coração univentricular

ISSN: 1524-4539 Copyright © 2007 American Heart Association. All rights reserved. Print ISSN: 0009-7322. Online

72514Circulation is published by the American Heart Association. 7272 Greenville Avenue, Dallas, TX

DOI: 10.1161/CIRCULATIONAHA.105.592378 2007;115;800-812 Circulation

Paul Khairy, Nancy Poirier and Lise-Andrée Mercier Univentricular Heart

http://circ.ahajournals.org/cgi/content/full/115/6/800located on the World Wide Web at:

The online version of this article, along with updated information and services, is

http://www.lww.com/reprintsReprints: Information about reprints can be found online at

[email protected]. E-mail:

Fax:Kluwer Health, 351 West Camden Street, Baltimore, MD 21202-2436. Phone: 410-528-4050. Permissions: Permissions & Rights Desk, Lippincott Williams & Wilkins, a division of Wolters

http://circ.ahajournals.org/subscriptions/Subscriptions: Information about subscribing to Circulation is online at

by on June 3, 2008 circ.ahajournals.orgDownloaded from

http://circ.ahajournals.org/cgi/content/full/115/6/800

http://circ.ahajournals.org/subscriptions/

mailto:[email protected]

http://www.lww.com/reprints

http://circ.ahajournals.org

Univentricular HeartPaul Khairy, MD, PhD; Nancy Poirier, MD; Lise-Andrée Mercier, MD

Abstract—As early as 1699, Chemineau described a heart composed of 2 auricles but only 1 ventricle.1 The univentricularheart has since fascinated the medical community. Unique in its complexity and scope, the univentricular heart hassparked intense debates about embryology and nomenclature, challenged our understanding of cardiovascularphysiology and hemodynamics, and inspired some of the most creative surgical and interventional approaches in humanhistory. The present report provides an overview of the nomenclature and classification of the univentricular heart,epidemiology and pathological subtypes, genetic factors, physiology, clinical features, diagnostic assessment, therapy,and postoperative sequelae. Although the present report touches on issues applicable to neonates and children withuniventricular hearts, the focus is on information of interest and relevance to the adult cardiologist. (Circulation. 2007;115:800-812.)

Key Words: heart diseases � ventricles � cyanosis � Fontan operation

Nomenclature and Classification

Nomenclature and classification of the univentricularheart remains a subject of heated debate. Additional

proposed terminology has included “single ventricle,” “cortriloculare biatrium (well-formed atrial septum),” “cor bilocu-lare (rudimentary or absent atrial septum),” “common ventri-cle,” and “functionally single ventricle.”2–4 The controversystems, in part, from the morphological heterogeneity encoun-tered and the recognition that truly solitary ventricles areexceedingly rare. More commonly, a second rudimentary orhypoplastic accessory ventricle is present, which justifies theterm “functional” single ventricle. It is generally agreed thatthe atrioventricular (AV) connection is central in defining theuniventricular heart. Van Praagh used the terms “single,”“common,” and “univentricular” interchangeably to describehearts with 1 ventricular chamber that receives both AVvalves or a common AV valve, excluding mitral and tricuspidatresia.2 Anderson’s unifying criterion is that the entire AVjunction be connected to 1 ventricular chamber, whichincludes hearts with 1 absent AV connection.3

Despite unresolved nomenclature issues, a classificationscheme relevant to surgery was proposed.5 A “single ventri-cle” was characterized as lacking 2 well-developed ventricles,which thereby excluded hearts with nonseptable but well-formed ventricles. Hypoplastic left heart syndrome wasrecognized as a common form of univentricular heart but wasclassified independently.6 The proposed definition of univen-tricular heart encompassed double inlet AV connections[double inlet left (DILV) or right ventricle], absence of 1 AVconnection (mitral or tricuspid atresia), common AV valveand only 1 well-developed ventricle (unbalanced commonAV canal defect), and only 1 well-developed ventricle and

heterotaxy syndrome (single ventricle heterotaxy syndrome).Heterotaxy syndromes refer to disorders of lateralizationwhereby the arrangement of abdominal and thoracic visceradiffer from normal and mirror-image of normal. By thesecriteria, the univentricular heart includes a broad category ofcongenital cardiac malformations characterized by both atriarelated entirely or almost entirely to 1 functionally singleventricular chamber.

A comprehensive nomenclature system should consideratriovisceral situs, relationship between systemic and pulmo-nary veins, AV valves, great arteries, and ventricular mor-phology. More specifically, the well-developed ventricle maybe designated left, right, or indeterminate. Left ventricleshave relatively smooth walls, fine trabeculations, and lackseptal chordal attachments of the AV valve. In contrast, rightventricles are more coarsely trabeculated and commonly havechordal attachments of the AV valve to the septal surface.With regard to the AV connection, a single, double, orcommon inlet may exist.7 Convention dictates that if �75%of a common AV valve annulus empties into 1 ventricularchamber, a common inlet connection is present. Single inletconnections may be characterized as mitral or tricuspidvalves. With double inlet connections, morphological AVvalve features may not be sufficiently distinct to distinguishmitral from tricuspid configurations. Such valves may best bedescribed as right- or left-sided.

Epidemiology and Pathological SubtypesNotwithstanding the lack of a uniformly applied nomencla-ture and classification system and inaccuracies from method-ological limitations inherent to population estimates of con-genital heart disease, a New England registry reported theincidence of univentricular heart to be 54 cases per million

From the Adult Congenital Heart Center, Montreal Heart Institute, Montreal, Canada.Correspondence to Dr Paul Khairy, Canada Research Chair, Electrophysiology and Adult Congenital Heart Disease, Adult Congenital Heart Center,

Montreal Heart Institute, 5000 Bélanger St, Montreal, Quebec, H1T 1C8, Canada. E-mail [email protected]© 2007 American Heart Association, Inc.

Circulation is available at http://www.circulationaha.org DOI: 10.1161/CIRCULATIONAHA.105.592378

800

Congenital Heart Disease for the Adult Cardiologist



live births.8 More recent estimates are substantially higher. Inhypoplastic left heart syndrome alone, the most commonform of univentricular heart, a crude median incidence of 2.3cases per 10 000 live births was derived when data waspooled from 36 studies that included a wide spectrum ofdisease severity, which ranged from mild left ventricularhypoplasia (amenable to biventricular repair) to aortic andmitral valve atresia with an absent left ventricle.9 Tricuspidatresia, the second most common subtype of univentricularheart, is thought to occur less than once for every 10 000 livebirths10 and was present in 2.9% and 1.4% of congenital heartdisease autopsy and clinical series, respectively.10

DILV comprises 1% of all congenital heart malforma-tions.11 In an autopsy series of 60 univentricular hearts thatexcluded mitral and tricuspid atresia, DILV was present in78%, double inlet right ventricle in 5%, and single ventricleheterotaxy syndrome in 13%.2,12 Unbalanced common AVcanal defects, which coexist with other malformations, wereidentified in 12%. Typically, a DILV contains a rudimentaryright ventricular chamber at its base. Great arteries may benormally related (type I or “Holmes heart”13), the aorta maybe anterior and rightward (type II) or leftward (type III), or“inverted” in a posterior and leftward orientation (type IV).2

Most commonly, the hypoplastic right ventricle is anteriorand to the left of the left ventricle, with L-transposition of thegreat arteries. In univentricular hearts of right ventricularmorphology, both great arteries usually arise from the rightventricle. The aorta is characteristically “malposed,” as it isanterior to or side-by-side with the pulmonary artery.14

Genetic FactorsCardiovascular malformations have been observed in 19% to33% of siblings with hypoplastic left heart syndrome.15,16

Although genetic determinants of other forms of univentric-ular heart have not been extensively elaborated, severalsubtypes that include DILV, single inlet, common inlet, andcomplex single ventricle heterotaxy syndromes are thought tobe polygenic in nature, with recurrence and transmission risksfar below that expected from Mendelian inheritance.17 In thepolygenic model, the phenotype is presumed to result fromadditive effects of multiple genes, interactions with othergenes and environmental factors, and stochastic effects.18 Therisk to siblings and offspring of affected individuals is similarand generally in the order of 2% to 5%.16,17,19 Concordancerates may be higher in specific subtypes.20

PhysiologyPhysiology of the univentricular heart depends on such keydeterminants as obstruction to outflow, inflow, and/or flowacross the atrial septum; systemic and pulmonary venousreturn; pulmonary vascular resistance; and AV valve regur-gitation. With severe systemic outflow obstruction, the neo-nate is dependent on right-to-left shunting through a patentductus arteriosus to maintain systemic output. Blood mixeswithin atrial and ventricular chambers and is predominantlyejected through the pulmonary valve to pulmonary andsystemic vascular beds via the pulmonary artery and patentductus arteriosus, in a ratio dependent on vascular resistanc-es.21 In contrast, with critical pulmonary outflow obstruction,

pulmonary blood flow is dependent on left-to-right shuntingacross a patent ductus arteriosus. Once again, systemic andpulmonary blood flows are interdependent and determined byresistances of the 2 circulations.

