Cardiac troponin T in neonates with respiratory distress

Objective

The purpose of this study is to assess cardiac troponin T(cTnT) in neonates with respiratory distress as a marker of myocardial dysfunction.

Cardiac troponin I in asphyxiated neonates

BACKGROUND: Cardiac troponins T (cTnT) and I (cTnI) are well-established markers in detecting myocardial ischemic damage in adults. Perinatal asphyxia is associated with cardiac dysfunction. OBJECTIVES: To evaluate serum concentrations of cTnI in asphyxiated neonates and to investigate whether cTnI is correlated with the traditional markers of asphyxia. METHODS: Blood samples were collected from 13 asphyxiated neonates (umbilical artery pH<7.18 and either a 1-min Apgar score<4 or a 5-min Apgar score<7) and 39 controls. Data on gestation, birth weight, sex, Apgar scores, mode of delivery, umbilical pH, creatinine, serum activity of aspartate and alanine aminotransferase, and QTc interval were investigated. RESULTS: Median (range) cTnI concentrations were significantly higher in asphyxiated neonates with respect to healthy infants: 0.36 microg/l (0.05-11) versus 0.04 microg/l (0.04-0.06); p<0.01. In asphyxiated babies, no statistically significant correlations were found between concentrations of cTnI and the other markers of asphyxia. CONCLUSIONS: In asphyxiated neonates, cTnI concentrations are higher with respect to healthy infants, suggesting the presence of myocardial damage in this group of high-risk patients. cTnI does not correlate with the traditional markers of asphyxia.     

Cardiac troponin I, cardiac troponin T and creatine kinase MB concentrations in umbilical cord blood of healthy term neonates

AIMS: To measure and compare cardiac troponin I, cardiac troponin T and creatine kinase MB concentrations in the umbilical cord blood of healthy term infants and to investigate the relationship between maternal and neonatal troponin values at birth. METHODS: Troponin I, troponin T and creatine kinase MB concentrations were measured from the umbilical cord samples of 85 healthy term neonates and in the blood samples of their respective mothers at birth. RESULTS: Median (interquartile range) umbilical cord concentrations were 0 microg/L (0-0) for troponin I, 0 microg/L (0-0.019) for troponin T and 4.90 microg/L (3.90-6.61) for creatine kinase MB. Troponin I and T concentrations were higher than the detection limit for the assay in 2 (2.3%) and 41 (48.2%) neonates, respectively. Two mothers (2.3%) had cTnT levels above the detection limit; none of them had increased levels of cTnI. CONCLUSION: Probably owing to differences in expression and assay detection limits, cord blood troponin T concentrations are frequently over the detection limit at birth, while troponin I is mostly undetectable and comparable with that in healthy pregnant women. These cardiac regulatory proteins are of neonatal origin and are not influenced by maternal levels.     

Cardiac troponin T in cord blood

BACKGROUND: Perinatal asphyxia is associated with cardiac dysfunction. This may be secondary to myocardial ischaemia. Cardiac troponin T is the ideal marker for myocardial necrosis. Elevated levels in cord blood may be associated with intrauterine hypoxia and increased perinatal morbidity. AIMS: To establish an upper limit of normal for cardiac troponin T concentration in the cord blood of infants. Relations between cardiac troponin T levels and other variables were investigated. METHODS: Cord blood samples were collected from 242 infants and analysed. Data on gestation, birth weight, sex, Apgar scores, respiratory status, and mode of delivery were recorded. RESULTS: A total of 242 samples were collected, and 215 samples from infants without respiratory distress were used to establish the 95th percentile of 0.050 ng/ml. The gestation of these infants ranged from 31 to 42 weeks and birth weight ranged from 1.4 to 5 kg. There were no relations between cardiac troponin T levels and the other variables in these healthy infants. Twenty seven infants developed respiratory symptoms requiring oxygen and/or ventilation. These infants had significantly higher cord cardiac troponin T levels than their healthy counterparts (median (interquartile range) 0.031 (0.010-0.084) v 0.010 (0.010-0.014) ng/ml respectively; p < 0.001). CONCLUSIONS: Cardiac troponin T levels in the cord blood are unaffected by gestation, birth weight, sex, or mode of delivery. Infants with respiratory distress had significantly higher cord cardiac troponin T levels, suggesting that cardiac troponin T may be a useful marker for myocardial damage in neonates.     

