Download Arrhythmia Surgery in Patients With and Without Congenital Heart

ORIGINAL ARTICLES: PEDIATRIC CARDIAC
PEDIATRIC CARDIAC SURGERY:
Arrhythmia Surgery in Patients With and Without
Congenital Heart Disease
Constantine Mavroudis, MD, Barbara J. Deal, MD, Carl L. Backer, MD, and
Sabrina Tsao, MD
Divisions of Cardiovascular-Thoracic Surgery and Cardiology, Children’s Memorial Hospital, and the Departments of Surgery and
Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois
Background. Arrhythmia surgery has favorably impacted the clinical course of debilitating atrial and ventricular arrhythmias in patients with and without congenital heart disease. This study reviews arrhythmia
mechanisms and documents long-term outcome of patients undergoing arrhythmia operations alone or associated with congenital heart repairs. The analysis excludes
Fontan conversion patients.
Methods. Between 1987 and 2007, arrhythmia operations were done in 11 patients without associated congenital heart disease and in 89 along with congenital
heart repairs. Mean age was 15.9 ⴞ 12.5 years (range, 7
days– 48 years); 7 were infants (mean age, 23 ⴞ 16 days).
Resternotomy was performed in 65 (65%). Two functional ventricles were present in 67 patients; 33 had 1
functional ventricle. Arrhythmias included macro-reentrant atrial tachycardia in 45, atrial fibrillation in 11,
accessory connections in 19, atrioventricular nodal reen-
try tachycardia in 6, focal atrial tachycardia in 6, and
ventricular tachycardia in 13.
Results. Operative mortality was 3 (3.0%) due to advanced associated congenital heart disease. There were 4
late deaths (4.0%) and 2 late cardiac transplants (2.0%).
Freedom from arrhythmia recurrence at 1 and 10 years
was 94% and 85% for atrial arrhythmias, and 85% and
68% for ventricular arrhythmias, respectively.
Conclusions. Successful surgical therapy for atrial arrhythmias can be performed safely with a high freedom
from recurrence rate in patients with and without associated congenital heart disease. Surgical ablation for
ventricular arrhythmias is less predictive. Complexity of
the underlying congenital heart disease and hemodynamic status may contribute to potential arrhythmia
recurrence or new onset arrhythmia manifestation.
(Ann Thorac Surg 2008;86:857– 68)
© 2008 by The Society of Thoracic Surgeons
T
ablative therapy. The purpose of this article is to update
[10] our long-term results of arrhythmia operations and
review arrhythmia mechanisms and the principles of
corrective ablative therapy.
he introduction and development of arrhythmia surgery in patients with and without associated congenital heart disease has enabled clinicians to treat
disabling arrhythmias not amenable to transcatheter ablative techniques [1– 8]. Because decreased cardiac output attributable to arrhythmias is compounded by coexisting unrepaired or residual congenital defects, the
initial or reoperative repair must include both physiologicanatomic correction as well as electrophysiologic correction if optimal long-term outcome and beneficial quality
of life are to be achieved [9].
Mechanisms underlying the various atrial and ventricular arrhythmias have been incompletely understood by
congenital heart surgeons owing to case-mix variability
in many congenital heart surgery centers. This leads to
an incomplete understanding of what is accomplished by
Accepted for publication April 23, 2008.
Presented at the Forty-fourth Annual Meeting of The Society of Thoracic
Surgeons, Fort Lauderdale, FL, Jan 28 –30, 2008.
Address correspondence to Dr Mavroudis, Division of CardiovascularThoracic Surgery-M/C #22, Children’s Memorial Hospital, 2300 Children’s
Plaza, Chicago, IL 60614; e-mail: [email protected].
© 2008 by The Society of Thoracic Surgeons
Published by Elsevier Inc
Material and Methods
Between 1987 and 2007, 211 patients had surgical intervention for arrhythmia. Of these, 111 had Fontan conversions
reported previously [11–13] and are not included in this
series. Of the remaining 100 patients, 89 underwent arrhythmia intervention in association with congenital heart
repairs and 11 (ⱕ 18 years of age) had intervention without
associated congenital heart repair. Mean age at operation
was 15.9 ⫾ 12.5 years (range, 7 days– 48 years); 7 were
infants (mean age, 23 ⫾ 16 days). Resternotomy was done in
65 of 100 patients (65%). Two functional ventricles were
present in 67. Arrhythmias included macro-reentrant atrial
tachycardia in 45, atrial fibrillation in 11, atrioventricular
nodal reentry tachycardia in 6, concealed and manifest
accessory connections in 19, focal (automatic) atrial tachycardia in 6, and ventricular tachycardia in 13. Some patients
0003-4975/08/$34.00
doi:10.1016/j.athoracsur.2008.04.087
PEDIATRIC CARDIAC
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PEDIATRIC CARDIAC
Single-ventricle variants
Heterotaxy/unbalanced
AVC
Pts,
No.
