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Usefulness of Esophageal Leads for Determining the Strategy of Pulmonary VeinAblation to Avoid Complications Associated With the Esophagus

Takumi Yamada, MDa,*, Yoshimasa Murakami, MDa, Taro Okada, MDa,Mitsuhiro Okamoto, MDa, Takeshi Shimizu, MDa, Junji Toyama, MDa,

Yukihiko Yoshida, MDb, Naoya Tsuboi, MDb, Teruo Ito, MDb, Masahiro Muto, MDc,Takahisa Kondo, MDc, Yasuya Inden, MDc, Makoto Hirai, MDc,

and Toyoaki Murohara, MDc

To avoid fatal complications after extensive pulmonary vein (PV) ablation, it has beenproved important to comprehend the anatomic relation between the PVs and theesophagus. In 42 consecutive patients with atrial fibrillation, PV ostial isolation wasperformed using a basket catheter. The shortest distance and anatomic relationbetween the esophageal lead and PV ostium, determined by successful PV ostialisolation, was analyzed in biplane fluoroscopic views. In 18 left superior PVs (LSPVs)(43%), 13 left inferior PVs (32%) (LIPVs), and all the right PVs (group A), theshortest distance was >10 mm in >1 of the biplane fluoroscopic views. In 4 LSPVs(10%) and 2 LIPVs (5%) (group B), the shortest distance was <5 mm in thefluoroscopic views. In the remaining PVs (group C), the esophagus was situateddirectly behind 10 LSPVs (24%) and 12 LIPVs (29%) (group C1), posteromedial to 1LSPV (2%) and 9 LIPVs (22%) (group C2), and medial to 9 LSPVs (21%) and 5LIPVs (12%) (group C3). The risk of esophagus-associated complications with abla-tion around the left PV ostia was suggested to be high in group B, very low in groupA, and relatively low in group C. In group C3, extensive PV ablation might increasethe risk of that complication. In conclusion, esophageal leads are useful for deter-mining strategies for PV ablation to avoid esophagus-associated complications, be-cause they enable comprehension of the anatomic relation between the PVs and the

esophagus. © 2006 Elsevier Inc. All rights reserved. (Am J Cardiol 2006;97:1494–1497)

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he pulmonary veins (PVs) have been demonstrated to behe major source of atrial fibrillation.1,2 Two catheter abla-ion techniques for atrial fibrillation, segmental ostial PVblation to electrically isolate the PVs from the left atrium 3,4

nd left atrial (LA) ablation to encircle the PVs and createinear lesions connecting the circles,5,6 have been used clin-cally. Recently, atrioesophageal fistulas have been reporteds a fatal complication after that extensive PV ablation.7

hus, it has become very important in catheter ablationround the PVs to comprehend the anatomic relation be-ween the PV ostia and the esophagus. In this study, thatnatomic relation was investigated using esophageal leadsnd biplane fluoroscopy.

• • •he study population consisted of 42 consecutive patients

33 men; 58 � 10 years) with paroxysmal atrial fibrillation

aDivision of Cardiology, Aichi Prefectural Cardiovascular and Respi-atory Center, Ichinomiya; bDivision of Cardiology, Nagoya Dai-ni Redross Hospital, Cardiovascular Center, Nagoya; and cDepartment of Car-iology, Nagoya University Graduate School of Medicine, Nagoya, Japan.anuscript received August 23, 2005; revised manuscript received and

ccepted November 28, 2005.* Corresponding author: Tel: 81-586-45-5000; fax: 81-586-45-6800.

oE-mail address: takumi-y@fb4.so-net.ne.jp (T. Yamada).

002-9149/06/$ – see front matter © 2006 Elsevier Inc. All rights reserved.oi:10.1016/j.amjcard.2005.11.084

nd without any structural heart disease. The mean LAimension was 34 � 5 mm (range 25 to 44), and the meaneft ventricular ejection fraction was 67 � 9% (range 47%o 90%). The electrophysiologic studies were performedfter the patients provided informed consent.

