Atrial
Fibrillation
in Children
Dorothy J. Radford, M.B., M.R.C.P.(UK), and Teruo lzukawa, M.D., F.R.C.P.(C)
From the Department of Paediatrics, Cardiology Division, Hospital for Sick Children, Toronto, Ontario, Canada
ABSTRACT. Atrial fibrillation is rare in children. Previous reports associated it with severe rheumatic heart disease and a poor prognosis. This review is of the unique experience of 35 cases of atrial fibrillation in children in the past 22 years; 23 patients were boys. The age of onset ranged from 1 day to 19 years (average, 8 years).
Associated cardiac conditions were severe rheumatic
mitral regurgitation (3 cases), cardiomyopathy (5), atrial tumors (2), infective endocarditis (1), paroxysmal atrial tachycardia of infants (4), idiopathic paroxysmal atrial
fibril-lation (1), Marfan’s syndrome with mitral regurgitation (1), endocardial fibroelastosis (1), and stnictural congenital heart malformations (17). Surgical correction of congenital heart lesions was directly related to the development of atrial
fibrillation in 14. Varying arrhythmias of the sick-sinus syndrome were observed in five children. The atrial
fibrilla-tion was paroxysmal or transient in 21 patients and persistent in 14.
Treatment depended on the underlying condition. Digoxin was used in all cases and cardioversion attempted in ten; no patient was given anticoagulants. Three children had cere-bral emboli, with residual defects. Eighteen patients are known to be alive, 13 are dead, and 4 are lost to follow-up.
Atrial fibrillation in childhood is an indication for complete investigation of the patient and for the institution of treatment appropriate to the underlying disease.
Pediat-tics,
59:250-256, 1977, ATRIAL FIBRILLATION, ARRHYTHMIA,HEART, SICK-SINUS SYNDROME.
subaortic stenosis’#{176} is well known, but the arrhythmia is more prone to develop in adults with such lesions.
In recent years the incidence of rheumatic heart disease has decreased considerably. How-ever, new problems with arrhythmias have arisen since the introduction of modern surgical
techniques for correcting congenital cardiac
11-13 In addition, the “sick-sinus
syn-drome” is now recognized in both adults’4’5 and children.’6’7 In this condition, which is character-ized by bradyarrhythmia and tachyarrhythmias, resolution of symptoms and therapeutic problems has occurred, with the onset of permanent atrial fibrillation, in adults.’82’ Whether this applies in
children is unknown.
The apparently changing face of the rare
childhood arrhythmia of atrial fibrillation
prompted us to review our experience with this condition and to assess the etiology and outlook.
PATIENTS AND METHODS
All cases of atrial arrhythmia were selected from the computerized record system of the cardiology department. The ECGs were
re-Atrial fibrillation is a rare arrhythmia in
child-hood.’3
The
majority
of reported
cases
have
been
in patients with severe rheumatic heart disease, in whom atrial fibrillation indicated a poor progno-sis.4_6 Association with atnal septal defect,78 Ebstein’s anomaly,9 and idiopathic hypertrophic
(Received March 22; revision accepted for publication June 21, 1976.)
Dr. Radford is the recipient of an Ontario Heart Foundation Fellowship.
ADDRESS FOR REPRINTS: (D.J.R.) Department of Paedi-atrics, Cardiology Division, Hospital for Sick Children, 555
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FIG. 1. EGG diagnostic of atrial fibrillation: the atrial deflections and ventricular responses are
totally irregular.
viewed, and cases in which atrial fibrillation had
been documented were studied.
Atrial fibrillation was diagnosed by the ECG
features of irregular and chaotic atrial deflections distorting the baseline, with varying
atrioventric-ular conduction resulting in completely irregular
Q
RS complexes22 (Fig. 1). We excluded cases inwhich the fibrillation had occurred transiently
only during cardiac catheterization or immedi-ately postoperatively.
