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PubMed2004

Autoimmune response in mothers of children with congenital and postnatally diagnosed isolated heart block: a population based study.

OBJECTIVE: To study the autoimmune response in mothers of children with isolated congenital heart block (CHB) and heart block (HB) diagnosed postnatally. METHODS: We reviewed the Finnish hospital registries for patients born between 1950 and 2000 and diagnosed with isolated HB before the age of 16 years. Clinical data and sera for the determination of autoantibodies were available from 67 mothers of children with CHB and from 37 mothers of children with postnatally diagnosed HB 9.9 years and 22.6 years (mean) after the index delivery, respectively. Maternal antibodies to 52 kDa and 60 kDa SSA and 48 kDa SSB were determined by time-resolved fluoroimmunoassay (TR-FIA) and by immunoblotting. Other marker antibodies for connective tissue diseases (CTD) were determined by immunoblot and/or by immunofluorescence. The control group comprised 136 mothers with primary Sjögren's syndrome (SS), systemic lupus erythematosus (SLE), or other CTD with healthy children. RESULTS: Sixty of our 67 mothers (90%) of children with CHB had antibodies to SSA or SSB by the methods initially used in this study. When retests and tests performed previously were taken into account, only 3 (4%) of the 67 mothers did not have any autoantibodies. Two (3%) of the 67 mothers had antibodies to dsDNA and one (1%) each to Jo-1/HRS, RNP-70 kDa, and histone proteins. Of 37 mothers of children with postnatally diagnosed HB, only 3 (8%) had any autoantibodies. Increased risk of having a child with CHB was indicated by maternal primary SS and high levels of anti-SSA and anti-SSB by all assays, whereas low risk was indicated by maternal SLE or other CTD and undetectable or low levels of the antibodies. No single anti-SSA or anti-SSB test was clearly superior to others, but in general, immunoblots were more specific than TR-FIA. CONCLUSION: Maternal autoimmune disorder is almost always associated with CHB but only rarely with postnatally diagnosed HB. Anti-SSA and anti-SSB are marker antibodies for mothers of children with CHB, and an increased risk of having an affected child is indicated by maternal primary SS and high titer antibodies to SSA and SSB.

Adult↗
PubMed1983

Effect of local lidocaine anesthesia on ventricular escape intervals during permanent pacemaker implantation in patients with complete heart block.

Transient asystole is often noted during the course of permanent pacemaker implantation in patients with complete heart block. Since subcutaneous lidocaine is frequently used as the local anesthetic agent for permanent pacemaker implantation, the effect of this drug on ventricular escape intervals was studied. Ventricular escape intervals after transient cessation of pacing were studied in 9 patients with complete heart block before and 10, 30, and 45 minutes after subcutaneous lidocaine administration for permanent pacemaker implantation. The total lidocaine dose ranged from 170 to 400 mg (1.9 to 9.5 mg/kg of body weight). Therapeutic blood levels were achieved in 7 patients. The mean ventricular escape interval before lidocaine was 1.83 +/- 0.32 seconds, which increased to 2.58 +/- 1.35, 2.96 +/- 1.06, and 2.68 +/- 1.27 seconds at 10, 30, and 45 minutes after lidocaine (p less than 0.02). The mean maximal escape interval before lidocaine was 2.06 +/- 0.30 seconds, which increased to 3.80 +/- 1.44 seconds (p less than 0.01), a mean increase of 84%. The percent increase in maximal escape interval was related directly to the peak lidocaine level achieved. After lidocaine administration, 5 patients had asystole greater than 4 seconds and 1 required resumption of pacing. Thus, subcutaneous lidocaine contributes to the occurrence of asystole seen during permanent pacemaker implantation. It is advisable to limit the amount of lidocaine administered during permanent pacemaker implantation to the minimum necessary to achieve adequate local anesthesia. Strong consideration should be given to the use of a temporary pacemaker in patients with complete heart block during permanent pacemaker implantation even in the absence of previous asystole.