With obstruction to pulmonary venous return, severe pul-monary hypertension may ensue. In the presence of an atreticor critically stenotic AV valve, unobstructed communicationbetween both venous inflows and the single ventricle requiresan unrestrictive atrial septal defect (ASD). With an atreticmitral valve, a restrictive ASD is physiologically similar topulmonary venous obstruction. In tricuspid atresia, the phys-iological effect of a restrictive ASD is akin to systemicvenous obstruction. In short, optimal physiology of theuniventricular heart requires good ventricular function with-out AV valve regurgitation, an unrestrictive ASD, and well-balanced systemic and pulmonary blood flow.

Clinical FeaturesClinical manifestations hinge on the presence or absence ofpulmonary outflow obstruction. Without pulmonary stenosis,infants with low pulmonary resistance present with signs andsymptoms typical of large left-to-right shunting, ie, conges-tive heart failure and failure-to-thrive.4,14 Because of in-creased pulmonary blood flow, cyanosis may not be apparent.Aortic outflow obstruction may compound already excessivepulmonary blood flow and worsen congestive heart failure.Some patients (eg, type IV DILV) may have a preferentialfavorable stream of systemic venous return to the pulmonaryartery and pulmonary venous return to the aorta.22 In contrast,an unfavorable stream with a transposition-like blood flowpattern may occur in patients with a right-sided subaorticright ventricle and straddling right AV valve. Cyanosis andsystemic hypoxemia may result.23

In the setting of a univentricular heart, a certain degree ofpulmonary stenosis is physiologically desirable to preventpulmonary overcirculation. Severe pulmonary stenosis oratresia may result in profound hypoxemia and cyanosis,however.

Diagnostic EvaluationElectrocardiogramsGiven the heterogeneity of the univentricular heart, the ECGappearance is highly variable. Patients with right atrialisomerism often have 2 separate sinus nodes, with a P-waveaxis that fluctuates with the prevailing pacemaker.24 Incontrast, most hearts with left atrial isomerism do not have ahistologically recognizable sinus node, with consonant slowatrial or junctional escape rates.25 The AV conduction systemmay be displaced, particularly in hearts with AV discordanceand AV canal defects. In L-looped single ventricles, theelongated course of the common bundle renders it susceptibleto complete AV block.26 With a ventricular D-loop and awell-formed right ventricle, the AV node is normallypositioned.27

In patients with tricuspid atresia, the PR interval is usuallynormal with tall and broad P-waves. Left axis deviation ischaracteristic.28 In the absence of a functional right ventricle, left

Khairy et al Univentricular Heart 801



ventricular forces are unopposed, as manifested by small r wavesand deep S waves over right precordial leads and tall r wavesover left precordial leads. In the most common subtype of DILV,AV conduction is often abnormal, with PR prolongation or ahigher degree AV block.29 Q-waves are absent over left prec-ordial leads and may be present over right precordial leads.Q-waves may also be seen in leads II, III, and aVF.30 In a seriesof 18 patients with univentricular hearts of right ventricularmorphology, the ECG revealed right ventricular hypertrophy inall and 11 had a superior frontal QRS axis.14

Radiological FeaturesThe chest x-ray is particularly helpful in assessment of pulmo-nary arterial vascularization and configuration of the greatarteries.31 Because pulmonary stenosis is less common in single

left ventricles, increased pulmonary arterial vascularizationevokes this diagnosis.4 An increased cardiac silhouette reflectsvolume overload. Dilation of the main and right pulmonaryartery may produce a prominent right upper heart border,described as a “waterfall” appearance.32 In DILV, the ascendingaorta silhouette is altered by the position of the rudimentary rightventricular chamber. When located anterior and leftward, aprominent left heart border is seen.31 In contrast, when therudimentary right ventricle is right-sided, the aortic silhouette isgenerally convex to the right.31 In patients with moderate tosevere pulmonary stenosis, common in univentricular hearts ofright ventricular morphology, pulmonary arterial vascularizationmay be normal or oligemic.14 The cardiac silhouette may bemildly enlarged if at all. With pulmonary atresia, systemic-to-pulmonary shunting may result in asymmetric pulmonary vas-cularization patterns.14,31

Figure 1. Aortopulmonary shunts. A, The classic Blalock-Taussig shunt consists of an end-to-side anastomosis of the subclavian andpulmonary artery. B, The modified Blalock-Taussig shunt consists of an interposition tube graft that connects the subclavian artery tothe ipsilateral pulmonary artery. C, A Waterston shunt consists of a connection between the ascending aorta and pulmonary artery. D,A Potts shunt involves a small communication between the descending aorta and ipsilateral pulmonary artery.

802 Circulation February 13, 2007



Noninvasive ImagingThe diagnosis and morphological subtype may be fullycharacterized by a systematic and thorough echocardiograph-ic appraisal, with particular attention to apical position, atrialsitus, AV relationship, and ventricular-arterial alignment. InDILV, there are usually 2 separate patent AV valves, buteither may be imperforate, stenotic, or regurgitant.7,33 Eithervalve may straddle the bulboventricular foramen.34 A com-mon AV valve with a 5-leaflet configuration is commonlyfound in univentricular hearts with atrial isomerism and isbest viewed from parasternal short axis and apical 4-chamberviews.2,7,33 In DILV, the rudimentary right ventricular cham-ber may be readily identified and localized, often in theparasternal short-axis view. In the most common subtype(type III), the rudimentary right ventricle gives rise to theaorta and well-formed left ventricle to the pulmonary artery.Left ventricular morphology may be inferred when the aortaemanates from an anterosuperior rudimentary chamber.7,33 Auniventricular heart with a well-formed right ventricle canoften be surmised to exist on the basis of typical rightventricular morphological characteristics.

Comprehensive hemodynamic assessment should includecolor-flow imaging and Doppler interrogation. An estimate ofAV valve stenosis or regurgitation severity should supple-ment status of the AV connection (single, double, or com-mon) and appraisal of straddling and overriding features.Restriction of the bulboventricular foramen may likewise beassessed by continuous wave Doppler imaging.

Of note, cardiac magnetic resonance imaging overcomesmany of the limitations of echocardiography and is of greatvalue in the demonstration of systemic and pulmonary venousanomalies, aortic arch malformations, and proximal pulmo-nary artery lesions.35 It may provide important insights in thepre- and postoperative assessment of patients with univen-tricular hearts.

Cardiac CatheterizationCardiac catheterization may provide a detailed assessment ofanatomic and functional features.36,37 Objectives includeassessment of hemodynamics, systemic and pulmonary ve-nous anatomy, AV and ventricular-arterial connections, ven-tricular morphology and function, pulmonary vascular resis-tance, aortic arch integrity, and systemic-pulmonarycollaterals. Patients with univentricular hearts characteristi-cally have a complete mix of systemic and pulmonary venouscirculations at the ventricular level. If one assumes a pulmo-nary venous oxygen saturation of 96% and normal systemicblood flow, the arterial oxygen saturation reflects totalpulmonary blood flow. As a rule of thumb, values �85% and�75% signify increased and decreased pulmonary bloodflow, respectively.36

The presence or absence of hemodynamic and anatomicabnormalities such as poor ventricular function, aortic coarc-tation, pulmonary artery distortion, increased pulmonaryvascular resistance, and abnormal collateral vessels are rele-vant to therapeutic management plans.37 Proponents of rou-tine preoperative cardiac catheterization assert that noninva-sive imaging may fail to visualize pulmonary arterydistortion, that cardiac catheterization is the only valid

method to measure pulmonary vascular resistance, and thatabnormal aortopulmonary collateral vessels may be identifiedand coil embolization performed if necessary.37 After initialpalliation, patients not suited for Fontan completion maybenefit from repeated catheterizations to reassess pulmonarypressures and magnitude of created shunts, and addresscomplications such as shunt stenosis, pulmonary artery ste-nosis, and pulmonary arteriovenous fistulae.