Some patients had had additional arrhythmias.
Careful differentiation between atrial fibrillation
and atrial flutter with varying block was
attempted (Fig. 2), and the latter cases were excluded. This left a total of 35 cases during the
past 22 years.
CLINICAL FEATURES
Twenty-three of the 35 children studied were
boys. The clinical data are shown in Table I. The
cardiac diagnoses had been confirmed by cardiac
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TABLE I
CLINICAL DATA ON 35 CHILDREN WITH ATRIAL FIBRILLATION
Patient No. Sex
Associated Cardiac Conditions Age at Atrial Fibrilla
Onset
tion (AF)
.
Type and Duration Outcome
1 F Rheumatic mitral regurgitation 10 yr Persistent for 9 mo before death Died; necropsy
2 NI Rheumatic heart disease; valve
surgery
14 yr Persistent despite mitral valve replacement and triscimpid repair
Alive, aged 20; in AF
3 1 Rheumatic heart disease; valve surgery
10 yr Paroxysmal until mitral valve replacement
Alive; in SR; spastic from cere-bral embolus
4 F Cardiomyopathy from
hemochroma-tosis; sick-sinus syndrome
19 yr Paroxysmal for 3 mo before death Died; necropsy
5 M Cardiomopathy 13 yr Persistent for 15 mo before death Died; necropsy
6 F Cardiomyopathy 10#{189}yr Persistent for 3 nio before death Died
7 F Cardiomopath 7 yr Paroxysmal for 4 yr before death Died
8 NI Cardiomyopath 13 yr Paroxysmal Alive, aged 20
9 Ni Rhabdomyoma of right atrium;
tu-berous sclerosis
2#{189}yr Persistent Lost to follow-up
10 NI Hepatoblastoma, with pulmonary and cardiac metastases
5#{190}yr Persistent for 4 da’vs before death Died; necropsy
11 NI Infective endocarditis; nephrotic syndrome
7#{189}yr Persistent for 20 days before death Died; necropsy
12 NI Congenital atrial flutter 1 day Transient Alive; in SR
1:3 NI Paroxysmal atrial tachycardia 3 ‘no Transient Alive; in SR
14 M Paroxysmal atrial tachycardia 3 mo Transient Alive; in SR
15 F Paroxysmal atrial tachycardia 3 mo Transient Alive; in SR
16 F Idiopathic paroxysmal atrial
fibrillation
13 yr Paroxysmal Alive
17 F Marfan’s syndrome; mitral regurgitation
10 yr Persistent for 3 mo before death Died; necropsy
18 NI Endocardial fibroelastosis 4 yr Paroxysmal for 2 days before death Died; necropsy
19 Ni Transposition of great vessels; Mits-tard operation; sick-sinus syn-drome
4 yr Paroxysmal since Mustard operation Alive
20 Ni Transposition of great vessels; Mtms-tard operation
4#{189}yr Transient; relieved by cardioversion Alive; in SR
21 F Transposition of great vessels; Mt,s-tard operation; sick sinus
syn-drome
5 yr Paroxysmal Alive; hemiparesis from
cere-bral embolus
catheterization and angiocardiography in most
cases and at necropsy also in nine. The atrial
fibrillation was sustained in 14, paroxysmal in 14, and only transient in 7.
The age at onset of atrial fibrillation ranged between 1 day and 19 years (average, 8 years). In the patients who died, the arrhythmia started one
day to four years before death; in four, death
occurred less than three weeks after its onset.
Eighteen patients are still alive, 13 are known to have died, and the present status of the other 4 (last seen between 1953 and 1968) is unknown. Cerebral embolism occurred in three children, all of whom have residual defects from the event.
Associated
Conditions
Three children had rheumatic heart disease with severe mitral regurgitation and giant left atria; one died before surgical intervention. The other two have prosthetic mitral valves: one has permanent atrial fibrillation, and the other has sinus rhythm but residual spasticity from a cere-bral embolus.
