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Congenital heart block in successive pregnancies: a case report and evaluation of risk with therapeutic consideration.

SS-A antibody has been found to bind to fetal cardiac tissue and is thought to mediate congenital heart block via transplacental passage. Recent papers have identified various risk factors thought to define subclasses of SS-A antibody-positive mothers at greater risk of delivering children with congenital heart block. Treatment modalities for antibody-mediated fetal insult are now expanding and being used clinically. We report a case of a clinically asymptomatic SS-A antibody-producing mother who gave birth to two SS-A antibody-positive children with congenital heart block. It is our hope that ongoing refinement of risk factors and effective therapy will result in successful in utero palliation of the effects of SS-A antibody.

Adult↗

Significantly increased maternal and fetal IgG autoantibody levels to 52 kD Ro (SS-A) and La(SS-B) in complete congenital heart block.

Antibodies to Ro(SS-A) are an important laboratory parameter of congenital heart block (CHB), but the maternal presence of anti-Ro(SS-A) antibodies does not always lead to this fetal acquired autoimmune disease. The current study investigated quantitative and qualitative differences of anti-52, -60 kD Ro(SS-A), 0La(SS-B) and -U1RNP(-C, -A, -68 kD) autoantibodies (either IgG or IgM) in sera derived from 16 infants with CHB and their mothers compared to eight healthy anti-Ro(SS-A) positive infants (controls) born to SLE mothers. No serum sample contained IgM auto-antibodies of the specificities investigated. Anti-60, 52 kD Ro(SS-A) and La(SS-B) IgG antibodies coincided in 9/16 CHB cases, exclusively (P < 0.05). Associated anti-52 kD Ro(SS-A) and -La(SS-B) IgG antibodies were detected in 14/16 CHB and in 3/8 control cases (P < 0.05). Anti-U1RNP 68 kD antibodies occurred in 1/16 CHB infants and in 4/8 controls. In general, newborn and maternal antibody patterns and reactivities were similar in all cases investigated. The fetal CHB sera contained significantly higher IgG levels of anti-52 kD Ro(SS-A) (P < 0.005) and -La(S-B) (P < 0.015) compared to control samples. Sera from mothers with CHB children had significantly higher levels of anti-52 kD Ro(SS-A) (P < 0.015) and -La(SS-B) (P < 0.015) IgG antibodies than those of the control group. Thus, the coincidence of anti-52 kD, -60 kD Ro(SS-A) and -La(SS-B) IgG antibodies as well as significantly increased levels of antibodies to 52 kD Ro(SS-A) and La(SS-B) are associated with evidence of complete congenital heart block. The data suggest that the known associated humoral autoimmune findings are exclusively of maternal origin.

Autoantibodies↗

Utilization of fetal scalp pH and direct fetal electrocardiogram in the intrapartum management of congenital complete heart block in an adolescent primigravida.

This case report documents the antepartum detection of congenital complete heart block in the fetus of an adolescent primigravida. Management utilizing direct fetal electrocardiogram and fetal scalp sampling is discussed. The report illustrates the appropriate management of a fetus in utero with congenital complete heart block and suggests procedures to be taken prior to delivery in the expectant management of a neonate with a congenital conduction defect.

Adolescent↗

Repair of tetralogy of Fallot after catheterization-induced complete heart block.

The case of a four-year-old boy with tetralogy of Fallot who developed complete heart block during cardiac catheterization and subsequently underwent surgical repair in the presence of heart block is presented. Return to normal sinus rhythm occurred on the 11th postoperative day, and the manner in which increased atrioventricular conduction appeared was documented with the use of a continuous Holter monitor. Placement of a temporary transvenous pacemaker, systemic heparinization in the preoperative period, and the insertion of a permanent epicardial wire during surgery were performed.

Cardiac Catheterization↗

Complete heart block--another HLA B27 associated disease manifestation.

An increased prevalence of ankylosing spondylitis and other HLA B27-associated rheumatic diseases has recently been demonstrated in a group of men with permanent pacemaker-treatment. The purpose of the present study was to find out if HLA B27 was associated with severe bradyarrhythmias also in the absence of rheumatic disease. The frequency of B27 was determined in 83 permanently paced men with complete heart block, in whom presence of radiological or clinical signs of a B27-associated rheumatic disease had been excluded. Eighty-four healthy subjects were HLA typed for comparison. HLA B27 was found in 17% of the patients and in 6% of the controls, a significant difference with P = 0.017 (Fisher's exact test). The present study suggests that, in a subgroup of patients with complete heart block, the development of heart block is B27-associated, and that the pathophysiological mechanism is similar to that leading to ankylosing spondylitis. Another B27-associated disease manifestation has been demonstrated.

