Type I IFN system activation in newborns exposed to Ro/SSA and La/SSB autoantibodies in utero.

OBJECTIVE: In utero exposure of the fetus to Ro/La autoantibodies may lead to congenital heart block (CHB). In the mother, these autoantibodies are associated with activation of the type I interferon (IFN)-system. As maternal autoantibodies are transferred to the fetus during pregnancy, we investigated whether the type I IFN-system is activated also in newborns of anti-Ro/La positive mothers, and whether fetal IFN activation is affected by maternal immunomodulatory treatment. METHODS: Blood drawn at birth from anti-Ro/La positive mothers, their newborns and healthy control pairs was separated into plasma and peripheral blood mononuclear cells (PBMC). PBMC were analysed directly or cultured. mRNA expression was analysed by microarrays, cell surface markers by flow cytometry, and IFNα levels by immunoassays. RESULTS: We observed increased expression of IFN-regulated genes and elevated plasma IFNα levels not only in anti-Ro/La positive women, but also in their newborns. CD14+ monocytes of both anti-Ro/La positive mothers and their neonates showed increased expression of Sialic acid-binding Ig-like lectin-1, indicating cellular activation. Notably, the IFN score of neonates born to mothers receiving immunomodulatory treatment was similar to that of controls, despite persistent IFN activation in the mothers. In both maternal and neonatal PBMC, IFNα production was induced when cells were cultured with anti-Ro/La positive plasma. CONCLUSIONS: Ro/La autoantibody-exposed neonates at risk of CHB have signs of an activated immune system with an IFN signature. This study further demonstrates that neonatal cells can produce IFNα when exposed to autoantibody-containing plasma, and that maternal immunomodulatory treatment may diminish the expression of IFN-regulated genes in the fetus.

Anti-Ro52 antibody level is an important marker of fetal congenital heart block risk in anti-Ro/SSA antibody positive pregnancy.

OBJECTIVE: The aims of this study are to determine the incidence of congenital heart block (CHB) in the Japanese population and identify maternal factors predicting fetal CHB in anti-Ro/SSA antibody positive pregnancy. METHODS: A retrospective study was performed using 52,147 clinical records of pregnancies followed in a single center. For 183 anti-Ro/SSA antibody-positive women, anti-Ro52 and Ro60 antibodies were measured, and the odds of CHB in relation to maternal clinical features were calculated by multivariate analysis. The receiver-operating characteristic (ROC) curves for predicting CHB were constructed for the titers of anti-Ro/SSA, anti-Ro52 and anti-Ro60 antibodies. RESULTS: Fetal CHB occurred in two pregnancies among those without known risks such as positive anti-Ro/SSA antibody or previous CHB-affected pregnancy, suggesting an incidence similar to that in Caucasian populations. As for the anti-Ro/SSA antibody positive pregnancies, the titers of anti-Ro/SSA, anti-Ro52 and anti-Ro60 antibodies were independent risk factors for fetal CHB and the use of corticosteroids before 18 gestational weeks was an independent protective factor. The area under the ROC was 0.84, 0.73 and 0.74 for anti-Ro52, anti-Ro60 and anti-Ro/SSA antibodies, respectively. CONCLUSION: CHB occurred in two among approximately 50,000 pregnancies without known risks such as positive anti-Ro/SSA antibody or previous delivery of CHB-affected babies. Measurement of anti-Ro52 antibody levels may be helpful in extracting a risk group of delivering CHB infants in the anti-Ro/SSA antibody positive pregnancy.

Low titer, isolated anti Ro/SSA 60 kd antibodies is correlated with positive pregnancy outcomes in women at risk of congenital heart block.

Congenital heart block (CHB) is an autoantibody mediated disorder presumably caused by placental transmission of maternal autoantibodies to Ro/SSA 52 kd, p200, Ro/SSA 60 kd, La/SSB ribonucleoproteins. This study investigated the clinical significance of isolated anti-Ro/SSA 52 kd, anti-p200, anti-Ro/SSA 60 kd, and anti-La/SSB antibodies in positive pregnant patients. One hundred sixty-three pregnant women positive to anti-Ro/SSA 52 kd and/or anti-Ro/SSA 60 kd and/or anti-La/SSB antibodies were prospectively enrolled in the study. Anti-Ro52, anti-Ro60, anti-p200, and anti-La antibodies were assayed using home-made ELISA assays. Isolated antibody positivity was found in 25 women (15.3%), while multiple antibody positivity in 138 (84.7%). Twenty-four developed CHB, and the 139 had a favorable pregnancy outcome. The prevalence of isolated anti-Ro/SSA 60 kd antibodies was significantly higher (p < 0.046) as the prevalence of lower mean antibody titers (p < 0.0001) in the later group. Confirmation of these results by large-scale studies could lead clinicians to recommend less stringent fetal echocardiography monitoring in women with isolated anti-Ro/SSA 60 kd antibodies.