Aged↗
PubMedDate not supplied

Q-T interval in congenital complete heart block.

The rate-corrected Q-T interval (Q-Tc) was measured in 273 children with congenital complete heart block. Fifty-nine had prolonged Q-Tc and 50 of these had symptoms. All 10 with isolated complete heart block, prolonged Q-Tc and bundle branch block had symptoms. The ventricular rate (VR) was significantly lower in patients with prolonged Q-Tc than in their age-matched controls. The outcome is worse for children with low VR and long Q-Tc than for those with low VR and normal Q-Tc. In 11 children a prolonged Q-Tc preceded symptoms by more than 1 month. This suggests that prolonged Q-Tc in children with congenital complete heart block can be of prognostic significance.

Adams-Stokes Syndrome↗
PubMed1996

Direct fetal therapy for hydrops secondary to congenital atrioventricular heart block.

BACKGROUND: The outcome for the fetus with hydrops fetalis secondary to complete congenital heart block is almost uniformly poor. Transplacental fetal therapy with inotropic drugs may be unreliable in the hydropic fetus. We describe our experience of direct fetal therapy with digoxin and furosemide in three cases. CASES: In the first two cases, fetal hydrops secondary to congenital heart block was detected at 33 and 31 weeks. Direct fetal therapy with digoxin and furosemide was given and the mothers received digoxin concurrently. The neonates were born normally at 35 weeks and 33 weeks; one required ventricular pacing, but both are currently alive and well. In the third case, fetal hydrops was detected at 24 weeks, when furosemide was used alone for direct fetal therapy. The mother developed chorioamnionitis at 29 weeks and was delivered by cesarean; the infant died of cardiac failure after 48 hours. CONCLUSION: Initial direct fetal therapy with digoxin and furosemide followed by transplacental treatment with digoxin and direct fetal therapy with diuretics might improve the perinatal salvage of hydropic fetuses with congenital heart block. Treatment must be individualized because development of infection and preterm labor might defeat the objective.

Adult↗
PubMed1992

The natural history of asymptomatic complete heart block. A case series from the Manitoba Follow-up Study.

Long-standing asymptomatic complete heart block is unusual in adults. The natural history of this condition with advancing age is unknown. Four cases of complete heart block documented in patients for 23 to 48 years are reported. These men had no evidence of structural heart disease and functioned normally without symptoms for many years. Three of the four subsequently developed symptoms and required permanent pacemaker insertion. These cases illustrate the good prognosis of asymptomatic complete heart block, but raise the concern that with advancing age, intervention with pacing frequently is necessary.

Adult↗
PubMed2004

Congenital complete heart block: fetal management protocol, review of the literature, and report of the smallest successful pacemaker implantation.

Fetuses with complete heart block have an increased mortality with most deaths occurring in utero or during infancy. The cardiac evaluation of these fetuses is difficult since the ventricular rate is low and the heart is dilated. We have implemented a strategy that includes the biophysical profile, which assesses fetal well-being, in combination with the cardiovascular profile that assesses cardiac function and the circulation. We present two cases of fetal complete heart block in which early delivery was recommended due to worsening cardiovascular profile scores. Biophysical profile scores were normal. Both babies were successfully treated, despite having risk factors that predicted poor outcomes. We hypothesize that our management protocol initiated intervention before fetal compromise, hydrops, and myocardial damage occurred. We recommend an evaluation of heart function in addition to an assessment of fetal well-being in fetuses with complete heart block. Early delivery should be considered if there is evidence of distress and/or deteriorating cardiac function.

Adult↗
PubMed1975

Complete heart block. Studies of atrial and ventricular pacemaker site and function.

