Van Hare, George F.

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Journal of the American College of Cardiology Vol. 56, No. 11, 2010
© 2010 by the American College of Cardiology Foundation ISSN 0735-1097/$36.00
Published by Elsevier Inc. doi:10.1016/j.jacc.2010.03.078EDITORIAL COMMENT
n the Evolution
f the Fontan Operation
rom an Electrophysiologist’s Perspective*
eorge F. Van Hare, MD
t. Louis, Missouri
he history of pediatric electrophysiology as a subspecialty
s inextricably bound up with the development of surgery for
omplex congenital heart disease, and in particular, the
reatment of the arrhythmias that result from these palliative
nd corrective operations. In a pediatric electrophysiology
enter, the most problematic of these post-operative ar-
hythmias are arguably the re-entrant atrial arrhythmias,
hich account for many hospitalizations and interventions.
f all the types of repairs that are performed, it is the
ontan repair that has over the years created the most
rouble with respect to atrial arrhythmias (1).
See page 890
The Fontan procedure itself has undergone numerous
hanges and continues to evolve. Initially, the Fontan
onsisted mainly of a direct connection between the right
trium to the pulmonary artery. Results were disappointing,
oth from hemodynamic and arrhythmia standpoints, and it
as recognized that a great deal of hydraulic energy is lost
n the atriopulmonary connection, leading to right atrial
ilation, low cardiac output, and often, pulmonary venous
bstruction. The prominence of atrial flutter (also known as
ntra-atrial re-entry tachycardia) led to the hypothesis that if
oor hemodynamics and right atrial stretch could be ame-
iorated, the incidence of atrial flutter might be lowered.
urther evolution of the Fontan involved various forms of
avopulmonary connection, allowing for more efficient
treaming of venous return to the pulmonary bed with less
oss of energy (2), and elimination of the potential for
ignificant right atrial dilation. One method of cavopulmo-
ary connection involves the creation of a lateral tunnel
either intracardiac or extracardiac), and the other involves
lacement of an external conduit, essentially bypassing the
Editorials published in the Journal of the American College of Cardiology reflect the
iews of the authors and do not necessarily represent the views of JACC or the
merican College of Cardiology.h
From Washington University/St. Louis Children’s Hospital, St. Louis, Missouri.
r. Van Hare has reported that he has no relationships to disclose.ight atrium entirely. Although, in general, centers have
bserved a lower incidence of atrial arrhythmias compared
ith the old-style atriopulmonary connection, atrial ar-
hythmias have not been eliminated. Simultaneously, the
ole of long atrial suture lines as barriers to impulse
ropagation that support the development of atrial flutter
as become well understood as, for example, in the Senning
nd Mustard procedure (3). Therefore, it is not surprising
hat atrial arrhythmias have not been eliminated simply by
ormalizing atrial pressures. The 2 main forms of Fontan
avopulmonary connection differ significantly in that the
ntracardiac lateral tunnel Fontan requires quite a lot of
trial surgery, whereas with the external conduit, the surgi-
al impact on the atrium is less extensive. Some have
roposed that a rationale for favoring the external conduit
ontan over the lateral tunnel would be the limitation of
urgical impact to the atrium and, consequently, an expec-
ation of a lower atrial arrhythmia incidence (4).
In this issue of the Journal, Stephenson et al. (5) report
heir findings in the analysis of patients enrolled in the
ediatric Heart Network’s Fontan Cross-Sectional study. A
otal of 520 pediatric patients were enrolled and evaluated,
ll of whom had 1 of the 3 types of Fontan operation, and
his is the largest series reported to date for whom this type
f data has been collected. Not unexpectedly, the incidence
f atrial arrhythmias in this group was high, 7.3%, with the
revalence increasing with age. Interestingly from the elec-
rophysiologist’s point of view, the incidence of atrial
rrhythmia was in direct relationship to the amount of atrial
isease and/or surgical impact: 19% in the atriopulmonary
onnection (highest, as expected), 7% in the intracardiac
ateral tunnel (atrial surgery without atrial dilation), 5% in
he extracardiac lateral tunnel (less extensive atrial surgery),
nd only 2% in the external conduit Fontan (the least
urgical impact on the atrium). One notes that the differ-
nce in incidence was not statistically significant between
he intracardiac lateral tunnel and the extracardiac conduit,
lthough the study was powered to detect a hazard ratio of
.5 or higher, and insufficient time may have passed to
emonstrate more substantial differences.
So where does this leave us? It is disappointing, but
erhaps not altogether surprising, that one observes some
trial arrhythmias in patients with the external conduit
ontan. Although Stephenson et al. (5) have not provided
s with additional details of the operations, for many
