Case report: Concurrent congenital complete atrioventricular block, Meckel's diverticulum and cerebral palsy in a 19-year-old male

A case report is described of a patient with cerebral palsy and Meckel's diverticulum presenting with congenital atrioventricular (AV) block. There is limited information of congenital heart block in adults, because most literature has been devoted to congenital heart block in childhood. This unique case is discussed with other patient groups' with congenital AV block. Long-term follow-up of congenital heart block is reviewed together with the concept of prophylactic pacemaker placement in symptom-free adults.

Neonatal lupus syndromes

Neonatal lupus has become an important model of passively acquired autoimmunity since the seminal observation in the late 1970s that sera from nearly all mothers of children with isolated congenital heart block (CHB) contain specific autoantibodies.

Optimal Pacing in Congenital Complete Atrioventricular Block of Immunological Origin: Interest of Multisite Stimulation

An infant with a congenital auriculoventricular block (CAVB) of immunological origin was diagnosed prenatally. The mother had Gougerot-Sjögren disease with positive anti-Sjogren's Syndrome A (SSA) and Sjogren's Syndrome B (SSB) serologies. Cardiac pacing was necessary and the epicardial route was chosen. Considering the left ventricular (LV) dilatation, bi-ventricular (BiV) stimulation was preferred to the usual DDD mode, presumed to have a deleterious long-term effect. Echographic parameters were better with BiV stimulation: the asynchronism induced by mono-RV stimulation was corrected and the QRS complexes were narrower. BiV pacing of a CAVB with LV dilation looks clinically and echographically attractive but needs to be validated in the long term.

Prenatal diagnosis of congenital complete heart block

Congenital complete heart block (CHB) is a conduction defect with an incidence in the general population of 1/15,000 to 1/22,000 live births. It is frequently associated with structural heart defects or maternal autoimmune disease. We describe a case of CHB associated with maternal systemic lupus erythematosus and review our previous cases and experience of CHB.

Early Detection of Regional Myocardial Dysfunction in Paced Children With Congenital Complete Atrioventricular Block

BACKGROUND

Right ventricular apical pacing leads to global left ventricular dysfunction. Assessment of regional myocardial function may allow for earlier detection of pacing-induced myocardial remodeling. The aim of this study was to evaluate regional myocardial function in paced children with congenital complete atrioventricular block (CCAVB).

METHODS

We investigated regional myocardial function using strain echocardiography and tissue velocity imaging in 10 paced children with CCAVB and in 14 age-matched healthy children. Echocardiograms of the paced children were obtained during intrinsic junctional rhythm.

RESULTS

All patients had normal biventricular size and global function. The time from R wave to peak regional strain rate and the time from R wave to peak regional myocardial tissue velocity were measured in nine segments. The differences between maximum and minimum values were used as a measure of contraction delay (dSR and dTV). Study group patients had significantly higher dSR and dTV values compared to the control group. Mean peak strain rates and peak tissue velocities obtained from same segments were significantly decreased in the study group compared to the control group. Regional dysfunction was more prominent in the areas of ventricular pacing. No significant correlation is found between the duration of pacing (2.5-18 years) and dSR, dTV, mean peak strain rates, or mean peak tissue velocities.

CONCLUSION

Pacing leads to regional myocardial dysfunction that can be detected with strain echocardiography and tissue velocity imaging during intrinsic junctional rhythm in children with CCAVB. Pacing-induced regional myocardial remodeling does not seem to progress with long-term right ventricular pacing in children with CCAVB.

Electrocardiographic abnormalities in infants born from mothers with autoimmune diseases a multicentre prospective study

OBJECTIVES

To assess the prevalence of congenital heart block (CHB) and electrocardiographic (ECG) abnormalities in infants of anti-Ro/SSA-positive women.

METHODS

Sixty anti-Ro-positive and 36 anti-Ro-negative patients were prospectively followed before/during pregnancy and underwent weekly fetal echocardiography from 18th to 26th weeks of gestational age. Infants' ECG and/or ECG-Holter were performed at 1, 3, 6 and 12 months. ECG of 200 consecutive neonates were used as a healthy control group.