Atrial and ventricular pacemaker function was studied in 20 patients with idiopathic chronic complete heart block using the rate response to an intravenous bolus dose of isoprenaline (5 mug/70 kg bodyweight). Pacemaker responses were compared with those of 16 normal control subjects. None of the patients was having syncopal attacks at the time of admission and they were therefore selected in that none required immediate pacing. Ten of the patients had His bundle electrograms; all were shown to have a pre-His type of atrioventricular block. Two major groups emerge from the responses to isoprenaline. (a) High risk group: 11 of the 14 patients with reduced ventricular pacemaker responses had frequent syncopal attacks; 8 of the patients with Adams-Stokes syncope had a bundle-branch block pattern, while 3 had a narrow QRS. These patients require pacing. (b) Low risk group: a low risk asymptomatic group (5 patients) was identified with atrial and ventricular responses to isoprenaline within normal range. One of these patients had a bundle-branch block pattern, while 4 had a narrow QRS. These patients might be managed without pacing. The atrial response to isoprenaline was reduced in 12 of the 20 cases, 10 of whom also had reduced ventricular responses. All 9 patients with bundle-branch block had reduced ventricular responses, while 7 had reduced atrial responses. This evidence indicates that cardiac conducting tissue pathophysiology is widespread in complete heart bolck. The present work suggests that consideration of the ventricular pacemaker function is important in assessing liability to syncope in complete heart block. While patients with Adams-Stokes attacks require pacing it is suggested that all asymptomatic patients with complete heart block and those with minor symptoms are assessed using studies of both ventricular pacemaker function and site. A low risk group not requiring a pacemaker may emerge after sufficient follow-up assessment.

Adams-Stokes Syndrome↗
PubMed1993

Antibody mediated complete congenital heart block in the fetus.

Complete congenital heart block (CCHB) affects 1:20,000-25,000 live births and is usually an atrioventricular block; 30-50% of fetuses with CCHB will have a structural anomaly, though recently attention has focused on the etiological influence of autoimmune disease, such as systemic lupus-erythematosus. The diagnosis is established by detailed two-dimensional ultrasound scanning of the heart to exclude anomaly coupled with M-mode echocardiography and Doppler blood velocity patterns in the major vessels to detect the uncoupling of atrial and ventricular rhythms. Risk factors for an affected child are discussed. A previously affected child, high titers of anti-Ro antibodies, the presence of anti-Ro (SS-A) and anti-La (SS-B), and maternal HLA DR3 confer high risk. Antibody mediated CCHB is irreversible. Plasmapheresis and immunosuppression have been attempted in affected mothers, with limited success, to reduce the likelihood of the fetus being affected, and steroids have been used to reduce the inflammatory reaction in the heart. In many cases the underlying pathology of the immune system adversely affects utero-placental function requiring careful monitoring of fetal well-being. CCHB renders fetal heart rate monitoring virtually useless, in the antenatal and intrapartum periods. Alternatives are explored.

Antibodies, Antinuclear↗
PubMed1997

VDD pacing in children with congenital complete heart block: advantages of a single pass lead.

A single pass lead for VDD pacing in complete heart block is well described in adults but there are only brief reports of its use in children. We used standard adult size single pass leads in ten children and adolescents aged 3.7-17.2 years (mean 9.9 years) and weighing 13.5-76 kg (mean 35.4 kg) with congenital complete heart block. One patient had coexisting congenital heart disease and had undergone surgery. A 2:1 atrioventricular block in one patient was presumed to be congenital in origin. In four patients, the VDD system was their first pacing system. In six of the patients, 1-4 previous systems had been used and simultaneous extraction of ventricular leads (6) and/or atrial leads (2) was performed. Four different types of lead were used: Brilliant IMP15Q (Vitatron); Brilliant + IMR15Q (Vitatron); CapSure 5032 (Medtronic); and Unipass 425-13 (Intermedics) with four different generators: Saphir 600 (Vitatron); Saphir II 620 (Vitatron); Thera VDD 8948 (Medtronic); and Unity 292-07 (Intermedics). All leads were introduced via a subclavian vein puncture and the atrial dipole was placed low in the right atrium to provide slack for further growth while maintaining atrial sensing. Ventricular thresholds ranged from 0.2-0.8 V. The minimal atrial amplitude was 0.7-4 mV and the maximum amplitude was 2.5-8 mV. There was one early microdisplacement and the lead was repositioned. Over a follow-up period ranging from 1-39 months (mean 20.4 months), all patients have maintained low ventricular pacing thresholds and adequate atrial signals for reliable pacing at rest and with exercise. During this time some have undergone considerable growth. The patient with coexisting congenital heart disease died suddenly at 3 years, but the pacing system had no fault at autopsy. The standard adult size single pass lead provides a simple means to enable reliable atrial synchronous ventricular pacing in growing children with complete heart block.

