Neonatal tachycardias: an update.
This review provides an updated framework for the diagnosis and management of neonatal tachycardias.
Anti-Arrhythmia Agents↗
Biomedical subjects
J R Skinner
Publications and source records attributed to J R Skinner.
Cardiorespiratory stability during echocardiography in preterm infants.
Blood pressure, heart rate, and oxygen saturation were monitored prospectively during 40 echocardiography recordings on 17 preterm infants (25-29 weeks; 510-1430 g), to examine whether echocardiography can be performed without disturbing cardiorespiratory status in preterm infants. There was no impact on absolute blood pressure. Heart rate increased by a mean of 4 beats per minute, and oxygen saturation decreased by a mean of 1% during echocardiography. While these changes reached statistical significance they are not of clinical significance as they remained well within ranges seen during control rest periods. All readings had greater minute-to-minute variability during echocardiography but differences were small and again remained within physiological ranges.
Blood Pressure↗
Is there a relation between SIDS and long QT syndrome?
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Autopsy↗
Near-miss SIDS due to Brugada syndrome.
A 19 day old infant was successfully resuscitated from ventricular fibrillation. The 12 lead ECG was normal, with a normal QT interval, and remains so over three years follow up. DNA analysis revealed a missense mutation (R1193Q) in the SCN5A gene, previously linked with familial sudden unexpected nocturnal death syndrome, also known as Brugada syndrome.
Electrocardiography↗
Use of the newborn screening card to define cause of death in a 12-year-old diagnosed with epilepsy.
Post-mortem investigation of sudden death in young people frequently reveals no overt cause for the death. Full investigation is hampered if tissue or blood is not retained for DNA analysis. We report a post mortem molecular diagnosis of long QT syndrome in a 12-year-old boy diagnosed with epilepsy who died suddenly playing sport. The DNA was extracted from an archived blood spot on his newborn screening ('Guthrie') card, which had been taken from him at 6 days of age. A missense mutation was detected in exon 5 of the KCNQ1 gene; R243C (835C > T), associated with long QT type 1. The same mutation was found in the mother (who now takes effective preventative therapy), but not in the sib who has now been reassured that she is not at risk of sudden death.
Arginine↗
The repeatability of echocardiographic determination of right ventricular output in the newborn.
BACKGROUND: Non-invasive measurement of left ventricular output has been shown to be a repeatable technique. Little is known about the repeatability using echocardiography in determining pulmonary arterial diameters or right ventricular output. AIMS: To find the most repeatable point at which to measure pulmonary arterial diameter, and to compare the repeatability of determining right ventricular output with left ventricular output. METHODS: We assessed the Intra-observer and inter-observer repeatability for measuring the diameter of the pulmonary trunk in 24 term and 26 preterm infants, respectively. Interobserver repeatability was assessed for the diameters of the pulmonary trunk and aorta, for stroke distance, and for left and right ventricular output. RESULTS: The coefficients of variation for intra-observer repeatability were 4%, 7.5% and 9% respectively for measurements of the pulmonary valve, the pulmonary trunk, and the right ventricular outflow tract. There were significant differences between observers for measurement of the pulmonary trunk (p<0.001) and right ventricular outflow tract (p=0.011) but not for the pulmonary valve measured in either its long (p=0.22) or short axis (p=0.22). Significant differences between observers were also found for the pulmonary stroke distance measured in the long axis (p=0.004) and aortic diameter at end-diastole (p<0.001). The other parameters did not differ significantly and were used to calculate right and left ventricular output, respectively. Mean left ventricular output was 241 mls/kg/min, with mean differences between observers of 0.6 mls/kg/min (95% confidence interval (CI): -39.2 to 40.3 mls/kg/min). Mean right ventricular output was 255 mls/kg/min, with mean differences of 0.3 mls/kg/min (95% CI: -24.1 to 23.4 mls/kg/min). CONCLUSION: Measuring the diameter of the pulmonary trunk at the base of the valvar hinge points was most repeatable. Repeatability of right ventricular output was similar to that of left, with absolute values similar to those published by other workers.
Analysis of Variance↗
Transcatheter patent ductus arteriosus occlusion: evolution of techniques and results from the 1990s.
OBJECTIVE: To review the evolution of transcatheter patent ductus arteriosus (PDA) occlusion techniques and results. METHODS: A single institution, retrospective review including all patients with intention to close a PDA from 1991 to 1998, with no exclusions. RESULTS: Rashkind occluder (n = 65), sideris double-button (n = 6), Cook detachable coil (n = 28) and Amplatzer ductal occluder (n = 4) were used. Successful implantation occurred in 99 of 103 patients. There was a need for a second transcatheter procedure to close residual ductal shunting in 12% of patients: Rashkind umbrellas (n = 8), double-button (n = 1), coils (n = 3). Eight patients (8%) required surgery, including 4 of 6 patients with the double-button occluder. CONCLUSIONS: The Rashkind occluder and the Sideris double-button device both had an unacceptably high rate of residual shunts requiring a second transcatheter procedure or surgical closure. Detachable coils and the Amplatzer ductal occluder have become the current technology of choice for transcatheter PDA closure with high success rates.