TABLE I‘(CorrrINuED)
Pat No.
ient Sex
Associated Cardiac Conditions Age at Atrial Fibrill
Onset
ation (AF)
Type and Duration Outcome
22 M Transposition of great vessels; Mustard operation
3 yr Persistent for 1 day before death Died aged 3 years
23 F Secundum atrial septal defect:
repaired
12#{189}yr Transient, starting 3 mo after surgery operation; resolved with digoxmn
Alive; in SR
24 F Common atrium: surgically
partitioned; sick-sinus syndrome
16 yr Paroxysmal Alive; varying rhythms
25 NI Total anomalous pulmonary venous
drainage: repaired; sick-sinus syndrome
2 yr Paroxysmal
-
Alive; varying rhythms26 M Tetralogy of Fallot: corrected; tricuspid valve replaced
18 yr Persistent Lost to follow-up since 1968
27 M Tetralogy of Fallot: repaired 15 yr Persistent Alive; in AF
28 M Pulmonary atresia: tricuspid and
pulmonary valves replaced
4 yr Transient; responded to
cardioversion
Alive; in SR; minor residual defects from cerebral
embolus
29 NI Pulmonary atresia: Blalock-Taussig shunt
13 yr Persistent for 5 mo before death Died; necrops
30 M Ebstein’s anomaly 6 yr Paroxysmal Lost to follow-up
31 M Ebstein’s anomaly; atrial septal defect closed
10 yr Persistent for 12 days before death Died
32 M Atrial septal defect; mitral stenosis; coarctation: corrective surgery
7 yr Paroxysmal Alive
33 F Congenital mitral regurgitation; coarctation: corrective surgery
11 yr Paroxysmal until mitral valve replaced
Alive; in SR
34 F Eisenmenger’s complex 13 yr Persistent for 1 mo before death Died; necropsy
35 NI Single ventricle 4 yr Transient; cardioversion successful Lost to follow-up
Two children had tumors involving the heart. Thoracotomy revealed an unresectable
rhabdo-myoma of the right atrium in one of these
patients, who also had tuberous sclerosis. The other child had had a hepatoblastoma resected four years earlier; atrial fibrillation developed four days before he died, and necropsy revealed lung metastases extending along the pulmonary
veins into the left atrium.
One patient had endocarditis resultant upon long-standing nephrotic syndrome and staphylo-coccal abscess of recent onset in the axilla. Atrial fibrillation developed 20 days before death and a vegetation on the mitral valve was found at
necropsy.
There were four cases of atrial tachycardia in
infancy. One neonate had been delivered by caesarian section because of fetal heart
irregular-ity; he had atrial flutter and atrial fibrillation on the first day of life, for which he was given digoxin therapy. Tachyarrhythmias developed at the age of 3 months in the other three infants; one had supraventricular tachycardia as well as atrial fibrillation, and the other two had atrial flutter, changing to atrial fibrillation during digoxin
ther-apy. None of the four patients had congenital heart disease, myocarditis, or Wolff
-Parkin-son-White syndrome; in all, the arrhythmias
resolved during digoxin therapy.
One girl was classified as having idiopathic paroxysmal atrial fibrillation. Her heart was
TABLE II
CARDIAC ABNORMALITIES IN 35 CHILDREN WITH Amii FIBRILLATION
Condition No.
Miscellaneous Heart Disease
Rheumatic heart disease 3
Cardiomyopathy 5
Tumor 2
Infective endocarditis 1
Paroxysmal atrial tachycardia of infancy 4
Idiopathic paroxysmal atrial fibrillation 1
Marfan’s syndrome - 1
Endocardial fibroelastosis 1
Total 18
Congenital Heart Malformations
Transposition of great vessels 4
Atrial septal defect 1
Common atrium 1
Total anomalous pulmonary veins 1
Tetrology of Fallot 2
Pulmonary atresia 2
Ebstein’s anomaly 2
Congenital mitral valve abnormality 2
Eisenmenger’s complex 1
Single ventricle 1
Total 17
preexcitation syndrome. Investigation, which included tests for thyroid function, pheochromo-cytoma, and systemic disease, revealed no abnor-mality.
