Asystoles during infancy recorded by home memory monitors. Benign events?

OBJECTIVES: To assess the frequency and clinical significance of asystole (sinus arrest > or = 2.0 seconds) and the incidence of bradycardia in infants prescribed home cardiorespiratory monitors and to test the hypothesis that asystoles are more likely to occur in preterm infants. DESIGN: Prospective, consecutive sample of monitor printouts. METHODS: All 291 printouts from the memory monitors of 161 patients received during a 2-month period were analyzed. SETTING: University hospital providing primary and referral care. MAIN OUTCOME MEASURES: Asystoles and bradycardias; clinical course of patients with asystoles. RESULTS: Eight patients (5.0%) had 32 episodes of asystole lasting 2.0 to 4.3 seconds (group 1). Fifty-three patients (32.9%) had true bradycardia alarms but no asystoles (group 2). One hundred patients (62.1%) had neither asystoles nor bradycardias (group 3). Preterm infants constituted 88% of group 1 and 81% of group 2 but only 58% of group 3. Infants were more likely to be full-term in group 3 than in the other 2 groups (chi 2, P = .02). Birth weights were lower in group 1 than in group 3 (P < .05, 1-tailed t test). There were 479 true bradycardias; 72.2% lasted 10 seconds or less, 26.3% were longer than 10 seconds but no more than 20 seconds, and 1.5% were longer than 20 seconds. None of the 8 patients with asystoles required resuscitation for their asystoles; all survived and were free of any life-threatening events after their monitors were discontinued and up until their first birthday. CONCLUSIONS: Asystoles occur more commonly in preterm infants; those pauses in the 2.0- to 4.0-second range seem to be benign. Studies of long-term recordings are needed to redefine asystole in both normal preterm and fullterm infants. These data would help further refine current guidelines for pacemaker implantation during infancy.

Cognitive functioning as a contraindication to organ transplant surgery: Dilemmas encountered in medical decision making.

A case is presented to illustrate some of the difficulties encountered when providing psychological consultation to evaluate the readiness of patients for pediatric heart-lung transplantation. The outcome of complex medical decision making can often hinge on information provided by the psychological consultant who is attempting to simultaneously serve the needs of the patient as well as the transplant team. Ethical dilemmas frequently arise when medical decision making is driven by limited health care resources and cost constraints. The utility of cognitive functioning as a variable in pediatric transplant decision making is discussed. Recommendations are made for further work in this area on both conceptual and empirical grounds to guide the integration of psychological information into transplant decision making as health care delivery continues to evolve in the future.

Neonatal lupus erythematosus. Report of serological and immunogenetic studies in twins discordant for congenital heart block.

Autoantibody, HLA studies and C4 phenotypes were performed on twins discordant for isolated congenital heart block. Serum from the mother and cord blood from the infants revealed Ro(SSA) and La(SSB) antibodies in all three sera. No significant difference in Ro(SSA) antibody titre was noted in the cord blood of either twin when compared with maternal titres, as detected by a sensitive ELISA assay. The infants' mother was HLA-DR3 positive. Both infants had identical HLA and C4 phenotypes. Immunoblot analysis revealed that sera from both mother and infants reacted with the 52-kDa Ro(SSA) macromolecule. Quantitative cord blood IgM levels were not elevated in either twin. This study indicates that placental transfer of anti-Ro(SSA) or anti-La(SSB) alone to the fetus is not sufficient for the expression of congenital complete heart block. We conclude from this experiment of Nature that there must be a second event determining which infant develops complete heart block, but this is unknown at present.

Neonatal lupus erythematosus syndrome: analysis of C4 allotypes and C4 genes in 18 families.

We examined 18 families with infants who had neonatal lupus erythematosus (NLE) syndrome to determine whether abnormalities in C4 phenotypes and genotypes were an additional risk factor for this syndrome. Fifteen of 18 mothers of infants with NLE (83%) had C4 null allotypes compared with 36% of population controls (p = less than .001). This increased frequency was due mainly to the presence of C4A null allotypes (11/18, 61%). C4 gene abnormalities, i.e., deletion or probable duplication, were present in 100% (16/16) of mothers of infants with NLE. The most common molecular genetic abnormality in mothers of infants with NLE in this study was deletion of C4A genes. Duplication of C4A and C4B loci was also commonly seen. Duplication of C4A genes was detected only in mothers of infants with complete congenital heart block (CCHB), and duplication of C4B was detected only in mothers of infants with dermatitis. No significant increase in C4A or C4B null allotypes or protein deficiencies was noted in mothers of infants with neonatal lupus when compared with anti-Ro(SS-A)-positive mothers delivered of clinically normal infants. Fathers of infants with NLE showed a trend toward increase in C4B null allotypes when compared with population controls (75%, 3/4, p = .06). The two infants with CCHB examined were C4B protein-deficient, in contrast to infants with lupus dermatitis, who had frequent C4B null allotypes but no C4B protein deficiency. C4B null allotypes were not seen in unaffected siblings of infants with NLE and in only 1 of 7 anti-Ro(SS-A)-positive mothers who delivered clinically normal infants. We conclude that inheritance of C4A null allotypes is not predictive of increased risk of neonatal lupus when present in anti-Ro(SS-A)-positive women. Examination of paternal and maternal C4 genes of additional infants with NLE, in particular those with CCHB, and of normal infants born to anti-Ro(SS-A)-positive mothers--and of the normal infants' parents--is required to determine if abnormal C4B genes are a critical factor rendering susceptibility to the NLE syndrome.