RESULTS

One of 61 fetuses of anti-Ro-positive mothers developed CHB (20th week); another anti-Ro-positive baby developed second degree atrioventricular (AV) block (30th week). The prevalence of transient first degree AV block detected post-natally was significantly higher in the anti-Ro-positive group, in comparison with healthy controls (P = 0.002). No differences in corrected QT (QTc) interval prolongation prevalence (>/=440 ms) was observed between the anti-Ro-positive and -negative groups, but both were significantly higher than that of the control population (P < 0.001). ECG-Holter showed QTc prolongation in 59% of infants of anti-Ro-positive and in 60% of infants of anti-Ro-negative mothers. Holter QTc was >/=470 ms in four infants of anti-Ro-positive group and two of anti-Ro-negative group. Known acquired causes of QTc prolongation were excluded.

CONCLUSIONS

This prospective study confirms the low occurrence of CHB in newborns from anti-Ro-positive mothers. ECG abnormalities (first degree AV block and QTc interval prolongation) are frequent in infants of mothers with autoimmune diseases, independently of maternal disease, autoantibody profile and treatment during pregnancy.

[Spinal anesthesia in a patient with congenital complete atrioventricular block]

Congenital complete atrioventricular block is a rare cardiac conduction abnormality that predisposes to arrhythmias and cardiac arrest. Recommendations for the anesthetic management of patients with this condition are based on the few case reports that have been published. We describe the successful use of spinal anesthesia for ankle osteosynthesis in a patient with asymptomatic congenital complete atrioventricular block detected during preoperative assessment.

Transient heart block in a neonate associated with previously undiagnosed maternal anti-Ro/SSA and anti-La/SSB antibodies

This report presents the case of an infant who was born with transient complete heart block. The cardiac rhythm converted to normal sinus rhythm within 12 hours of life. Following the diagnosis in this infant of congenital heart block, both the mother and the infant were tested for autoantibodies. Both were found to be strongly positive for anti-Ro/SSA antibodies. The infant was also weakly positive for the anti-La/SSB antibodies and her mother moderately positive for the same. Congenital heart block associated with these maternal antibodies is well documented in the literature; however, this is the only reported case that documents a transient nature of the complete heart block.

Long-term follow-up after pacemaker implantation in neonates and infants

BACKGROUND

Pacemaker (PM) system implantation in neonates and infants is often complicated by hemodynamic instability, small vessel size, and abnormal cardiovascular anatomy. Thus, an open surgical approach for epicardial lead insertion is often required. We assessed the long-term outcomes after epicardial PM implantation in this age group.

METHODS

Between 1992 and 2004, 22 consecutive patients underwent PM implantation within the first year of life. Bipolar steroid-eluting epicardial leads (Medtronic CapSure Epi 10366 and 4968) were inserted through median sternotomy, the sybxyphoid approach, or thoracotomy, and connected to various pulse generators.

RESULTS

Pacemakers were implanted at a median age of 35 days (range, 1 to 300). Intracardiac anatomy was abnormal in 17 patients. Indications for PM therapy were heart block in 18 patients and sinus node dysfunction in 4 patients. During a median follow-up of 4.6 years (range, 4 days to 12.8 years), 7 devices were replaced owing to end of battery life (n = 6) or elective device repositioning (n = 1), at a median of 4.1 years (range, 1 to 7.8). One dislodged ventricular lead and 2 atrial lead sensing failures were observed. Sensing, pacing thresholds, and lead impedances showed good implant and stable follow-up values.

CONCLUSIONS

Pacemaker-associated morbidity is low. Pacemaker system complications with epicardial leads are rare. Battery life is relatively shorter compared with children and adults because of the fast heart rate and complete PM dependency in most of these children. Even for neonates and infants, modern pacemaker therapy is feasible, safe, and effective.

Ventricular Function and Long-Term Pacing in Children with Congenital Complete Atrioventricular Block

OBJECTIVE

To determine the sequela of right ventricular pacing in children with congenital complete atrioventricular block.

BACKGROUND

Pacing is a well-accepted therapy for patients with congenital complete atrioventricular block. The long-term sequela of right ventricular pacing in this population has not been well described.

METHODS

We performed a cohort study on all patients with congenital complete atrioventricular block who underwent pacemaker implantation at our institution from 1972 to 2004. Patients with associated congenital heart disease or ventricular dysfunction prior to pacemaker implantation were excluded.