Surgical ManagementGeneral objectives of initial surgical palliation are to provideunobstructed systemic outflow, unobstructed systemic andpulmonary venous return, and controlled pulmonary bloodflow. In patients with severe pulmonary obstruction oratresia, this is currently accomplished by an aortopulmonaryshunt, such as a modified Blalock-Taussig shunt (Figure 1),or bidirectional cavopulmonary anastomosis (Glenn shunt). Itis worthwhile to note that adult patients today benefit fromsurgical techniques performed decades ago, which includeend-to-side anastomosis of the subclavian artery to pulmo-nary artery (Figure 1A) and termino-terminal cavopulmonaryanastomoses. Pulmonary circulations solely dependent onaortopulmonary collaterals pose particular challenges andmay require unifocalization of collaterals as a component ofa staged surgical approach.38 Initial palliation in patients withunrestrictive pulmonary blood flow may consist of pulmo-nary artery banding or division with creation of an aortopul-monary shunt to limit pulmonary blood flow.39 Pulmonarybanding has been associated with adverse outcomes after theFontan procedure, however, and may result in subaorticobstruction.40

A bidirectional Glenn shunt or superior cavopulmonaryshunt is now performed at about 6 months of age (Figure 2).Obstructions or distortions to the pulmonary arterial tree arecorrected during this intervention. A Fontan procedure iscompleted sometime between 18 months and 4 years of age,which thereby separates pulmonary from systemic circula-

Figure 2. The bidirectional Glenn shunt consists of an end-to-side anastomosis of the divided superior vena cava to the undi-vided pulmonary artery. The modified Blalock-Taussig shunt,shown in white, was taken down and oversewn.




tions (Figure 3). Table 1 lists the initial proposed criteria forFontan completion.41 Although criteria such as normal sinusrhythm have been discounted,42 and others that include agelimits have been modified,43 several have withstood thescrutiny of large retrospective analyses.44

Developed in 1971 for tricuspid atresia,45 the Fontan proce-dure has undergone multiple modifications to encompass severalforms of palliative surgery that divert systemic venous return tothe pulmonary artery, usually without interposition of a subpul-monary ventricle. The classic Fontan involved a valved conduitbetween the right atrium and pulmonary artery.45 Currently,most adults will have had a modified Fontan, which consists ofdirect anastomosis of the right atrium to pulmonary artery

(Figure 3A). In 1987, de Leval et al proposed a major variationthat consisted of an end-to-side anastomosis of the superior venacava to the undivided right pulmonary artery, a compositeintraatrial tunnel with the right atrial posterior wall, and aprosthetic patch to channel the inferior vena cava to thetransected superior vena cava (Figure 3B).46 Total cavopulmo-nary connections may also be performed as extracardiac tunnels,with inferior vena caval flow directed to the pulmonary arteryvia an external conduit (Figure 3C). As in the intracardiac lateraltunnel, the superior vena cava is anastomosed to the pulmonaryartery.47 In addition, Fontan pathways may be “fenestrated” bycreation of an ASD in the baffle or patch to provide an escapevalve that allows right-to-left shunting, which may be beneficial

Figure 3. Variations of Fontan surgery. A, The modified classic Fontan; B, the intracardiac lateral tunnel Fontan; C, the extracardiacFontan. In (A), the modified Blalock-Taussig shunt, shown in white, was taken down and oversewn. In (C), permanent atrial epicardialpacemaker leads are illustrated in gray.




early after the surgical procedure.48 If hemodynamics are favor-able, these fenestrations can later be closed by a transcatheterapproach.49

In patients with univentricular hearts and systemic outflowobstruction, the most severe form of which is hypoplastic leftheart syndrome, a variation of Norwood stages that culminatein a Fontan-type circulation is often indicated.50 Less than 3decades ago, patients with hypoplastic left heart syndromehad no viable surgical options and died as neonates. Objec-tives of the Norwood stage 1 procedure, performed within thefirst 2 weeks of life, are to provide unobstructed pulmonaryvenous return, permanent systemic outflow from the rightventricle, and temporary pulmonary blood supply to allow thepulmonary vasculature to develop and mature. The mainpulmonary artery is divided, the proximal portion is anasto-mosed to the ascending aorta, the aortic arch is repaired andaugmented, and pulmonary blood flow is maintained via amodified Blalock-Taussig shunt50,51 (Figure 4A) or Gore-Texshunt from the right ventricle (Figure 4B).52 “Hybrid” vari-ants have been described.53 The Norwood stage II procedure,performed before 6 months of age, consists of a bidirectionalGlenn shunt or hemi-Fontan and closure of the Blalock-Taussig shunt.50,54 Between 18 months and 3 years of age, thestage III procedure completes the total cavopulmonary Fon-tan by connection of the inferior vena cava to the pulmonaryartery. Overall mortality was recently reported to be 39%after stage I, 9.5% after stage II, and 10% after stage III.55 Alower-risk subgroup with an 86% hospital survival rate aftera Norwood stage I procedure was retrospectively identified.56

When this staged approach cannot be performed, cardiactransplantation is considered.

Natural HistoryAs a group, patients with unrepaired univentricular heartshave a poor prognosis. In the largest series of unoperatedpatients (n�83), Moodie et al reported that 70% with well-formed single left ventricles died before age 16, with anannual attrition rate of 4.8%.57 The natural history is evenbleaker for patients with univentricular hearts of right ven-tricular morphology, with 50% survival 4 years after diagno-sis.57 The most common causes of mortality were arrhyth-mias, congestive heart failure, and sudden unexplained death.

Ammash and Warnes reviewed their experience with 13unoperated adults with univentricular hearts to determinewhich characteristics permitted long-term survival and to

assess associated complications.58 Eleven patients had DILVwith transposed great arteries, 1 patient had DILV withnormally related great arteries, and 1 patient had tricuspidatresia. The oldest patient was 66 years old. All had eithermoderate-to-severe pulmonary stenosis or pulmonary hyper-tension. The left ventricular ejection fraction was normal(n�11) or mildly depressed (n�2), and no patient had morethan mild AV valve regurgitation. Twelve patients reportedgood functional capacity and worked full- or part-time. Thus,despite the overall grim prognosis in unoperated patients,some adults with DILV, transposition of the great arteries,and well-balanced circulations may survive into their seventhdecade with acceptable functional capacity and preservedventricular function.58

As exemplified in Figure 5, it is worthwhile to note that asubgroup of adults with univentricular hearts who wereconsidered high-risk Fontan candidates have had cavopulmo-nary or aortopulmonary shunts for sustained palliation. The

Figure 4. A, Norwood stage I procedure; B, Sano modification.

