Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Heart Block”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 793 records · Page 44Linked to original sources
PubMed2005

Anti-SSA/Ro and anti-SSB/La antibody-mediated congenital heart block.

When anti-SSA/Ro antibodies are present in sera of mothers with connective tissue diseases, the incidence of congenital heart block (CHB) has been reported to be 1-2% in live births. The risk of recurrence of CHB in a subsequent child remains limited to 10-16%. CHBs are usually complete but CHB of the first or second degree can also be observed. In some cases, CHB is associated with endocardial fibroelastosis. Late-onset cardiomyopathy may occur later in life in these children. The mortality of CHB, which is predominant in utero and in the first months of life, is an estimated 16-19%. A pacemaker is required in about 66% of cases. Curative treatment of CHB is based on fluorinated steroids (dexamethasone or betamethasone) that do cross the placenta in an active form. Guidelines are available but further studies are needed to optimize treatment.

Antibodies, Antinuclear↗
PubMed2006

Impaired clearance of apoptotic cardiocytes is linked to anti-SSA/Ro and -SSB/La antibodies in the pathogenesis of congenital heart block.

The role of cardiocytes in physiologic removal of apoptotic cells and the subsequent effect of surface binding by anti-SSA/Ro and -SSB/La antibodies was addressed. Initial experiments evaluated induction of apoptosis by extrinsic and intrinsic pathways. Nuclear injury and the translocation of SSA/Ro and SSB/La antigens to the fetal cardiocyte plasma membrane were common downstream events of Fas and TNF receptor ligation, requiring caspase activation. As assessed by phase-contrast and confirmed by confocal microscopy, coculturing of healthy cardiocytes with cardiocytes rendered apoptotic via extrinsic pathways revealed a clearance mechanism that to our knowledge has not previously been described. Cultured fetal cardiocytes expressed phosphatidylserine receptors (PSRs), as did cardiac tissue from a fetus with congenital heart block (CHB) and an age-matched control. Phagocytic uptake was blocked by anti-PSR antibodies and was significantly inhibited following preincubation of apoptotic cardiocytes with chicken and murine anti-SSA/Ro and -SSB/La antibodies, with IgG from an anti-SSA/Ro- and -SSB/La-positive mother of a CHB child, but not with anti-HLA class I antibody. In a murine model, anti-Ro60 bound and inhibited uptake of apoptotic cardiocytes from wild-type but not Ro60-knockout mice. Our results suggest that resident cardiocytes participate in physiologic clearance of apoptotic cardiocytes but that clearance is inhibited by opsonization via maternal autoantibodies, resulting in accumulation of apoptotic cells, promoting inflammation and subsequent scarring.

Animals↗
PubMed1975

[Syncopal convulsions with myocarditis in childhood. A case contribution to the transitory pacemaker treatment of myocarditis-induced heart block].

A ten-year-old girl was admitted to hospital with convulsions due to Adams-Stokes syndrome as a complication of complete heart block. A rheumatic myocarditis was causing the conduction defect. As a temporary measure a pacemaker was used to treat the extremely serious condition. In addition, cortisone, antibiotics and antiphlogistics were given for treatment of the underlying disease. The child was discharged from hospital in good condition with a long-term therapy of penicillin.

Adams-Stokes Syndrome↗
PubMed1995

Clinical and serological identification of 2 forms of complete heart block in children.