RESULTS

A total of 63 patients were included in the study. The median age at pacemaker implantation was 6.5 years, with an average follow-up of 9.9 years. The cumulative dysfunction free survival at 20 years was 92%. In total, four patients (6%) were noted to develop LV dysfunction an average of 15.1 years after pacemaker implantation. Of 30 patients who were paced for >10 years, only three (10%) developed echocardiographic evidence of LV dysfunction. Right ventricular apex pacing and prolonged QRS duration were found to be predictive of decreased long-term LV systolic function (P < 0.05).

CONCLUSIONS

Left ventricular dysfunction in patients with congenital complete atrioventricular block is a rare finding, even in those who have been paced for more than 10 years. Right ventricular apex pacing and prolonged QRS duration may be associated with decreased ventricular function over time. At this time, with such a low incidence of cardiac dysfunction, right ventricular pacing should be considered an acceptable first-line therapy in this population.

Different temporal expression of immunodominant Ro60/60 kDa-SSA and La/SSB apotopes

Opsonization of apoptotic cardiocytes by maternal anti-Ro/SSA and anti-La/SSB antibodies contributes to tissue injury in the neonatal lupus syndrome. The objective of the current study was to quantify the surface membrane expression of Ro/La components during different phases of apoptosis and map the Ro/La apotopes (epitopes expressed on apoptotic cells) bound by cognate antibodies. Multi-parameter flow cytometry was used to define early and late apoptotic populations and their respective binding by monospecific anti-Ro and anti-La IgGs. Anti-Ro60 bound specifically to early apoptotic Jurkat cells and remained accessible on the cell surface throughout early and late apoptosis. In contrast, anti-La bound exclusively to late apoptotic cells in experiments controlled for non-specific membrane leakage of IgG. Ro52 was not accessible for antibody binding on either apoptotic population. The immunodominant NH2-terminal and RNA recognition motif (RRM) epitopes of La were expressed as apotopes on late apoptotic cells, confirming recent in vivo findings. An immunodominant internal epitope of Ro60 that contains the RRM, and is recognized by a majority of sera from mothers of children with congenital heart block (CHB) and patients with primary Sjögren's syndrome, was also accessible as an apotope on early apoptotic cells. The distinct temporal expression of the immunodominant Ro60 and La apotopes indicates that these intracellular autoantigens translocate independently to the cell surface, and supports a model in which maternal antibody populations against both Ro60 and La apotopes act in an additive fashion to increase the risk of tissue damage in CHB.

Evolution of left ventricular function in paediatric patients with permanent right ventricular pacing for isolated congenital heart block: a medium term follow-up

AIMS

We aimed to assess the evolution of left ventricular (LV) systolic function in children with right ventricular apical (RVA) pacing for isolated congenital heart block (ICHB) and to identify possible predictors of LV function deterioration. Right ventricular apical pacing can be detrimental to LV function in a significant number of adults. Effects in children are still controversial.

METHODS AND RESULTS

Left ventricular shortening fraction (LV SF) and QRS duration were retrospectively assessed in 45 children with RVA pacing for ICHB: before pacemaker (PM) implantation, immediately after and then regularly during a follow-up of 58.69 +/- 45.23 months. Patients were categorized as stable or deteriorators according to an arbitrarily chosen cut-off point of > or =7% decrease in LV SF. Lupus status was unknown. Overall LV SF did not change significantly (41.42% +/- 8.21 before pacing, 39.77% +/- 7.03 immediately after PM implant, 37.43% +/- 9.91 with chronic pacing, P = NS). Deteriorators (n = 13) had significantly higher baseline heart rate (57.5 +/- 8.7 vs. 46.9 +/- 10.5 bpm, P < 0.05) and baseline LV SF (46.17 +/- 8.13 vs. 38.4 +/- 6.4%; P < 0.05), a significantly higher proportion of them being implanted before 2 years of age: 8 of 13 (61.5%) vs. 5 of 25 (20%) in the stable group (P < 0.05). Deteriorators had a higher incidence of an initial epicardial lead and narrower native QRS.

CONCLUSION

Permanent RVA pacing for ICHB does not necessarily affect LV function in children. The risk of deterioration of LV function seems to be higher in children with higher baseline heart rate and better baseline LV SF, especially with pacing at a younger age, a narrower native QRS and RVA epicardial pacing site.

Left ventricular epicardial VVI pacing for a congenital complete heart block with severe myocardial dysfunction: Shall epicardial pacing wires be positioned left?