Original Criteria Proposed for Fontan Completion

Age �4 years to �15 years

Normal sinus rhythm

Normal systemic venous return

Normal right atrial volume

Mean pulmonary artery pressure �15 mm Hg

Pulmonary arteriolar resistance �4 Wood units/m2 body surface area

Pulmonary artery to aortic diameter ratio �0.75

Left ventricular ejection fraction �0.60

Competent mitral valve

Absence of pulmonary artery distortion




clinical course of this “intermediate” group of patients is lesswell characterized. Arrhythmias are a major cause of latemorbidity and are associated with ventricular dysfunction anddeath.59,60 Long-term ventricular function appears better pre-served with cavopulmonary shunts that unload the singleventricle when compared with aortopulmonary shunts.60

Management of Cyanotic Patients WithUniventricular HeartBecause unoperated and partially palliated patients sufferfrom chronic cyanosis, early detection and treatment ofmultisystemic repercussions is essential. Hematologic de-rangements include erythrocytosis, iron deficiency, thrombo-emboli, and bleeding diathesis.61 Hyperviscosity symptomsconsist of fatigue, headache, dizziness, visual disturbances,paresthesias, myalgias, and altered mentation. Although iso-volumic phlebotomy is no longer routinely performed, it maybe indicated in iron-replete patients with moderate to severesymptoms or prophylactically in the preoperative settingwhen hematocrit levels exceed 65%. In the presence ofiron-deficiency anemia, cautious iron repletion is recom-mended.62 Bleeding diatheses range from mild to life-threatening and are associated with altered coagulation fac-tors, thrombocytopenia, and platelet dysfunction.61 Whenindicated, antiplatelet and anticoagulant therapy should bejudiciously monitored. Citrate should be adjusted for plasmavolume when prothrombin and partial thromboplastin timesare measured, especially if hematocrit levels exceed 55%.61

Neurological complications include cerebral hemorrhage,thromboemboli from right-to-left shunting, and cerebral abscess-es.63,64 Air filters are recommended for central and peripheralintravenous lines to prevent paradoxical air embolization. Renalcomplications include progressive glomerulosclerosis from rel-ative hypoperfusion, which justifies hydration prior to proce-dures that involve contrast agents. Hyperuricemia is attributed todecreased resorption of uric acid.65 Consequently, nephrolithia-sis, urate nephropathy, and gout may ensue. Additional rheuma-tological complications include hypertrophic osteoarthropathy in30% of patients.66 Symptomatic hyperuricemia and gout shouldbe treated as per usual, although nonsteroidal antiinflammatoryagents are best avoided. Cholelithiasis is also common inpatients with cyanotic heart disease; acute cholecystitis mayrequire surgery.

In general, noncardiac surgery should be undertaken only ifessential, particularly in the presence of Eisenmenger physi-ology.67 Given the susceptibility of such patients to minorvariations in systemic or pulmonary vascular resistance,caregivers experienced in cardiac anesthesia and postopera-tive intensive care management are central to multidisci-plinary management. In the absence of Eisenmenger physi-ology, pregnancy in the context of cyanotic heart disease hasbeen associated with �30% incidence of maternal cardiovas-cular complications and prematurity.68 An oxygen saturation�85% was predictive of increased risk.

In general, follow-up should include a thorough historywith particular attention to hyperviscosity symptoms, bleed-ing diatheses, gallstones, and neurological, rheumatological,and renal complications. In addition to comprehensive car-diac work-up with ascertainment of functional capacity and

oxygen saturation levels at rest and during exercise, standardblood tests should encompass complete blood count, ferritin,clotting profile, renal function, and uric acid.69

History and Long-Term Sequelae inOperated Patients

Benefits of Fontan palliation are well defined, with anactuarial survival of 91% at 10 years with lateral tunnels70

and 78% at 12 years in patients with DILV, 83% of whom

Figure 5. Cardiac magnetic resonance angiography in a patientwith situs inversus, congenitally corrected transposition of thegreat arteries, mitral and pulmonary atresia, and left-sided Glennshunt (GS). The arrow indicates 50% narrowing of the Glennshunt at the site of anastomosis with the left pulmonary artery(LPA). Note the multiple left lower lobe pulmonary arteriovenousmalformations.

Figure 6. Subcostal echocardiographic view of the right atrium(RA) in a patient with a modified classic Fontan forD-transposition of the great arteries, multiple muscular ventricu-lar septal defects, a functional single ventricle, and atrialtachyarrhythmias. The arrow indicates a well-delineated throm-bus in the dilated right atrium.




had atriopulmonary connections.71 Nevertheless, the Fontancirculation constitutes a hemodynamic compromise. Withbiventricular optimal fluid dynamics, caval pressures aretypically �10 mm Hg and mean pulmonary pressures exceed15 mm Hg. Fontan physiology is paradoxical in that itimposes systemic venous hypertension with concomitantpulmonary arterial hypotension.72 Consequently, potentialcomplications are numerous and include arrhythmias, throm-boemboli (Figure 6), hepatic dysfunction, protein-losing en-teropathy, and worsening cyanosis from pulmonary venouscompression, systemic venous collateralization, or pulmonaryarteriovenous malformations.

All patients with Fontan physiology should be followed upby specialized teams with regular and comprehensive surveil-lance to prevent, detect, and manage complications.69,73 Inaddition to a thorough clinical history and physical examina-tion, minimum tests includes resting oximetry, 12-lead ECG,chest x-ray, echocardiography with Doppler interrogation,complete blood count, biochemical analyses for liver functiontests, serum protein, albumin levels, and occasional Holtermonitoring.69 Additional work-up may require transesopha-geal echocardiography, exercise spiroergometry, cardiacmagnetic resonance imaging, isotopic ventriculography, com-plete heart catheterization, and electrophysiological study.

ArrhythmiasAt mid-term follow-up, sinus node dysfunction occurs in 13%to 16% of patients with modified classic Fontans and contin-ues to increase with time.74 Atrial tachyarrhythmias areprevalent, challenging, and associated with substantial mor-bidity. These arrhythmias are notoriously resistant to antiar-rhythmic pharmacological therapy and, in some patients, mayresult in rapid hemodynamic deterioration and heart failure.75

Although the occurrence of atrial tachycardias increase with

follow-up duration and depend on the particular type ofrepair, they have been reported in up to 57% of patients.60

The most common form is a macro-reentrant circuit, termedintraatrial reentrant tachycardia. These circuits may be com-plex or multiple.76 With the use of such tools as3-dimensional mapping systems and irrigated-tip ablationcatheters, transcatheter procedures are immediately success-ful in �80% of cases in dedicated centers (Figure 7).77

Although recurrences and development of new arrhythmiasremain problematic, to the order of 30% to 45% 6 to 12months after ablation,78,79 quality-of-life measures areimproved.78

When atrial tachyarrhythmias are detected, underlyinghemodynamic causes, such as obstruction of the right atriumto pulmonary artery anastomosis, should be sought andanticoagulation pursued.69 Patients with failing Fontans andatrial arrhythmias should be considered for surgical conver-sion to a lateral tunnel or extracardiac conduit with concom-itant arrhythmia surgery.80,81 In the patient with refractoryatrial tachyarrhythmias but no other indication for surgicalrevision, we favor a transcatheter ablation approach in light ofits efficacy and low risk, with repeat procedures as required.

Thromboemboli and Hepatic DysfunctionIn addition to such thrombotic risk factors as atrial arrhyth-mias, distended and sluggish Fontan pathways, and intravas-cular prosthetic material, hepatic impairment with multipleclotting factor abnormalities have been described. Theseinclude decreased levels of protein C, protein S, and anti-thrombin III.82 Increased platelet reactivity has also beenrecognized.83 Hepatic congestion and cirrhosis are common,whereas hepatic adenoma and hepatocellular carcinoma occurless frequently.84 Hemodynamic assessment is required in anypatient with ongoing liver dysfunction. In the absence of

Figure 7. A 32-year-old man with intractable atrial tachyarrhythmias and a modified classic Fontan underwent electrophysiological study and trans-catheter ablation. A, Contrast angiography of the Fontan pathway in a posteroanterior view. Note the massive right atrial dilation, patent atriopulmo-nary connection, and divided main pulmonary artery (MPA). A permanent pacemaker lead is positioned at the atriopulmonary junction (Lead). Thearrows indicate position of a reference catheter (Ref) inserted via the right internal jugular vein and screwed into the medial right atrial wall. B, A leftlateral view of a 3-dimensional electroanatomic map. Local activation times in tachycardia are color-coded with earliest to latest signals in white, red,yellow, green, light blue, dark blue, and purple, respectively. A focal atrial tachycardia is noted, with concentric spread of activation from the whitecenter indicated by the arrow.




atrial arrhythmias, the role of long-term antiplatelet or anti-coagulation therapy remains poorly defined. Asymptomaticpulmonary emboli are frequently identified.85 Some retro-spective reviews support antiplatelet therapy,86 whereas oth-ers suggest that anticoagulants are more effective,87,88 andstill others discourage routine anticoagulation.89

Protein-Losing EnteropathyLoss of protein via the gastrointestinal tract occurs in 3.7% ofpatients with Fontan-type surgery and is clinically character-ized by fatigue, peripheral edema, pleural and pericardialeffusions, ascites, and chronic diarrhea.90 The diagnosis isconfirmed by low serum albumin and increased fecal �1-antitrypsin levels. Protein-losing enteropathy is thought to bemediated in part by chronically elevated central venouspressures. Other risk factors include longer cardiopulmonarybypass time and morphologic right ventricular anatomy.91 Inpatients with generalized edema, the 5-year survival rate is�50%.90 Multiple therapeutic approaches have been de-scribed with anecdotal successes. These include dietarymodifications with high-protein and high–medium-chain tri-

glycerides, afterload reduction agents, inotropic agents, hep-arin, albumin infusions, octreotide, prednisone, creation of anatrial fenestration, Fontan revision, and cardiac transplanta-tion.90 As the mean time between Fontan palliation anddiagnosis of protein-losing enteropathy is 6.9 years,71 mostadult survivors will have undergone some form of surgicalintervention.

