Postnatal Changes in Left Ventricular Volume and Contractility in Healthy Term Infants

To evaluate how the size of the ductus arteriosus affects neonatal left ventricular (LV) volume and contractility, we serially obtained two-dimensional and Doppler echocardiograms at 2, 12, 24, and 120 hours after birth in 20 healthy infants. LV volume was calculated by the biplanar Simpson's rule, and ductus arteriosus size with left-to-right shunting was measured by two-dimensional and Doppler echocardiography. At 2 hours, the ductus arteriosus was at its maximal size, and the LV end-diastolic volume was 1.2-fold higher than at the subsequent hours after birth. Additionally, there was a significant linear correlation between the end-diastolic volume and the ductal diameter. In contrast, the peripheral vascular resistance, derived from blood pressure measurements and Doppler echocardiography, was lowest at 2 hours of age. The mean normalized systolic ejection rate, an index of contractility, remained constant throughout the study period. These results suggest that alterations in the LV end-diastolic volume soon after birth depend on changes in ductal flow, which in turn is affected by ductal diameter, and that the neonatal left ventricle operates at its maximal performance with limited contractility during ductal patency.     

Serial Pulsed Doppler Assessment of Pulmonary Artery Pressure in Very Low Birth-Weight Infants

We assessed pulmonary artery pressure (PAP) during the early neonatal period in very low birth-weight (VLBW) infants using serial echocardiographic measurements of the ratio of the pulmonary artery acceleration time to the right ventricular ejection time corrected by heart rate [AT:RVET(c)]. Eighty-four VLBW infants weighing less than 1500 g were examined using serial color Doppler echocardiography from 3 hours to day 7 after birth. The AT:RVET(c) of infants born after 30 weeks of gestation showed a rapid, significant increase during the early neonatal period, whereas those of the groups born at less than 30 weeks showed no significant increase before day 14. At 24 hours after birth, the AT:RVET(c) values of VLBW infants did not correlate well with either the ratio of the right preejection period to the right ventricular ejection time on M-mode echocardiography or the pressure gradient between the right ventricle and the right atrium, as estimated by tricuspid regurgitation on pulsed Doppler echocardiography. The AT:RVET(c) value for the chronic lung disease (CLD) group did not differ significantly from that for the oxygen-dependent group at any assessment point. During the early neonatal period, the AT:RVET(c) of VLBW infants, as calculated by pulsed Doppler echocardiography, differed with their gestational age and did not appear to correlate well with PAP. Our data also suggest that AT:RVET(c) values may not be a good predictor of the subsequent occurrence of CLD in VLBW infants.     

Prenatal Diagnosis of Severe Aortic Stenosis

We sought to identify echocardiographic markers that might be useful for managing fetuses with significant aortic stenosis. The study was a retrospective review of fetal echocardiographic studies and postnatal outcomes of all fetuses diagnosed with significant aortic stenosis who did not have a hypoplastic left ventricle on the initial echocardiogram. Where possible, fetal echocardiographic measurements included the aortic, mitral, pulmonary, and tricuspid valve annulus sizes; left ventricular dimensions and volume; septal and left ventricular wall thicknesses; and echocardiographic Doppler interrogation of the left heart and oval fossa. Observations also included an assessment of ascites, pericardial effusion, and endocardial fibroelastosis. Prenatal measurements were compared to postnatal outcomes. Four patients (group 1) had either clinically successful relief of their aortic obstruction (n= 3) or required no intervention (n= 1). Five fetuses evolved to the hypoplastic left heart syndrome (group 2). These infants demonstrated little or no growth in left ventricular, aortic valve, or mitral valve dimensions on serial examination. They also more often exhibited mitral stenosis, severe restriction of interatrial shunting, and early to mid second trimester left ventricular dilatation. Serial measurements of fetal cardiac size and function are helpful for predicting the postnatal outcome of fetuses with aortic stenosis.     

