(Circulation. 2001;103:538.)
© 2001 American Heart Association, Inc.
Clinical Investigation and Reports |
Coronary Artery Stenosis After Radiofrequency Catheter Ablation of Accessory Atrioventricular Pathways in Children With Ebstein’s Malformation
From the Department of Pediatric Cardiology and Pediatric Intensive Care, Hannover Medical School, Hannover, Germany.
Correspondence to Harald Bertram, MD, Pediatric Cardiology and Pediatric Intensive Care, Hannover Medical School, Carl-Neuberg-Straße 1, D-30625 Hannover, Germany. E-mail Bertram.Harald{at}mh-hannover.de
 |
Abstract |
|---|
 Top Abstract IntroductionMethodsDiscussionReferences |
|---|
Background—Complications concerning the coronary arteries that are directly related to radiofrequency catheter ablation procedures have not been reported in children. Coronary artery lesions, however, have been demonstrated after the endocardial application of radiofrequency current in young animals.
Methods and Results—Two boys with Ebstein’s anomaly of the tricuspid valve developed clinically asymptomatic coronary artery stenosis after radiofrequency catheter ablation of right-sided accessory atrioventricular pathways with standard catheter technology.
Conclusions—The complication of coronary artery stenosis demonstrates a substantial risk after right atrial free wall radiofrequency current application in children. The risk of late coronary alterations should be considered when the use of catheter ablation procedures to young patients is proposed.
Key Words: ablation • stenosis • pediatrics • Wolff-Parkinson-White syndrome • Ebstein’s malformation
|
Introduction |
|---|
|
TopAbstractIntroductionMethodsDiscussionReferences |
|---|
The mid- or long-term effects of radiofrequency current (RFC) delivery to mature and growing myocardium have not been defined yet.1 2 3 In consideration of the proximity of the coronary arteries to the ablation sites of accessory pathways (APs), the coronary arteries might be at risk during ablation procedures.1 Obstruction of the right coronary artery (RCA) as a late sequelae after RFC application to the tricuspid valve annulus has been described in an animal model.4 5 It has been inferred that in humans, ablation procedures that target right free wall APs may damage the RCA.3
No permanent damage to the coronary arteries caused by RFC catheter ablation in pediatric patients has been reported in the literature. We report on 2 children, 4 and 6 years old at the time of catheter ablation, who subsequently developed coronary artery stenosis close to the endocardial RFC application sites.
|
Methods |
|---|
|
TopAbstractIntroductionMethodsDiscussionReferences |
|---|
Electrophysiological Study and Ablation Procedure
Venous access to the heart was achieved through the femoral vessels. A heparin bolus of 100 IE/kg body wt was administered at the beginning of the study, followed by 24 hours of continuous intravenous heparin (200 IE · kg body wt-1 · d-1) after the procedure. Two diagnostic quadripolar electrode catheters (5F to 6F, Josephson; CR Bard) were placed in the His bundle region and the right ventricle, respectively. Then 6F or 7F steerable mapping and ablation catheters (Dr Osypka GmbH and Medtronic CardioRhythm, respectively) equipped with an integrated thermistor or thermocouple at the 4-mm tip electrode were positioned under fluoroscopic control according to the ECG findings, which defined the location of the AP as reported previously.6 7 RFC was delivered with a radiofrequency generator (HAT 300; Dr Osypka GmbH; or Atakr; Medtronic CardioRhythm) in the unipolar mode against a plate electrode under the back of the patients with simultaneous registration of temperature, power output (796 to 1340 J), and impedance (80 to 120
). Surface ECG and bipolar intracardiac electrograms were
displayed continuously. Standard RFC applications (target temperature
70°C, power output limited to 30 W) were continued for 30 seconds.
The total number of RFC applications were 5 in the first patient
(maximum temperature 74°C) and 21 in the second patient during 3
ablation sessions, respectively. In the latter patient, 6 RFC impulses
with a maximum temperature of 50°C and a total energy of 8771 J were
applied in the area of the subsequent coronary artery stenosis. The
cumulative energy delivered per fiber was 2434 J in the first and
10 822 J in the second patient, respectively. The overall duration of
the ablation sessions including the preceding electrophysiological
study (EPS) in these patients varied between 125 and 210 minutes, and
the fluoroscopy time varied between 12 and 47 minutes. Both patients
received acetylsalicylic acid (ASA) at 2 to 3
mg · kg-1 · d-1
for the next 6 months after catheter ablation.