Worsening CyanosisIn the absence of an atrial fenestration, the transcutaneousoxygen saturation in patients with Fontan procedures usuallyexceeds 94%.92 Common causes of worsening hypoxemiainclude progressive deterioration of ventricular function withor without AV valve regurgitation, shunting through a baffleleak or residual interatrial communication,93 pulmonary veincompression by a giant right atrium (Figure 8) or aorta,94

systemic venous collateralization, pulmonary arteriovenousmalformations (Figure 9), pulmonary pathology that includesa restrictive respiratory function pattern, hepatic venousconnection to the coronary sinus or left atrium, right-to-leftinteratrial shunting via small thebesian veins, and diaphrag-matic paresis.

Exercise Tolerance and Quality of LifeImpaired exercise capacity in patients with Fontan physiol-ogy is characteristically associated with reduced vital capac-ity, high residual volume-to–total lung capacity ratio, lowarterial saturation with hypocapnia, and skeletal muscledysfunction.95 Exercise capacity is not improved by a 10-week course of enalapril.96 Left ventricular morphologyindependently predicts higher peak oxygen uptake consump-tion.97 Despite reductions in exercise tolerance, repeatedhospital admissions, and comorbidities, many patients withuniventricular hearts report a satisfactory quality of life asassessed by the Duke questionnaire.98 Younger age is asso-ciated with better quality of life. In adults with Fontanphysiology, quality-of-life assessment showed physical func-tion, mental health, and general health perception to be

Figure 8. Transverse magnetic resonance image of a patientwith a modified classic Fontan for tricuspid atresia and severerotoscoliosis. The arrow designates the site where the massivelyenlarged right atrium (RA) compresses the right upper pulmo-nary vein (RUPV).

Figure 9. Selective pulmonary angiography of theright lower lobe in a patient with tricuspid atresiaand unidirectional Glenn shunt. A, Multiple pulmo-nary arteriovenous malformations. B, One residualpulmonary arteriovenous malformation after trans-catheter coil occlusion.




significantly lower than normal controls, as determined by aShort Form 36 questionnaire.99 In particular, quality of lifewas substantially impaired by reoperations, arrhythmias, andthromboembolic events.

PregnancyIn the patient with Fontan physiology who contemplatespregnancy, we favor a multidisciplinary approach that in-cludes availability of high-risk obstetric care, specializedcardiology assessment and follow-up, and genetic counseling.In carefully selected candidates with favorable hemodynam-ics, pregnancy may be successfully undertaken with relativelylow risk to the mother and fetus.100,101 Careful surveillance iswarranted with prompt recognition of symptoms related tosystemic venous congestion, increased AV valve regurgita-tion, atrial and ventricular arrhythmias, thromboemboli, andparadoxical emboli if the Fontan is fenestrated.69,100

Noncardiac Perioperative CareParticular vigilance is mandated when noncardiac surgery isrequired in the patient with Fontan physiology. If present,worsening cyanosis should be addressed prior to surgery.Close monitoring of hemodynamic factors is crucial; pulmo-nary blood flow is dependent on systemic venous pressureand highly sensitive to minor variations in pulmonary vascu-lar resistance, which may be modulated by anesthetics,hypoxemia, atelectasis, thromboemboli, or pneumonia.102

Both excess volume loading and volume depletion withdecreased venous return (eg, positive pressure ventilation)should be avoided, and oxygenation optimized. Early in-volvement of experienced anesthesiology and intensive carepersonnel is essential to prevent complications from changesin preload or pulmonary vascular resistance.

Fontan ConversionSurgical revision should be considered in patients with failingFontan circulations; experienced centers report combinedperioperative cardiac transplantation and mortality rates of2.4% to 6.7%.81,103,104 Perceived advantages of Fontan con-version to a lateral or extracardiac conduit include a lowerincidence of atrial arrhythmias and thrombosis related toatrial distension and improved hemodynamics.72,81 Surgerytypically involves debulking of the right atrium, removal ofthrombus, excision of right atrial scar tissue, epicardialpacemaker implantation, a modified right atrial Maze proce-dure and, in patients with prior documented atrial fibrillation,a left-sided Maze procedure as well.81,105 Left-sided Mazeprocedures are not routinely recommended, given the longerischemic time.81,105

Case series with short-term follow-up report promisingresults, with arrhythmia recurrence rates of 13% to 30%.80,81

Advantages of the extracardiac versus intracardiac lateraltunnel include a decreased incidence of sinus node dysfunc-tion,103 although not consistently so,104,106 and avoidance ofpotential thromboembolic risk associated with intracardiacprosthetic material.72 If atrial arrhythmias recur, however,access to the arrhythmia substrate via a transbaffle puncturemay be considerably complicated by an extracardiac conduit.In our opinion, this constitutes a noteworthy drawback giventhe real potential for late arrhythmias and limited successwith pharmacological therapy (Figure 10).

Conclusion“Univentricular heart” denotes a wide variety of rare andcomplex congenital cardiac malformations whereby bothatria predominantly egress into a functional single ventricle.Although most patients will be managed by a staged surgicalapproach in view of an ultimate Fontan procedure, a minority

Figure 10. A 12-lead ECG in a 31-year-old woman with tricuspid atresia, atrial septal defect, ventricular septal defect, and classic mod-ified Fontan later converted to an extracardiac conduit with a right atrial Maze procedure. Recurrent persistent intraatrial reentranttachycardia with a ventricular response rate of 167 beats per minute was electrically cardioverted.




will not undergo Fontan palliation either because they main-tain reasonably balanced systemic and pulmonary circula-tions or as a result of unfavorable hemodynamics. Manage-ment of the adult with a univentricular heart thereforeencompasses a thorough appreciation of diverse anatomicvariants, tenuous cardiovascular physiology, multisystemicrepercussions of cyanotic heart disease, and postoperativesequelae in surgically palliated patients. Follow-up by dedi-cated multidisciplinary teams with expertise in all facets ofadult congenital heart disease is essential to the optimal careof these patients. Although many questions about best med-ical, interventional, and surgical therapies remain, provisionof educated care in the current era should ensure that themajority of patients born with univentricular hearts thrivewell into their adult years.

AcknowledgmentsThe authors wish to thank Drs Patricia Ugolini and Éléonore Paquet,Department of Radiology, Montreal Heart Institute, for their expertassistance in preparing and interpreting cardiac magnetic resonanceimages.

Source of FundingThis work was supported in part by the Canada Research Chair inAdult Congenital Heart Disease and Electrophysiology (Dr Khairy).

DisclosuresNone.

References1. Peacock TB. Malformations of the heart. In: Peacock TB, ed. On

Malformations of the Human Heart: With Original Cases. London, UK:John Churchill; 1858:10–102.

2. Van Praagh R, Ongley PA, Swan HJ. Anatomic types of single or commonventricle in man: morphologic and geometric aspects of 60 necropsiedcases. Am J Cardiol. 1964;13:367–386.