Adolescent↗

Ventricular pacing improves exercise tolerance in patients with chronic heart block.

Exercise capacity was assessed by means of a simple six minute walking test in a group of 18 patients with heart block whose only presenting symptom was breathlessness. None was in overt cardiac failure. Patients were studied before and after implantation of a transvenous, ventricular, demand pacing system (study group). Eight patients with an implanted pacemaker admitted for elective generator replacement were assessed in the same manner (control group). Exercise capacity in the study group was significantly increased within 48 hours of pacing, and this improvement was maintained in most patients during the follow up period of up to 30 months. In contrast, exercise capacity was unaffected by generator replacement in the control group. Simple ventricular pacing produces symptomatic benefit in patients with heart block accompanied by breathlessness. This benefit is apparent within 48 hours of pacing and is maintained; it can be assessed objectively by a six minute walking test.

Aged↗

Management with a staged approach of the premature hydropic fetus due to complete congenital heart block.

UNLABELLED: The management of the preterm fetus with hydrops due to complete congenital heart block is difficult. The outcome is frequently associated with significant morbidity and mortality. Two fetuses presented at the post menstrual age of 29 and 30 weeks respectively with severe hydrops due to complete heart block. The following staged approach was adopted: (1) enhance fetal lung maturation with maternal corticosteroids and thyroid releasing hormone for 48 h; (2) elective Caesarean section; (3) classical neonatal management consisting of intubation and ventilation, drainage of all cavities with effusions; (4) increase neonatal heart rate by administration of i.v. isoprenaline, by bipolar trans-oesophageal pacing or epicutaneo-oesophageal pacing; (5) after the regression of the hydrops, start epicardial pacing after implantation of 2 or 3 temporary epicardial 3/0 pacemaker; (6) implantation of a permanent abdominal pacing system with steroid epicardial tip once the threshold exceeds 20 mA or when the baby weighs more than 1500 g. In these patients a permanent pacing system was implanted at the ages of 8 weeks (2045 g) and 4 weeks (1560 g) respectively. No major complications occurred; the cardiac outcome with 37 and 34 months of follow up is excellent. CONCLUSION: This proposed staged approach with temporary epicardial leads can improve the outcome of hydropic fetuses due to complete congenital AV block.

Adult↗

Prevalence and morbidity of heart block in Devon.

In a survey in the Exeter area 139 patients with some degrees of abnormal atrioventricular conduction were notified by 282 family doctors. Per 100,000 of the population the prevalence of second-degree and thrid-degree heart block was estimated to be 17.3, of complete block past or present 15.6, and of complete block at the time of survey 13.1. Heart block was commoner in men than women, the sex ratio being 1.4 to 1; its prevalence increased steeply with age, and the morbidity rate was less than that reported by others. If the morbidity figures quoted in this survey are representative of the general population, it reaffirms the policy that pacemakers should be recommended for selected patients only.

Adolescent↗

Ethanol induction of complete heart block in swine.

OBJECTIVES: A method for the induction of complete heart block (CHB) by ethanol injection and its success rate in a pig model of acute right ventricular failure is reported. Additionally, a review of the literature for the induction of CHB in laboratory animals is detailed. The literature review was undertaken to both compare our rate of success with other methods and provide insight into our technique and refine its implementation. BACKGROUND: Animal models of CHB have facilitated the understanding of therapeutics for various cardiac pathologies in humans. In our laboratory, CHB in pigs is used for complete control of heart rhythm in studies of biventricular pacing. MATERIALS AND METHODS: Experiments carried out on pigs in our laboratory that required the induction of CHB were reviewed retrospectively. In addition, review of the literature for creating CHB in animals was undertaken. Our success rate was compared to that of other groups. RESULTS: Our success rate (93%) is similar to other models of CHB, in general, and to those models that used the injection of caustic substances with thoracotomy. CONCLUSIONS: Review of the literature indicates that our success rate is comparable to other groups and that, although many approaches have been described in both open- and closed-chest models, success is likely dependent on the practice and skill of the experimenter. In addition, review of the literature has afforded us new perspectives on the experimental induction of CHB.

Animals↗

Complete heart block during cardiac catheterization in a normal individual.

A 44-year-old white male who developed third-degree heart block during cardiac catheterization is presented. Right heart catheterization precipitated bifascicular block, right bundle branch block with left posterior hemiblock, and resulted in third-degree heart block during the left heart procedure. It is recommended that multiple electrocardiographic lead monitoring be considered during cardiac catheterization in order to recognize more easily high-risk conduction disturbances, ie a bifascicular block pattern with frontal plane axis shifts.

Adult↗

Myocyte transplantation for treatment of complete heart block.