Age-Related Variation in Left Ventricular Myocardial Contractile State Expressed by the Stress Velocity Relation

The assessment of ventricular function plays an important role in the pre- and postoperative management of many congenital heart abnormalities. Normal ranges in left ventricular systolic function indices have been defined during childhood and age-related alterations in left ventricular myocardial contractile state have recently been reported. This study was carried out to investigate the developmental changes in left ventricular contractile state expressed by the endsystolic meridional stress (ESS)/rate-corrected velocity of circumferential fiber shortening (VCFc) relation, calculated by echo in normal children and young adults. We examined 146 healthy subjects (80 males and 66 females), mean age 70.85 ± 63.89 months (range 0.5–228) and body surface area (BSA) 0.807 ± 0.47 (range 0.18–2.01) with no clinical and echocardiographic evidence of cardiac disease and with normal blood pressure. The subjects were divided into three groups according to age: <6 months (group 1, n= 32), 6–36 months (group 2, n= 34), and >36 months (group 3, n= 80). Enddiastolic volume and mass (M) of the left ventricle were measured by M-mode Echo. ESS was considered as an index of afterload and the VCFc as an index of systolic ventricular function. The left ventricular ejection time used for the calculation of VCFc was measured from aortic flow obtained by PW–Doppler. The ESS/VCFc relation was used to assess left ventricular contractility. Systolic blood pressure, volume, and mass of the left ventricle increase with age. The gradual increase in pressure despite a stable mass/volume ratio [M/V = 0.900 + (0.0007 × age); r= 0.27, p < 0.005] resulted in a substantial increase of afterload [ESS = 29.78 + (0.116 × age); r= 0.58, p < 0.0001]. VCFc showed an inverse hyperbolic regression with afterload [VCFc = 1.01 + (7.598/ESS); r= 0.59, p < 0.0001]. The regression lines (best linear fit) between VCFc and ESS are significantly different in the three groups. The Y intercept was higher and the slope steeper in group 1 [VCFc = 1.74 − (0.017 × ESS); r= 0.65, p < 0.0005] vs group 2 [VCFc = 1.54 − (0.008 × ESS); r= 0.58, p < 0.001] and group 3 [VCFc = 1.52 − (0.007 × ESS); r= 0.57, p < 0.0001]. These data indicate that, in children, the volume and mass of the left ventricle increase, whereas the M/V ratio remains relatively constant; the progressive increase in arterial blood pressure explains the increase of afterload. The VCFc is higher in the first few years of life compared to that seen in older children due to reduced afterload and increased contractile state. Left ventricular contractility, expressed as ESS/VCFc relation, is thus inversely proportional to age. In the first months of life the left ventricular myocardium exhibits a higher basal contractile state and a greater sensitivity to changes in afterload. For obtaining an accurate assessment of left ventricular function, the ESS/VCFc relation in different age groups should be measured.     

Plasma and urine riboflavin during riboflavin-free nutrition in very-low-birth-weight infants

BACKGROUND: Very-low-birth-weight (VLBW; birth weight <1500 g) infants receive enteral and parenteral nutriture that provides greater daily riboflavin (vitamin B2) than does term infant nutriture, and elevated plasma riboflavin develops in these infants after birth. The purpose of this study was to measure plasma and urine riboflavin concentrations in VLBW infants during riboflavin-free nutrition. Our hypothesis was that elevated plasma riboflavin develops in VLBW infants because of high daily intake and immature renal riboflavin elimination. METHODS: Eighteen clinically healthy VLBW infants received parenteral nutrition and preterm infant formula during the first postnatal month. On postnatal days 10 and 28, the infants received specially prepared riboflavin-free enteral and parenteral nutrition for the 24-hour study period. Serial collections of plasma were made at time 0 and at 12 and 24 hours. Urine was collected continuously for the 24-hour period in 4-hour aliquots. Samples were analyzed for riboflavin concentration. RESULTS: During the 24-hour riboflavin-free study period on postnatal day 10, plasma riboflavin decreased 56% from 185 +/- 37 ng/mL (mean +/- SEM), and urine riboflavin decreased 75% from 3112 +/- 960 mg/mL. Similarly, on postnatal day 28, plasma riboflavin decreased 79% from 184 +/- 32 ng/mL, and urine riboflavin concentration decreased 91% from 5092 +/- 743 ng/mL during the 24-hour riboflavin-free study period. Riboflavin half-life (t(1/2)) was 18.5 hours on postnatal day 10 and decreased 48% by postnatal day 28. Riboflavin elimination was 145.1 +/- 20.6 mg/kg per day on postnatal day 10 and increased 40% by postnatal day 28. CONCLUSION: The VLBW infants who received parenteral nutrition and preterm infant formula had elevated plasma riboflavin on postnatal days 10 and 28. Plasma riboflavin t(1,2) was shorter and renal riboflavin elimination was greater on postnatal day 28 than on postnatal day 10. Plasma riboflavin was normal after 24 hours of riboflavin-free nutrition. The pattern of plasma and urine riboflavin in VLBW infants suggests a lower daily intake would maintain plasma riboflavin close to normal.     