Myxedema Coma Secondary to Central Hypothyroidism: A Rare but Real Cause of Altered Mental Status in Pediatrics.

BACKGROUND: Myxedema coma (MC), a medical emergency defined as severe hypothyroidism leading to altered mental status, is more common in older women with hypothyroidism. METHODS/RESULTS: A 7-year-old Caucasian male with chromosome 1q deletion presented with altered mental status preceded by milestone regression. His presenting labs results were: thyroid-stimulating hormone (TSH) 0.501 µIU/ml and free thyroxine (T4) <0.5 ng/dl. His morning cortisol level was 8.1 µg/dl with repeat testing, while TSH was 1.119 µIU/ml and free T4 was 0.5 ng/dl. Low-dose cosyntropin test showed baseline and peak cortisol levels of 1.9 and 16 µg/dl, respectively. Aside from altered mental status, heart block was present in addition to hypothermia and hypercarbia. Diffuse cerebral cortical and corpus callosum atrophy were seen on MRI. An intravenous (i.v.) stress dose of hydrocortisone was administered for 24 h prior to an i.v. loading dose of levothyroxine. His activity level subsequently returned to baseline within 48 h after treatment had been initiated. CONCLUSION: Though MC is rare, occurring mainly with noncompliance in primary hypothyroidism, it may occur at the diagnosis of secondary hypothyroidism. Based on features like hypothermia, hypoventilation, and cardiovascular instability occurring in the setting of central hypothyroidism, it should be suspected and managed urgently in order to avert the associated high mortality resulting from treatment delays.

Plasmapheresis, intravenous immunoglobulins and bethametasone - a combined protocol to treat autoimmune congenital heart block: a prospective cohort study.

OBJECTIVES: At the moment there are no standard guidelines for the treatment of autoimmune congenital heart block (CHB). We set out to carry out a prospective cohort study to evaluate the benefits, limits, and safety of a combined therapy protocol to treat antibody-related CHB. METHODS: Twelve consecutive pregnant patients positive to anti-SSA/Ro ± anti-SSB/La antibodies in whom CHB was detected were prospectively evaluated from 2009 to 2014. The treatment protocol consisted of: weekly plasmapheresis, fortnightly intravenous immunoglobulins (IVIG), and daily 4 mg betamethasone from CHB detection until delivery; IVIG was administered to the neonates soon after birth. RESULTS: At the time CHB was detected, six of the foetuses presented atrioventricular blocks of 2(nd) degree type and six of 3(rd) degree type. Two of the foetuses with a 2(nd) degree block reverted to a 1st degree block and one to a normal atrioventricular conduction. The condition was stable throughout the pregnancy in the other three cases of 2(nd) degree block. All six 3(rd) degree blocks were stable during pregnancy and confirmed at birth. After a mean of 37.6 months ± 19.6 SD post-birth, the infants with 1st, normal sinus rhythm, and 2(nd) degree blocks at birth were all found to be stable. During the follow-up (29 months ± 19.8 SD), pacemakers were implanted in three of the six infants with 3(rd) degree blocks. CONCLUSIONS: This combined therapy seems to be effective and safe in treating 2(nd) degree CHB, while its efficacy in treating 3rd degree CHB remains to be established.

Intracardiac echocardiography for immediate detection of intracardiac thrombus formation.

An 85-year-old man with persistent atrial flutter (AFL) with slow ventricular rate of 44/min, causing fatigue and presyncope, was referred for urgent treatment. In spite of thromboembolic risk scale value 4, he had not been treated with anticoagulants because of high risk of bleeding. The decision was made to perform urgent catheter ablation to interrupt and cure AFL. Intracardiac echocardiography probe was placed in the pulmonary artery and visualized left atrial appendage free from thrombus with its proper function. Heparin was administered and AFL stopped during energy application. Intracardiac echocardiography showed immediate thrombus formation in left atrial appendage owing to complete atrial standstill and no retrograde conduction during hemodynamically effective escape nodal rhythm. This case report shows that in patients with sinus node disease effective ablation of AFL with escape rhythm without retrograde conduction to the atria may result in complete 'electrically induced' atrial standstill and immediate thrombus formation.