Case Reports
Patient 1
The first patient was a boy with Ebstein’s anomaly
of the tricuspid valve, moderate tricuspid regurgitation, and
Wolff-Parkinson-White (WPW) syndrome who experienced recurrent episodes
of symptomatic paroxysmal supraventricular tachycardia (SVT) despite
medical treatment (propafenone/sotalol) since his second year of life.
At the age of 6 years (body weight 22 kg), an EPS was performed. Two
right-sided APs were identified in the posterior and posteroseptal
locations, respectively. The posteroseptal AP was successfully ablated
with the fourth energy pulse. The subsequent surface ECG did not
exhibit repolarization abnormalities
(Figure 1A
). RFC application for interruption of the
posterior pathway resulted in tachycardia termination after 10 seconds,
accompanied by distinct ST-segment elevation predominantly in surface
ECG leads II, III, and aVF
(Figure 1B). Energy delivery was continued for a total of 15
seconds. The repolarization abnormalities subsequently normalized
within 20 minutes
(Figure 1C). A baseline angiogram of the RCA was not
performed. After nitroglycerin instillation into the ostium of the RCA,
the subsequent coronary angiogram was considered normal. No additional
RFC pulses were applied despite still inducible SVT, and medical
therapy was continued. There was no elevation of myocardial enzymes
after the ablation procedure. During follow-up, ECGs predominantly
showed sinus rhythm with right bundle-branch block pattern without
repolarization abnormalities suspicious for myocardial ischemia.
Intermittent preexcitation, however, was present. Because of recurrent
SVT episodes despite medical treatment, a second EPS was performed 20
months later. Endocardial mapping again revealed the identical right
posterior location of the remaining AP. Simultaneously performed
selective coronary angiograms clearly demonstrated a severe narrowing
of the posterolateral branch of the RCA over a distance of 11 mm
(Figure 2, top and bottom) in direct proximity to the mapping
catheter
(Figure 3, top and bottom). No further RFC applications were
carried out. Fluor-desoxy-glucose (FDG)-PET of the heart revealed a
homogeneous myocardial glucose uptake except for a small zone of
markedly reduced metabolic activity inferobasal, representing a
transmural scar
(Figure 4). This area correlated with the coronary stenosis
in the RCA angiogram, displaying its functional evidence. More than 2
years later, the boy is asymptomatic concerning clinical signs of
myocardial ischemia. He is currently free of SVT under antiarrhythmic
medical therapy (5 mg/kg sotalol) and receives 100 mg/d
ASA.
|
|
|
|
Patient 2
The second patient also had Ebstein’s malformation
of the tricuspid valve with moderate tricuspid regurgitation, an atrial
septal defect (ASD), and WPW syndrome. An aortopulmonary shunt had been
inserted at 4 months of age. The child experienced recurrent paroxysmal
SVT episodes since he was a newborn. Medical therapy consisted of 4
drugs, including amiodarone. During EPS at the age of 2.9 years, a
right anterolateral AP was successfully ablated. The preexcitation
pattern on the surface ECG disappeared, and ventriculoatrial
dissociation was proved with right ventricular stimulation at 500 ms.
However, symptomatic SVT reoccurred a few months later. A second EPS
was carried out 13 months later (body weight 17.7 kg), combined with
hemodynamic catheterization to evaluate interventional ASD closure.
Selective coronary angiography demonstrated normal coronary arteries. A
right posterolateral concealed AP was identified and successfully
ablated. No repolarization abnormalities were noted during any of the
ablation procedures or during follow-up. Interventional catheterization
with closure of the ASD (CardioSEAL septal occluder) and coil occlusion
of the stenotic aortopulmonary shunt was carried out 14 months after
the last RFC application. Selective coronary angiography during this
procedure documented stenosis in the marginal branch of the RCA over a
distance of 12 mm
(Figure 5, top and bottom). Functional relevance was again
proved with FDG-PET, which disclosed a diminished coronary flow reserve
of lateral portions of the posterior wall after adenosine
administration
(Figure 6). This area corresponded well with the myocardial
regions supplied by the marginal branch of the RCA. At 30 months after
the last ablation procedure, there still is no clinical evidence of
myocardial ischemia. No further SVTs occurred during follow-up, and
this patient also receives 50 mg/d
ASA.