3. Anderson RH, Becker AE, Wilkinson JL. Proceedings: morphogenesis andnomenclature of univentricular hearts. Br Heart J. 1975;37:781–782.

4. Marin-Garcia J, Tandon R, Moller JH, Edwards JE. Common (single)ventricle with normally related great vessels. Circulation. 1974;49:565–573.

5. Jacobs ML, Mayer JE Jr. Congenital Heart Surgery Nomenclature andDatabase Project: single ventricle. Ann Thorac Surg. 2000;69(4 Suppl):S197–S204.

6. Tchervenkov CI, Jacobs ML, Tahta SA. Congenital Heart Surgery Nomen-clature and Database Project: hypoplastic left heart syndrome. Ann ThoracSurg. 2000;69(4 Suppl):S170–S179.

7. Huhta JC, Seward JB, Tajik AJ, Hagler DJ, Edwards WD. Two-dimensionalechocardiographic spectrum of univentricular atrioventricular connection.J Am Coll Cardiol. 1985;5:149–157.

8. Fyler DC, Buckley LP, Hellenbrand WE, Cohn HE. Report of the NewEngland Regional Infant Cardiac Program. Pediatrics. 1980;65:375–461.

9. Hoffman JI, Kaplan S. The incidence of congenital heart disease. J Am CollCardiol. 2002;39:1890–1900.

10. Rao PS. Tricuspid atresia. Curr Treat Options Cardiovasc Med. 2000;2:507–520.

11. Franklin RC, Spiegelhalter DJ, Anderson RH, Macartney FJ, Rossi FilhoRI, Douglas JM, Rigby ML, Deanfield JE. Double-inlet ventricle presentingin infancy: I: Survival without definitive repair. J Thorac Cardiovasc Surg.1991;101:767–776.

12. Van Praagh R, Ongley PA, Swan HJ. Anatomic types of single or commonventricle in man: morphologic and geometric aspects of 60 necropsiedcases. Am J Cardiol. 1964;13:367–386.

13. Dobell AR, Van Praagh R. The Holmes heart: historic associations andpathologic anatomy. Am Heart J. 1996;132(2 Pt 1):437–445.

14. Shinebourne EA, Lau KC, Calcaterra G, Anderson RH. Univentricular heartof right ventricular type: clinical, angiographic and electocardiographicfeatures. Am J Cardiol. 1980;46:439–445.

15. Loffredo CA, Chokkalingam A, Sill AM, Boughman JA, Clark EB, ScheelJ, Brenner JI. Prevalence of congenital cardiovascular malformations amongrelatives of infants with hypoplastic left heart, coarctation of the aorta, andd-transposition of the great arteries. Am J Med Genet A. 2004;124:225–230.

16. Gill HK, Splitt M, Sharland GK, Simpson JM. Patterns of recurrence ofcongenital heart disease: an analysis of 6,640 consecutive pregnanciesevaluated by detailed fetal echocardiography. J Am Coll Cardiol. 2003;42:923–929.

17. Weigel TJ, Driscoll DJ, Michels VV. Occurrence of congenital heart defectsin siblings of patients with univentricular heart and tricuspid atresia.Am J Cardiol. 1989;64:768–771.

18. Burn J, Brennan P, Little J, Holloway S, Coffey R, Somerville J, DennisNR, Allan L, Arnold R, Deanfield JE, Godman M, Houston A, Keeton B,Oakley C, Scott O, Silove E, Wilkinson J, Pembrey M, Hunter AS. Recur-rence risks in offspring of adults with major heart defects: results from firstcohort of British collaborative study. Lancet. 1998;351:311–316.

19. Shapiro SR, Ruckman RN, Kapur S, Chandra R, Galioto FM, Perry LW,Scott LP 3rd. Single ventricle with truncus arteriosus in siblings. AmHeart J. 1981;102(3 Pt 1):456–459.

20. Whittemore R, Wells JA, Castellsague X. A second-generation study of 427probands with congenital heart defects and their 837 children. J Am CollCardiol. 1994;23:1459–1467.

21. Nelson DP, Schwartz SM, Chang AC. Neonatal physiology of the func-tionally univentricular heart. Cardiol Young. 2004;14(Suppl 1):52–60.

22. Rahimtoola SH, Ongley PA, Swan HJ. The hemodynamics of common (orsingle) ventricle. Circulation. 1966;34:14–23.

23. Macartney FJ, Partridge JB, Scott O, Deverall PB. Common or singleventricle: an angiocardiographic and hemodynamic study of 42 patients.Circulation. 1976;53:543–554.

24. Wren C, Macartney FJ, Deanfield JE. Cardiac rhythm in atrial isomerism.Am J Cardiol. 1987;59:1156–1158.

25. Momma K, Takao A, Shibata T. Characteristics and natural history ofabnormal atrial rhythms in left isomerism. Am J Cardiol. 1990;65:231–236.

26. Bharati S, Lev M. The course of the conduction system in single ventriclewith inverted (L-) loop and inverted (L-) transposition. Circulation. 1975;51:723–730.

27. Wilkinson JL, Dickinson D, Smith A, Anderson RH. Conducting tissues inuniventricular heart of right ventricular type with double or common inlet.J Thorac Cardiovasc Surg. 1979;77:691–698.

28. Neill CA, Brink AJ. Left axis deviation in tricuspid atresia and singleventricle: the electrocardiogram in 36 autopsied cases. Circulation. 1955;12:612–619.

29. Shaher RM. The electrocardiogram in single ventricle. Br Heart J. 1963;25:465–473.

30. Elliott LP, Ruttenberg HD, Eliot RS, Anderson RC. Vectorial analysis of theelectrocardiogram in common ventricle. Br Heart J. 1964;26:302–311.

31. Elliott LP, Gedgaudas E. The roentgenologic findings in common ventriclewith transposition of the great vessels. Radiology. 1964;82:850–865.

32. Carey LS, Ruttenberg HD. Roentgenographic features of common ventriclewith inversion of the infundibulum: corrected transposition with rudi-mentary left ventricle. Am J Roentgenol. 1964;92:652–668.

33. Bevilacqua M, Sanders SP, Van Praagh S, Colan SD, Parness I.Double-inlet single left ventricle: echocardiographic anatomy with emphasison the morphology of the atrioventricular valves and ventricular septaldefect. J Am Coll Cardiol. 1991;18:559–568.

34. Rice MJ, Seward JB, Edwards WD, Hagler DJ, Danielson GK, Puga FJ,Tajik AJ. Straddling atrioventricular valve: two-dimensional echocardio-graphic diagnosis, classification and surgical implications. Am J Cardiol.1985;55:505–513.

35. Festa P, Ait Ali L, Bernabei M, De Marchi D. The role of magneticresonance imaging in the evaluation of the functionally single ventriclebefore and after conversion to the Fontan circulation. Cardiol Young.15(Suppl 3):51–56, 2005.

36. Lock JE, Keane JF, Fellows KE. The use of catheter intervention proceduresfor congenital heart disease. J Am Coll Cardiol. 1986;7:1420–1423.

37. Nakanishi T. Cardiac catheterization is necessary before bidirectional Glennand Fontan procedures in single ventricle physiology. Pediatr Cardiol.2005;26:159–161.

38. Sullivan ID, Wren C, Stark J, de Leval MR, Macartney FJ, Deanfield JE.Surgical unifocalization in pulmonary atresia and ventricular septal defect:a realistic goal? Circulation. 1988;78(5 Pt 2):III5–III13.

39. Malcic I, Sauer U, Stern H, Kellerer M, Kuhlein B, Locher D, BuhlmeyerK, Sebening F. The influence of pulmonary artery banding on outcome afterthe Fontan operation. J Thorac Cardiovasc Surg. 1992;104:743–747.




40. Jensen RA Jr, Williams RG, Laks H, Drinkwater D, Kaplan S. Usefulnessof banding of the pulmonary trunk with single ventricle physiology at riskfor subaortic obstruction. Am J Cardiol. 1996;77:1089–1093.

41. Choussat A, Fontan F, Besse B, Vallot F, Chauve A, Bricaud H. Selectioncriteria for Fontan’s procedure. In: Anderson RH, Shinebourne EA, eds.Paediatric Cardiology. New York: Churchill Livingstone; 1978:559–566.