Reactivity to the p305 Epitope of the α1G T-Type Calcium Channel and Autoimmune-Associated Congenital Heart Block.

BACKGROUND: Only 2% of mothers positive for anti-SSA/Ro (Ro) antibodies have children with congenital heart block (CHB). This study aimed to determine whether reactivity with p305, an epitope within the α1G T-type calcium channel, confers added risk over anti-Ro antibodies. METHODS AND RESULTS: Using sera from anti-Ro-exposed pregnancies resulting in offspring with CHB, no disease but CHB-sibling, and no disease and no CHB-sibling, as well as disease (lupus without anti-Ro) and healthy controls, reactivities were determined for binding to Ro60, p305, and an epitope within Ro60, p133-Ro60, which shares structural properties with p305, including key amino acids and an α-helical structure. Candidate peptides were further evaluated in an in vitro model that assessed the binding of maternal antibodies to apoptotic cells. In anti-Ro-positive mothers, anti-p305 autoantibodies (>3 SD above healthy controls) were detected in 3/59 (5%) CHB pregnancies, 4/30 (13%) unaffected pregnancies with a CHB-sibling, and 0/42 (0%) of unaffected pregnancies with no CHB-sibling. For umbilical bloods (61 CHB, 41 healthy with CHB sibling), no association of anti-p305 with outcome was detected; however, overall levels of anti-p305 were elevated compared to mothers during pregnancy in all groups studied. For anti-p133-Ro60, reactivity paralleled that of anti-p305. In the screen employing apoptotic cells, p133-Ro60, but not p305, significantly attenuated the binding of immunoglobulin G isolated from a mother whose child had CHB (42.1% reduced to 13.9%, absence/presence of p133-Ro60, respectively, P<0.05). CONCLUSIONS: These data suggest that anti-p305 is not a robust maternal marker for assessing increased risk of CHB during an anti-SSA/Ro pregnancy.

Plasma exchange effectively removes 52- and 60-kDa anti-Ro/SSA and anti-La/SSB antibodies in pregnant women with congenital heart block.

BACKGROUND: Pregnant women positive for 52- and 60-kDa anti-Ro/SSA and anti-La/SSB antibodies can suffer from congenital heart block (CHB), a passively acquired autoimmune disease. STUDY DESIGN AND METHODS: We evaluated the efficacy of plasma exchange (PE) in removing 52- and 60-kDa anti-Ro/SSA and anti-La/SSB antibodies in pregnant women with CHB treated with a combined therapy including PE, intravenous immunoglobulins, and steroids. Antibody levels were monitored in 10 consecutive pregnant women diagnosed with CHB and prospectively followed between 2009 and 2013. Assaying was performed using a homemade enzyme-linked immunosorbent assay test on blood samples collected immediately before and after PE sessions. RESULTS: A significant decrease in mean post-PE antibody levels was noted in all the cases examined. An analysis of antibody level trends in the samples collected before PE sessions showed that there was a steady, significant decrease in 90% of the patients with 52-kDa anti-Ro/SSA, in 80% of those with 60-kDa anti-Ro/SSA antibodies, and in 100% of those with anti-La/SSB antibodies. CONCLUSION: This study demonstrates that PE is effective in removing antibodies linked to the pathogenesis of CHB. PE treatment was found to have a long-term efficacy in all the women positive for anti-La/SSB antibodies and in most of the women positive for 52- and 60-kDa anti-Ro/SSA antibodies. It is interesting that the significant, immediate, and long-term fall in antibody levels that was observed in these patients took place in all the women whose CHB was reversed. This finding could give PE an important role in the treatment of CHB.

Anti-Ro/SSA-p200 antibodies in the prediction of congenital heart block. An Italian multicentre cross-sectional study on behalf of the 'Forum Interdisciplinare per la Ricerca nelle Malattie Autoimmuni (FIRMA) Group'.