Adolescent↗
Haemodynamic effects of altering arterial oxygen saturation in preterm infants with respiratory failure.
AIMS: To examine the haemodynamic effects of brief alteration in arterial oxygenation in preterm infants with respiratory failure. METHODS: Eighteen preterm infants with respiratory failure, aged 9-76 hours, underwent detailed Doppler echocardiographic assessment at 86%, 96%, and 100% SaO2, achieved by altering the FIO2. Sixteen were receiving intermittent positive pressure ventilation, median FIO2 0.45 (0.20-0.65), median mean airway pressure 12 cm H2O (0-20). SaO2 was stable for 15 minutes at each stage. Four parameters of pulmonary arterial pressure were measured: peak velocity of tricuspid regurgitation and peak velocity of left to right ductal flow, TPV:RVET ratio and PEP:RVET ratio, measured at the pulmonary valve, along with flow velocity integrals at the aortic and pulmonary valves, and systemic arterial pressure. Ductal size was graded into closed, small, moderate, large with imaging, pulsed and continuous wave Doppler. RESULTS: Between 86% and 96% SaO2, there were no consistent changes, but in three of the 12 with a patent ductus arteriosus (PDA) there was ductal constriction, with complete closure in one. Between 96% and 100% SaO2, peak ductal flow velocity rose significantly in four of eight with a PDA. Ductal constriction occurred in four infants; in three this was associated with a significant fall in aortic flow integral and a rise in aortic pressure (4-6 mm Hg). Overall, 11 infants went from 86% to 100% SaO2 and pulmonary arterial pressure fell significantly in seven. CONCLUSION: A brief rise in SaO2 within the range maintained by most neonatal units can cause significant ductal constriction. The fall in pulmonary arterial pressure with 100% SaO2 seen in most infants was associated with a fall in pulmonary blood flow (or no change), rather than a rise, indicating that the dominant haemodynamic effect was ductal constriction rather than pulmonary vasodilation.
Confidence Intervals↗
Development of a system to record cardiac output continuously in the newborn.
Intermittent recordings of Doppler flow velocity and cardiac output are of value during intensive care of the sick newborn infant but result in repeated disturbance of the child. We describe a new device for making continuous precordial recordings of Doppler flow velocity from the pulmonary artery in healthy resting newborn infants. Optimal probe siting was evaluated in six babies, and signals were found to be best when the pulmonary artery was insonated from the mid left parasternum. Continuous recordings were made in 13 other babies. Pulmonary artery velocities and, by calculation, cardiac output were measured continuously over periods ranging from 24 to 60 min. Median right ventricular output ranged widely from 148 to 246 mL x kg(-1) x min(-1). In contrast, for individual babies, the values were remarkably stable: the interquartile ranges varied from 13.2 to 29.9 mL x kg(-1) x min(-1). The simultaneous display of signal power allowed independent assessment of artifactual changes in cardiac output. This technique is feasible in healthy term infants and now requires evaluation in the intensive care setting where it may provide useful information concerning trends and short-term variability in right ventricular output.
Cardiac Output↗
Atrial fibrillation with neonatal pulmonary lymphangiectasia.
A female infant born at 28 weeks' gestation was found to have mild hydrops foetalis. Initial echocardiography showed a structurally normal heart. During the first week of life, episodic atrial tachycardia with 1:1 or 2:1 conduction was seen, requiring therapy with digoxin. The infant remained ventilator dependent, with a persistent, chylous pleural effusion which contained a preponderance of lymphocytes. Congenital pulmonary lymphangiectasia (CPL) was confirmed histologically. Worsening episodes of atrial tachycardia, including episodes of atrial fibrillation, were further investigated and a repeat echocardiogram revealed thickening of the entire right atrial wall. The cardiac findings of a thickened right atrial wall with the histological signs of myocarditis were thought to be the cause of paroxysms of atrial fibrillation, an extremely rare arrhythmia in the neonatal period. To the authors' knowledge there have been no previous reports of CPL in association with the cardiac abnormalities described herein.
Atrial Fibrillation↗
Echocardiography on the neonatal unit: a job for the neonatologist or the cardiologist?
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Cardiology↗
Allatostatin in hemocytes of the cockroach Diploptera punctata.