6
Single LV
7
Single RV
9
TGA–Prior atrial repair
1
Prior valved conduit repair
9
Initial valve or conduit
placement - Prior
repair
9
2
Initial repair
1
Left modified Blalock-Taussig shunt ⫹ pulmonary
artery arterioplasty
Initial Fontan–5 patients (⫹ PM [4] or PM lead [1])
TV plasty ⫹ 1½ repair ⫹ PM revision
Initial Fontan–6 patients (⫹ PM [5] or PM lead [1])
TVR post-Fontan ⫹ PM revision
TVR post-Fontan ⫹ PM revision ⫹ incomplete
right maze due to retained lateral tunnel; 6th
intracardiac procedure
Initial Fontan–7 patients (⫹ PM [5] or PM lead [1])
Arterial switch operation with Mustard takedown
⫹ PM revision
PA-VSD, conduit replacement ⫹ PM (4)
TGA, conduit replacement
CCTGA, conduit replacement
Perioperative Events
None
AT recurrence 1 month post-Fontan
¡ overdrive pacing, amiodarone
in patient with dextrocardia,
right-dominant unbalanced AVC
Fontan takedown 3 days post-op in
heterotaxy patient
None
None
None
Late Postoperative Events
BDCPA, pulmonary venous stenosis
repair in heterotaxy patient
AT recurrence with cardioversion 4.5
years post-op
None
Late death 11 months post-Fontan
Fontan (Uhl anomaly)
None
Late death from ventricular failure
AT recurrences 3.5 and 5 years
post-TVR
TVR 4.7 years post-Fontan–1 patient
VAD 1 day post-op ¡ death 2
weeks post-op
None
None
None
Aortic atresia/stenosis, conduit replacement (2)
Truncus arteriosus, conduit replacement ⫹ truncal
valve replacement
Tetralogy of Fallot, prior ventriculotomy; RV-PA
conduit placement (2) or PVR (2)
None
None
VT 9 months post-op ¡ AICD–1 patient
None
TVR 6 months post-op ¡ VAD ¡
transplant 7 months post-op
None
None
None
None
PA-IVS, prior valvotomy; RV-PA conduit
placement ⫹ TV annuloplasty
Complete AVC; TVR ⫹ mitral valvuloplasty
Tricuspid stenosis, post-valvuloplasty; TVR
Tricuspid regurgitation in CCTGA, post-AICD for
VT; TVR
Residual aortic stenosis/insufficiency, residual
VSD, prior ventriculotomy; TV plasty ⫹ VSD
patch ⫹ AV replacement
TV annuloplasty (Ebstein) ⫹ pulmonary valvotomy
Residual VSD (of multiple) ⫹ pulmonary artery
arterioplasty
Partial AVC
None
None
None
None
None
None
None
Stroke 2 months post-op
None
None
None
None
None
None
None
None
Ann Thorac Surg
2008;86:857– 68
VSD - Prior repair
Congenital Heart Disease Surgery
MAVROUDIS ET AL
ARRHYTHMIA SURGERY
Diagnosis
858
Table 1. Clinical Characteristics and Outcomes of Patients Undergoing Modified Right Atrial Maze Procedure for Macro-Reentrant Atrial Tachycardia
45
TOTAL
859
had more than one arrhythmia and were treated with
techniques appropriate for the particular substrates. Clinical features of all patients are noted in Tables 1 to 6.
All patients had symptoms that were mostly related to
recurrent arrhythmias and included congestive heart failure, syncope, palpitations, and patients in unstable hemodynamic compromise. Ten patients had prior transcatheter
ablation procedures that failed for a variety of reasons,
including lack of adequate venous access, hemodynamic
instability during arrhythmia, complexity of anatomy and
cyanotic heart disease, or emergence of new arrhythmias
after successful ablation of the initial arrhythmia. In 54
patients preoperative electrophysiology studies were performed to determine the tachycardia mechanism and anatomic foci. Excluded were neonates with focal atrial tachycardia or Ebstein anomaly and patients with hemodynamic
compromise or atrial fibrillation.