One patient had Marfan’s syndrome, with severe mitral regurgitation and enlargement of the left atrium; she died in congestive cardiac failure in 1956. Endocardial fibroelastosis was
diagnosed clinically in one boy and necropsy
showed gross dilatation of both atria.
The other 17 patients had structural congenital heart malformations, which are summarized in Table II. One patient who had Ebstein’s anomaly and those who had Eisenmenger’s complex or single ventricle did not undergo surgery. In the other 14, atrial fibrillation developed at various intervals after operation.
Therapy
Digoxin was given to all 35 patients, together with quinidine in four and propranolol in five. No
anticoagulants were used.
Cardioversion was successful in six children and failed in four. The failures occurred in two infants
with tachyarrhythmias in whom sinus rhythm was later restored by drug therapy, in one patient with rheumatic heart disease in whom normal sinus rhythm occurred after surgery, and in one patient with cardiomyopathy who died of this
disease some time later.
Sixteen patients underwent surgery of their basic lesions: 2 had rheumatic valve disease and
14 had congenital heart disease. Both patients with rheumatic disease had mitral replacements, with tricuspid annuloplasty in one and excision of a huge left atrial appendage in the other. The latter patient is now in sinus rhythm.
The operations for transposition of the great arteries, common atrium, and total anomalous pulmonary venous drainage involved insertion of an atrial baffle or patch, and closure of the atrial septal defect was by suturing. Two patients with
tetralogy of Fallot and one with pulmonary atresia had severe tricuspid regurgitation postop-eratively and were treated by further surgery to the tricuspid valve. The other patient with
pulmonary atresia had a systemic-to-pulmonary
artery anastomosis; he died six years later, and necropsy revealed severe dilation of the right
atrium.
One patient with Ebstein’s anomaly underwent suture closure of two associated atrial septal defects in 1961. Ten months later, atrial fibrilla-tion developed and his clinical condition deterio-rated; an attempt to decompress the atrium by incising the septum was unsuccessful and he died.
Both children with congenital mitral valve abnormalities had coarctation of the aorta. One required annuloplasty for mitral regurgitation, after which atrial fibrillation developed; the mitral valve was replaced later, and normal sinus rhythm ensued. The other child had mitral stenosis and an atrial septal defect treated by valvotomy and atrial septal repair; he still has paroxysms of atrial fibrillation, seven years later.
Of the 16 patients who underwent surgery, three are dead (one with Ebstein’s anomaly, one with pulmonary atresia, and one with transposi-tion of the great vessels). Five continue to have paroxysmal atrial fibrillation (four with sick-sinus
syndrome and one following mitral valvotomy), two have permanent atrial fibrillation (one with rheumatic heart disease and one with tetralogy of Fallot), and the status of one is unknown. Five remain in sinus rhythm, three after surgery for atrioventricular valvular regurgitation and two
Sick-Sinus Syndrome
The sick-sinus syndrome developed in five patients (cases 4, 19, 21, 24, and 25), character-ized by the following bradyarrhythmias and tachyarrhythmias: sinus arrest and junctional bradycardia, atrial ectopic beats, atrial flutter, supraventricular tachycardia, and atrial fibrilla-tion. One patient died (case 4; hemochromatosis cardiomyopathy from thalassemia). The others were operated on for congenital heart lesions
(
transposition of the great vessels in two, a common atrium in one, and total anomalous pulmonary-venous drainage in one); three have been treated by cardioversion for tachyarrhyth-mias, without problems. These four patients, who have never had cardiac pacemakers, are beingmaintained on antiarrhythmia drugs; none has
had sustained atrial fibrillation.