Cord blood cardiac troponin T and troponin I levels in multiple-gestation neonates

The increased mortality and morbidity rates in multiple-gestation neonates are not completely understood. Troponin measurements have a role in situations where the evaluation of the cardiac damage is difficult, such as in cases of unexplained intrauterine fetal growth restriction or death. These conditions, along with perinatal hypoxic risk and in utero ischemic damage, are frequently found in multiple gestations. In this context, a myocardial damage could be expected more frequently in multiple than in singleton births. We hypothesized that cord blood cardiac troponin T and troponin I, markers of myocardial damage, could be different between singleton and multiple pregnancies and, among twins, between the first- and the second-born twin. Troponins T and I and creatine kinase MB concentrations were not increased in twins at birth and were not different between the first- and the second-born twin. These data suggest that myocardial damage, evaluated by cardiac troponin T, troponin I, and creatine kinase MB measurements, does not seem to be a relevant problem in multiple-gestation neonates.     

Cardiac troponin I concentrations in neonates with hypoxic-ischaemic encephalopathy

Aim: Myocardial dysfunction is a frequent sequel of perinatal asphyxia. Cardiac troponin I (cTnI) is a marker of myocardial injury and a surrogate marker of myocardial dysfunction in adults, but there are few data in neonates. Our aim was to compare serum cTnI concentrations with clinical severity of encephalopathy and with duration of inotropic support in asphyxiated neonates. Methods: Retrospective study of 60 neonates admitted with hypoxic‐ischaemic encephalopathy (HIE). cTnI concentrations measured within 36 h of birth were compared with clinical grade of HIE (Sarnat‐Sarnat classification) and with duration of inotropic support. Results: Serum cTnI concentrations and duration of inotropic support were significantly greater with increasing severity of HIE. Median (95% CI) cTnI concentrations were 0.04 μg/L (0.02–0.07 μg/L) in grade 1 HIE, 0.12 μg/L (0.08–0.20 μg/L) in grade 2 HIE and 0.67 μg/L (0.41–1.35 μg/L) in grade 3 HIE. Median (95% CI) duration of inotropic support required was 0 h (0–24 h) in grade 1 HIE, 28 h (0–118 h) in grade 2 HIE and 48 h (0–140 h) in grade 3 HIE. Conclusion: In asphyxiated neonates, cTnI concentrations within 36 h of birth correlate strongly with clinical grade of HIE and with duration of inotropic support. Early cTnI concentrations may provide a useful proxy marker for the anticipated severity of myocardial dysfunction.     

Concentrations of cardiac troponin T in neonates with and without respiratory distress

AIMS: To establish a practical postnatal reference range for cardiac troponin T in neonates and to investigate concentrations in neonates with respiratory distress. METHODS: Prospective investigation in a tertiary neonatal unit, recruiting infants with and without respiratory distress (sick and healthy infants respectively). Concentrations of cardiac troponin T were compared between sick and healthy infants, accounting for confounding variables. RESULTS: A total of 162 neonates (113 healthy and 49 sick infants) had samples taken. The median (interquartile range) cardiac troponin T concentration in the healthy infants was 0.025 (0.01-0.062) ng/ml, and the 95th centile was 0.153 ng/ml. There were no significant relations between cardiac troponin T and various variables. The median (interquartile range) cardiac troponin T concentration in the sick infants was 0.159 (0.075-0.308) ng/ml. This was significantly higher (p < 0.0001) than in the healthy infants. In a linear regression model, the use of inotropes and oxygen requirement were significant associations independent of other basic and clinical variables in explaining the variation in cardiac troponin T concentrations. CONCLUSIONS: Cardiac troponin T is detectable in the blood of many healthy neonates, but no relation with important basic and clinical variables was found. Sick infants have significantly higher concentrations than healthy infants. The variations in cardiac troponin T concentration were significantly associated with oxygen requirement or the use of inotropic support in a regression model. Cardiac troponin T may be a useful marker of neonatal and cardiorespiratory morbidity.     

