Home use of a compact, 12‑lead ECG recording system for newborns

BACKGROUND

An easy-to-operate ECG recorder should be useful for newborn screening for heart conditions, by health care workers - or parents. We developed a one-piece electrode strip and a compact, 12‑lead ECG recorder for newborns.

METHOD

We enrolled 2582 newborns in a trial to assess abilities of parents to record a 12‑lead ECG on their infants (2-4 weeks-old). Newborns were randomized to recordings by parents (1290) or our staff (1292 controls). Educational backgrounds of parents varied, including 64% with no more than a high school diploma.

RESULTS

For newborns randomized to parent recorded ECGs, 94% of parents completed a 10-minute recording. However, 42.6% asked for verbal help, and 12.7% needed physical help. ECG quality was the same for recordings by parents versus staff.

CONCLUSIONS

By use of a one-piece electrode strip and a compact recorder, 87% of parents recorded diagnostic quality ECGs on their newborn infants, with minimal assistance.

Comparison of formulas for calculation of the corrected QT interval in infants and young children

OBJECTIVE

To compare 4 heart rate correction formulas for calculation of the rate corrected QT (QTc) interval among infants and young children.

STUDY DESIGN

R-R and QT intervals were measured from digital electrocardiograms. QTc were calculated with the Bazett, Fridericia, Hodges, and Framingham formulas. QTc vs R-R graphs were plotted, and slopes of the regression lines compared. Slopes of QTc-R-R regression lines close to zero indicate consistent QT corrections over the range of heart rates.

RESULTS

We reviewed electrocardiograms from 702 children, with 233 (33%) <1 year of age and 567 (81%) <2 years. The average heart rate was 122 ± 20 bpm (median 121 bpm). The slopes of the QTc-R-R regression lines for the 4 correction formulas were -0.019 (Bazett); 0.1028 (Fridericia); -0.1241 (Hodges); and 0.2748 (Framingham). With the Bazett formula, a QTc >460 ms was 2 SDs above the mean, compared with "prolonged" QTc values of 414, 443, and 353 ms for the Fridericia, Hodges, and Framingham formulas, respectively.

CONCLUSIONS

The Bazett formula calculated the most consistent QTc; 460 ms is the best threshold for prolonged QTc. The study supports continued use of the Bazett formula for infants and children and differs from the use of the Fridericia correction during clinical trials of new medications.

Genetic variants for long QT syndrome among infants and children from a statewide newborn hearing screening program cohort

OBJECTIVES

Autosomal recessive long QT syndrome (LQTS), or Jervell and Lange-Nielsen syndrome (JLNS), can be associated with sensorineural hearing loss. We aimed to explore newborn hearing screening combined with electrocardiograms (ECGs) for early JLNS detection.

STUDY DESIGN

In California, we conducted statewide, prospective ECG screening of children ≤ 6 years of age with unilateral or bilateral, severe or profound, sensorineural or mixed hearing loss. Families were identified through newborn hearing screening and interviewed about medical and family histories. Twelve-lead ECGs were obtained. Those with positive histories or heart rate corrected QT (QTc) intervals ≥ 450 ms had repeat ECGs. DNA sequencing of 12 LQTS genes was performed for repeat QTc intervals ≥ 450 ms.

RESULTS

We screened 707 subjects by ECGs (number screened/number of responses = 91%; number of responses/number of families who were mailed invitations = 54%). Of these, 73 had repeat ECGs, and 19 underwent gene testing. No subject had homozygous or compound heterozygous LQTS mutations, as in JLNS. However, 3 individuals (with QTc intervals of 472, 457, and 456 ms, respectively) were heterozygous for variants that cause truncation or missplicing: 2 in KCNQ1 (c.1343dupC or p.Glu449Argfs*14; c.1590+1G>A or p.Glu530sp) and 1 in SCN5A (c.5872C>T or p.Arg1958*).

CONCLUSIONS

In contrast to reports of JLNS in up to 4% of children with sensorineural hearing loss, we found no examples of JLNS. Because the 3 variants identified were unrelated to hearing, they likely represent the prevalence of potential LQTS mutations in the general population. Further studies are needed to define consequences of such mutations and assess the overall prevalence.

Primary vs. delayed resection for obstructive left-sided colorectal cancer: impact of surgery on patient outcome

PURPOSE

By comparing surgical outcomes between primary and delayed resection, we addressed whether and how surgical strategies impacted prognosis of patients with left-sided colorectal cancer underwent emergency curative resection.

METHODS

Between January 1980 and December 2002, a total of 143 patients were identified who presented with obstructive left-sided colorectal cancer and received emergency curative resection in Taipei Veterans General Hospital. Patients were stratified according to the timing of tumor resection into two groups: primary resection and delayed resection. Demographic data of the patients, characteristics of the tumors, and short-term and long-term outcomes were analyzed and compared between the two groups.