Adolescent↗
PubMed1989

Fetal and neonatal congenital complete heart block.

Fifteen cases of congenital complete heart block were diagnosed in utero or at birth, over a nine-year period. Six cases were confirmed by fetal echocardiography between 22 and 36 weeks of gestation. Two cases were treated in utero for cardiac failure, and serial ultrasonography was used to monitor the progress. Structural heart disease was present in seven (47%) infants; in four of these infants the defect was a corrected transposition of the great arteries. Ventricular pacing was required in seven patients--four infants with anatomically-normal hearts and three infants with associated structural heart disease. Eight children did not require permanent pacing, and remained well after a mean follow-up period of 23 months (range, one to 72 months). The mortality was highest in those patients with structural heart disease, three of whom died as neonates. Only one baby died with an anatomically-normal heart. Antinuclear antibodies were present in the mothers of seven of the eight infants who were born with a structurally-normal heart. Four mothers either had pre-existing connective-tissue disease or had developed manifestations of such disease subsequent to pregnancy. Of this group, all the women were antibody-seropositive to the nuclear antigen SS-A during pregnancy. Mothers of three infants had antinuclear antibodies in low titres, were seronegative for antibody to SS-A and remained free of the manifestations of connective-tissue disease. Six of the seven most-recent cases have been diagnosed in utero, which confirms a trend towards the more-frequent prenatal diagnosis of congenital heart disease as a result of the increased use of fetal monitoring and ultrasonography.

Antibodies↗
PubMed1998

Perinatal monitoring of fetal well-being in the presence of congenital heart block.

We present a case of congenital complete heart block associated with maternal autoantibodies in which a normal labor and delivery could safely be allowed to proceed despite the absence of the usual tool of electronic fetal heart rate monitoring for fetal distress, by the technique of rupturing membranes and using a fetal scalp electrode electrocardiographic tracing to assess the fetal atrial rate.

Echocardiography, Doppler, Pulsed↗
PubMed1989

Sinus of Valsalva aneurysm presenting with complete heart block.

An elderly woman presented with sudden unresponsiveness and complete heart block and subsequently expired. Postmortem examination revealed an aneurysm of the right sinus of Valsalva impinging on the cardiac conducting tissue. Only a few cases associated with complete heart block have been previously reported.

Aged↗
PubMed1977

Multiple arrhythmias detected during nocturnal monitoring in patients with congenital complete heart block.

Twenty patients with congenital complete heart block (CHB) were monitored with ECG tape recordings while awake and asleep. Episodes of marked ventricular slowing during sleep (R-R greater than 3000 msec., i.e. less than 20 beats/min) were noted in 35% (7/20). Most of these sudden R-R prolongations were 2:1 or 3:1 exit block of the junctional focus. Atrial and ventricular rate changes were mostly concordant in 2/3 but the remainder demonstrated fixed ventricular rates while atrial rates varied normally, suggesting a "sick" or "lazy" junctional focus. Other arrhythmias were found in 60% (12/20), including several types of rhythms in three patients. One child with previously unsuspected superimposed multiple arrhythmias later had a syncopal episode despite proven supra-Hisian block. The multiple patterns of atrial and ventricular rate changes found indicate complex feedback mechanisms, suggesting that congenital CHB is not a single entity. Since a significant number of patients demonstrated one or another of these unexpected and potentially hazardous findings, we recommend that congenital block patients be carefully studied, including Holter monitoring done on a regular basis.