Infrequently, arrhythmia was not inducible in the catheterization laboratory, in which case intraoperative mapping
was attempted. Intraoperative epicardial mapping was performed in 51 patients; those with atrial fibrillation or hemodynamic instability during arrhythmia were excluded.
Mapping was performed early in the series with a handheld probe or a multiple-array epicardial sock; it is now
performed with 2 decapolar probes.
Standard surgical techniques for arrhythmia ablation
were used, which included resection, isolation, and cryoablation of affected atrial or ventricular tissue [1– 8]. Cryoablation in the early part of our experience was performed
using 3-, 5-, and 15-mm circular probes (Frigitronics, Cooper Surgical Inc, Shelton CT) at ⫺60°C for 90-second lesions. Since 2003, we have used malleable linear CryoCath
probes to place 60-second lesions at ⫺150°C (CryoCath
Technologies Inc, Montréal, Québec, Canada).
Macro-reentrant atrial tachycardia (Fig 1) was ablated by
either an isthmus ablation (early in the series) or a standard
or modified right atrial maze procedure that was specific for
the anatomic substrates: patients with 1 ventricle (primary
Fontan) [13] or patients with 2 ventricles [7]. Ablative
therapy principles for anatomically complex patients with
macro-reentrant atrial tachycardia are based on the normal
pattern of atrial electrical impulses and the paths that these
impulses take around natural or created obstacles to stimulate the atrioventricular node.
Macro-reentrant atrial tachycardia circuits require an
area of slow conduction together with an area of unidirectional block. Potential anatomic obstacles in the right
atrium include the orifices of the venae cavae, orifice of
the hepatic vein, the coronary sinus, anomalous pulmonary venous return, the atrial septal defect/patch or fossa
ovalis, juxtaposition of the atrial appendages, and the
tricuspid annulus. Correspondingly, there are anatomic
barriers (orifices) in the left atrium as well: the pulmonary veins, a left-sided superior vena cava, anomalous
systemic venous return, or the mitral annulus. In addition, scar from jet lesions or prior incisions, or electrically
inert tissue due to stretch or fibrosis, may act as areas of
slow conduction or unidirectional block. Areas between
anatomic obstacles create an isthmus of tissue that serves
PEDIATRIC CARDIAC
AICD ⫽ automatic implantable cardioverter defibrillator;
AT ⫽ macro-reentrant atrial tachycardia;
AV ⫽ aortic valve;
AVC ⫽ atrioventricular canal;
BDCPA ⫽ bidirectional cavopulmonary
artery anastomosis;
CCTGA ⫽ congenitally corrected transposition of the great arteries;
LV ⫽ left ventricle;
PA-IVS ⫽ pulmonary atresia-intact ventricular septum;
PA-VSD ⫽ pulmonary
atresia-ventricular septal defect;
PM ⫽ pacemaker;
PVR ⫽ pulmonary valve replacement;
RFA ⫽ radiofrequency ablation;
RV ⫽ right ventricle;
RV-PA ⫽ right ventricle-to-pulmonary
artery;
TGA ⫽ transposition of the great arteries;
TV ⫽ tricuspid valve;
TVR ⫽ tricuspid valve replacement;
VAD ⫽ ventricular assist device;
VSD ⫽ ventricular septal defect;
VT ⫽
ventricular tachycardia.
1 operative mortality
1
No structural heart disease
Diagnosis
Table 1. (Continued)
Pts,
No.
None
Congenital Heart Disease Surgery
None
Perioperative Events
PM 3 years post-op for bradycardia; AT
at 5 years ¡ transcatheter RFA
atrioventricular node
3 Recurrences; 1 new onset VT
2 Late deaths; 1 late transplant
MAVROUDIS ET AL
ARRHYTHMIA SURGERY
Late Postoperative Events
Ann Thorac Surg
2008;86:857– 68
860
MAVROUDIS ET AL
ARRHYTHMIA SURGERY
Ann Thorac Surg
2008;86:857– 68
Table 2. Clinical Characteristics and Outcomes of Patients Undergoing Cox-Maze IIIa Procedure for Atrial Fibrillation
Diagnosis
PEDIATRIC CARDIAC
Single ventricle variants
Heterotaxy
Single LV
Single RV
Prior repair/palliation
Initial repair
Totals
a
Patients,
No.