RESULTS

The demographic data and tumor characteristics did not differ between the two groups except for more rectal cancers in the delayed resection group (P=0.021). Primary resection group had a higher anastomotic leakage rate (P=0.017) and a trend toward a higher mortality rate, which did not reach statistical significance (P=0.063). The median follow-up intervals were similar (60.4 vs. 58.3 months; P=0.79). The median survival tended to be longer in delayed resection group (66 vs. 105 months; P=0.088). Overall five-year and ten-year survival for primary resection were 43.7 and 31.9 percent, respectively, compared with 67.2 and 53.2 percent, respectively, for delayed resection.

CONCLUSIONS

Delayed resection seems to be a safer procedure and provided a better oncologic outcome compared with primary resection in obstructive left-sided colorectal cancer under emergency situations.

B-type natriuretic peptide in children after cardiac transplantation

BACKGROUND

The normal B-type natriuretic peptide (BNP) concentration and the significance of increased BNP concentration in children after orthotopic heart transplant (OHT) remain unknown. We sought to determine plasma BNP concentrations in relation to post-transplant time and to explore factors associated with increased BNP in pediatric OHT recipients.

METHODS

We obtained plasma BNP concentrations in 44 pediatric patients at 1 to 171 months after OHT. All patients underwent endomyocardial biopsies and echocardiography. We analyzed the association between BNP and post-transplant time, as well as the association between BNP concentration and left ventricular end-diastolic dimension (LVEDD) after transplantation.

RESULTS

The age of study patients ranged from 0.9 to 21.2 years (mean, 11.4 +/- 6.2 years; median, 10.5 years). We evaluated BNP concentrations immediately after transplantation. The mean BNP concentration decreased exponentially to 100 pg/ml by 14 weeks after OHT. Although BNP concentration relative to time after OHT varied among individuals, all patients with multiple measurements showed predictable rates of decrease. This decrease in BNP concentration was not associated with changes in LVEDD.

CONCLUSIONS

Plasma BNP concentration was elevated in children after OHT and decreased exponentially in time to 100 pg/ml by 14 weeks after OHT. The decrease in BNP concentration was unrelated to left ventricular dimension.

Outcome of patients with double-inlet left ventricle or tricuspid atresia with transposed great arteries

OBJECTIVES

We sought to determine the long-term outcomes and risk factors for mortality in patients with double-inlet left ventricle (DILV) or tricuspid atresia with transposed great arteries (TA-TGA).

BACKGROUND

Patients with DILV or TA-TGA are at risk of systemic outflow obstruction and a poor outcome. The impact of various management strategies on the long-term outcomes of these patients remains unknown.

METHODS

We reviewed the outcomes of 164 consecutive pediatric patients with DILV or TA-TGA who underwent surgical palliation between 1983 and 2002. Patients with a Holmes heart or heterotaxy syndrome or who were lost to follow-up (n = 24) were excluded. Risk factors for mortality or the need for orthotopic heart transplantation (OHT) were assessed by multivariate analysis.

RESULTS

There were 105 patients with DILV and 35 patients with TA-TGA. The overall mortality rate, including OHT, was 29%. Patients with DILV had a lower mortality rate than patients with TA-TGA (23% vs. 49%, p = 0.007). Multivariate analysis showed the presence of arrhythmia and pacemaker requirement as independent risk factors for mortality, whereas pulmonary atresia or stenosis and pulmonary artery banding were associated with decreased mortality. Gender, era of birth, aortic arch anomaly, and systemic outflow obstruction were not risk factors. The perioperative and overall mortality were similar between patients who underwent the Damus-Kaye-Stansel procedure beyond the neonatal period and those had subaortic resection.

CONCLUSIONS

The mortality of patients with DILV or TA-TGA remains high. The outcomes of these patients are influenced by restriction of pulmonary blood flow, arrhythmia, and pacemaker requirement. Surgical palliation to relieve systemic outflow obstruction is not associated with a poor outcome.

Usefulness of B-type natriuretic peptide as a noninvasive screening tool for cardiac allograft pathology in pediatric heart transplant recipients

We examined the utility of B-type natriuretic peptide (BNP) in the evaluation of pediatric orthotopic heart transplant recipients for allograft pathology by measuring the serum BNP levels at the time of either screening echocardiography and biopsy, or at the time of clinical rejection. There was a significant difference (p <0.0001) in the BNP levels in 37 patients in the group with evidence of pathology compared with those without evidence. There was also 100% sensitivity and 100% negative predictive value of BNP levels >100 pg/ml for identifying graft pathology.