We hypothesize that it may be possible to treat complete heart block by transplanting right atrial myocytes directly into the ventricular wall where they may set the rate of ventricular contraction at their own intrinsic rate. The biologic background for this conjecture has already been determined to a large extent. However, a few critical unanswered biologic questions must be addressed before the development of this suggested new therapy becomes a mere technologic exercise.

Animals↗

Chloroquine related complete heart block with blindness: case report.

A 27-year old African woman with history of regular chloroquine ingestion presented with progressive deterioration of vision, easy fatiguability, dyspnoea, dizziness progressing to syncopal attacks. Ophthalmological assessment revealed features of chloroquine retinopathy, cardiac assessment revealed features of heart failure and a complete heart block with right bundle branch block pattern. The heart block was treated by pacemaker insertion and the heart failure resolved spontaneously following chloroquine discontinuation. She however remains blind.

Adult↗

Associated cardiac lesions in patients with radiation-induced complete heart block.

We investigated the clinical, electrophysiological, haemodynamic and angiographic aspects of four patients (two men and two women, aged 31-46 years) who developed complete heart block 13-20 years after therapeutic irradiation of the chest for Hodgkin's disease. The initial cardiac symptom was syncope in three, effort intolerance in one. The electrocardiogram recorded third-degree atrioventricular block in three patients, right bundle branch block and posterior fascicular block in one. The electrophysiological study, performed in three cases, showed that the block was infranodal in two. Three patients had significant coronary arterial stenoses, that involved the ostia in two. All patients had mild-to-moderate aortic and mitral regurgitation. One patient had haemodynamic signs of constriction. Another patient had recurrent pericardial effusions. All had echocardiographic evidence of a thickened pericardium. Cardiac involvement can be extensive in patient with radiation-induced heart block. Because coronary artery disease can be particularly severe, coronary angiography appears to be warranted in such patients.

Adult↗

Complete heart block as a rare complication of treatment with chloroquine.

Antimalarials are well established disease modifying antirheumatic drugs. A rare and underappreciated treatment difficulty is cardiac complication, in particular conduction disturbances. We describe 2 more patients that developed complete heart block after high dose, longterm treatment. Patient 1, a 73-year-old woman with longstanding rheumatoid arthritis, had taken chloroquine (250 mg/day) for 12 years when she developed complete heart block requiring a permanent pacemaker. Patient 2, a 40-year-old woman with discoid lupus erythematosus, was taking chloroquine from 1979 until 1996. Depending on the clinical disease activity, she intermittently increased the dose from 250 to 750 mg/day. In 1994, she developed complete heart block and a permanent pacemaker had to be implanted. Intensive investigations in both cases did not reveal another underlying cause for conduction disturbances; the atrioventricular block was probably due in both cases to chloroquine related cardiac toxicity. This toxicity seems to be restricted to longterm, high dose treatment; however, it should be kept in mind in patients with preexisting conduction disturbances during longterm treatment.

Adult↗

Surgical technique to reduce the risks of heart block following closure of ventricular septal defect in atrioventricular discordance.

Traumatic heart block remains a major concern after ventricular septal defect (VSD) closure in patients with atrioventricular discordance. A technique of closing the VSD, placing the suture line on the morphologically right side of the septum without opening the systemic ventricle, is described. This was used in 13 consecutive patients. The VSD was closed through the right atrium in eight patients, the left ventricle in three patients, the right atrium and the left ventricle in one patient, and through the right ventricle in one patient with atrioventricular disordance and ventriculo-arterial concordance. All patients were in sinus rhythm preoperatively, two exhibited atrioventricular dissociation before intracardiac manipulation began, and 11 patients were in sinus rhythm postoperatively. No major arrhythmia could be attributed to the closure of the VSD.

Adolescent↗

Congenital heart block in newborns of mothers with connective tissue disease.

Of 22 children with congenital complete heart block (CCHB) available for study, 14 (63.6%) were born to 11 mothers with clinical or laboratory evidence of connective tissue disease, primarily lupus erythematosus (LE). Seven mothers had both clinical and laboratory evidence of disease while four had only positive laboratory studies including fluorescent antinuclear antibody, rheumatoid factor, and depressed complement levels. In adults with systemic LE, pathologic changes in the collagen surrounding the conduction system have led to the fibrosis and death from heart block. Antinuclear antibodies of the IgG class cross the placental barrier and newborn infants have been reported with transient skin lesions of lupus. Placental transmission of such antibodies may affect the fetal cardiac conduction system, surrounding collagen, and myocardium, leading in some cases to CCHB. This is probably one important etiologic factor in CCHB even though the mother is asymptomatic during her pregnancy.

Antibodies, Antinuclear↗