OBJECTIVES: To verify the association between the presence of specific anti-52 Ro/SSA-p200 antibodies and congenital heart block (CHB). METHODS: 207 pregnant Italian women carrying anti-Ro/SSA Ab were retrospectively evaluated. Anti-p200 Ab were investigated in the mothers' sera by ELISA (Euro-Diagnostica,Wieslab SS-A p200). RESULTS: CHB occurred in 42 children (34 complete CHB), whereas 165 were not affected. All CHB cases were previously identified with an ELISA screening for anti-Ro/SSA 60 kD Ab. Anti-p200 Ab were more frequently positive (81.0% vs. 59.1%, p=0.013) and at a higher titer in CHB mothers (Absorbance ratio: 2.030 (0.208-4.052) vs. 0.925 (0.200-3.816); p=0.017). This association was maintained even when the 42 mothers of children with CHB were compared with a control group matched for age and diagnosis (80.9% vs. 50.0%; p=0.006). The presence of anti-p200 Ab provided an odds ratio (OR) for CHB of 2.98 (CI: 1.30-6.83), which was higher than that of other variables, such as maternal disease and other antibody specificities. CHB risk significantly decreased in the absence of this fine specificity (OR:0.34, CI: 0.15-0.77). However, while the negative predictive value related to anti-Ro/SSA 60 kD Ab ELISA was 100%, almost 20% of mothers negative for anti-p200 Ab delivered babies with CHB. CONCLUSIONS: Anti-p200 antibodies seem to be associated with CHB with a higher probability than anti-Ro/SSA Ab, and therefore may be an additional test to identify mothers at higher risk to deliver affected children. An ELISA screening for anti-Ro/SSA 60 kD Ab is nevertheless mandatory given the probability of developing CHB also in the absence of anti-p200 Ab.

Heart failure after transvenous closure of atrial septal defect associated with atrial standstill and thiamine-responsive megaloblastic anemia.

Despite advances in device closure for atrial septal defect, post-closure heart failure remains a clinical problem in adult patients but is seen only rarely in children. An eight-year-old boy, who had been followed by a local pediatrician with the diagnosis of diabetes mellitus and congenital heart disease, was consulted to us for cardiac re-evaluation. Electrocardiography demonstrated absent P waves, and echocardiography revealed enlargement of the right ventricle and both atria and secundum atrial septal defect. With the diagnosis of atrial standstill, secundum atrial septal defect and thiamine-responsive megaloblastic anemia, acute heart failure developed after transvenous closure of the atrial septal defect, which improved dramatically with thiamine and supportive treatment.

Local electrogram delay recorded from left ventricular lead at implant predicts response to cardiac resynchronization therapy: retrospective study with 1 year follow up.

BACKGROUND: Considerable proportion of patients does not respond to the cardiac resynchronization therapy (CRT). This study investigated clinical relevance of left ventricular electrode local electrogram delay from the beginning of QRS (QLV). We hypothesized that longer QLV indicating more optimal lead placement in the late activated regions is associated with the higher probability of positive CRT response. METHODS: We conducted a retrospective, single-centre analysis of 161 consecutive patients with heart failure and LBBB or nonspecific intraventricular conduction delay (IVCD) treated with CRT. We routinely intend to implant the LV lead in a region with long QLV. Clinical response to CRT, left ventricular (LV) reverse remodelling (i.e. decrease in LV end-systolic diameter - LVESD ≥10%) and reduction in plasma level of NT-proBNP >30% at 12-month post-implant were the study endpoints. We analyzed association between pre-implant variables and the study endpoints. RESULTS: Clinical CRT response rate reached 58%, 84% and 92% in the lowest (≤105 ms), middle (106-130 ms) and the highest (>130 ms) QLV tertile (p < 0.0001), respectively. Longer QRS duration (p = 0.002), smaller LVESD and a non-ischemic cardiomyopathy (both p = 0.02) were also univariately associated with positive clinical CRT response. In a multivariate analysis, QLV remained the strongest predictor of clinical CRT response (p < 0.00001), followed by LVESD (p = 0.01) and etiology of LV dysfunction (p = 0.04). Comparable predictive power of QLV for LV reverse remodelling and NT-proBNP response rates was observed. CONCLUSION: LV lead position assessed by duration of the QLV interval was found the strongest independent predictor of beneficial clinical response to CRT.

Congenital heart block: evidence for a pathogenic role of maternal autoantibodies.