DISCUSSION
Etiology
The association of atrial fibrillation with severe left atrial enlargement is well known,2:3.2 and necropsy studies have demonstrated damage to the sinoatrial node, fibrosis of the internodal tracts, and occlusion of the nodal artery.26 In the majority of our patients we documented atrial distension (particularly by regurgitant valve lesions) or irritation (by surgery or tumor). Endo-cardial fibroelastosis, also, may be associated with atrial arrhythmias2728; its pathology includes severe atrial fibrosis and dilatation. Thus, mechanical factors play a role in the genesis of atrial fibrillation.
In addition, the electrophysiological changes of
asynchrony of conduction and refractoriness render the atria vulnerable to fibrillation.2329 This mechanism is most strongly implicated in cardio-myopathy, in which atrial fibrillation develops in a diseased myocardium and usually heralds sudden death, presumably from ventricular fibril-lation. It has been shown that patients with the sick-sinus syndrome have atrial disease as well as local sinus-node injury.30 Thus, in this syndrome also, atrial fibrillation is engendered by both mechanical and electrophysiological changes.
Paroxysmal atrial tachyarrhythmias are well
known in infancy3’ and also occur in utero.32 They
usually carry a good prognosis, the majority never recurring after the first year of life. Although the prognosis is said to be poor if atrial fibrillation is present,33 this has not been our experience, as all four of our patients are alive and well: two had atrial fibrillation before therapy, and two had
atrial flutter initially which changed to fibrilla-tion when digoxin treatment was started. (There was no evidence of toxicity, but drug induction of this arrhythmia was implicated in these last two patients.) The girl with idiopathic paroxysmal atrial fibrillation (case 16, Table I) presented a rare problem: she did not fit the category of “lone atrial fibrillation,” which occurs predominantly in older men and is not paroxysmal,3 and had no known family history that would justify calling the condition “benign familial.”35
Therapy
In our series, the mainstay of treatment has been digoxin to control the ventricular rate and give inotropic support. In some cases it was
necessary to add propranalol or quinidine.
Anti-coagulants have not been used: consideration
might be given to their use, but in children the control of such therapy and the risks of hemor-rhage usually outweigh the potential value.
The question of cardioversion is important. Cenerally accepted contraindications for this procedure are (1) long-standing atrial fibrillation,
(
2) enlarged atria, and (3) associated cardiacfailure.22 These would apply particularly to patients with cardiomyopathy. A modern concept
is that atrial fibrillation due to rheumatic heart
disease is initially reversible, but later irreversible due to pathological changes in the atria secondary to the arrhythmia itself.23 Thus, early cardiover-sion is indicated, and such an approach is impor-tant in children with rheumatic or congenital heart disease. Also, appropriate surgical int#{233}rven-tion is necessary in these conditions when atrial
distension and high intra-atrial pressures can be reduced.
Prognosis
Prognosis obviously depends on the underlying cardiac disease, but it can be worsened by the onset of atrial fibrillation. Our experience with rheumatic heart disease is small, but has shown that a surgical approach can halt clinical deterio-ration. Cardiomyopathies have a generally poor prognosis, with a rapidly downhill course once atrial fibrillation develops. Contrary to previous statements,33 our experience suggests that atnal fibrillation occurring with other atrial tachyar-rhythmias in infancy has the same good prognosis for survival and nonrecurrence as these
arrhythmias. Operation to correct congenital
long-term natural history in these cases is not yet known.
IMPLICATIONS
From this review it is evident that atrial fibrillation is still a rare arrhythmia in children but can occur in association with a wide variety of conditions. We conclude that atrial fibrillation in infancy or childhood is not necessarily a sign of irreversible deterioration. Its recognition is an indication for complete investigation of the patient, and when the underlying condition is treatable, therapy should be aggressive, with drugs, cardioversion, and surgery, as appro-priate.
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