OBJECTIVE: To study the association of maternal antibodies to Ro(SSA) and/or La(SSB) with isolated complete congenital heart block (CCHB) in children according to the child's age at detection. METHODS: Sera from 17 mothers of 18 children with CCHB of unidentified cause were studied. Autoantibodies were measured by double immunodiffusion, enzyme linked immunosorbent assay (ELISA), Western blot, and immunoprecipitation from cell extracts. Statistical analysis used the chi 2 test with Yates' correction. RESULTS: CCHB was diagnosed in 12 children of 11 mothers before the age of 3 mo (Group A) and in 6 children of 6 mothers after the age of 17 mo (Group B). Seven Group A mothers and no Group B mother had connective tissue disorders; autoantibodies were found in 9/11 Group A and in 1/6 Group B mothers (p < 0.01). Eight Group A children needed a pacemaker and one other died of cardiac insufficiency, whereas only one of the 6 Group B children needed a pacemaker. Interestingly, this latter child was the only one from Group B whose mother's serum contained autoantibodies. Irrespective of their age at diagnosis, the children with CCHB who needed a pacemaker and the one who died were born to mothers with autoantibodies (p < 0.001). CONCLUSION: CCHB detected before the age of 3 mo is highly associated with the presence of anti-Ro(SSA)/La(SSB) in the mothers, while CCHB diagnosed later is generally not. For epidemiological studies, the former type should be considered early onset as opposed to late onset CCHB in the latter type. Establishing this clinicoserological distinction is also important for the children, since it alerts the clinician to a more severe prognosis (necessity of a pacemaker), even in the rare occurrence of late diagnosed CCHB.

Adolescent↗
PubMed1982

Pacemaker implantation in a neonate with congenital complete heart block--a case report.

Reported herein is our experience with pacemaker implantation in a neonate with complete AV block and without other concomitant cardiac anomalies. A male fetus exhibited an intrauterine heart block rate of about 40 beats per minute on the electrocardiogram. An emergency pacemaker implantation was attempted at birth by means of intravenous temporary pacing to relieve signs of congestive heart failure. On the 28th day of life, a myocardial electrode was fixed on the right ventricular wall and the generator was positioned on the left side of the subcutaneous abdominal wall. A technical device was designed by means of packing pacemaker wire in a loop-forming fashion with a silastic sheet and was made in such a way as to adjust with growth of the patient. During the 2 year follow-up period, this technique proved to be effective. Our experience also supports the contention that pacemaker implantation in the newborn is feasible and beneficial in the treatment of congenital complete AV block.

Cardiac Pacing, Artificial↗
PubMedDate not supplied

A case of maternal subclinical Sjögren's syndrome associated with congenital heart block.

A case of subclinical Sjögren's syndrome was diagnosed when the patient delivered a baby with SSA antibody-positive congenital heart block (CHB). The mother had been asymptomatic throughout her life. The laboratory findings including sialography, lip biopsy, Schirmer's test and a Rose-Bengal test showed Sjögren's syndrome. Such an asymptomatic case is termed subclinical Sjögren's syndrome. Thus, it was important to investigate an asymptomatic mother who delivers a SSA antibody-positive CHB baby.

Acidosis, Renal Tubular↗
PubMed1988

Subsidiary pacemaker function in complete heart block after His-bundle ablation.

To investigate the electrophysiological properties of ventricular impulse formation after His-bundle ablation in 11 patients, incremental ventricular overdrive stimulation studies were performed. The studies, which were spread over a follow-up period of up to 601 days, were carried out invasively with temporary leads as well as noninvasively with the implanted pacemakers and chest wall inhibition. The overdrive pacing rate was increased in steps of 10 beats/min, and the pacing duration was 2 minutes at each level. Ten out of 11 patients had a reliable ventricular escape rhythm; in the remaining patient, consistently no subsidiary pacemaker function was observed up to 10 seconds. In 83% of the studies, incremental ventricular overdrive stimulation caused progressive suppression of ventricular impulse formation with exponential increase in ventricular recovery time and progressive postrecovery subsidiary pacemaker depression. In the remaining 17%, ventricular recovery time showed a heterogeneous response to overdrive stimulation--as possible cause alterations in the sympathetic tone and limitations attributable to the method used are discussed. The results of this study demonstrate a rate-dependent overdrive suppression of subsidiary ventricular pacemaker tissue. This can be of clinical importance in patients with complete heart block and rate-adaptive pacemakers because sudden pacemaker failure or temporary pacemaker inhibition at high stimulation rates may cause Stokes-Adams attacks not reproducible at lower pacing rates.

Aged↗
PubMed1988

Complete congenital heart block: risk of occurrence and therapeutic approach to prevention.