|
|
|
Discussion |
|---|
|
TopAbstractIntroductionMethodsDiscussionReferences |
|---|
Coronary Artery Affections After Catheter Ablation
No cases of direct damage to the coronary arteries in children undergoing ablation procedures have been published so far. Late evaluation of the coronary arteries in children after catheter ablation, however, has not been reported from any center.1
There have been several anecdotal reports on either acute6 7 8 9 10 11 12 13 14 15 or chronic16 17 coronary artery complications during RFC catheter ablation procedures in adults, almost exclusively confined to the left coronary artery. These complications have generally been considered as catheter-induced dissections of the left coronary artery6 8 9 11 16 or embolic events10 11 12 13 rather than direct physical thermic effects of the RFC application. Nevertheless, myocardial infarctions due to RFC-induced thrombotic occlusion of the marginal branch of the circumflex artery and a posterior right atrial coronary artery, respectively, have been described.14 17 In addition, chronic left main coronary artery occlusion in a young woman 2 years after RFC application in the left ventricle has been reported.16
Experimental Studies
Animal studies have contributed important findings to
the risk of coronary artery involvement after RFC ablation. After the
creation of lesions at the right atrial aspect of the tricuspid valve
annulus in young pigs, a significant narrowing of the RCA lumen (25%
and 40%, respectively) due to intimal thickening was found in 2 of 5
animals after 6 months.4 The
hypothesis that RFC ablation procedures may damage the RCA has been
confirmed in a subsequent experimental study with the same animal
model.5 Right atrial lesions
that extend to the adjacent right coronary artery and lead to coronary
artery obstruction from increased fibrous tissue content in adventitia
and media with additional intimal thickening were found in 3 of 8
animals after 12 months. Narrowing of the coronary artery lumen could
be documented by intracoronary ultrasound in all 3 animals during
follow-up studies 6 and 9 months after RFC delivery, respectively,
whereas angiography failed to demonstrate coronary artery stenosis in
all animals
affected.5
Risk Factors
Clinical and experimental data demonstrate the risk of
late coronary artery lesions after RFC application at the tricuspid
valve annulus, but risk factors that contribute to coronary artery
involvement after endocardial energy delivery are not yet defined.
Small hearts and the proximity between the tip of the ablation catheter
and the coronary artery, as well as cumulative energy exposure, might
be considered risk factors. Animal studies in young pigs that address
the effects of RFC application on the coronary arteries did not show a
significant difference in the mean endocardial lesion–to–coronary
artery distance between affected and unaffected
animals,4 5 but
there was a tendency to a shorter distance between the endocardial
ablation site and the RCA in hearts with coronary artery
involvement.5 Multivariate
analysis could not demonstrate an effect of energy delivery parameters
on the resulting lesion
volume.4 5
Whether patients with Ebstein’s anomaly of the tricuspid valve are at an increased risk to develop coronary artery lesions after RFC application remains speculative. There are no major differences in the tricuspid annulus/coronary artery relationship between patients with Ebstein’s malformation and subjects with normal hearts.18 19 The wall of the atrialized right ventricle is known as thinned and fibrotic,18 but data concerning the thickness of the right atrial wall in pediatric patients with Ebstein’s disease have not been published.
In general, patients with Ebstein’s malformation and right free wall atrioventricular APs tend to undergo more difficult ablation procedures with the need for multiple energy applications and often require >1 ablation procedure to be cured of paroxysmal SVT.20 21 Multiple APs are common in these patients. Even at centers with much experience, primary failure rates of RFC ablation in patients with Ebstein’s disease reach 24%,20 combined with significant recurrence rates.20 21 The number of RFC applications as well as the cumulative energy applied to our 2 patients are well within the range reported for ablation procedures in patients with Ebstein’s disease.20
Time Course of Coronary Artery Stenosis After
Catheter Ablation
The development of coronary artery stenosis must be
considered a late complication of RFC application. Early reevaluation
failed to demonstrate coronary artery lesions in adult dogs
histologically22 23
and in adult patients
angiographically.24 The
ST-segment elevation during RFC application in the first patient was
initially considered as transient thermic irritability that caused
coronary artery spasm, as has been reported
previously.6 11 25
Beyond this, transient repolarization abnormalities that mimic
myocardial ischemia often occur after the ablation of manifest APs.
These latter findings are considered to be due to cardiac memory rather
than to myocardial ischemia during
ablation.2 26
The unexpected formation of a long-segment coronary artery
stenosis
(Figures 2
and 5), however, emphasizes the need for late
control studies at least 12 months after the ablation procedure.
Selective coronary artery angiography ideally combined with
intracoronary ultrasound should be performed in every patient with
transient signs of myocardial ischemia during RFC application. A
control angiography after 12 months should also be attempted in all
children with Ebstein’s anomaly who undergo ablation of
atrioventricular APs. Considering the results of the experimental
studies,4 5 this
recommendation may even be expanded to all children after the ablation
of right free wall APs to provide more insight into the incidence of
coronary artery stenosis after RFC catheter ablation in structurally
normal hearts.