Cardiac troponin T: its role in the diagnosis of clinically suspected acute myocarditis and chronic dilated cardiomyopathy in children

This study was conducted to assess the use of the serum cardiac troponin T (cTnT) level as a noninvasive indicator to differentiate acute myocarditis and chronic dilated cardiomyopathy in pediatric patients. Myocarditis and dilated cardiomyopathy are clinically difficult to differentiate. Endomyocardial biopsy proved to be quite useful. However, the nature of the procedure--invasiveness, time-consuming, and limited sensitivity--caused some concerns, especially in pediatric patients. Hence, we attempted to find an alternative method that could give a prompt diagnosis of acute myocarditis. Twenty cases with clinically suspected myocarditis or dilated cardiomyopathy and a control group of 21 cases with moderate left-to-right shunt and congestive heart failure were recruited. History, physical examination, electrocardiogram, chest roentgenogram, echocardiogram, cTnT, creatine kinase MB isoenzyme (CK-MB mass), and/or endomyocardial biopsy were compared. The gold standard used to diagnose myocarditis is endomyocardial biopsy (Dallas criteria) and/or recovery from cardiovascular problems within 6 months of follow-up. Ten patients were diagnosed as having myocarditis (group 1) and 10 with chronic dilated cardiomyopathy (group 2). The control group of 21 cases was designated as group 3. The median serum cTnT levels were 0.088 (0.04-3.11), 0.010 (0.010-0.990), and 0.010 (0.010-0.550) ng/ml in groups 1, 2, and 3, respectively. The mean CK-MB mass level for groups, 1, 2, and 3 were 18.35 (7.14-70.00), 4.80 (0.54-108.00), and 2.26 (0.95-7.06) ng/ml. The study showed that both the cTnT and CK-MB mass levels were significantly higher in group 1 than either group 2 or group 3. Histopathology was studied in 9 cases. In 2 of 5 cases and in all 4 cases in group 1 and group 2 histopathology was pathologically proved. Levels of cTnT and CK-MB were significantly higher for myocarditis than for dilated cardiomyopathy and left-to-right shunt with CHF. Further study is needed to assess the optimum cTnT level for differentiating both conditions.     

Outcomes after acute symptomatic seizures in neonates

Acute symptomatic seizures are a common sign of neurological dysfunction and brain injury in neonates and occur in approximately one to three per 1000 live births. Seizures in neonates are usually a sign of underlying brain injury and, as such, are commonly associated with adverse outcomes. Neurological morbidities in survivors often co-occur; epilepsy, cerebral palsy, and intellectual disability often occur together in the most severely affected children. Risk factors for adverse outcome include prematurity, low Apgar scores, low pH on the first day of life, seizure onset <24 or >72 h after birth, abnormal neonatal neurological examination, abnormal neonatal electroencephalographic background, status epilepticus, and presence and pattern of brain injury (particularly deep gray or brainstem injury). Despite this list of potential indicators, accurate prediction of outcome in a given child remains challenging. There is great need for long-term, multicenter studies to examine risk factors for, and pathogenesis of, adverse outcomes following acute symptomatic seizures in neonates.     

Cardiac troponin T and creatine kinase MB mass concentrations in children receiving anthracycline chemotherapy

Anthracyclines (doxorubicin, daunorubicin, and derivatives) are among the most effective antineoplastic drugs for pediatric cancer with dose-limiting acute and longterm cardiotoxicity. The exact mechanism of the development of cardiomyopathy is still not clear. Anthracyclines may induce subclinical acute myocardial injury leading to lysis of a limited number of myocytes. Alternatively, myocytes may experience a transient loss of cytoplasmic membrane integrity. Both conditions may lead to a transient efflux of small amounts of cytoplasmic enzymes and other proteins specific to the heart muscle fibers. To test these hypotheses we assayed plasma creatine kinase (CK) MB mass and cardiac specific troponin T (TnT). CKMB may be released even in case of reversible cell membrane injury, while prolonged elevation of TnT is the most sensitive and specific marker of limited myocardial necrosis. Thirty-five anthracycline-containing chemotherapy courses in 22 children with cancer were analyzed. CKMB mass and TnT concentrations were within the normal range in all children before anthracycline therapy. Within 72 hours from anthracycline therapy no increment of one of these two marker proteins was detected (ANOVA for repeated measures, P = 0.94 [TnT] and 0.25 [CKMB]). We conclude that only minimal if any acute necroses of cardiac myocytes occur after anthracycline therapy. Even membrane integrity appears to be maintained within the first 3 days after anthracycline therapy, in the absence of electrocardiographic or echocardiographic signs of acute cardiotoxicity. © 1995 Wiley-Liss, Inc.     