1
2
1
5
2
Congenital Heart Disease Surgery
Mitral valvuloplasty, 1½ ventricular
repair, ascending aorta aneurysm
repair (post-Konno) ⫹ PM
revision
Initial Fontan at 9 years ⫹ initial PM
PA-IVS post-RVOT patch; TVR, 1½
ventricular repair, RV-PA
conduit ⫹ PM lead only
a
Multisite AT PM (removal AICD)
Aortic stenosis post-AV/MV
replacement, AICD; Konno ⫹ AV/
MV replacement ⫹ LV aneurysm
repair
Complete AVC; mitral valvuloplasty
Partial AVC; mitral valvuloplasty ⫹
redo patch repair ⫹ initial PM
Mitral regurgitation
post-valvuloplasty; MV
replacement
PS-TS; takedown Glenn ⫹ PVR ⫹
RVOT patch ⫹ PM
Sinus venosus ASD ⫹ PAPVC repair
⫹ initial PM
Mitral valvuloplasty,
cardiomyopathy
11
Perioperative Events
Late Postoperative Events
None
None
None
None
None
None
Death 10 days post-op
None
ORT 10 months post-op
PM 10 days post-op
None
None
None
None
None
None
None
AT episodes 1, 2.5, and 2.8
years post-op
None
None
None
1 operative death
1 new-onset ORT; 1
new-onset AT
Pulmonary isolation by epicardial cryoablation without cardiopulmonary bypass because of hemodynamic instability.
AICD ⫽ automatic implantable cardioverter defibrillator;
ASD ⫽ atrial septal defect;
AT ⫽ macro-reentrant atrial tachycardia;
AV ⫽ aortic
valve;
AVC ⫽ atrioventricular canal;
LV ⫽ left ventricle;
MV ⫽ mitral valve;
ORT ⫽ orthodromic reciprocating tachycardia;
PA-IVS ⫽
pulmonary atresia-intact ventricular septum;
PAPVC ⫽ partial anomalous pulmonary venous connection;
PM ⫽ pacemaker;
PS-TS ⫽
pulmonary stenosis-tricuspid stenosis;
PVR ⫽ pulmonary valve replacement;
RV ⫽ right ventricle;
RV-PA ⫽ right ventricle-to-pulmonary
artery;
RVOT ⫽ right ventricular outflow tract;
TVR ⫽ tricuspid valve replacement.
as a natural target for the interruption of a macroreentrant circuit.
The goal of cryoablation therapy is to transform an
area of slow conduction to an area of no conduction by
interrupting the electrical corridor (isthmus) between
adjacent obstacles or scars, while preserving sinoatrial
and atrioventricular nodal function. A patient with a
separate hepatic vein entry into the right atrium, for
example, will require cryoablation lesions to connect the
inferior vena cava os to the coronary sinus os, the hepatic
vein os to the coronary sinus os, and the hepatic vein os
to the tricuspid annulus; remaining lesions are standard
for the right-sided maze procedure. These principles (Fig
1A) can be applied to all other natural and created
obstacles; it is important to recognize that these principles do not apply to focal atrial tachycardias, which arise
from discrete foci.
Atrial fibrillation was treated by left atrial Cox-maze III
procedure in addition to modified or standard right atrial
maze, depending on the anatomic substrate [7, 8], using a
combination of incisions and cryoablation lesions. Selective cryoablation modification of the atrioventricular
nodal slow pathway in the region of the coronary sinus
was used to treat atrioventricular nodal reentry tachycardia (Fig 2). Accessory connections (Fig 3A and B) were
divided by both epicardial and endocardial resection
techniques. Focal (automatic) atrial tachycardia (Fig 4)
was treated by isolation, resection, or cryoablation of the
affected atrial tissue [3]. Ventricular tachycardia was
ablated by a combination of endocardial resection and
cryoablation, or epicardial resection and cryoablation
based on the identified pathology [5].