生后早期床旁心脏超声预测极低出生体重儿动脉导管持续开放的研究(英文翻译)

目的 探讨出生早期床旁心脏超声预测极低出生体重儿（very low birth weight infant,VLBWI）动脉导管持续开放的价值。 方法 回顾性选取2020年3月至2021年6月收治的51例VLBWI为研究对象,入院时日龄≤3 d并且住院时间≥14 d。根据出生14 d及28 d动脉导管未闭（patent ductus arteriosus,PDA）直径大小分为3组：大PDA组（PDA直径≥2 mm）、小PDA组（PDA直径<2 mm）和PDA关闭组（PDA直径=0 mm）,比较3组间生后72 h的心脏超声参数。采用受试者工作特征（receiver operating characteristic,ROC）曲线评估生后72 h心脏超声参数预测生后14 d和28 d动脉导管持续开放（PDA直径≥2 mm）的价值。 结果 生后14 d时,大PDA组有17例,小PDA组11例,PDA关闭组23例;生后28 d时,大PDA组有14例,小PDA组9例,PDA关闭组26例。3组患儿间胎龄、出生体重、肺泡表面活性物质应用及低血压发生率的比较差异有统计学意义（P<0.05）。生后72 h的PDA直径、左肺动脉舒张末期流速、左心室输出量、左心室输出量/上腔静脉血流与生后14 d及28 d时动脉导管持续开放有关（P<0.05）;左心房/主动脉根部直径与生后28 d时动脉导管持续开放有关（P<0.05）。ROC曲线结果显示,生后72 h PDA直径预测生后14 d及28 d动脉导管持续开放的曲线下面积最大,分别为0.841和0.927;其次是左肺动脉舒张末期流速,其曲线下面积分别为0.793和0.833。 结论 生后72 h的床旁心脏超声指标,尤其是PDA直径及左肺动脉舒张末期流速,可预测VLBWI生后14 d和28 d动脉导管持续开放,为后续PDA早期目标性治疗策略的实施提供依据。     

Myocardial function in term and preterm infants. Influence of heart size,gestational age and postnatal maturation

Background

Sparse knowledge exists on the differences in cardiac function between term and preterm infants. This study examines the impact of heart size, gestational age and postnatal maturation on myocardial function.

Aim

To assess and compare serial echocardiographic indices of myocardial function in term and moderately preterm infants.

Methods

Longitudinal, prospective, observational echocardiographic cohort study of 45 healthy term infants examined at day three and at 12–20 weeks postnatal age and 53 moderately preterm infants (gestational age 31–35 weeks) examined at day three and at term equivalent (4–10 weeks postnatal age).

Outcomes

Primary: Systolic mitral and tricuspid annular plane excursions and annular peak systolic pulsed wave tissue Doppler (pwTDI) velocities.Secondary: Indices normalized for heart size.

Results

On day three, all indices were higher in the term than in the preterm infants whereas normalized systolic pwTDI velocities were lower in the term infants and normalized excursions showed no difference. All indices increased with advanced postnatal age. The indices in term infants on day three were lower than in preterm infants at term equivalent, with and without normalization. After postnatal maturation in both groups, all indices were higher in the term group (except left pwTDI), whereas normalized indices showed no consistent pattern.

Conclusions

Myocardial function indices increased with gestational age at birth and more profoundly with postnatal maturation. Serial examinations of non-normalized and normalized myocardial function indices showed no sustained differences between the preterm and the term infants.Normalization by heart size may be of value when assessing myocardial function in infants.     