In conclusion, there are substantial late tissue effects after catheter ablation with RFC in the young. The development of coronary artery stenosis in 2 children with Ebstein’s malformation demonstrates a potential risk of right atrial RFC applications in children. These findings are supported by the results of animal studies in structurally normal hearts. Long-term follow-up that includes reevaluation of the coronary arteries seems to be mandatory in children with Ebstein’s malformation who undergo right free wall RFC applications and in every patient with signs of myocardial ischemia during energy application.
Received February 29, 2000; revision received September 7, 2000; accepted September 19, 2000.
|
References |
|---|
|
TopAbstractIntroductionMethodsDiscussionReferences |
|---|
1. Van Hare GF. Indications for radiofrequency catheter ablation in the pediatric population. J Cardiovasc Electrophysiol. 1997;8:952–962.[Medline] [Order article via Infotrieve]
2.
Morady F.
Radio-frequency ablation as treatment for cardiac arrhythmias.
N Engl J Med. 1999;340:534–544.
3.
Wellens HJJ.
Catheter ablation of cardiac arrhythmias: usually cure, but
complications may occur.
Circulation. 1999;99:195–197.
4. Paul T, Bökenkamp R, Mahnert B, et al. Coronary involvement early and late after radiofrequency current application in young pigs. Am Heart J. 1997;133:436–440.[Medline] [Order article via Infotrieve]
5. Bökenkamp R, Wibbelt G, Sturm M, et al. Effects of intracardiac radiofrequency current application on coronary artery vessels in young pigs. J Cardiovasc Electrophysiol. 2000;11:565–571. .[Medline] [Order article via Infotrieve]
6. Calkins H, Sousa J, El Atassi R, et al. Diagnosis and cure of the Wolff-Parkinson-White syndrome or paroxysmal supraventricular tachycardias during a single electrophysiologic test. N Engl J Med. 1991;324:1612–1618.[Abstract]
7.
Calkins H, Langberg
J, Sousa J, et al. Radiofrequency catheter ablation of accessory
atrioventricular connections in 250 patients.
Circulation. 1992;85:1337–1342.
8.
Calkins H, Yong P,
Miller JM, et al. Catheter ablation of accessory pathways,
atrioventricular nodal reentrant tachycardia, and the atrioventricular
junction: final results of a prospective, multicenter clinical trial.
Circulation. 1999;99:262–270.
9. Janeira LF. Coronary artery dissection complicating radiofrequency catheter ablation via the retrograde approach. Pacing Clin Electrophysiol. 1998;21:1327–1328.[Medline] [Order article via Infotrieve]
10. Lesh MD, Coggins DL, Ports TA. Coronary air embolism complicating transseptal radio-frequency ablation of left free-wall accessory pathways. Pacing Clin Electrophysiol. 1992;15:1105–1108.[Medline] [Order article via Infotrieve]
11. Lesh MD, Van Hare GF, Scheinman MM, et al. Comparison of the retrograde and transseptal methods for ablation of left free wall accessory pathways. J Am Coll Cardiol. 1993;22:542–549.[Abstract]
12. Thakur RK, Klein GJ, Yee R. Radiofrequency catheter ablation in patients with Wolff-Parkinson-White syndrome. Can Med Assoc J. 1994;151:771–776.[Abstract]
13. Hope EJ, Haigney MC, Calkins H, et al. Left main coronary thrombosis after radio-frequency ablation: successful treatment with percutaneous transluminal angioplasty. Am Heart J. 1995;129:1217–1219.[Medline] [Order article via Infotrieve]
14.
Chatelain P,
Zimmermann M, Weber R, et al. Acute coronary occlusion secondary to
radiofrequency catheter ablation of a left lateral accessory pathway.
Eur Heart J. 1995;16:859–861.
15. Saul JP, Hulse JE, De W, et al. Catheter ablation of accessory atrioventricular pathways in young patients: use of long vascular sheaths, the transseptal approach and a retrograde left posterior parallel approach. J Am Coll Cardiol. 1993;21:571–583.[Abstract]
16. Pons M, Beck L, Leclercq F, et al. Chronic left main coronary artery occlusion: a complication of radiofrequency ablation of idiopathic left ventricular tachycardia. Pacing Clin Electrophysiol. 1997;20:1874–1876.[Medline] [Order article via Infotrieve]
17. Stancak B, Jurkovic I, Pella J, et al. Subacute morphologic changes in the heart after radiofrequency ablation in the area of the atrioventricular junction. Bratisl Lek Listy. 1997;98:616–619.[Medline] [Order article via Infotrieve]
18.