We present the case of a patient with a congenital complete heart block (CHB) who developed a severe dilated hypokinetic cardiomyopathy whilst paced with a right-sided epicardial wire inserted by an anterior approach. She dramatically and rapidly improved both clinically and echocardiographically, once a single pacing wire was inserted on the left ventricular (LV) wall towards the apex by left thoracotomy. Based upon recent literature, attention is drawn to the fact that left-inserted epicardial pacing wires should probably be considered for pediatric patients in whom atrio-ventricular or inter-ventricular pacing might not be possible to achieve, or else as a consistent approach for small patients requiring VVI epicardial pacing.

Characterization of T-cell population in children with prolonged fetal exposure to dexamethasone for anti-Ro/SS-A antibodies associated congenital heart block

The objectives of the study were to characterize the production, function and survival of T lymphocytes of children with prolonged fetal exposure to dexamethasone for anti-Ro/SS-A antibodies associated congenital complete heart block. The analysis of thymic function, studied by measuring the level of T-cell receptor excision circles, was performed by real time PCR, the composition of T-cell subpopulation was evaluated by flow cytometry and the T-cell diversity was assayed by heteroduplex analysis. T-cell competence was gauged at two functional levels by determining the proliferation and the number of T-cell divisions and by measuring gamma-interferon production after mitogenic stimulation. We observed that the thymic output, distribution of T-cell subsets, thymidine incorporation, number of T-cell divisions, and y-interferon production were comparable to those of age-matched control. On the contrary, heteroduplex analysis demonstrated the presence of both polyclonal and oligoclonal peripheral T-cell repertoires. In conclusion, the analysis of the T-cell compartment in children with prolonged intrauterine exposure to high dose dexamethasone did not disclose any relevant abnormality, except a restriction of T-cell receptor diversity in some patients.

[Epicardial atrial pacing using an active fixation bipolar endocardial lead in children]

Good performance was observed over 10 years after implantation of bipolar epicardial atrial pacing using an active fixation bipolar endocardial lead in 3 pediatric patients with congenital heart block. The bipolar endocardial lead which was supposed to be fixed transvenously was implanted on the atrial surface by first screwing the lead's helix into the myocardium. The catheter was then laid down on the atrial surface, and both electrodes were wrapped by the atrial tissue. The good performance of this pacing lead seemed to depend on stable positioning of the electrode. This lead is superior to the commercially available, and steroid eluting epicardial bipolar pacing lead, on the point of its small size in head and body, and could be applied to dual chamber pacing in smaller children.

Medium-term follow-up and modes of failure following epicardial pacemaker implantation in young children

AIMS

Young children suffering from congenital or post-operative AV-block require life-long pacemaker stimulation. Due to the anatomical prerequisites initially epicardial electrodes are implanted and the generator is placed in the upper abdominal wall. The following study investigated modes of failure leading to reoperation in this group of technically challenging patients.

METHODS AND RESULTS

Between October 2000 and May 2005, a total of 21 infants (age 3 days to 5 years) underwent pacemaker implantation using a subxyphoidal incision for newborns (and a partial lower or complete median sternotomy for older children). Nine patients had previous cardiac surgery for complex congenital defects. The remaining 12 young children suffered from congenital AV-Block (CAVB). Twenty-one bipolar epicardial electrodes (Medtronic Capsure epi) were fixed to the right ventricle, 15 had additional implantation of a bipolar atrial lead. The pacemaker generator (Medtronic Kappa 701) was implanted into the right upper abdominal wall. Indications for revision were recorded. No mortality was observed; pacing and sensing parameters remained stable up to a 5-year follow-up. A total of four reoperations occurred. Three of the four revisions were caused by ventricular electrode fracture. At revision, two electrodes were broken at the crossing between the pericardial cavity and the abdominal wall, one bipolar lead at the Y-division into the two tip electrodes. One reoperation was due to a pacemaker recall. All revisions were performed without complications.

CONCLUSION

In our institute epicardial pacing in young children was associated with a satisfactory clinical outcome, but also a significant number of failures leading to reoperation, mainly due to electrode fracture caused by the muscular activity of this patient group. Reoperations were performed at a low risk.

Age-related role of ambulatory electrocardiographic monitoring in risk stratification of patients with complete congenital atrioventricular block

AIMS

The aim of the paper was to assess the importance of 24 h electrocardiographic Holter monitoring in determining predictive factors for Adams-Stokes (AS) attacks and heart failure (HF) in children and adolescents with complete congenital atrioventricular block (CCAVB).