42. Alboliras ET, Porter CB, Danielson GK, Puga FJ, Schaff HV, Rice MJ,Driscoll DJ. Results of the modified Fontan operation for congenital heartlesions in patients without preoperative sinus rhythm. J Am Coll Cardiol.1985;6:228–233.

43. Pearl JM, Laks H, Drinkwater DC, Capouya ER, George BL, Williams RGModified Fontan procedure in patients less than 4 years of age. Circulation.1992;86(5 Suppl): II100–II105.

44. Fontan F, Kirklin JW, Fernandez G, Costa F, Naftel DC, Tritto F,Blackstone EH. Outcome after a “perfect” Fontan operation. Circulation.1990;81:1520–1536.

45. Fontan F, Baudet E. Surgical repair of tricuspid atresia. Thorax. 1971;26:240–258.

46. de Leval MR, Kilner P, Gewillig M, Bull C. Total cavopulmonary con-nection: a logical alternative to atriopulmonary connection for complexFontan operations: experimental studies and early clinical experience.J Thorac Cardiovasc Surg. 1988;96:682–695.

47. Marcelletti C, Corno A, Giannico S, Marino B. Inferior vena cava-pulmo-nary artery extracardiac conduit: a new form of right heart bypass. J ThoracCardiovasc Surg. 1990;100:228–232.

48. Bridges ND, Mayer JE Jr, Lock JE, Jonas RA, Hanley FL, Keane JF, PerrySB, Castaneda AR. Effect of baffle fenestration on outcome of the modifiedFontan operation. Circulation. 1992;86:1762–1769.

49. Goff DA, Blume ED, Gauvreau K, Mayer JE, Lock JE, Jenkins KJ. Clinicaloutcome of fenestrated Fontan patients after closure: the first 10 years.Circulation. 2000;102:2094–2099.

50. Norwood WI. Hypoplastic left heart syndrome. Cardiol Clin. 1989;7:377–385.

51. Daebritz SH, Nollert GD, Zurakowski D, Khalil PN, Lang P, del Nido PJ,Mayer JE Jr, Jonas RA. Results of Norwood stage I operation: comparisonof hypoplastic left heart syndrome with other malformations. J ThoracCardiovasc Surg. 2000;119:358–367.

52. Sano S, Ishino K, Kado H, Shiokawa Y, Sakamoto K, Yokota M, KawadaM. Outcome of right ventricle-to-pulmonary artery shunt in first-stagepalliation of hypoplastic left heart syndrome: a multi-institutional study. AnnThorac Surg. 2004;78:1951–1957.

53. Akintuerk H, Michel-Behnke I, Valeske K, Mueller M, Thul J, Bauer J,Hagel KJ, Kreuder J, Vogt P, Schranz D. Stenting of the arterial duct andbanding of the pulmonary arteries: basis for combined Norwood stage I andII repair in hypoplastic left heart. Circulation. 2002;105:1099–1103.

54. McGuirk SP, Griselli M, Stumper O, Rumball EM, Miller P, Dhillon R, deGiovanni JV, Wright JG, Barron DJ, Brawn WJ. Staged surgical man-agement of hypoplastic left heart syndrome: a single-institution 12-yearexperience. Heart. 2005;92:364–370.

55. Krasemann T, Fenge H, Kehl HG, Rukosujew A, Schmid C, Scheld HH,Tjan TD, Vogt J. A decade of staged Norwood palliation in hypoplastic leftheart syndrome in a midsized cardiosurgical center. Pediatr Cardiol. 2005;26:751–755.

56. Stasik CN, Goldberg CS, Bove EL, Devaney EJ, Ohye RG. Currentoutcomes and risk factors for the Norwood procedure. J Thorac CardiovascSurg. 2006;131:412–417.

57. Moodie DS, Ritter DG, Tajik AJ, O’Fallon WM. Long-term follow-up inthe unoperated univentricular heart. Am J Cardiol. 1984;53:1124–1128.

58. Ammash NM, Warnes CA. Survival into adulthood of patients with unop-erated single ventricle. Am J Cardiol. 1996;77:542–544.

59. Day RW, Etheridge SP, Veasy LG, Jenson CB, Hillman ND, Di Russo GB,Thorne JK, Doty DB, McGough EC, Hawkins JA. Single ventricle pal-liation: greater risk of complications with the Fontan procedure than with thebidirectional Glenn procedure alone. Int J Cardiol. 2006;106:201–210.

60. Gatzoulis MA, Munk MD, Williams WG, Webb GD. Definitive palliationwith cavopulmonary or aortopulmonary shunts for adults with single ven-tricle physiology. Heart. 2000;83:51–57.

61. Perloff JK, Rosove MH, Child JS, Wright GB. Adults with cyanotic con-genital heart disease: hematologic management. Ann Intern Med. 1988;109:406–413.

62. Oechslin E. Hematological management of the cyanotic adult with con-genital heart disease. Int J Cardiol. 97(Suppl 1):109–115, 2004.

63. Perloff JK, Marelli AJ, Miner PD. Risk of stroke in adults with cyanoticcongenital heart disease. Circulation. 1993;87:1954–1959.

64. Khairy P, Landzberg MJ, Gatzoulis MA, Mercier LA, Fernandes SM, CoteJM, Lavoie JP, Fournier A, Guerra PG, Frogoudaki A, Walsh EP, Dore A.Transvenous pacing leads and systemic thromboemboli in patients withintracardiac shunts: a multicenter study. Circulation. 2006;113:2391–2397.

65. Perloff JK. Systemic complications of cyanosis in adults with congenitalheart disease: hematologic derangements, renal function, and urate metab-olism. Cardiol Clin. 1993;11:689–699.

66. McLaughlin GE, McCarty DJ Jr, Downing DF. Hypertrophic osteoar-thropathy associated with cyanotic congenital heart disease. Ann InternMed. 1967;67:579–587.

67. Ammash NM, Connolly HM, Abel MD, Warnes CA. Noncardiac surgery inEisenmenger syndrome. J Am Coll Cardiol. 1999;33:222–227.

68. Presbitero P, Somerville J, Stone S, Aruta E, Spiegelhalter D, Rabajoli F.Pregnancy in cyanotic congenital heart disease: outcome of mother andfetus. Circulation. 1994;89:2673–2676.

69. Therrien J, Dore A, Gersony W, Iserin L, Liberthson R, Meijboom F,Colman JM, Oechslin E, Taylor D, Perloff J, Somerville J, Webb GD. CCSConsensus Conference 2001 update: recommendations for the managementof adults with congenital heart disease. Part I. Can J Cardiol. 2001;17:940–959.

70. Stamm C, Friehs I, Mayer JE Jr, Zurakowski D, Triedman JK, Moran AM,Walsh EP, Lock JE, Jonas RA, Del Nido PJ. Long-term results of the lateraltunnel Fontan operation. J Thorac Cardiovasc Surg. 2001;121:28–41.

71. Earing MG, Cetta F, Driscoll DJ, Mair DD, Hodge DO, Dearani JA, PugaFJ, Danielson GK, O’Leary PW. Long-term results of the Fontan operationfor double-inlet left ventricle. Am J Cardiol. 2005;96:291–298.

72. de Leval MR. The Fontan circulation: a challenge to William Harvey? NatClin Pract Cardiovasc Med. 2005;2:202–208.

73. Landzberg MJ, Murphy DJ Jr, Davidson WR Jr, Jarcho JA, Krumholz HM,Mayer JE Jr, Mee RB, Sahn DJ, Van Hare GF, Webb GD, Williams RG.Task force 4: organization of delivery systems for adults with congenitalheart disease. J Am Coll Cardiol. 2001;37:1187–1193.

74. Cohen MI, Wernovsky G, Vetter VL, Wieand TS, Gaynor JW, Jacobs ML,Spray TL, Rhodes LA. Sinus node function after a systematically stagedFontan procedure. Circulation. 1998;98(19 Suppl):II352–II358.

