulus. 6 Thus, in a case where success is not achieved with a reasonable ablation attempt along the annulus, an epicardial course of the accessory pathway with insertion away from the annulus should be suspected, and the importance of mapping away from the annulus for the earliest atrial activation during ORT cannot be overemphasized. In a series of 29 patients with failed left sided accessory pathway ablations, Long et al reported atrial insertion sites away from mitral annulus in 7 cases. 6 Out of these 7 cases, accessory pathways were related to left atrial appendage in 5 cases and left atrial roof in 2 cases. 6 In the total pool of the registry data as reported in this study, these cases are rare and constituted only 0.35% of all the left sided accessory pathways. 6 Accessory pathways connecting to left atrial appendage have been uncommonly reported. They may be associated with abnormalities of the left atrial appendage like dilatation and aneurysm. When endocardial ablation is not successful, ablation can be attempted from the coronary sinus if pathway is located on the left side. 7,8 In occasional cases epicardial ablation can be done after obtaining epicardial access 9 and rarely surgical access and dissection of the atrial appendage during palliative/corrective cardiac surgery can be used to treat resistant cases. 9 Use of sheath angiograms are useful to confirm the access and location of the catheters and site of successful ablation in complex heart diseases. This case demonstrates successful ablation of an accessory pathway in a criss-cross heart from the left atrial appendage and annulus using a conventional mapping system. This case highlights the importance of understanding cardiac anatomy well before and during the case, employing standard mapping techniques to diagnose common arrhythmias and of mapping at uncommon locations away from the annulus to detect and successfully treat rare epicardial connections of pathways in patients with complex congenital heart disease.

1. Brugada J, Katritsis DG, Arbelo E, Arribas F, Bax JJ, Blomström-Lundqvist C, Calkins H, Corrado D, Deftereos SG, Diller GP, Gomez-Doblas JJ, Gorenek B, Grace A, Ho SY, Kaski JC, Kuck KH, Lambiase PD, Sacher F, Sarquella-Brugada G, Suwalski P, Zaza A; ESC Scientific Document Group. 2019 ESC Guidelines for the management of patients with supraventricular tachycardia. The Task Force for the management of patients with supraventricular tachycardia of the European Society of Cardiology (ESC). Eur Heart J. 2020; 41(5): 655-720. 2. Anderson RH, Shinebourne EA, Gerlis LM. Criss-cross atrioventricular relationships producing paradoxical atrioventricular concordance or discordance. Their significance to nomenclature of congenital heart disease. Circulation. 1974; 50: 176–180. 3. Alberto Lopez J, Angelini P, Lufschanowski R. Successful ablation of atrioventricular node reentry tachycardia in a patient with crisscross heart and situs inversus levocardia. J Interv Card Electrophysiol. 2006; 17(2):133-7. 4. Hluchy J, Prull MW, Brandts B. Radiofrequency ablation of a left lateral atrioventricular accessory pathway in a 13-year-old boy with a criss-cross heart guided by nonfluoroscopic imaging. J Electrocardiol. 2014; 47(3):311-5. 5. Watanabe S, Yoshida Y, Suzuki T, Nakamura Y. Successful catheter ablation using real-time ultrasound-assisted 3-D electroanatomical mapping system for atrioventricular accessory pathway in a 1-year-old girl with criss-cross heart. HeartRhythm Case Rep. 2016; 2(4):351-355. 6. Long DY, Dong JZ, Sang CH, Jiang CX, Tang RB, Yan Q, Yu RH, Li SN, Salim M, Yao Y, Lin T, Ning M, Ma CS. Ablation of left-sided accessory pathways with atrial insertion away from the mitral annulus using an electroanatomical mapping system. J Cardiovasc Electrophysiol. 2013 Jul;24(7):788-92. 7. Sun Y, Arruda M, Otomo K, et al. Coronary sinus-ventricular accessory connections producing posteroseptal and left posterior accessory pathways: Incidence and electrophysiological identification. Circulation 2002; 106: 1362–7. 8. Müller MJ, Fischer O, Dieks J, Schneider HE, Paul T, Krause U. Catheter ablation of coronary sinus accessory pathways in the young. Heart Rhythm. 2023; 20(6): 891-9. 9. Valderrábano M, Cesario DA, Ji S, et al. Percutaneous epicardial mapping during ablation of difficult accessory pathways as an alternative to cardiac surgery. Heart Rhythm 2004; 1: 311–3. 10. Mah D, Miyake C, Clegg R, et al. Epicardial left atrial appendage and biatrial appendage accessory pathways. Heart Rhythm 2010; 7:1740–5. Figure legends Figure 1 a. 12 lead surface electrocardiogram at presentation shows a narrow complex tachycardia with likely 1:1 ventriculo-atrial association. Note the superior axis and predominant R wave in lead V1; b. Baseline 12 lead electrocardiogram during normal sinus rhythm after termination of tachycardia with adenosine, revealing a short PR interval and pre-excitation with negative delta wave in leads I and aVL, while positive delta waves in V1 and inferior leads. Figure 2 Intracardiac electrograms with the channels labelled at the left, a. at the time of mapping the tachycardia at the left atrio-ventricular valvular annulus during the ongoing orthodromic re-entrant tachycardia. Note the fused ventricular and atrial electrogram at the distal ablation catheter with the atrial electrogram 46 msec earlier than the distal coronary sinus activation; b. at the successful site of ablation which led to the termination of tachycardia, but persistence of preexcitation during sinus rhythm. Note the predominance of atrial signal at the ablation catheter (suggesting position in the atrium away from annulus) which is 56 msec earlier than the distal coronary sinus activation. Also note that the orthodromic re-entrant tachycardia is slower and has a change in axis and morphology of the QRS on the surface electrocardiogram. This suggests that the tachycardia has an aberrant conduction at a faster rate as noted in the figures 1a and 2a; c. at the time of elimination of pre-excitation. Note that there is pre-excitation on the first beat which is eliminated in the next. Figure 3 a. Fluoroscopic image in the RAO 30 o view showing the position of the decapolar catheter in the coronary sinus, quadripolar catheter in the levoposed right ventricle through the right ventricle and the ablation catheter placed through the sheath at the successful site in the left atrium; b. sheath angiogram after removing the ablation catheter after successful ablation revealing that the successful site was inside the left atrial appendage superior to the annulus by nearly 2 centimeter. Information & Authors Information Version history Copyright This work is licensed under a Non Exclusive No Reuse License.

Authors Metrics & Citations Metrics Article Usage 225views 140downloads Citations Download citation Raghav Bansal, Shomu Bohora. Wolff-Parkinson-White syndrome in a criss-cross heart with a rare left atrial appendage accessory pathway. Authorea. 19 September 2025. DOI: https://doi.org/10.22541/au.175826003.37860596/v1 DOI: https://doi.org/10.22541/au.175826003.37860596/v1 If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download. For more information or tips please see 'Downloading to a citation manager' in the Help menu.