Postoperative electrophysiology studies were performed in all surviving patients before hospital discharge
except those with atrial fibrillation or focal atrial tachycardia. Postoperative pacing protocols for atrial tachycardia included atrial incremental pacing, and single, double, and triple atrial extrastimulation in a minimum paced
cycle length of 200 milliseconds. Patients with ventricular
tachycardia underwent provocative stimulation consisting
of single, double, and triple extrastimulation at two paced
cycle lengths from both the right ventricular apex and
outflow tract. Postoperative studies were performed in
baseline state and during isoproterenol infusion.
Consistent with our previously reported protocols,
patients with atrial arrhythmias (other than atrial fibril-
Ann Thorac Surg
2008;86:857– 68
MAVROUDIS ET AL
ARRHYTHMIA SURGERY
861
Diagnosis
Single ventricle variants
Heterotaxy
Single LV
Ebstein
TGA – Prior arterial
switch
Double outlet right
ventricle – Prior
pulmonary artery
band
Initial repair
No structural heart
disease
Totals
# Pts
Congenital Heart Disease
Surgery
2
Initial Fontan ⫹ initial PM ⫹
maze for AT
Initial Fontan
3
TV plasty ⫹ 1½ ventricular repair
Ebstein repair (with PA-IVS)
1
Perioperative Events
None
Postoperative Arrhythmia
Occurrence
ORT ⱕ 1 year ¡ transplant 3
years post-op
WPW recurrence 3 years post-op
Ebstein repair ⫹ VSD repair
Repeat surgical ablation
4 days post-op
None
Intraoperative death in
11-day-old
None
1
ASD secundum repair
MV replacement ⫹ PM revision
None
None
AT 18 months post-op, successful
transcatheter RFA 5 years
post-op
None
None
1
Intraventricular tunnel repair
None
None
3
Partial AVC repair
ASD secundum patch repair
Scimitar syndrome repair
8
Repair catheter aortic perforation
⫹ limited epicardial mapping
and epicardial cryoablation
No associated surgery (7)
None
None
Repeat surgical ablation
8 days post-op
None
None
None
LV aneurysm repair 5 months
post-op
Recurrence 3 months post-op –
left accessory connection
Repeat surgical ablation
4 days post-op – 1
patient
None – 6 patients
None
19
1 operative death
AT 3 years post-op
Repeat surgical ablation 9
months post-op – 1 patient
PM 3.5 years post-op – 1 patient
4 recurrences; 2 new-onset AT
1 late transplant
ASD ⫽ atrial septal defect;
AT ⫽ macro-reentrant atrial tachycardia;
AVC ⫽ atrioventricular canal;
LV ⫽ left ventricle;
MV ⫽ mitral
valve;
ORT ⫽ orthodromic reciprocating tachycardia;
PM ⫽ pacemaker;
PA-IVS ⫽ pulmonary atresia-intact ventricular septum;
RFA ⫽
radiofrequency ablation;
TGA ⫽ transposition of the great arteries;
TV ⫽ tricuspid valve;
VSD ⫽ ventricular septal defect;
WPW ⫽
Wolff-Parkinson-White syndrome.
lation) received ␤-blockade for 3 months postoperatively;
patients with atrial fibrillation received amiodarone therapy for 3 months postoperatively. Patients with inducible
sustained ventricular tachycardia postoperatively received implantable defibrillators. Arrhythmia recurrence
was assessed at routine visits by review of symptoms,
comprehensive electrocardiographic monitoring, and interrogation of pacemakers or implanted defibrillators.
Consulting statistician constructed freedom from arrhythmia recurrence graphs using the life-test procedure
product-limit survival estimates. Institutional Review
Board approval for this retrospective study was obtained,
and the need for informed consent was waived.
Results
Surgical Outcome
Three patients died, for an operative mortality of 3%
(Tables 1, 2, and 3); two deaths have been previously
reported [10]. The third occurred in a 36-year-old man
with an unoperated on univentricular heart and incessant atrial fibrillation causing severe decompensation. He
underwent epicardial cryoablative pulmonary venous
isolation because of reticence to perform a Cox-maze
procedure, which would require cardiopulmonary bypass. He had rapid recurrence and died 10 days after the
operation.
Late deaths occurred in 4 patients (see Tables 1, 4); one
death that occurred after attempted takedown of a Mustard procedure was previously reported [10].