75. Khairy P, Dore A, Talajic M, Dubuc M, Poirier N, Roy D, Mercier LA.Arrhythmias in adult congenital heart disease. Expert Rev Cardiovasc Ther.2006;4:83–95.

76. Triedman JK, Alexander ME, Berul CI, Bevilacqua LM, Walsh EP. Elec-troanatomic mapping of entrained and exit zones in patients with repairedcongenital heart disease and intra-atrial reentrant tachycardia. Circulation.2001;103:2060–2065.

77. Triedman JK, DeLucca JM, Alexander ME, Berul CI, Cecchin F, Walsh EP.Prospective trial of electroanatomically guided, irrigated catheter ablation ofatrial tachycardia in patients with congenital heart disease. Heart Rhythm.2005;2:700–705.

78. Triedman JK, Alexander ME, Love BA, Collins KK, Berul CI, BevilacquaLM, Walsh EP. Influence of patient factors and ablative technologies onoutcomes of radiofrequency ablation of intra-atrial re-entrant tachycardia inpatients with congenital heart disease. J Am Coll Cardiol. 2002;39:1827–1835.

79. Kannankeril PJ, Anderson ME, Rottman JN, Wathen MS, Fish FA. Fre-quency of late recurrence of intra-atrial reentry tachycardia after radiofre-quency catheter ablation in patients with congenital heart disease.Am J Cardiol. 2003;92:879–881.

80. Setty SP, Finucane K, Skinner JR, Kerr AR. Extracardiac conduit with alimited maze procedure for the failing Fontan with atrial tachycardias. AnnThorac Surg. 2002;74:1992–1997.

81. Mavroudis C, Deal BJ, Backer CL. The beneficial effects of total cavopul-monary conversion and arrhythmia surgery for the failed Fontan. SeminThorac Cardiovasc Surg Pediatr Card Surg Annu. 2002;5:12–24.

82. Tomita H, Yamada O, Ohuchi H, Ono Y, Arakaki Y, Yagihara T, EchigoS. Coagulation profile, hepatic function, and hemodynamics followingFontan-type operations. Cardiol Young. 2001;11:62–66.

83. Ravn HB, Hjortdal VE, Stenbog EV, Emmertsen K, Kromann O, PedersenJ, Sorensen KE. Increased platelet reactivity and significant changes incoagulation markers after cavopulmonary connection. Heart. 2001;85:61–65.

84. Ghaferi AA, Hutchins GM. Progression of liver pathology in patientsundergoing the Fontan procedure: chronic passive congestion, cardiac cir-rhosis, hepatic adenoma, and hepatocellular carcinoma. J Thorac Car-diovasc Surg. 2005;129:1348–1352.

85. Varma C, Warr MR, Hendler AL, Paul NS, Webb GD, Therrien J. Prev-alence of “silent” pulmonary emboli in adults after the Fontan operation.J Am Coll Cardiol. 2003;41:2252–2258.




86. Barker PC, Nowak C, King K, Mosca RS, Bove EL, Goldberg CS. Riskfactors for cerebrovascular events following Fontan palliation in patientswith a functional single ventricle. Am J Cardiol. 2005;96:587–591.

87. Seipelt RG, Franke A, Vazquez-Jimenez JF, Hanrath P, von Bernuth G,Messmer BJ, Muhler EG. Thromboembolic complications after Fontanprocedures: comparison of different therapeutic approaches. Ann ThoracSurg. 2002;74:556–562.

88. Kaulitz R, Ziemer G, Rauch R, Girisch M, Bertram H, Wessel A, HofbeckM. Prophylaxis of thromboembolic complications after the Fontan operation(total cavopulmonary anastomosis). J Thorac Cardiovasc Surg. 2005;129:569–575.

89. Mahnke CB, Boyle GJ, Janosky JE, Siewers RD, Pigula FA. Anticoagu-lation and incidence of late cerebrovascular accidents following the Fontanprocedure. Pediatr Cardiol. 2005;26:56–61.

90. Mertens L, Hagler DJ, Sauer U, Somerville J, Gewillig M. Protein-losingenteropathy after the Fontan operation: an international multicenter study.PLE study group. J Thorac Cardiovasc Surg. 1998;115:1063–1073.

91. Powell AJ, Gauvreau K, Jenkins KJ, Blume ED, Mayer JE, Lock JE.Perioperative risk factors for development of protein-losing enteropathyfollowing a Fontan procedure. Am J Cardiol. 2001;88:1206–1209.

92. Magee AG, McCrindle BW, Mawson J, Benson LN, Williams WG,Freedom RM. Systemic venous collateral development after the bidirec-tional cavopulmonary anastomosis: prevalence and predictors. J Am CollCardiol. 1998;32:502–508.

93. Gamillscheg A, Beitzke A, Stein JI, Rupitz M, Zobel G, Rigler B. Trans-catheter coil occlusion of residual interatrial communications after Fontanprocedure. Heart. 1998;80:49–53.

94. O’Donnell CP, Lock JE, Powell AJ, Perry SB. Compression of pulmonaryveins between the left atrium and the descending aorta. Am J Cardiol.2003;91:248–251.

95. Durongpisitkul K, Driscoll DJ, Mahoney DW, Wollan PC, Mottram CD,Puga FJ, Danielson GK. Cardiorespiratory response to exercise aftermodified Fontan operation: determinants of performance. J Am CollCardiol. 1997;29:785–790.

96. Kouatli AA, Garcia JA, Zellers TM, Weinstein EM, Mahony L. Enalaprildoes not enhance exercise capacity in patients after Fontan procedure.Circulation. 1997;96:1507–1512.

97. Ohuchi H, Yasuda K, Hasegawa S, Miyazaki A, Takamuro M, Yamada O,Ono Y, Uemura H, Yagihara T, Echigo S. Influence of ventricular mor-phology on aerobic exercise capacity in patients after the Fontan operation.J Am Coll Cardiol. 2001;37:1967–1974.

98. Saliba Z, Butera G, Bonnet D, Bonhoeffer P, Villain E, Kachaner J, Sidi D,Iserin L. Quality of life and perceived health status in surviving adults withuniventricular heart. Heart. 2001;86:69–73.

99. van den Bosch AE, Roos-Hesselink JW, Van Domburg R, Bogers AJ,Simoons ML, Meijboom FJ. Long-term outcome and quality of life in adultpatients after the Fontan operation. Am J Cardiol. 2004;93:1141–1145.

100. Khairy P, Ouyang DW, Fernandes SM, Lee-Parritz A, Economy KE,Landzberg MJ. Pregnancy outcomes in women with congenital heartdisease. Circulation. 2006;113:517–524.

101. Canobbio MM, Mair DD, van der Velde M, Koos BJ. Pregnancy outcomesafter the Fontan repair. J Am Coll Cardiol. 1996;28:763–767.

102. Hosking MP, Beynen FM. The modified Fontan procedure: physiology andanesthetic implications. J Cardiothorac Vasc Anesth. 1992;6:465–475.

103. Nurnberg JH, Ovroutski S, Alexi-Meskishvili V, Ewert P, Hetzer R, LangePE. New onset arrhythmias after the extracardiac conduit Fontan operationcompared with the intraatrial lateral tunnel procedure: early and midtermresults. Ann Thorac Surg. 2004;78:1979–1988.

104. Kumar SP, Rubinstein CS, Simsic JM, Taylor AB, Saul JP, Bradley SM.Lateral tunnel versus extracardiac conduit Fontan procedure: a concurrentcomparison. Ann Thorac Surg. 2003;76:1389–1396.

105. Mavroudis C, Backer CL, Deal BJ, Johnsrude C, Strasburger J. Totalcavopulmonary conversion and maze procedure for patients with failure ofthe Fontan operation. J Thorac Cardiovasc Surg. 2001;122:863–871.

106. Morales DL, Dibardino DJ, Braud BE, Fenrich AL, Heinle JS,Vaughn WK, McKenzie ED, Fraser CD Jr. Salvaging the failingFontan: lateral tunnel versus extracardiac conduit. Ann Thorac Surg.2005;80:1445–1451.




coração univentricular

Health & Medicine

theuniventricular heart

american heart association

terms single

present report

updated information

absent av connection

common av valve

md liseandre mercier