A retrospective literature review revealed that in 41% of cases of complete congenital heart block (CCHB) there was at least one other affected sibling, emphasizing the considerable risk of carrying a second affected fetus with CCHB. Therefore an aggressive approach was taken to prevent CCHB in a fetus with a high risk for the condition as defined by (1) presence of DR3 and high titers of antibodies to SSA(Ro) and SSB(La) in the mother (2) previous history of CCHB in a sibling. In a feasibility study, thrice weekly plasmapheresis was initiated in the 19th week of gestation to remove antibodies from the maternal circulation in advance of major placental transport to the developing fetus. Prednisone was also administered to decrease antibody synthesis. The concentration of total maternal IgG and antibodies to SSA(Ro) and SSB(La) were decreased by greater than 60% during the course of therapy. Planned delivery of a healthy baby was done at 36 weeks.

Adult↗
PubMed1978

The risk of advanced heart block in surgical patients with right bundle branch block and left axis deviation.

The risk of advanced atrioventricular block during anesthesia was studied prosepctively in 44 patients with right bundle branch block and left axis deviation who underwent a total of 52 operations over a 14 month period. All patients had continuous electrocardiographic monitoring throughout anesthesia induction, operation, and surgical recovery. Of the 52 operative procedures, 24 were done under general anesthesia, 11 under spinal, and 17 under local. The preoperative cardiac rhythms were atrial fibrillation in two patients, atrial tachycardia with block in one patient, atrial flutter in one patient, and sinus rhythm in the remaining patients. Temporary pacemakers were inserted preoperatively in six patients, usually because of PR interval prolongation on the preoperative electrocardiogram. There was only one episode of transient complete heart block in 51 of the 52 operative procedures. In two of the six patients with temporary pacemakers, significant pacer-related ventricular irritability occurred. This study indicates that temporary pacemaker insertion is rarely required in patients with chronic right bundle branch block and left axis deviation who require noncardiac surgery.

Adult↗
PubMed1988

An autopsy case of congenital complete heart block in a newly born of a mother with systemic lupus erythematosus.

An autopsy case of congenital atrioventricular (AV) heart block is described. A newborn infant of a mother with systemic lupus erythematosus died 10 h after birth. Autopsy revealed hematoxylin bodies in the AV node, central fibrous body, and fibrous annulus of the heart. Also, immunoglobulin G (IgG) localization in the hematoxylin bodies was demonstrated by an immunoperoxidase technique. It is suggested that IgG or immune complexes crossed the placenta and that the immune deposition directly injured the cardiac conduction system, causing AV block.

Atrioventricular Node↗
PubMed1998

Induction of in vitro heart block is not restricted to affinity purified anti-52 kDa Ro/SSA antibody from mothers of children with neonatal lupus.

The ability of affinity purified anti-52 kDa Ro/SSA antibody from patients without obstetric history of neonatal lupus to cause heart block using an experimental model was investigated. IgG-enriched fractions from sera of 20 systemic lupus erythematosus (SLE) and one Sjögren's syndrome (SS) all positives for anti-Ro/SSA antibodies as detected by CIE, were perfused on isolated whole rabbit hearts. Only six (29%) samples induced A-V block, five of them presenting low anti-Ro/SSA titre. All of them recognized the 52 kDa isoform on ELISA whereas only one had a concomitant binding to the 60 kDa protein. Moreover, affinity purified antibodies from two sera previously known to induce A-V block were obtained by affinity chromatography using a column containing the full-length 52 kDa Ro/SSA fusion protein. Paired eluate and effluent devoid of anti-52 kDa activity from the same patient were individually perfused in whole hearts. The ability to cause cardiac blockade was restricted to the affinity anti-52 kDa eluates. In addition, anti-52 kDa eluates from three IgG fractions that primarily failed to induce blockade remained ineffective. The present study has added to our knowledge that affinity anti-52 kDa Ro/SSA antibodies from mothers with healthy infants are capable of causing in vitro cardiac conduction disturbances. A prospective follow up of these patients will better delineate the clinical usefulness of this experimental model.

Antibodies, Antinuclear↗