METHODS AND RESULTS

Forty-five patients were divided into two groups according to the presence of AS attacks and HF and six age-related subgroups. The following parameters of 24 h electrocardiographic Holter monitoring were analysed: (i) minimum heart rate (HR), (ii) maximum HR, (iii) average HR, (iv) daytime HR (v) rhythm and conduction disturbance. Adams-Stokes attacks and HF occurred in 10 and 8 patients, respectively (40%). Five of six neonates with HF had maximum HR < 74 bpm and daytime HR < 58 bpm. Maximum HR below 68 bpm and daytime HR below 52 bpm were recorded in all the children up to 8 years of age with AS attacks and HF and only in 3 of 14 asymptomatic patients. All the patients above 8 years of age with AS attacks had maximum HR below 62 bpm. Of 6 patients with daytime HR < 50 bpm AS attacks were present in two. Episodes of marked ventricular slowing during sleep were registered in 4 of 10 (40%) patients and in 3 of 27 (11%) symptomless patients.

CONCLUSION

Risk factors for development of AS attacks and HF in patients with CCAVB include: (i) maximum HR < 74 bpm in neonates, <68 bpm up to the age of 8 and <62 bpm at ages above 8, (ii) daytime HR <58 bpm in neonates and < 52 bpm till the age of 8, and (iiii) abrupt pauses in ventricular rate that are at least twice the basic cycle length after the neonatal period.

Electrocautery-induced asystole in a scoliosis patient with a pacemaker

Pediatric heart condition management may include a variety of implanted cardiac devices. Monopolar electrocautery (Bovie) produces significant electromagnetic interference to these devices. This interference can alter the function of a cardiac generator resulting in a variety of complications including impaired cardiac output and asystole. We report the case of a 16 plus 2-year-old girl who presented with idiopathic scoliosis and a past medical history significant for complete congenital heart block treated with a DDD*** pacemaker. During surgery, the use monopolar electrocautery caused the patient to develop asystole and loss of pulsatile blood pressure. Electrocautery was subsequently terminated, the patient then returned to a normal sinus rhythm and blood pressure normalized.

A Case of Neonatal Lupus Erythematosus Presenting Delayed Dilated Cardiomyopathy With Circulating Autoantibody to Annexin A6

Patients with neonatal lupus erythematosus (NLE) often have congenital heart block with or without heart failure and are born to mothers who have anti-SS-A and/or anti-SS-B antibodies. NLE has been considered to result from the placental transmission of maternal autoantibodies into the fetal circulation causing myocardial damage. We report a case of NLE with congenital heart block who had undergone pacemaker implantation at the age of 17, and then developed dilated cardiomyopathy (DCM) at the age of 19, which is much later than in most other cases. The patient's mother was positive for anti-SS-A and anti-SS-B antibodies, whereas the patient was negative for both anti-SS-A and anti-SS-B antibodies. There were some autoantibodies against cell surface antigens of cardiac myocytes in the serum from the patient, and annexin A6 was identified as one of the autoantigens. This is the first report demonstrating that annexin A6 is involved in the myocardial injury in patients with NLE. The results indicate that inhibition of annexin A6 function may prevent autoantibody-mediated myocardial injury in at least some cases of DCM.

Specificity and effector mechanisms of autoantibodies in congenital heart block

Complete congenital atrio-ventricular (AV) heart block develops in 2-5% of fetuses of Ro/SSA and La/SSB autoantibody-positive pregnant women. During pregnancy, the Ro/SSA and La/SSB antibodies are transported across the placenta and affect the fetus. Emerging data suggest that this happens by a two-stage process. In the first step, maternal autoantibodies bind fetal cardiomyocytes, dysregulate calcium homestasis and induce apoptosis in affected cells. This step might clinically correspond to a first-degree heart block, and be reversible. La/SSB antibodies can bind apoptotic cardiomyocytes and thus increase Ig deposition in the heart. The tissue damage could, as a second step, lead to spread of inflammation in genetically pre-disposed fetuses, progressing to fibrosis and calcification of the AV-node and subsequent complete congenital heart block. Early intrauterine treatment of an incomplete AV-block with fluorinated steroids has been shown to prevent progression of the heart block, making it clinically important to find specific markers to identify the high-risk pregnancies.