Postoperative arrhythmia

Postoperative arrhythmia is a major cause of morbidity and mortality after cardiac surgery for congenital heart disease. Rhythm disturbances that may be well tolerated in a normal heart often cause hemodynamic instability when they occur in the immediate postoperative period. In the face of pre-existing myocardial dysfunction resulting from preoperative pressure or volume overload, patients with congenital heart conditions are especially vulnerable to rhythm disturbances after cardiac surgery. Cardiopulmonary bypass, intraoperative injury to the conduction system and myocardium, postoperative metabolic abnormalities, electrolyte disturbances, and increased adrenergic tone in response to the stress of the surgery or inotropic agents are also known factors associated with increased risk of arrhythmia in the immediate postoperative period. Surgically related arrhythmia can also present in the late postoperative period, particularly in association with surgical incision sites and surgically induced hemodynamic abnormalities. Early and late postoperative arrhythmias are important risk factors for morbidity and mortality after surgical treatment of many forms of congenital heart disease. This review describes the incidence of the most common forms of arrhythmia and recent advances in their diagnosis and treatment.

Outcome of staged surgical approach to neonates with single left ventricle and moderate size bulboventricular foramen

Neonates with double-inlet left ventricle or tricuspid atresia with transposed great arteries and a bulboventricular foramen (BVF) area <2 cm(2)/m(2) develop BVF obstruction. This study examined the outcome of neonates with BVF area between 1 and 2 cm(2)/m(2) whose BVF was bypassed after the neonatal period. We reviewed 29 neonates with double-inlet left ventricles (n = 18) or tricuspid atresia (n = 11) and transposed great arteries. The study group consisted of 9 patients with neonatal BVF areas of 1 to 2 cm(2)/m(2) who did not undergo repair of the BVF obstruction as a neonate. The comparison group consisted of 8 "ideal" patients without BVF obstruction. Precavopulmonary shunt data from cardiac catheterization and echocardiogram and outcomes of the cavopulmonary shunt were compared. Study group patients developed a mild BVF gradient (18 +/- 10 mm Hg by cardiac catheterization) by a mean of 7 months. Left ventricular wall thickness, however, remained in the normal range (4.2 +/- 0.3 mm) and was not statistically different from the comparison group (4.1 +/- 0.4 mm). No difference was found in the precavopulmonary mean pulmonary artery pressure (15 +/- 5 vs 15 +/- 6 mm Hg), transpulmonary gradient (8 +/- 4 vs 8 +/- 5 mm Hg), and left ventricular end-diastolic pressure (7 +/- 2 vs 8 +/- 3 mm Hg). One patient in the study group died from respiratory syncytial virus pneumonia while awaiting cavopulmonary shunt. Neither group had mortality from the cavopulmonary shunt. The lengths of hospital stay were comparable (8.3 +/- 3.7 vs 8.9 +/- 6.0 days). Thus, neonates with BVF area between 1 and 2 cm(2)/m(2) develop mild but hemodynamically insignificant BVF gradient by 7 months of age. This group of patients can be managed safely with relief of BVF obstruction later in infancy.

Roles of the three major phosphorylation sites of hepatitis B virus core protein in viral replication

Hepatitis B virus (HBV) core protein is a phosphoprotein. Its three major phosphorylation sites have been identified at the serine residues located at amino acids 157, 164, and 172. In order to investigate the role of core protein phosphorylation in HBV replication, these three serine residues were mutated to alanine to mimic nonphosphorylated serine or to glutamic acid to mimic phosphoserine. The nonphosphorylated core protein analog did not package the HBV pregenomic RNA, and the phosphorylated analog packaged the pregenomic RNA but failed to support viral DNA replication. These results indicate that the core protein phosphorylation may be important for pregenomic RNA packaging and that its dephosphorylation may be important for viral DNA replication. The individual roles of these three major phosphorylation sites in HBV replication were further investigated by being mutated to alanine in different combinations. The results showed that the serine residue at amino acid 157 was not essential for pregenomic RNA packaging, whereas the serine residues at amino acids 164 and 172 were more important. Furthermore, the serine residue at amino acid 157 was not essential for viral DNA replication or viral maturation.

Evidence that the B2 chain of laminin is responsible for the neurite outgrowth-promoting activity of astrocyte extracellular matrix

Extracellular matrix (ECM) derived from cerebral cortical astrocytes stimulates neurite outgrowth from pheochromocytoma (PC12) cells in the absence of the classical nerve growth factor (NGF). We have shown here that astrocyte ECM can also stimulate neurite outgrowth from primary cultures of central nervous system (CNS) neurons. Using PC12 cells for a quantitative assay, we also demonstrated that the neurite growth-promoting activity increased as the astrocytes matured in vitro: ECM from older astrocytes (3-12 weeks in vitro) exhibited two-fold more neurite growth-promoting activity than ECM for younger astrocytes (5 days to 2 weeks in vitro). We applied various antibodies to identify the neurite growth-promoting factor of astrocyte ECM and found that anti-laminin inhibited neurite outgrowth by 50%, whereas anti-fibronectin and anti-NGF had no effect. Immunoblots, using laminin chain-specific antibodies, and cDNA hybridization of laminin mRNA demonstrated that cultured astrocytes synthesize only the B2 chain of laminin. This suggests that the B2 chain of laminin suffices to stimulate neurite outgrowth.