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Anti-SSA/Ro antibodies and the heart: more than complete congenital heart block? A review of electrocardiographic and myocardial abnormalities and of treatment options.

Apart from complete and incomplete congenital heart block (CHB), new cardiac manifestations related to anti-SSA/Ro antibodies have been reported in children born to mothers bearing these antibodies. These manifestations include transient fetal first-degree heart block, prolongation of corrected QT (QTc) interval, sinus bradycardia, late-onset cardiomyopathy, endocardial fibroelastosis and cardiac malformations. Anti-SSA/Ro antibodies are not considered pathogenic to the adult heart, but a prolongation of the QTc interval has recently been reported in adult patients and is still a matter of debate. Treatment of CHB is not well established and needs to be assessed carefully. The risks and benefits of prenatal fluorinated steroids are discussed.

Adult↗

First-trimester fetal heart block and increased nuchal translucency: an indication for early fetal echocardiography.

Prevalence of congenital heart disease increases with nuchal translucency (NT) thickness. First-trimester fetal bradycardia may result from heart block associated with complex congenital heart disease. We report two cases detected in the first trimester of pregnancy, in which both fetuses showed an increased nuchal translucency and bradycardia. Fetal karyotype was normal in both fetuses. First-trimester fetal echocardiography was performed and, in both cases, complex congenital heart disease was diagnosed. We discuss the added role of fetal heart rate in first-trimester ultrasound screening, in fetuses with increased nuchal translucency and normal karyotype. We stress, as well, the importance of echocardiography performed in the first trimester as a potential tool for early diagnosis in selected cases.

Adult↗

Neonatal lupus and congenital complete heart block: manifestations of passively acquired autoimmunity.

The neonatal lupus syndromes, which comprise transient hematologic and cutaneous disorders as well as the permanent manifestation of heart block, are considered to result from injury by passively acquired maternal autoantibodies. The active placental transport of maternal IgG antibodies becomes operative late in the second trimester coincident with the time at which bradycardia and myocarditis become evident. Surprisingly there are no clinically detectable abnormalities in the maternal hearts. The recognition that antibodies to the SSA/Ro-SSB/La ribonucleoprotein complex were found in 85% of sera from mothers of offspring with neonatal lupus was an important advance and directed attention to these antigens as potential candidates despite their intracellular location. In the present review we describe an experimental approach to the treatment of a fetus diagnosed by in utero echocardiogram to have congenital complete heart block and to the prevention of this condition in an at-risk pregnancy. In an attempt to more specifically define the relevant antigen-antibody systems involved in the pathogenesis of neonatal lupus we have utilized the technique of immunoblot to evaluate sera from mothers of offspring with permanent manifestations of neonatal lupus including heart block and hepatic fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoantigens↗

Pacing in preterm with hydrops fetalis due to congenital complete heart block.

Hydrops fetalis due to congenital complete heart block (CCHB) is a rare condition. The outcome of the preterm fetus with hydrops fetalis due to CCHB is poor, and is frequently associated with significant morbidity and mortality. The management of this condition is difficult. We report our experience in a hydropic preterm using staged pacing by applying left ventricular epicardial pacing with a temporary pacemaker and subsequently, left ventricular epicardial pacing with a permanent pacemaker.

Cardiac Pacing, Artificial↗

Creating permanent complete heart block by indirect cauterization without atriotomy.

We created permanent complete heart block (CHB) in 11 dogs without atriotomy by means of indirect cauterization of the atrioventricular (A-V) bundle with a partially insulated wire placed through a small puncture in the atrial wall and guided by palpation. In six acute studies and five chronic studies, all dogs exhibited permanent CHB. To test the block, isoproterenol increased both atrial and ventricular rates 200%-400% without affecting the block. Atropine had no effect on ventricular rate or block.

Animals↗

Fetal ventricular rate in case of congenital complete heart block is increased by ritodrine. Case report.

We encountered a case of fetal bradycardia (57 bpm) induced by heart block. The continuous intravenous administration of ritodrine to a mother to treat fetal brady-cardia at 28 weeks of gestation successfully increased the fetal ventricular rate by 15 bpm (from 57 to 72 bpm). Pregnancy was continued for 10 weeks, and fetal cardiac failure did not occur. The fetal ventricular rate gradually decreased to 52 bpm after discontinuation of the ritodrine infusion. It is suggested that maternal administration of ritodrine can be considered in a case of life-threatening fetal bradycardia induced by complete heart block.

Adult↗

Comparison of patients with acute anterior or posterior myocardial infarcts with and without complete heart block.

The differences between myocardial infarct (MI) size, amount, and type of conduction fiber injury and outcome in patients with acute anterior or posterior (inferior) MI with or without complete heart block (CHB) were compared. In patients with acute anterior MIs with CHB the infarcts were larger, CHB was more persistent, necrosis involved the more anterior portions of the conduction system, and the terminal event was cardiogenic shock; whereas in the smaller acute posterior MIs with CHB, the CHB was usually transient, necrosis involved the more posterior portions of the conduction system, and terminal arrhythmias were the main cause of death. This is the first quantitative study that documents the larger size of anterior infarcts with complete heart block in comparison with posterior infarcts with complete heart block.

Heart Block↗

Heart block associated with spinocerebellar ataxia type 2.

