Canadian Journal of Cardiology 29 (2013) 130.e7–130.e9 www.onlinecjc.ca
Case Report
Monomorphic Ventricular Tachycardia 25 Years PostSurgical Ablation for Wolff–Parkinson–White
Jacqueline Joza, MD,a Giuliano Becker, MD,b Pierre Pagé, MD,c and Vidal Essebag, MD, PhDa,b
a Division of Cardiology, McGill University Health Centre, Montréal, Québec, Canadab Division of Cardiology, Sacre-Coeur Hospital, Montreal, Québec, Canada
c Division of Cardiac Surgery, University of Montreal, Sacre-Coeur Hospital, Montreal, Québec, Canada
ABSTRACTThe first surgical ablation of an accessory pathway for the treatment ofWolff–Parkinson–White (WPW) syndrome was performed in 1968,and surgery remained first-line therapy until the advent of catheterablation techniques in the early 1990s. Current indications for surgicalablation of WPW syndrome are limited to ablation failures. To this day,there has been no long-term follow-up of these surgically treated pa-tients. We describe the case of a man, aged 54 years, who developedventricular tachycardia 25 years after surgical ablation of WPW. This isfirst reported case of ventricular tachycardia following an epicardialsurgical cryoablation technique for WPW.
RÉSUMÉLa première ablation chirurgicale d’une voie accessoire pour le traite-ment du syndrome Wolff–Parkinson–White (WPW) a été réalisée en1968; cette chirurgie est demeurée le traitement de première lignejusqu’à l’avènement des techniques d’ablation par cathéter au débutdes années 1990. Les indications actuelles d’ablation chirurgicale dusyndrome WPW sont limitées aux échecs de l’ablation. À ce jour, il n’ya pas eu de suivi à long terme de ces patients traités par chirurgie.Nous décrivons le cas d’un homme de 54 ans chez qui une tachycardieventriculaire est apparue 25 ans après l’ablation chirurgicale du WPW.C’est le premier cas de tachycardie ventriculaire rapporté à la suited’une technique de cryoablation chirurgicale épicardique du WPW.
Ventricular tachycardia post surgical ablation for Wolff–Parkinson–White (WPW).
Case ReportA man, aged 54 years, presented to hospital with new-onset
sustained palpitations. He denied any chest pain or dyspnea.There was no family history of sudden cardiac death. His elec-trocardiogram revealed a monomorphic ventricular tachycar-dia (VT) with left bundle-branch pattern at 197 beats per min-ute, which was terminated by electrical cardioversion (Fig. 1).Electrocardiogram in sinus rhythm did not show any pre-exci-tation but was notable for T-wave inversion in leads V1through V3. Of note, no epsilon wave was noted. Subsequentcoronary angiography was normal. A transthoracic echocardio-gram showed a left ventricular ejection fraction of 50% withinferior wall motion abnormality, as well as right ventricular
Received for publication June 28, 2012. Accepted July 15, 2012.
Corresponding author: Dr Vidal Essebag, McGill University Health Cen-tre, 1650 Cedar Ave, Room E5-200, Montreal, Québec H3G 1A4, Canada.
dilatation and mild-to-moderate hypokinesis in the right cor-onary artery territory.
The patient’s medical history was notable only for a sur-gical ablation for symptomatic WPW syndrome performedin 1986. At that time, an intraoperative epicardial mappingstudy revealed both right posteroseptal and left posterolat-eral accessory pathways. After extracorporeal circulation wasestablished, an epicardial technique was used to access theposterior right and left atria. Cryoablation was applied onthe atrial wall, slightly overlapping the atrioventricular (AV)groove and the first millimetres of the ventricular myocar-dium. No further evidence of pre-excitation was observedpost ablation, and he remained asymptomatic for 25 years.