ndications, an external conduit Fontan still requires a large
triotomy (e.g., to perform atrial septectomy or plicate a
alve). The Fontan is not a legacy operation like the
enning procedure for transposition, and with improved
urvival for the Norwood/Sano operation, more and more
hildren will be coming to surgery for Fontan completion,
nd so the management of these arrhythmias will continue
o occupy us. Speaking from the point of view of the person
olding the ablation catheter, all forms of cavopulmonary
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898 Van Hare JACC Vol. 56, No. 11, 2010
Evolution of the Fontan September 7, 2010:897–8onnection are problematic as they limit access to the atrial
ass via the caval veins. The external conduit is likely the
ost problematic in terms of access. Various approaches
re available, including crossing a fenestration, puncturing
he conduit itself (6), entering the roof of the atrium via the
uperior vena cava and left pulmonary artery (7), direct
ransthoracic entry into the heart (8), and approaching the
tria in a retrograde fashion after crossing the aortic and
trioventricular valves. None of these approaches are easy,
nd they all either limit catheter maneuverability or have
ignificant risks of complications.
Perhaps, in view of the fact that we have been unable to
void atrial arrhythmias despite extensive evolution in the
ontan procedure, it is time to consider what might be done
t the time of Fontan completion to prevent these arrhyth-
ias, as suggested by Collins et al. (9) in their prospective
rial of strategically placed atrial incisions to prevent the
ccurrence of flutter. Certainly, after 15 years of experi-
nce with entrainment mapping and electroanatomic map-
ing of arrhythmia circuits in patients after the Fontan
rocedure (3,10), we should be able to come to a better
nderstanding of the exact elements of surgical technique
hat create the substrate for atrial arrhythmia, and apply this
nowledge to prevent this surgical complication in the
uture.
eprint requests and correspondence: Dr. George F. Van Hare,
ashington University/St. Louis Children’s Hospital, One Chil-
ren’s Place/Campus, Box 8116–NWT, St. Louis, Missouri 63110.
-mail: vanhare@kids.wustl.edu. K
aEFERENCES
1. Garson A Jr., Bink-Boelkens M, Hesslein PS, et al. Atrial flutter in the
young: a collaborative study of 380 cases. J Am Coll Cardiol 1985;6:
871–8.
2. Bove EL, de Leval MR, Migliavacca F, Guadagni G, Dubini G.
Computational fluid dynamics in the evaluation of hemodynamic
performance of cavopulmonary connections after the Norwood proce-
dure for hypoplastic left heart syndrome. J Thorac Cardiovasc Surg
2003;126:1040–7.
3. Van Hare GF. Electrical-anatomic correlations between typical atrial
flutter and intra-atrial re-entry following atrial surgery. J Electrocardiol
1998;30 Suppl:77–84.
4. Petrossian E, Reddy VM, Collins KK, et al. The extracardiac conduit
Fontan operation using minimal approach extracorporeal circulation:
early and midterm outcomes. J Thorac Cardiovasc Surg 2006;132:
1054–63.
5. Stephenson EA, Lu M, Berul CI, et al. Arrhythmias in a contempo-
rary Fontan cohort: prevalence and clinical associations in a multi-
center cross-sectional study. J Am Coll Cardiol 2010;56:890–6.
6. El-Said HG, Ing FF, Grifka RG, et al. 18-year experience with
transseptal procedures through baffles, conduits, and other intra-
atrial patches. Catheter Cardiovasc Interv 2000;50:434 –9, discus-
sion 440.
7. Mehta C, Jones T, De Giovanni JV. Percutaneous transcatheter
communication between the pulmonary artery and atrium following an
extra-cardiac Fontan: an alternative approach to fenestration avoiding
conduit perforation. Catheter Cardiovasc Interv 2008;71:936–9.
8. Nehgme RA, Carboni MP, Care J, Murphy JD. Transthoracic
percutaneous access for electroanatomic mapping and catheter ablation
of atrial tachycardia in patients with a lateral tunnel Fontan. Heart
Rhythm 2006;3:37–43.
9. Collins KK, Rhee EK, Delucca JM, et al. Modification to the Fontan
procedure for the prophylaxis of intra-atrial reentrant tachycardia:
short-term results of a prospective randomized blinded trial. J Thorac
Cardiovasc Surg 2004;127:721–9.
0. Mandapati R, Walsh EP, Triedman JK. Pericaval and periannular
intra-atrial reentrant tachycardias in patients with congenital heart
disease. J Cardiovasc Electrophysiol 2003;14:119–25.ey Words: arrhythmia y congenital heart disease y Fontan y intra-
trial re-entrant tachycardia y prevalence.


On the Evolution of the Fontan Operation From an Electrophysiologist's Perspective⁎⁎Editorials published in the Journal of the American College of Cardiologyreflect the views of the authors and do not necessarily represent the views of JACCor the American College of Cardiology.

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On the Evolution of the Fontan Operation From an Electrophysiologist's Perspective⁎⁎Editorials published in the Journal of the American College of Cardiologyreflect the views of the authors and do not necessarily represent the views of JACCor the American College of Cardiology.

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