During pregnancy in autoimmune conditions, maternal autoantibodies are transported across the placenta and may affect the developing fetus. Congenital heart block (CHB) is known to associate with the presence of anti-Ro/SSA and anti-La/SSB antibodies in the mother and is characterized by a block in signal conduction at the atrioventricular (AV) node. The mortality rate of affected infants is 15% to 30%, and most live-born children require lifelong pacemaker implantation. Despite a well-recognized association with maternal anti-Ro/La antibodies, CHB develops in only 1% to 2% of anti-Ro-positive pregnancies, indicating that other factors are important for establishment of the block. The molecular mechanisms leading to complete AV block are still unclear, and the existing hypotheses fail to explain all aspects of CHB in one comprehensive model. In this review, we discuss the different specificities of maternal autoantibodies that have been implicated in CHB as well as the molecular mechanisms that have been suggested to operate, focusing on the evidence supporting a direct pathogenic role of maternal antibodies. Autoantibodies targeting the 52-kDa component of the Ro antigen remain the antibodies most closely associated with CHB. In vitro experiments and animal models of CHB also point to a major role for anti-Ro52 antibodies in CHB pathogenesis and suggest that these antibodies may directly affect calcium regulation in the fetal heart, leading to disturbances in signal conduction or electrogenesis or both. In addition, maternal antibody deposits are found in the heart of fetuses dying of CHB and are thought to contribute to an inflammatory reaction that eventually induces fibrosis and calcification of the AV node, leading to a complete block. Considering that CHB has a recurrence rate of 12% to 20% despite persisting maternal autoantibodies, it has long been clear that maternal autoantibodies are not sufficient for the establishment of a complete CHB, and efforts have been made to identify additional risk factors for this disorder. Therefore, recent studies looking at the influence of genetic and environmental factors will also be discussed.

Umbilical cord blood levels of maternal antibodies reactive with p200 and full-length Ro 52 in the assessment of risk for cardiac manifestations of neonatal lupus.

OBJECTIVE: Maternal anti-Ro autoantibodies are associated with cardiac manifestations of neonatal lupus (cardiac NL), yet only 2% of women with this reactivity have an affected child. Identification of a more specific marker would channel intense monitoring to fetuses at greater risk. This study aimed to determine whether autoantibodies against Ro 52 amino acids 200-239 (p200) confer added risk over autoantibodies to full-length Ro 52, Ro 60, or La. METHODS: Anti-Ro-exposed pregnancies resulting in cardiac NL or no cardiac manifestations were identified from the Research Registry for Neonatal Lupus and the PR Interval and Dexamethasone Evaluation study. Umbilical cord (n = 123) and maternal (n = 115) samples were evaluated by enzyme-linked immunosorbent assay. RESULTS: The frequencies of p200, Ro 52, Ro 60, and La autoantibodies were not significantly different between affected and unaffected children. However, neonatal anti-Ro 52 and Ro 60 titers were highest in cardiac NL and their unaffected siblings compared to unaffected neonates without a cardiac NL sibling. Although both maternal anti-Ro 52 and p200 autoantibodies were less than 50% specific for cardiac NL, anti-p200 was the least likely of the Ro autoantibodies to be false-positive in mothers who have never had an affected child. Titers of anti-Ro 52 and p200 did not differ during a cardiac NL or unaffected pregnancy from the same mother. CONCLUSION: Maternal reactivity to p200 does not confer an added risk to fetal conduction defects over full-length Ro 52 or Ro 60 autoantibodies. Mothers who may never be at risk for having an affected child have lower anti-Ro 60 titers and may require less stringent echocardiographic monitoring compared to women with high-titer autoantibodies.

Dynamic variations of P-wave duration in a patient with acute decompensated congestive heart failure.

Interatrial block is an abnormally delayed atrial activation, characterized at ECG by prolonged P-wave duration (more than 110 ms), irrespective of morphology. We report the case of a patient with acute decompensated severe congestive heart failure, that at hospital admission showed a prolonged P-wave, which reverted after diuretic therapy. The dynamic change of the atrial P-wave correlates with clinical evolution and serum level modification of B-type natriuretic peptide.

A combination therapy to treat second-degree anti-Ro/La-related congenital heart block: a strategy to avoid stable third-degree heart block?

While mainly based on the use of fluorinated steroids, there is no standard management of anti-Ro/La-related congenital heart block (CHB). This is a report concerning two consecutive cases of anti-Ro/La-related second-degree block treated with betamethasone (4 mg/day), weekly plasmapheresis, and intravenous immunoglobulins (IVIGs; 1 g/kg) administered every 15 days, a therapy that was begun shortly after CHB was detected and continued until delivery. The newborns were also treated with IVIG (1 g/kg) soon after birth and continued fortnightly until the anti-Ro/La antibody levels became undetectable. In both cases second-degree AV block reverted to a stable sinus rhythm with a first-degree atrioventricular (AV) block. Moreover, there was no recurrence of CHB when therapy was suspended, as confirmed by a 29 month and an eight month follow-up, respectively.