Operations were performed as emergencies in 2 surviving patients who had acute hemodynamic decompensation. One patient without congenital heart disease
presented with cardiogenic shock due to focal atrial
tachycardia and was brought to the operating for an
emergency ventricular assist device. He underwent electrophysiologic mapping of the right atrium and resection
of the arrhythmogenic focus in the right atrial appendage
PEDIATRIC CARDIAC
Table 3. Clinical Characteristics and Outcomes of Patients Undergoing Surgical Ablation for Accessory Connection-Mediated
Tachycardia
862
MAVROUDIS ET AL
ARRHYTHMIA SURGERY
Ann Thorac Surg
2008;86:857– 68
Table 4. Clinical Characteristics and Outcomes of Patients Undergoing Pathway Modification for Atrioventricular Nodal
Reentry Tachycardia
PEDIATRIC CARDIAC
Patients,
No
Diagnosis
Single-ventricle variants
Heterotaxy
3
TGA—prior atrial repair
2
PS-IVS—prior valvuloplasty
1
Totals
6
Congenital Heart Disease Surgery
Initial Fontan ⫹ PM lead only
Initial Fontan ⫹ initial PM
Pulmonary venous stenosis repair ⫹
mitral valvuloplasty ⫹ initial PM
(post-BDCPA, TAPVC repair)
Re-do atrial baffle ⫹ PM
Arterial switch operation with
Senning takedown ⫹ PM
RV-PA conduit placement ⫹ TV
ring annuloplasty
Perioperative
Events
Late Postoperative Events
None
None
None
None
None
Pulmonary venous stenosis ¡ death
2 months post-op
None
None
Arterial switch elsewhere 11 months
post-op ¡ death
None
None
None
2 late deaths
BDCPA ⫽ bidirectional cavopulmonary artery anastomosis;
PM ⫽ pacemaker;
PA-IVS ⫽ pulmonary atresia-intact ventricular
septum;
RV-PA ⫽ right ventricle-to-pulmonary artery;
TAPVC ⫽ total anomalous pulmonary venous connection;
TGA ⫽ transposition of the
great arteries;
TV ⫽ tricuspid valve.
curred in 17 of 100 (17%) patients. Three patients with
accessory connections who were operated on early in our
series (1989 to 1991), before transcatheter ablation procedures were standard therapy, underwent a second surgical ablation postoperatively at 4, 4, and 8 days, respectively, because of recurrent tachycardia; 1 patient had
late recurrence. A fourth patient, also early in the series,
underwent surgical ablation 9 months postoperatively
because of late recurrence of accessory connectionmediated tachycardia. Additional patients underwent
early reoperation for ventricular assist device placement,
Fontan takedown, control of bleeding, thoracic duct liga-
with conversion to normal sinus rhythm. No assist device
was implanted; gradual normalization of ventricular
function ensued without arrhythmia recurrence. Another patient with a left-sided accessory connection
and aortic perforation during a transseptal procedure
before catheter ablation had limited epicardial mapping with epicardial cryoablation. Accessory connection function later recurred and was treated with
␤-blocking medication.
The median postoperative hospital stay was 9 days
(range, 4 to 278 days). Early postoperative surgical complications requiring return to the operating room oc-
Table 5. Clinical Characteristics and Outcomes of Patients Undergoing Lesion Ablation/Resection for Focal Atrial Tachycardia
Diagnosis
Single ventricle variants
Single RV
Initial Repair
Patients,
No.
Congenital Heart Disease
Surgery
Perioperative Events
1
Norwood
None
4
Tetralogy of Fallot; repair
with subvalvar RVOT
patch ⫹ cryoablation of
focal atrial tachycardia
site ⫹ isthmus
cryoablation for AT
Multiple VSD
ASD secundum patch repair
None
No structural heart
disease
1
TOTALS
6
Patent foramen ovale
primary closure
None, in patient with
associated atrial
fibrillation, AT
ASD ⫽ atrial septal defect;
AT ⫽ macro-reentrant atrial tachycardia;
pacemaker;
RFA ⫽ radiofrequency ablation;
RV ⫽ right ventricle;
artery connection;
VSD ⫽ ventricular septal defect.