An electrophysiological study was performed during thepatient’s admission for his VT. There was no ventricularpre-excitation and no retrograde accessory pathway. Ven-tricular stimulation induced a VT of right ventricular originwith 260-millisecond cycle length. Subsequent 3-dimen-sional electroanatomic mapping revealed an area of low volt-age at the basal lateral right ventricle close to the tricuspidannulus (Fig. 2). There were late potentials within this areaof scar and middiastolic potentials during VT induced by
programmed electrical stimulation, consistent with scar-
130.e8 Canadian Journal of CardiologyVolume 29 2013
Figure 1. Initial presenting electrocardiogram showing monomorphic ventricular tachycardia with left bundle-branch pattern at 197 beats per
minute.
Figure 2. Anteroposterior (AP) view of 3-dimensional electroanatomic map of the right ventricle demonstrating large area of low voltage (scar)along the basal free wall. Colour scale: As indicated in the top right corner, red represents bipolar voltages � 0.5 mV (considered scar) withvoltages progressively increasing from yellow to green to blue to purple (voltages � 1.22 mV). The large white tag indicates the site with
middiastolic potentials during the induced clinical ventricular tachycardia where ablation resulted in slowing and termination of the tachycardia.
Joza et al.VT Post Surgical Ablation for WPW
130.e9
mediated re-entrant VT. This VT was successfully ablated ata site with middiastolic potential, with progressive slowingand termination of VT during ablation. Repeat ventricularstimulation induced another right VT (cycle length, 390milliseconds), exiting from the inferior basal right ventric-ular (RV) region. Ablation of this VT resulted another,faster VT (cycle length, 310 milliseconds) exiting more in-feriorly along the basal scar, and this was pace terminatedwithout further ablation attempt. The decision was made tocommence sotalol and to insert an implantable defibrillator,given the multiple VT morphologies induced.
DiscussionThis is the first reported case of VT due to a ventricular scar
following an epicardial surgical WPW ablation. Two previouscase reports exist describing newly diagnosed VT 9 and 20 yearsafter endocardial surgical ablation, the first requiring a secondsurgical ablation and the second treated with catheter radiofre-quency ablation.1
Scar-related re-entry is the most common cause of sus-tained monomorphic VT in patients with structural heartdisease resulting mainly from old myocardial infarction, car-diomyopathies, and surgical incisions.2 In our patient, it isunclear whether the scar is a direct result of the past cryole-sion to the basal RV or an ischemic insult resulting frommechanical injury to branches of the right coronary arterysustained during surgical dissection and mobilization ofthe AV fat pad to expose the AV junction. Considering theextent and distribution of scar burden in the RV and therelatively small area of cryoablation, it seems more likely aconsequence of mechanical injury. The absence of cardiacmagnetic resonance imaging prior to implantable cardio-verter-defibrillator insertion limits our ability to fully ex-clude differential diagnoses such as arrhythmogenic rightventricular dysplasia, cardiac sarcoid, or a dilated cardiomy-opathy limited to the right ventricle. However, no familyhistory was present in our patient, and there was no evidenceof sarcoid involving other organs, making these diagnoses
less likely.
The original curative therapy for patients diagnosed withWPW syndrome relied on surgical ablation, of which 2main techniques emerged, the endocardial and epicardialtechniques. The endocardial approach begins by an incisionin the atrial endocardium, after which exposure of the ac-cessory pathway is performed.3 The epicardial approach isbased on the knowledge that the vast majority of accessorypathways course within the AV groove (epicardial accessorypathways) and therefore do not require dissection into car-diac chambers.4 The right ventricle may be subject to isch-emia during posteroseptal accessory pathway ablation be-cause of the necessary dissection of the right atrioventricularfat pad and the mobilization of the right coronary artery,together with its small branches.5 The long-term risk of VTfollowing surgical WPW ablation remains unknown andrequires further investigation.
Funding SourcesDr Essebag is the recipient of a Clinician Scientist award
from the Canadian Institutes of Health Research (CIHR).
DisclosuresThe authors have no conflicts of interest to disclose.
References
1. Hillock RJ, Roberts-Thomson KC, McGavigan AD, Kalman JM. Mono-morphic ventricular tachycardia related to Wolff-Parkinson-White surgery.Europace 2007;9:130-3.
2. Stevenson WG, Soejima K. Catheter ablation for ventricular tachycardia.Circulation 2007;115:2750-60.