Allatostatins are neuropeptides that inhibit the production, by the corpora allata, of a major insect hormone, juvenile hormone. These peptides are produced by cells of the brain and ganglia as well as by midgut endocrine cells. Transport from these sites may contribute to the allatostatin content in the hemolymph (insect blood). Using a monoclonal antibody against Diploptera punctata allatostatin I (A-P-S-G-A-Q-R-L-Y-G-F-G-L-NH2) and in situ hybridization with a digoxigenin-labeled cRNA probe generated from a portion of the allatostatin gene, it is demonstrated that allatostatin is present in and synthesized by granular hemocytes of D. punctata. About 5% of the hemocytes react with anti-allatostatin antibody and a similar number hybridize with a cRNA probe that detects allatostatin-specific mRNA. Electron micrographs showed that allatostatin-immunoreactive material occurs in membrane-bound, uniformly dense granules that frequently fill fusiform-shaped cells. Allatostatin in cell and plasma fractions of hemolymph quantified by enzyme-linked immunosorbent assay and by bioassay for inhibition of juvenile hormone synthesis in vitro indicated that about equal quantities (0.1-0.2 fmol/microl) are present in cell and plasma fractions. The production of allatostatin by hemocytes suggests that allatostatins may function as regulatory peptides in hemolymph activities in addition to their other known functions.
Animals↗
Multicenter evaluation of the MicroScan Rapid Gram-Negative Identification Type 3 Panel.
The accuracy and performance of the revised MicroScan Rapid Gram-Negative Identification Type 3 Panel (Dade MicroScan Inc., West Sacramento, Calif.) were examined in a multicenter evaluation. The revised panel database includes data for 119 taxa covering a total of 150 species, with data for 12 new species added. Testing was performed in three phases: the efficacy, challenge, and reproducibility testing phases. A total of 405 fresh and stock gram-negative isolates comprising 54 species were tested in the efficacy phase; 96.8% of these species were identified correctly in comparison to the identification obtained either with the API 20E system (bioMérieux Vitek, Hazelwood, Mo.) or by the conventional tube method. The number of correctly identified isolates in the challenge phase, including new species added to the database, was 221 of 247, or 89.5%, in comparison to the number correctly identified by the conventional tube method. A total of 465 isolates were examined for intra- and interlaboratory identification reproducibility and gave an agreement of 464 of 465, or 99.8%. The overall reproducibility of each individual identification test or substrate was 14,373 of 14,384, or 99.9%. The new Rapid Gram-Negative Identification Type 3 Panel gave accurate and highly reproducible results in this multiple-laboratory evaluation.
Evaluation Studies as Topic↗
A regional study of presentation and outcome of hypertrophic cardiomyopathy in infants.
OBJECTIVE: To describe regional incidence, presentation, and outcome of idiopathic (familial) and Noonan syndrome related infant hypertrophic cardiomyopathy (HCM) between 1969 and 1994. DESIGN: Case series. SETTING: Regional cardiac referral unit of the South West Region of England and south Wales, population approximately four million. PATIENTS: 21 cases of idiopathic (or familial) HCM, and eight infants with Noonan syndrome. MAIN OUTCOME MEASURES: Survival and persistence or resolution of symptoms or cardiac hypertrophy. RESULTS: Incidence: eight cases between 1969 and 1982 (idiopathic 6, Noonan 2), 21 cases between 1982 to 1994 (idiopathic 15, Noonan 6). Mode of presentation: cardiac failure, 17 (59%); murmur, 9 (30%); cyanosis, 2 (7%); family history, 1 (7%). Age at presentation: 0-7 days, 16 (55%); 8 days-4 months, 9 (31%); 5-12 months, 4 (14%). OUTCOME: five deaths (17%), all < 1 year, all from progressive cardiac failure (idiopathic 3, Noonan 2). Four of these five had not received beta blockade. Among the 24 survivors (follow up 1.3-23.2 years, median 5.5 years) hypertrophy had resolved in nine (38%) (idiopathic 8, Noonan 1), was mild and asymptomatic in seven (29%), and was symptomatic or severe in eight (33%). All 10 infants presenting with septal thickness > 1.3 cm have persistent cardiac hypertrophy. CONCLUSIONS: Mortality in infant HCM is much lower than previously reported and resolution is more frequent. This may reflect increased detection of less severe forms in addition to the success of aggressive medical management including beta blockade.
Adrenergic beta-Antagonists↗
Haemodynamic features at presentation in persistent pulmonary hypertension of the newborn and outcome.