A 10.5Fr octapolar catheter (6-mm electrode width and5-mm interelectrode spacing; TO 8, Dr. Osypka, Grenzach-yhlen, Germany) was inserted by way of the nose into the

sophagus. The position of the third or fourth proximallectrode at the left superior PV (LSPV) ostium was con-rmed in the LA phase of the pulmonary arteriogram. Cath-terization into the left atrium was performed with a singleuncture and 2-sheath technique (1 sheath [8Fr, St. Judeedical, AF Division, Minnetonka, Minnesota] for an ab-

ation catheter and another [8.5Fr, Soft Tip EP Sheath, EPechnologies, Boston Scientific Corporation, San Jose, Cal-

fornia] for a mapping catheter).In all cases, PV mapping and PV ostial isolation were

erformed using the same technique we previously reported.8

31-mm multielectrode basket catheter (Constellation, EPechnologies), which consisted of 8 splines (A to H) withight 1-mm electrodes and 2-mm interelectrode spacing,as deployed within the target PV coaxially to its long axis

nd with its most proximal electrodes positioned at the PV

stium using biplane fluoroscopic guidance and contrast

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1495Arrhythmias and Conduction Disturbances/Esophageal Lead Efficacy for PV Ablation

edium. The QMS2 (EP Technologies, Boston Scientificorporation) is a computerized 3-dimensional mapping sys-

em that can construct a 3-dimensional color map from aotal of 56 bipolar electrograms recorded by a multielec-rode basket catheter.8 An animation of a 3-dimensionalotential map, which could reflect a series of electricalctivations, was used to reveal the style of the electricalonnection between the left atrium and PVs, distribution ofhe PV musculature, and activation pattern within the PVs.he short stay of the activation wavefront near the outer

rame of the 3-dimensional PV potential map before theongitudinal propagation, which reflected a conduction de-ay, was defined as indicating the LA–PV junction at whichontinuous fractionated potentials connecting the LA poten-ials and PV potentials were observed. The serial activationatterns moving around the outer frame of the 3-dimen-ional PV potential map before the longitudinal propagationere defined as indicating the LA–PV junction. The onsetf a centrifugal activation at the LA–PV junction was iden-ified as a previous electrical connection. In the ablationrocedure, a radiofrequency application was delivered tohe preferential electrical connection identified by the-dimensional PV potential map with the guidance of aavigation system (Astronomer, EP Technologies, Bostoncientific Corporation) associated with the multielectrodeasket catheter. Radiofrequency energy was delivered withtarget temperature of 55°C and maximum power output of0 W (EPT-1000TC generator, EP Technologies), using an

igure 1. Schema showing anatomic relation between esophagus and leforresponding to schema. Group A, shortest distance between esophagealr shortest distance between esophageal lead and LPV ostium in left anteriAO-Sd �5 mm; group C1, RAO-Sd �5 mm and LAO-Sd �5 mm but �

m; group C3, �5 mm but �10 mm and LAO-Sd �5 mm. AV � aorticnferior PV; RA � right atrium; RI � right inferior PV.

-mm tip catheter (Blazer II 5770T, EP Technologies). The p

MS recording was performed after every radiofrequencypplication; if the elimination of a target electrical connectionas confirmed, another electrical connection was identified

nd ablated. Successful PV ostial isolation was defined asither the abolition or dissociation of the distal PV potentials.

The shortest distance and anatomic relation between thesophageal lead and PV ostia, determined by successful PVstial isolation, was analyzed retrospectively in the biplaneuoroscopic views (right anterior oblique 30° and left an-

erior oblique views 60°). The anatomic relation betweenhe esophageal lead and PV ostia was classified into 3roups (group A, shortest distance �10 mm in �1 of theiplane fluoroscopic views; group B, shortest distance �5m in the biplane fluoroscopic views; and group C, the

emaining PVs; Figure 1). Group C was classified into 3maller groups (group C1, shortest distance �5 mm in theight anterior oblique view and �5 mm and �10 mm in theeft anterior oblique view; group C2, shortest distance �5m and �10 mm in fluoroscopic views; and group C3,

hortest distance �5 mm and �10 mm in the right anteriorblique view and �5 mm in the left anterior oblique view;igure 1). The esophagus was situated directly behind the

eft PV (LPV) ostia in group C1, posteromedial to that inroup C2, and medial to that in group C3.

Continuous variables are expressed as the group mean �D. The anatomic relations between the esophageal leadnd PV ostia in groups A to C were compared by thehi-square test. Statistical significance was set at a value of

PV) ostium (Os) and 2-dimensional computed tomographic (CT) imageLPV Os in right anterior oblique fluoroscopic view (RAO-Sd) �10 mm

ue fluoroscopic view (LAO-Sd) �10 mm; group B, RAO-Sd �5 mm and; group C2, RAO-Sd �5 mm but �10 mm and LAO-Sd �5 mm but �10DA � descending aorta; ESO � esophagus; LA � left atrium; LI � left

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1496 The American Journal of Cardiology (www.AJConline.org)

QMS mapping with a multielectrode basket catheter waserformed in 42 LSPVs, 42 superior right PVs, 41 leftnferior PVs (LIPVs), and 24 inferior right PVs in 42 pa-ients. One LPV with a common trunk in which a multi-lectrode basket catheter could be positioned appropriatelyas included in the group of LSPVs. Successful PV ostial

solation was achieved in all the PVs for which QMS map-ing was available.