Congenital heart block: identification of autoantibody binding site on the extracellular loop (domain I, S5-S6) of alpha(1D) L-type Ca channel.

Congenital heart block (CHB) is an autoimmune disease associated with autoantibodies against intracellular ribonucleoproteins SSB/La and SSA/Ro. The hallmark of CHB is complete atrioventricular block. We have recently established that anti-SSA/Ro -SSB/La autoantibodies inhibit alpha(1D) L-type Ca current, I(Ca-L), and cross-react with the alpha(1D) Ca channel protein. This study aims at identifying the possible binding sites on alpha(1D) protein for autoantibodies from sera of mothers with CHB children. GST fusion proteins of the extracellular regions between the transmembrane segments (S5-S6) of each of the four alpha(1D) Ca channel protein domains I-IV were prepared and tested for reactivity with sera from mothers with CHB children and controls using ELISA. Sera containing anti-Ro/La autoantibodies from 118 mothers with CHB children and from 15 mothers with anti-Ro/La autoantibodies but have healthy children, and from 28 healthy mothers without anti-Ro/La autoantibodies and healthy children were evaluated. Seventeen of 118 (14.4%) sera from mothers with CHB children reacted with the extracellular loop of domain I S5-S6 region (E1). In contrast, only 2 of 28 (7%) of sera from healthy mothers (-anti-Ro/La) and healthy children reacted with E1 loop and none (0 of 15) of sera from healthy mothers (+anti-Ro/La) and healthy children reacted with the E1 loop. Preincubation of E1 loop with the positive sera decreased the O.D reading establishing the specificity of the response. Electrophysiological characterization of the ELISA positive sera and purified IgG showed inhibition (44.1% and 49.8%, respectively) of the alpha(1D) I(Ca-L) expressed in tsA201 cells. The inhibition was abolished when the sera were pre-incubated with E1 fusion protein. The results identified the extracellular loop of domain I S5-S6 of L-type Ca channel alpha(1D) subunit as a target for autoantibodies from a subset of mothers with CHB children. This novel finding provides insights into the potential development of therapeutic peptides that could bind to the pathogenic antibodies and prevent CHB.

Correlation analysis of atrial natriuretic peptide concentration, echocardiographic left atrial and left ventricular dimensions, and renal function parameters in patients after permanent pacemaker implantation.

BACKGROUND: Atrial endocrine function was established in the second half of the 20th century, confirming the role of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in the physiology of the cardiovascular system. The present study was undertaken to evaluate changes in ANP and echocardiographic parameters within the first month after VVI and DDD pacemaker implantation and to evaluate correlations between the parameters. METHODS: The study population consisted of group I--20 VVI patients aged 71-90 years (mean age 77.5 +/- 5.9) and group II--20 DDD/VDD patients aged 49-81 years (mean age 68.9 +/- 11). Fifteen healthy volunteers aged 58-80 years (mean age 72.7 +/- 2.8) served as controls. Correlations between ANP levels and cardiac cavity dimensions and between ANP and parameters of renal function were studied. RESULTS: Blood levels of ANP decreased after pacemaker implantation: in the VVI group from 168.61 +/- 81.95 pg/1000 microL to 118.04 +/- 61.06 pg/1000 microL at 7 days and to 121.4 +/- 71.90 pg/1000 microL at 30 days; and in the DDD/VDD group from 134.89 +/- 83.11 pg/1000 microL to 104.96 +/- +/- 57.09 pg/1000 microL at 7 days and to 110.82 +/- 53.32 pg/1000 microL at 30 days. There was a significant correlation between ANP levels and left atrial size in the DDD/VDD group--0.598 (p = 0.005) and 0.593 (p = 0.005) and left ventricular dimensions--0.499 (p = 0.024) and 0.485 (p = 0.030). CONCLUSIONS: ANP decreases significantly after pacing implementation in patients selected for implantation of VVI and DDD/VDD pacemakers. ANP correlates significantly with echocardiographic measurements in patients selected for DDD/VDD pacemakers, but no significant correlation is observed in VVI patients qualifying for permanent pacemaker due to atrioventricular block.