None
None
None
Focal atrial tachycardia
recurred immediate
post-op period ¡
transcatheter RFA
Late Postoperative Events
BDCPA; extracardiac TCPC ⫹
PM lead; bradycardia ¡ PM
7.3 years post-op
None
None
Recurrence at 5.75 years post-op
¡ metoprolol
None
Recurrence 10 months post-op ¡
dofetilide; transcatheter RFA
⫻2 at left pulmonary veins 2
years post-op
2 recurrences
BDCPA ⫽ bidirectional cavopulmonary artery anastomosis;
PM ⫽
RVOT ⫽ right ventricular outflow tract;
TCPC ⫽ total cavopulmonary
Ann Thorac Surg
2008;86:857– 68
MAVROUDIS ET AL
ARRHYTHMIA SURGERY
863
Diagnosis
Tetralogy of Fallot
Postrepair, w/ventriculotomy
Patients,
No.
2
ASD secundum - Postrepair, with severe RV
cardiomyopathy (Uhl
anomaly)
1
Initial repair
3
No structural heart disease
TOTALS
Perioperative Events
Late Postoperative Events
6
Postrepair, no
ventriculotomy
TGA, VSD-LVOTO
post-Rastelli
Congenital Heart
Disease Surgery
RV-PA conduit
replacement (2)
RV-PA conduit
replacement and
PM removal
PVR (initial) ⫹ PM
revision
PVR ⫹ RV aneurysm
repair ⫹ AICD
revision
RVOT obstruction
resection ⫹ patch
augmentation
RV-PA conduit
replacement ⫹
maze ⫹ PM
revision
RV-PA conduit
replacement ⫹
maze ⫹ PM
removal for
planned later
AICD
TV ring annuloplasty
⫹ RV aneurysm
repair ⫹ 1½
ventricular repair
⫹ right maze
procedure for AT
⫹ AICD
RV-PA conduit for
absent pulmonary
valve
VSD patch repair
VSD patch repair
1
13
None
None
Inducible VT ¡ AICD 7
days post-op
AICD 3 years post-op
None
New-onset AT 4 years post-op
None
New-onset AT 10 years post-op
None
None
None
None
Inducible VT¡AICD 8
days post-op
Recurrent VT; dilated
cardiomyopathy ¡ transplant
candidate
None
Recurrent VT 4 months post-op; VT
catheter ablation 1.8 years
post-op; subsequent recurrent VT
- Ligation thoracic duct
1 mo post-op
None
None
None
None
- New onset AT 1.8 years post-op
¡ successful transcatheter RFA
None
2 recurrences; 3 new-onset AT
None
AICD ⫽ automatic implantable cardioverter defibrillator;
ASD ⫽ atrial septal defect;
AT ⫽ macro-reentrant atrial tachycardia;
PM ⫽
pacemaker;
PVR ⫽ pulmonary valve replacement;
RFA ⫽ radiofrequency ablation;
RV ⫽ right ventricle;
RV-PA ⫽ right ventricle-topulmonary artery;
RVOT ⫽ right ventricular outflow tract;
TGA, VSD-LVOTO ⫽ transposition of the great arteries ⫹ ventricular septal defect ⫹
left ventricular outflow tract obstruction;
TV ⫽ tricuspid valve;
VSD ⫽ ventricular septal defect.
tion, sternal instability, delayed sternal closure, and device placement in 6 or revision in 2.
Two patients required cardiac transplantation late after
the operation (Tables 1, 3). A third patient is under
consideration for cardiac transplantation (Table 6).
Freedom from arrhythmia recurrence, as determined
by documented persistent clinical recurrence more than
3 months postoperatively [14], was 94% and 85% for atrial
arrhythmias at 1 and 10 years, respectively, representing
nine recurrences in 87 patients (10%; 3 macro-reentrant
atrial, 4 accessory connection-mediated, and 2 focal atrial
tachycardias), and 85% and 68% for ventricular arrhythmias at 1 and 10 years, respectively, representing two
recurrences in 13 patients (15%; Fig 5).
New-onset tachycardias were not included in recur-
rence calculations. They were present at follow-up in an
additional 8 patients (Tables 1 to 6).
Comment
In our previous report of 29 patients [10], we demonstrated that arrhythmia surgical interventions in association with initial and reoperative congenital heart repairs
are effective, efficacious, and in some cases, life saving.