A 20-year-old man was discharged from the U.S. Army because of increasing gait abnormalities. One year later, he developed episodes of syncope secondary to high-degree atrial/ventricular block with periods of complete heart block and ventricular asystole. A permanent dual-chamber, rate-responsive cardiac pacemaker was implanted. At age 29 years, an abnormal expansion of the CAG trinucleotide repeat in the ataxin-2 gene on chromosome 12 was identified. This case suggests that cardiac conduction abnormalities should be included as part of the recognized clinical heterogeneity of spinocerebellar ataxia type 2.

Adult↗

Torsade de pointes and syncopal attacks in a 26-year old woman with congenital complete heart block and prolonged QT interval.

A 26-year old woman with congenital complete heart block and prolonged QT interval presented for the first time with syncopal attacks associated with torsade de pointes in adulthood. Cardioversion followed by overdrive pacing was needed to finally control the unstable rhythm. During episodes of non-capture, paraoxysms of torsade de pointes leading to ventricular flutter were recorded by a 24-hour ambulatory electrocardiographic monitoring. Beta-blockade and permanent ventricular pacing finally abolished both the syncopal attacks and the torsade phenomena. The prognosis of congenital complete heart block associated with QT prolongation resembles that of the Romano-Ward syndrome. Recognition of this variant would facilitate earlier treatment of this rare but potentially lethal disorder.

Adult↗

An analysis of the circadian rhythmicity of atrial and ventricular rates in complete heart block.

A 19 year old female human subject with complete heart block was put at complete bed rest for 63 hours during which a Lead II EKG was monitored at half hour intervals. Atrial and ventricular rates demonstrated cyclic activity with peaks during the day and troughs during the night. A correlation coefficient of plus 0.85 and a slope of plus 1.0 from a linear regression between atrial and ventricular rates demonstrated a close parallel. Calculation of the crosscovariances confirmed the observed cyclic activity with a period of 24 hours and phase angle of zero degrees between the two chambers. The data may be explained by one or all of the following mechanisms: (1) both chambers are subject to the same internal milieu, (2) autonomic nervous system discharge and associated reflexes may integrate relative changes in rate, (3) direct mechanical or electrotonic forces may result in alteration of rates in direct proportion to the magnitude of the dominant chamber, (4) program which operates independent of external factors. The question remains for direct experimental data to demonstrate whether the observed phenomenon is an intrinsic biologic rhythm within the heart or in its control system.

Adult↗

Role of HLA in congenital heart block: susceptibility alleles in mothers.

In congenital heart block (CHB), abnormal maternal immunisation leads to autoantibody production against SS-A/Ro and SS-B/La antigens. These maternal antibodies are transferred across the placenta to the unborn child and are believed to transmit irreversible immunological injury in developing foetal heart tissue, thus causing 3rd-degree atrioventricular block. The mothers may suffer from systemic lupus erythematosus (SLE) or primary Sjögren's syndrome (SS), but they may be asymptomatic. Women with primary SS show a typical autoimmune HLA antigen pattern, namely higher frequency of HLA B8 and DR3 than in the normal population. The HLA pattern may affect individual ability to resist infecting bacteria and viruses and to response in various ways to autoantigens. It is probable that other factors such as genetic regulation of immune response are involved in CHB. We compared the HLA class I and class II alleles of mothers having CHB children with those of women suffering from primary SS and having healthy children, and with those of healthy Finns. Antibodies against 52-kD and 60-kD SS-A/Ro and 48-kD SS-B/La antigens were compared between the two groups of mothers. Our results show that anti-SS-A/Ro antibody-positive mothers all show a strong association with known autoimmune-predisposing HLA alleles, however, the mothers of CHB children differ in some HLA class I alleles, and especially in HLA haplotypes, from mothers of healthy children. Mothers with HLA A1, Cw7, B8 and without B15 are at particularly high-risk of having CHB children.

Alleles↗

Immediate and persistent complete heart block following a horse kick.

Nonpenetrating chest trauma has been reported to cause acute and transient disorders of impulse formation and propagation, including intraventricular conduction delay and heart block. We report a case of immediate and sustained complete heart block following blunt chest injury.

Animals↗

Heart block, sudden death, and atrioventricular node mesothelioma.

We report a case of mesothelioma of the atrioventricular node with congenital complete heart block and sudden death in a 15-year-old girl. This benign tumor probably represents a hamartoma derived from mesothelium with a constant anatomic location and uniform association with heart block. The clinical course of such patients, however, has been variable. The tumor has been associated with sudden, unexpected death in infancy or adolescence, but has more often been discovered as an incidental finding at autopsy in a middle-aged or elderly patient.

Adolescent↗

Asymmetric septal hypertrophy presenting with cardiogenic shock, complete heart block, and septal infarction despite normal coronaries.

A 37-year-old man, brought in following a syncopal episode, was found to be in cardiogenic shock with a complete infranodal heart block. A temporary transvenous pacemaker and an intra-aortic balloon pump were inserted emergently. Cardiac catheterization revealed a high left ventricular end-diastolic pressure but normal coronary vasculature. An echocardiogram demonstrated a hyperdynamic left ventricle, severe hypokinesis of the septum, and asymmetric septal hypertrophy. An endomyocardial biopsy showed myofibril hypertrophy and disarray. The patient required implantation of a permanent pacemaker for full recovery. Although arrhythmias are common in asymmetric septal hypertrophy, complete atrioventricular block is rare but can cause syncope and cardiogenic shock. This is the first case, reported in the literature, of asymmetric septal hypertrophy in which the patient presented with cardiogenic shock and complete heart block secondary to a septal infarction, despite normal coronaries, and in whom a myocardial biopsy was performed. The case report is followed by a review of the literature on hypertrophic cardiomyopathy associated with complete heart block.

Adult↗