Eighteen LSPVs (43%), 13 LIPVs (32%), and all theight PVs were included in group A; 4 LSPVs (10%) andLIPVs (5%) in group B; and 20 (47%) LSPVs and 26

63%) LIPVs in group C. Ten LSPVs (24%) and 12 LIPVs29%) were included in group C1; 1 LSPV (2%) and 9IPVs (22%) in group C2; and 9 LSPVs (21%) and 5 LIPVs

12%) in group C3 (Figure 2). In the LSPVs, the number ofroup A and group C patients was significantly greater thanhat of group B (p � 0.0005 and p � 0.0001, respectively),nd that of group A patients was higher than that of group2 (p �0.0001) and group C3 patients (p �0.05). In theIPVs, the number of group A and group C patients wasignificantly higher than that of group B patients (p � 0.002nd p � 0.0001, respectively), and that of group A patientsas higher than that of group C3 patients (p �0.03). That ofroup B patients was significantly smaller than that of group1 patients (p � 0.003) and that of group C2 patients (p �.02). No complications associated with placement of thesophageal leads occurred in any of the cases.

igure 2. Catheter positions and results. Group A, left superior PV (LSPVIPV 2 (5%); group C1, LSPV 10 (24%) and LIPV 12 (29%); group C2, L

ablation catheter; CS � coronary sinus; ESO � esophageal catheter. L

• • • i

xtensive catheter ablation around the PVs, which requireshigh radiofrequency power because of its longer ablation

ines and the thicker myocardial wall, may increase the riskf a fatal complication of an atrioesophageal fistula.7 There-ore, it has proved to be very important to comprehend thenatomic relation between the LPVs and esophagus and aood landmark to show the location of the esophagus iseeded. This study has addressed the efficacy of esophagealeads for comprehending the location of the esophagus andts relation to the LPV ostia. Esophageal leads deployed inhe esophageal lumen cannot indicate the esophageal wall.owever, computed tomographic analysis has revealed that

he mean thickness of the anterior aspect of the esophagealall adjacent to the posterior left atrium is 3.6 mm.9 Aistance of �5 mm between the LPV ostia and esophagealeads should suggest direct contact of the wall of the LPVstia with the esophageal wall. Analysis of esophageal tem-erature monitoring during radiofrequency ablation fortrial fibrillation revealed that heating of the esophagusccurred with radiofrequency lesions created within 10 mmf the esophagus.10 A distance of �10 mm between thePV ostia and esophageal leads should guarantee a safe

adiofrequency application to the LPV ostia, which wouldvoid esophagus-associated complications. On the basis ofhese reasons, the risk of complications associated with thesophagus during ablation around the LPV ostia was sug-ested to be high in 10% of the LSPVs and 5% of the LIPVs

3%) and left interior PV (LIPV) 13 (32%); group B, LSPV 4 (10%) and2%) and LIPV 9 (22%); group 3, LSPV 9 (21%) and LIPV 5 (12%). ABLleft anterior oblique; RA � right anterior oblique.

) 18 (4SPV 1 (

n group B. The risk was suggested to be very low in 43%

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1497Arrhythmias and Conduction Disturbances/Esophageal Lead Efficacy for PV Ablation

f the LSPVs and 32% of the LIPVs in group A andelatively low in 52% of the LSPVs and 63% of the LIPVsn group C. In the group B patients, extensive catheterblation away from the LPV ostia would result in less riskf those complications than would ostial ablation. In 21% ofhe LSPVs and 12% of the LIPVs in group C3, extensive PVblation of the LA posterior wall would have increased theisk of those complications. Because the relation betweenhe LPV ostia and esophagus is highly variable, the strategyf catheter ablation around the LPVs should be modifiedase by case according to that relation to avoid the fatalomplication of atrioesophageal fistula. Some reports9,11,12

ave demonstrated the efficacy of 3-dimensional imaging inomprehending the anatomic relation between the LPVs orA and the esophagus. The static esophageal delineationith those imaging devices cannot evaluate the dynamic

elation between them for multiple reasons, including auto-omic tone, patient position, the push of the ablation cath-ter tip on the LA wall, and so on. Therefore, esophagealeads may have some advantages over 3-dimensional imag-ng during real-time monitoring of the esophagus.