新生儿心导管术26例分析

目的：新生儿心导管术在我国开展很少,该文总结了26例新生儿心导管术,探讨了其特点及在先天性心脏病诊断和治疗中的重要性。方法：新生儿患者26例,年龄5～28d,体重2300～4500g。行右室造影24例,左心系统造影20例;肺静脉楔入造影6例;其中10例行房间隔球囊造口术。结果：诊断紫绀型复杂心血管畸形20例,无紫绀型心血管畸形4例。2例行先天性心脏病术后心内临时起搏器安装。心导管术中非致死性有意义并发症占15.3%,无死亡者。结论：心导管术依然是诊断新生儿复杂心血管畸形最为准确的方法;介入性心导管在新生儿心导管术中将保持重要地位。     

Usefulness of cardiac troponin T and echocardiography in the diagnosis of hypoxic myocardial injury of full-term neonates

BACKGROUND: Perinatal asphyxia constitutes a significant problem influencing neonatal mortality and morbidity. OBJECTIVES: The aim of the present work was to provide evidence of the usefulness of cardiac troponin T (cTnT) and echocardiographic investigations in the diagnosis of heart damage in full-term infants after intrauterine hypoxia. MATERIAL AND METHODS: The subjects were 39 asphyxiated and 44 term infants without fetal anoxia. Quantitative determinations of cTnT were performed between 12 and 24 h of life. Two-dimensional Doppler and color Doppler studies were performed at the bedside. We evaluated fractional shortening (FS), cardiac output (CO), cardiac index (CI), tricuspid (TI) and mitral (MI) insufficiency. RESULTS: Asphyxiated infants presented increased cTnT (mean 0.141+/-0.226 vs. 0.087+/-0.111 ng/ml; p<0.01) and TI (38.5 vs. 11.4% of population; p<0.05) compared to healthy infants. CO, CI and FS remained in the same range. CONCLUSIONS: We found cTnT to be the most useful among accessible diagnostic tools used in post-hypoxic heart damage in neonates. The data from our relatively small population study suggest a cTnT value of >0.1 ng/ml as a reliable marker of myocardial injury in neonates. Further study should be performed to generate a receiver-operator characteristic curve to discover what the cut-off level should be.     

Sequential cardiac troponin T following delivery and its relationship with myocardial performance in neonates with respiratory distress syndrome

We measured serial cardiac troponin T in babies with respiratory distress syndrome and in “healthy” controls (no cardiorespiratory support required). We investigated relationships between cardiac troponin T and myocardial performance in respiratory distress syndrome. This was a prospective observational study at a large tertiary maternity unit that recruited 104 “healthy” babies from whom individual samples were collected. A further 24 infants with respiratory distress syndrome and 14 “healthy” preterm infants had serial sampling over the first three days. We measured fractional shortening in 14 of the infants with respiratory distress syndrome. Cardiac troponin T rose from a median (interquartile range) of 10 (10–11) pg/mL on day one to 34 (22–46) pg/mL by day three, p=0.005, in “healthy” babies. In respiratory distress syndrome levels were higher, 91 (46–135) pg/mL at 6 (5–7) hours of age, p<0.001, and remained so for all three days. In babies with respiratory distress syndrome on day one cardiac troponin T correlated negatively with fractional shortening, Rho=−0.831, p<0.001, but this correlation did not persist. In “healthy” babies there is a minimal rise of cardiac troponin T by day 3. In respiratory distress syndrome there is an early and sustained elevation of cardiac troponin T, with a negative relationship with fraction shortening, suggesting significant myocardial damage of antenatal/intrapartum origin, giving rise to measurable dysfunction. This work was carried out at Liverpool Women's Hospital & Royal Liverpool Children's NHS Trust Funding for this study came from The Newborn Appeal, a charity associated with Liverpool Women's Hospital     

Correlation of cardiac troponin T levels with inotrope requirement,hypoxic-ischemic encephalopathy,and survival in asphyxiated neonates