Ho SY, Goltz D,
McCarthy K, et al. The atrioventricular junctions in Ebstein
malformation. Heart. 2000;83:444–449.
19.
Schreiber C, Cook
A, Ho SY, et al. Morphologic spectrum of Ebstein’s malformation:
revisitation relative to surgical repair.
J Thorac Cardiovasc Surg. 1999;117:148–155.
20.
Cappato R,
Schlüter M, Weiß C, et al. Radio-frequency current catheter ablation
of accessory atrioventricular pathways in Ebstein’s anomaly.
Circulation. 1996;94:376–383.
21. Reich JD, Auld D, Hulse E, et al. The Pediatric Radiofrequency Ablation Registry’s experience with Ebstein’s anomaly. J Cardiovasc Electrophysiol. 1998;9:1370–1377.[Medline] [Order article via Infotrieve]
22.
Huang SK, Graham
AR, Bharati S, et al. Short- and long-term effects of transcatheter
ablation of the coronary sinus by radiofrequency energy.
Circulation. 1988;78:416–427.
23. Franklin JO, Langberg JJ, Oeff M, et al. Catheter ablation of canine myocardium with radiofrequency energy. Pacing Clin Electrophysiol. 1989;12:170–176.[Medline] [Order article via Infotrieve]
24. Solomon AJ, Tracy CM, Swartz JF, et al. Effect on coronary artery anatomy of radiofrequency catheter ablation of atrial insertion sites of accessory pathways. J Am Coll Cardiol. 1993;21:1440–1444.[Abstract]
25. Lesh MD, Van Hare GF, Schamp DJ, et al. Curative percutaneous catheter ablation using radiofrequency energy for accessory pathways in all location: results in 100 consecutive patients. J Am Coll Cardiol. 1992;19:1303–1309.[Abstract]
26. Kalbfleisch SJ, Sousa J, El-Atassi R, et al. Repolarisation abnormalities after catheter ablation of accessory atrioventricular connections with radio-frequency current. J Am Coll Cardiol. 1991;18:1761–1766.[Abstract]
This article has been cited by other articles:
 |
|
 |
|
  B. Brembilla-Perrot, F. Chometon, L. Groben, S. Ammar, J. Bertrand, C. Marcha, J.L. Cloez, A. Tisserand, O. Huttin, C. Tatar, et al. Interest of non-invasive and semi-invasive testings in asymptomatic children with pre-excitation syndrome Europace, September 1, 2007; 9(9): 837 - 843. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. P. Walsh Interventional Electrophysiology in Patients With Congenital Heart Disease Circulation, June 26, 2007; 115(25): 3224 - 3234. [Full Text] [PDF]
|
|
|
|
 |
|
 L. Bockeria, E. Golukhova, M. Dadasheva, A. Revishvili, A. Levant, V. Bazaev, F. Rzaev, and T. Kakuchaya Advantages and disadvantages of one-stage and two-stage surgery for arrhythmias and Ebstein's anomaly Eur. J. Cardiothorac. Surg., October 1, 2005; 28(4): 536 - 540. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Miyazaki, A. D. Blaufox, D. L. Fairbrother, and J. P. Saul Cryo-ablation for septal tachycardia substrates in pediatric patients: Mid-term results J. Am. Coll. Cardiol., February 15, 2005; 45(4): 581 - 588. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. Kirsh, G. J. Gross, S. O'Connor, R. M. Hamilton, and Cryocath International Patient Registry Transcatheter cryoablation of tachyarrhythmias in children: Initial experience from an international registry J. Am. Coll. Cardiol., January 4, 2005; 45(1): 133 - 136. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Fayad, T. Modine, T. Le Tourneau, C. Decoene, R. Azzaoui, S. Al-Ruzzeh, J. M. Lablanche, and H. Warembourg Circumflex artery stenosis induced by intraoperative radiofrequency ablation Ann. Thorac. Surg., October 1, 2003; 76(4): 1291 - 1293. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. D. Blaufox, G. L. Felix, and J. P. Saul Radiofrequency Catheter Ablation in Infants <=18 Months Old: When Is It Done and How Do They Fare?: Short-Term Data From the Pediatric Ablation Registry Circulation, December 4, 2001; 104(23): 2803 - 2808. [Abstract] [Full Text] [PDF]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||