This study did not include the higher risk patients withhronic atrial fibrillation, a dilated left atrium, and structuraleart disease. None of the right PVs overlapped with thesophagus, probably because of the limited study popula-ion. Because this study was a retrospective analysis, theatheter ablation strategy was not actually modified with theuidance of the esophageal leads. Additional study iseeded to confirm the efficacy of esophageal leads in theractical catheter ablation procedure for a larger variety ofatients with atrial fibrillation.

1. Haissaguerre M, Jais P, Shah DC, Takahashi A, Hocini M, Quiniou G,Garrigue S, Le Mouroux A, Le Matayer P, Clementy J. Spontaneousinitiation of atrial fibrillation by ectopic beats originating in the pul-monary veins. N Engl J Med 1998;339:659–666.

2. Chen SA, Hsieh MH, Tai CT, Prakash VS, Yu WC, Hsu TL, Ding YA,

Chang MS. Initiation of atrial fibrillation by ectopic beats originating

from pulmonary veins: electrophysiologic characteristics, pharmacologicresponses, and effects of radiofrequency ablation. Circulation 1999;100:1879–1886.

3. Haissaguerre M, Shah DC, Jais P, Hocini M, Yamane T, DeisenhoferI, Chauvin M, Garrigue S, Clementy J. Electrophysiological break-throughs from the left atrium to the pulmonary veins. Circulation2000;102:2463–2465.

4. Oral H, Knight BP, Tada H, Ozaydin M, Chugh A, Hassan S, ScharfC, Lai SWK, Greenstein R, Pelosi F, Strickberger A, Morady F.Pulmonary vein isolation for paroxysmal and persistent atrial fibrilla-tion. Circulation 2002;105:1077–1081.

5. Pappone C, Rosanio S, Oreto G, Tocchi M, Gugliotta F, VicedominiG, Salvati A, Dicandia C, Mazzone P, Santinelli V, Gulletta S, Chier-chia S. Circumferential radiofrequency ablation of pulmonary veinostia: a new anatomic approach for curing atrial fibrillation. Circula-tion 2000;102:2619–2628.

6. Oral H, Christoph S, Chugh A, Hall B, Cheung P, Good E, VeerareddyS, Pelosi F, Morady F. Catheter ablation for paroxysmal atrial fibril-lation: segmental pulmonary vein ostial ablation versus left atrialablation. Circulation 2003;108:2355–2360.

7. Pappone C, Oral H, Santinelli V, Vicedomini G, Lang CC, MangusoF, Torracca L, Benussi S, Alfieri O, Hong R, et al. Atrio-esophagealfistula as a complication of percutaneous transcatheter ablation of atrialfibrillation. Circulation 2004;109:2724–2726.

8. Yamada T, Murakami Y, Muto M, Okada T, Okamoto M, Shimizu T,Toyama J, Yoshida Y, Tsuboi N, Ito T, et al. Computerized three-dimensional potential mapping with a multielectrode basket cathetercan be useful for pulmonary vein electrical disconnection. J IntervCard Electrophysiol 2005;12:23–33.

9. Lemola K, Sneider M, Desjardins B, Case I, Han J, Good E, TamirisaK, Tsemo A, Chugh A, Bogun F, et al. Computed tomographic anal-ysis of the anatomy of the left atrium and the esophagus: implicationsfor left atrial catheter ablation. Circulation 2004;110:3655–3660.

0. Redfearn DP, Trim GM, Skanes AC, Petrellis B, Krahn AD, Yee R,Klein GJ. Esophageal temperature monitoring during radiofrequencyablation of atrial fibrillation. J Cardiovasc Electrophysiol 2005;16:589–593.

1. Pollak SJ, Monir G, Chernoby MS, Elenberger CD. Novel imagingtechniques of the esophagus enhancing safety of left atrial ablation.J Cardiovasc Electrophysiol 2005;16:244–248.

2. Kottkamp H, Piorkowski C, Tanner H, Kobza R, Dorszewski A,Schirdewahn P, Gerds-Li JH, Hindricks G. Topographic variability ofthe esophageal left atrial relation influencing ablation lines in patients

with atrial fibrillation. J Cardiovasc Electrophysiol 2005;16:146–150.