The surgical arrhythmia techniques for accessory connections, focal atrial tachycardia, and atrioventricular
nodal reentry tachycardia have been well described in
patients with structurally normal hearts [1–3] and in
patients with 2 ventricles and simple associated heart
defects such as atrial septal defect [4 – 8]. This series
PEDIATRIC CARDIAC
Table 6. Clinical Characteristics and Outcomes of Patients Undergoing Endocardial Resection/Cryoablation for Ventricular
Tachycardia
864
MAVROUDIS ET AL
ARRHYTHMIA SURGERY
Ann Thorac Surg
2008;86:857– 68
PEDIATRIC CARDIAC
Fig 1. (A) Cavotricuspid-isthmus dependent macro-reentrant atrial tachycardia. As depicted, the “playing field” is the right atrium, where a premature atrial contraction might encounter block in the atrial septum (broken line) and proceed in an alternate route down the right atrial free wall.
The wave front may encounter an area of slow conduction (squiggly arrow), in this case between the inferior vena cava, tricuspid valve, and the coronary sinus (CS). The delay encountered as the wave front traverses the area of slow conduction allows the atrial septum to recover conduction. The
wave front exits the isthmus and proceeds up the atrial septum. Interruption of this circuit is targeted at the inferior isthmus due to the clearly identified landmarks in proximity. (AV ⫽ atrioventricular; SA ⫽ sinoatrial.) (B) Schematic representation of the possible lines of ablation to treat macro-reentrant atrial tachycardia in the presence of various atrial anomalies associated with complex congenital heart disease. These atrial anomalies do not generally occur together, and the demonstrated lines of block are not meant to be incorporated into every operation. They are depicted only as guidelines on which to base an ablative operation when unusual anatomic obstacles are encountered in the performance of the
maze procedure. (avn ⫽ atrioventricular node; CS ⫽ coronary sinus; FO ⫽ foramen ovale; HV ⫽ hepatic vein; IVC ⫽ inferior vena cava; LAA
⫽ left atrial appendage; LSVC ⫽ left superior vena cava; MV ⫽ mitral valve; PV ⫽ pulmonary veins; RAA ⫽ right atrial appendage; RSVC
⫽ right superior vena cava; TAPVR ⫽ total anomalous pulmonary venous return; TV ⫽ tricuspid valve.)
describes our attempt to apply ablative principles developed in structurally normal hearts to complex forms of
congenital heart disease and critically ill patients.
Our arrhythmia recurrence rate for atrial tachycardia
in congenital heart patients (Fig 5) compares favorably
with other reports [15–17]. The recurrences can be explained by anatomic, electrophysiologic, and hemodynamic variability that present significant challenges to
the principles of arrhythmia ablation. Important anatomic variability that impacted arrhythmia ablative techniques included bilateral venae cavae, separate atrial
entry of the hepatic veins, anomalous pulmonary venous
return, absence of the coronary sinus, common atrioventricular valve, juxtaposed atrial appendages, and dilated
coronary sinuses. These variations tended to occur in
diagnoses known to have anomalous conduction systems
and poorly defined accessory connections such as crisscross heart with single ventricle and straddling atrioventricular valve, single ventricle with heterotaxy, and single
ventricle with l-transposition.
Most of our recurrences tended to be in patients with
residual accessory connections and macro-reentrant
atrial tachycardias in whom preoperative and improvised
intraoperative electrophysiologic studies presented various challenges. It was not uncommon to treat a patient
for one arrhythmia only for another and unrelated ar-
rhythmia to occur using a different pathway. Hemodynamic variability, preoperative ventricular dysfunction,
and hesitation to prolong the cross-clamp time for complex intracardiac procedures led us to perform an abbreviated arrhythmia operation in 3 patients whose arrhythmias recurred. Whether more aggressive operative
solutions would have resulted in better outcomes or
given rise to adverse events must be left to speculation.
The outcomes do underline the necessity of performing
established arrhythmia operations; abbreviated procedures are likely to result in recurrence.
The characteristics of our patients with macroreentrant atrial tachycardia include those with prior
operations and atrial enlargement due to hemodynamic
aberrations (Table 1). The largest category in this group is
patients with a univentricular heart who underwent
first-time Fontan operations. Other categories include
patients who had reoperation for tetralogy of Fallot/
double-outlet right ventricle or conduit replacement for
right ventricular-to-pulmonary artery continuity, which a
large multicenter study showed was related to late arrhythmia development and late sudden death [18]. Risk
factors associated with these conditions establish the
substrate for macro-reentrant atrial tachycardia propagated by an area of slow conduction, which could be the
coronary sinus-inferior vena cava isthmus or around a