BACKGROUNDCardiac involvement in neonates with perinatal asphyxia not only complicates perinatal management but also contributes to increased mortality. AIMTo assess cardiac troponin T (cTnT) levels in asphyxiated neonates and their correlation with echocardiography findings, inotrope requirement, hypoxic-ischemic encephalopathy (HIE) stages, and mortality.METHODScTnT levels, echocardiographic findings, the requirement of inotropes, HIE stages, and outcome were studied in neonates of gestational age ≥ 34 wk with perinatal asphyxia.RESULTSAmong 57 neonates with perinatal asphyxia, male gender, cesarean section, forceps/vacuum-assisted vaginal delivery and late preterm included 33 (57.9%), 23 (40.4%), 3 (5.3%), and 12 (21.1%) respectively. The mean gestational age was 38.4 wk (1.6 wk). HIE stages I, II, and III were observed in 7 (12.3%), 37 (64.9%), and 9 (15.8%) neonates respectively. 26 (45.6%) neonates had echocardiographic changes and 19 (33.3%) required inotropes. cTnT levels were elevated in 41 (71.9%) neonates [median (IQR); 0.285 (0.211-0.422) ng/mL]. The Median cTnT level showed an increasing trend with increasing changes in echocardiography (P = 0.002). Two neonates with mitral regurgitation and global hypokinesia had the highest cTnT levels (1.99 and 0.651 ng/mL). Of 31 neonates with normal echocardiography, 18 (58.06%) showed elevated cTnT. cTnT levels were significantly higher in those who required inotropic support than those who did not (P = 0.007). Neonates with HIE stage III had significantly higher cTnT levels compared to those with HIE stage I/II (P = 0.013). Survivors had lower median cTnT levels [0.210 (0.122-0.316) ng/mL] than who succumbed [0.597 (0.356-1.146) ng/mL].CONCLUSIONcTnT levels suggestive of cardiac involvement were observed in 71.9% of asphyxiated neonates. cTnT levels correlated with echocardiography findings, inotrope requirement, HIE stages, and mortality.     

Cardiac adaptation in small for gestational age neonates after prenatal hemodynamic disturbances

BACKGROUND: Small for gestational age neonates with prenatal hemodynamic disturbances are at increased risk for neonatal morbidity. Investigations of fetal cardiac function have proved some functional impairments. The aim of the study was to investigate postnatal cardiac adaptation in these neonates in comparison with neonates without prenatal hemodynamic impairments. METHODS AND RESULTS: Forty-one neonates with prenatal hemodynamic disturbances and 40 neonates with undisturbed prenatal hemodynamics were observed during the first 5 days of life. Doppler sonographic measurements of left ventricular time intervals, stroke volume, cardiac output and the incidence of patent ductus arteriosus were obtained in all neonates of both groups. Heart rate and blood pressure were recorded simultaneously. RESULTS: A higher incidence of patent ductus arteriosus and a diminished stroke volume, but increased cardiac output, based on a significantly increased heart rate, were determined in SGA neonates with prenatal hemodynamic disturbances. In contrast, systolic left ventricular time intervals were not changed in these neonates, as expected. CONCLUSIONS: The described findings could be signs of persistent hemodynamic impairments in growth-retarded neonates with prenatal disturbed hemodynamics. The neonates revealed a reduced ability to compensate the prenatal hemodynamic disturbances. This aspect should be included in the discussion of perinatal management in cases of severe growth retardation.     

心肌钙蛋白在小儿先天性心脏病介入治疗中的变化

心肌肌钙蛋白Ⅰ（cardiac troponinⅠ,cTn—Ⅰ）已作为一种高度特异和敏感的心肌损伤标志物在临床得到广泛的应用。     

心肌钙蛋白-I与心肌钙蛋白-T诊断小儿病毒性心肌炎的初步比较研究

目的 比较心肌钙蛋白-I、T（cTnI、T）对小儿病毒性心肌炎（VMC）的诊断价值。方法 20例临床上诊断为VMC（急性期）或疑似VMC患儿，分别在入院后不同时间静脉采血，同步检测血清cTnI、T，并与非心肌炎（NMC）其他疾病组比较。结果 NMC其他疾病组血清cTnI、T均阴性；VMC组各阳性4例（40％）；疑似VMC组分别阳性2例（20％）、1例（10％）。结论 在小儿VMC诊断中，cTnI、T的阳性率差异无显著性。     

Furosemide and acute kidney injury in neonates

Furosemide is a commonly used loop diuretic in neonatal intensive care. The common indications for the use of diuretics in neonates are fluid retention with adequate circulating blood volume, congestive heart failure, chronic lung disease (now rarely used) and acute kidney injury. This article discusses the pathophysiology of acute kidney injury in neonates and explores and maps the role of furosemide in this clinical situation. This is meant to be an easy to read, easy to digest, practical review for the jobbing clinician.