Thirty four newborns presenting with persistent hypoxaemia in the first three days of life underwent detailed haemodynamic assessment using Doppler echocardiography, including measurements of pulmonary arterial pressure (PAP), left ventricular (LV) function, and left ventricular output (LVO). Results were compared with values from 51 healthy babies, and those of survivors were compared with non-survivors. Four of the 34 babies were excluded from this analysis because one was found to have transposed great arteries, one had a large left-to-right shunt with no evidence of persistent pulmonary hypertension, and two had diffuse skeletal myopathy. Tricuspid regurgitation was present in 70%, permitting systolic PAP estimation. The pulmonary:systemic arterial pressure ratio range was 0.7:1 to 1.83:1 (mean 1.02:1). A patent duct was present in 83%, and flow patterns indicated PAP approaching, or above, systemic pressure in all. Systolic time interval ratio TPV/RVET (time to peak velocity at the pulmonary valve/right ventricular ejection time) was mostly (65%) in the normal range, and did not correlate with other PAP measurements. LV function was below the 10th centile in only 11%, but values for LVO lay below the 10th centile in 41%, and for left ventricular stroke volume index (LSVI) in 66%. Results of 18 survivors were compared with 10 non-survivors (excluding two premature babies who died early with pulmonary interstitial emphysema). There were no significant differences for any parameter of PAP or LV function, but LVO and LSVI were significantly lower in non-survivors: LVO survivors (mean (SD)), 205 (57), non-survivors 138 (63) ml/kg/minute (P < 0.01); LSVI survivors, 1.29 (0.51), non-survivors 0.86 (0.31) ml/kg (P < 0.05). All four babies with LVO < 100 ml/kg/minute died, and 6/7 babies with LSVI < 1 ml/kg died. Detailed echocardiographic evaluation shows that the haemodynamic features of persistent pulmonary hypertension are diverse and that clinical diagnosis can be incorrect. Low LV output and stroke volume, usually with normal LV function, were the only Doppler echocardiographic parameters to predict subsequent death. This correlation with outcome requires further prospective evaluation.
Blood Pressure↗
Aortopulmonary collateral arteries mimicking symptomatic ductal shunting in a preterm infant.
A preterm infant with bronchopulmonary dysplasia presented with clinical and Doppler echocardiographic features suggesting a left-to-right ductal shunt. The duct was ligated surgically. Clinical and echocardiographic signs did not change after ligation. Detailed colour Doppler examination ultimately showed several aortopulmonary collateral arteries giving rise to continuous turbulent flow in the main and left pulmonary arteries, similar to that seen with left-to-right ductal shunting.
Aorta↗
Cardiovascular abnormalities in end stage renal failure: the effect of anaemia or uraemia?
Children with end stage renal failure and anaemia have an increased cardiac index and often gross ventricular hypertrophy. Correction of anaemia with recombinant human erythropoietin (r-HuEpo) for less than six months results in a reduction in the cardiac index without a significant reduction in left ventricular hypertrophy. Seven children receiving dialysis (group 1) were studied to determine whether a reduction in left ventricular hypertrophy would occur after a 12 month period of r-HuEpo. A decrease in the cardiac index was seen by six months, and a significant reduction in left ventricular mass index and cardiothoracic ratio was seen by 12 months. Successful renal transplantation also results in a reduction in the cardiac index and left ventricular hypertrophy, but the relative contributions of correction of anaemia and correction of biochemical disturbance is unknown because they usually improve simultaneously. To investigate this, six children (group 2) who already had a mean haemoglobin concentration of 107 g/l while receiving dialysis were followed up for 12 months after successful transplantation. They showed no significant change in haemoglobin concentration, but a dramatic improvement in biochemistry. There was no significant change in cardiovascular function. Anaemia is the more dominant influence on cardiovascular function in end stage renal failure.
Adolescent↗
Cardiac abnormalities in end stage renal failure and anaemia.
Thirteen anaemic children on dialysis were assessed to determine the incidence of cardiac changes in end stage renal failure. Nine children had an increased cardiothoracic ratio on radiography. The electrocardiogram was abnormal in every case but no child had left ventricular hypertrophy as assessed by voltage criteria. However, left ventricular hypertrophy, often gross, was found on echocardiography in 12 children and affected the interventricular septum disproportionately. Cardiac index was increased in 10 patients as a result of an increased left ventricular stroke volume rather than heart rate. Left ventricular hypertrophy was significantly greater in those on treatment for hypertension and in those with the highest cardiac index. Abnormal diastolic ventricular function was found in 6/11 children. Children with end stage renal failure have significant cardiac abnormalities that are likely to contribute to the high cardiovascular mortality in this group. Anaemia and hypertension, or its treatment, probably contribute to these changes. Voltage criteria on electrocardiogram are of no value in detecting left ventricular hypertrophy. Echocardiography must be performed, with the results corrected for age and surface area, in order to detect and follow these abnormalities.
Adolescent↗