Echocardiographic Evaluation of Systolic and Diastolic Function in Postoperative Coarctation Patients

Postoperative coarctation (CoA) patients are often found to have signs of persistent myocardial dysfunction. M-mode echocardiography was performed to study left ventricular (LV) size, mass, and systolic function and Doppler ultrasonography to study LV filling and flow velocity in the LV outflow tract and aorta in 28 ``healthy' postoperative CoA patients (5–21 years) and 28 age- and sex-matched controls. The early (E) and late (A) diastolic transmitral velocities were significantly higher in the patient group than in the controls (p < 0.05). Other diastolic parameters (isovolumic relaxation time, E/A ratio, and deceleration time of the early diastolic velocity) were similar in the two groups (p= NS). The left atrial diameter, LV wall average, end-diastolic diameter of the LV and LV mass were higher in the patients than controls (p < 0.05). The patients also had a higher stroke volume, cardiac output, and cardiac index than the controls (p < 0.01). The fractional shortening was similar in the two groups (p= NS). Blood flow velocities in both the LV outflow tract and aorta were higher in the patients than the controls (p < 0.0002). We found LV hypertrophy with signs of a hyperdynamic circulation (increased cardiac index and stroke volume) in our patients. An increase in A is associated with LV hypertrophy and seems to be a sensitive marker of diastolic abnormality. The rise in E is paradoxical but has been seen in other studies. The increased blood flow velocity in the LV outflow tract suggests obstruction to LV outflow and increased flow in the descending aorta is due to residual coarctation.     

Catch-up growth of head circumference of very low birth weight,small for gestational age preterm infants and mental development to adulthood

OBJECTIVE: To examine the influence of postnatal energy quotient (EQ, energy intake/kg body weight per day) on head circumference (HC) growth and mental development of very low birth weight (VLBW), small for gestational age (SGA, <10th percentile) preterm infants. STUDY DESIGN: SGA VLBW preterm infants (n = 46) with primarily symmetric intrauterine growth restriction were compared with 62 appropriate for gestational age (AGA) VLBW preterm infants and 73 term infants from the Bonn Longitudinal study. RESULTS: Twenty-seven of 46 (59%) of the SGA preterm infants showed complete HC catch-up growth by the age of 12 months, but mostly before 6 months after term (HC catch-up group). These infants had significantly higher mean EQs from day 2 to 10 than the group of 19 infants without HC catch-up (EQ, 95 vs 78). Mean EQs correlated significantly with developmental and intelligence quotients (DQ/IQ) from 18 months to 6 years. As adults, the HC of the HC catch-up group was not significantly different from that of the AGA preterm infants, the term infants, and their parents. The group without HC catch-up had smaller HC as adults. CONCLUSIONS: Our data suggest that early postnatal high-energy nutrient intake for SGA preterm infants is needed to promote HC catch-up growth and to prevent negative consequences of undernutrition.     

Echocardiographic assessment of early circulatory status in preterm infants with suspected intrauterine infection

OBJECTIVE: To assess early circulatory status in very low birthweight (VLBW) infants with suspected intrauterine infections. PATIENTS: Thirteen VLBW infants who were diagnosed with prenatal infections because of raised serum IgM at birth (infectious group), and 39 infants matched for gestational age and birth weight (control group). METHODS: Echocardiographic assessments were performed consecutively from birth to day 28 in all VLBW infants. Left ventricular output (LVO) and left ventricular stroke volume (LVSV) were measured using Doppler echocardiography. Pulsed Doppler assessment of pulmonary artery pressure (PAP) was performed using the corrected ratio of the pulmonary artery acceleration time to the right ventricular ejection time (AT/RVET(c)). Blood flow in the superior mesenteric artery (SMA) was also evaluated by Doppler ultrasound. RESULTS: Mean LVO and LVSV were both significantly higher in the infectious group than in the control group at 12 hours (LVO; 188 v 154 ml/kg/min) and 72 hours (LVO; 216 v 173 ml/kg/min) of life. Pulsed Doppler assessment of PAP showed that mean AT/RVET(c) values were significantly lower in the infectious group than in the control group at 48 hours, 96 hours, day 14, and day 28. In the analysis of SMA flow velocities, both peak systolic velocities and time averaged velocities had decreased significantly in the infectious group compared with the control group at 24 hours, 36 hours, 96 hours, and day 28. CONCLUSIONS: VLBW infants with suspected prenatal infection showed a unique circulation status, namely high cardiac output, latency of high PAP, and low organ flow.     