Adolescent↗
PubMed1994

Neonatal lupus erythematosus. Report of serological and immunogenetic studies in twins discordant for congenital heart block.

Autoantibody, HLA studies and C4 phenotypes were performed on twins discordant for isolated congenital heart block. Serum from the mother and cord blood from the infants revealed Ro(SSA) and La(SSB) antibodies in all three sera. No significant difference in Ro(SSA) antibody titre was noted in the cord blood of either twin when compared with maternal titres, as detected by a sensitive ELISA assay. The infants' mother was HLA-DR3 positive. Both infants had identical HLA and C4 phenotypes. Immunoblot analysis revealed that sera from both mother and infants reacted with the 52-kDa Ro(SSA) macromolecule. Quantitative cord blood IgM levels were not elevated in either twin. This study indicates that placental transfer of anti-Ro(SSA) or anti-La(SSB) alone to the fetus is not sufficient for the expression of congenital complete heart block. We conclude from this experiment of Nature that there must be a second event determining which infant develops complete heart block, but this is unknown at present.

Adult↗
PubMed1992

Reversibility and benign recurrence of complete heart block in athletes.

In two patients, symptoms associated with complete heart block and physical training resolved with deconditioning. In one patient, symptoms recurred after resumption of training but she has remained well for 4 years without a pacemaker. This suggests that complete heart block induced by fitness is benign, even when symptomatic.

Adult↗
PubMed1983

Left ventricular function at rest and during exercise in congenital complete heart block: a radionuclide angiographic evaluation.

This study evaluates intrinsic cardiac performance during upright exercise in patients with congenital complete heart block. Left ventricular ejection fraction and volume were measured at rest and peak upright exercise with radionuclide angiography in 5 patients aged 11 to 39 years with congenital complete heart block: 4 were in New York Heart Association class I and 1 was in class II. The resting cardiac output was maintained at a normal level by an increase in end-diastolic volume rather than by a decrease in end-systolic volume. The left ventricular ejection fraction was normal at rest in all patients, but an abnormal response to exercise was noted in 3 patients. There was no appreciable change in the end-diastolic volume during exercise. Thus, patients with congenital complete heart block utilize the Starling mechanism to maintain normal resting cardiac output, but the response to exercise is usually abnormal even in the absence of symptoms.

Adolescent↗
PubMed1983

Complete heart block in chronic chloroquine poisoning.

Complete heart block of recent onset is reported and is attributed to chronic chloroquine abuse. Total blood chloroquine was more than two times higher in this patient than in 4 patients following therapeutic doses of chloroquine, and chloroquine basic metabolites were also proportionally higher in this patient's blood.

Chloroquine↗
PubMed1999

In utero treatment of fetal complete heart block with terbutaline. A case report.

BACKGROUND: Isolated fetal complete heart block is an uncommon finding, with a mortality rate of 20-30%. Various treatment modalities have been reported, with no consistent success. CASE: Fetal complete heart bock was diagnosed in a 30-year-old woman at 29 weeks' gestation. She had an elevated antinuclear antibody and anti-SSA antibody titer. Fetal cardiac decompensation was detected at 32 weeks. After a trial of intravenous isoproterenol without significant side effects, she was treated with oral terbutaline. An increase in the fetal ventricular rate and complete resolution of hydrops fetalis occurred. A male infant was delivered by cesarean section, at term, and underwent cardiac pacemaker implantation at 4 days of age. CONCLUSION: The treatment of fetal complete heart block is controversial. Premature delivery with cardiac pacing is associated with high morbidity and mortality. We report prenatal treatment with oral sympathomimetic medication, which allowed delivery to be delayed until term, with a successful outcome.

Administration, Oral↗