Left and Right Ventricular Myocardial Performance Index (Tei Index) in Very-Low-Birth-Weight Infants

This study presents a report of serial assessment of ventricular myocardial performance index (Tei index) in very-low-birth-weight (VLBW) infants. One hundred ninety-five VLBW infants, weighing <1,500 g, who were admitted to the neonatal intensive care units at Kakogawa Municipal Hospital between September 2000 and August 2004. Left ventricular (LV) and right ventricular (RV) Tei indexes were assessed consecutively from birth to day 28 in all VLBW infants using pulsed-Doppler echocardiography. The mean values of the LV Tei index rose rapidly from 3 to 12 h after birth and then fell significantly after 24 h. Those of the RV Tei index increased slightly from 3 to 12 h, then decreased drastically after 24 h. The LV Tei index was found to correlate inversely with LV output and LV ejection fraction in the early neonatal period, while the relationship between the LV Tei index and the LV E/A velocity ratio was not significant. The RV Tei index was inversely correlated with RV output. In conclusion, both of the ventricular Tei indexes in VLBW infants showed drastic and significant changes on the first to second day after birth.     

Blood lysophosphatidylcholine (LPC) levels and characteristic molecular species in neonates: prolonged low blood LPC levels in very low birth weight infants

Lysophosphatidylcholine (LPC) has various stimulatory effects on many types of immune cells. The purpose of our study was to characterize blood LPC levels and to determine the composition of LPC molecular species (LPCs) in the neonatal period. Thirty-six neonates were enrolled in this study and then grouped according to birth-weight as follows: non-very low birth weight (NVLBW); >or=1,500 g (n=17), and very low birth weight (VLBW); <1,500 g (n=19). Sixteen healthy normal adults were used as controls. Levels of total blood LPC and LPCs (16:0-, 18:0-, 18:1-, 18:2-, and 20:4-LPC species) were measured using HPLC coupled with tandem mass spectrometry. Total blood LPC levels at birth in neonates in both groups (NVLBW and VLBW) were significantly lower than those of adult levels. In NVLBW infants, LPC levels reached adult levels at postnatal day 3 compared with VLBW infants, who attained adult levels after postnatal day 57 (around full-term). The composition of the LPCs was different not only between neonates and adults, but between NVLBW and VLBW infants. These findings may be associated with the difference of immunity among adults, NVLBW, and VLBW infants.     

Changes in left ventricular output from fetal to early neonatal life

Using pulsed Doppler and two-dimensionally directed M-mode echocardiographic techniques, we measured left ventricular (LV) output, stroke volume, heart rate, LV end-diastolic dimension (LVEDD), LV end-systolic dimension, and LV percent fractional shortening (%FS) in 34 normal term infants 12 to 24 hours before parturition and thereafter serially 1, 24, and 96 hours after birth. Stroke volume was calculated as the product of the aortic flow velocity integral and aortic valve area. There was a twofold increase in LV output 1 hour after birth (fetal 170 +/- 46 ml/min/kg vs 1 hour 327 +/- 66 ml/min/kg; p less than 0.01) which was associated with significant increases in stroke volume, %FS, and LVEDD (stroke volume 1.21 +/- 0.33 ml/kg vs 2.25 +/- 0.37 ml/kg; %FS 34.3% +/- 5.8% vs 37.7% +/- 5.4%; LVEDD 15.4 +/- 1.1 mm vs 17.7 +/- 1.4 mm). Heart rate did not change 1 hour after birth. During the subsequent hours after birth, LV output decreased significantly to a value of 245 +/- 56 ml/min/kg (p less than 0.01) at 24 hours, which did not change 96 hours after birth. There were significant declines in stroke volume, LVEDD, and heart rate 24 hours after birth (stroke volume 2.02 +/- 0.42 ml/kg; LVEDD 17.0 +/- 1.1 mm; heart rate 121 +/- 11 beats/min). The %FS remained unchanged within the first 96 hours of age. These results indicate that the major regulator of LV output immediately after birth is stroke volume and not heart rate. The increase in stroke volume is related to an increase in LV size and LV myocardial contractility. Our data provide a useful basis for the interpretation of abnormal LV function in the early neonatal period.     

Effect of Dexamethasone Therapy on the Neonatal Ductus Arteriosus

Patent ductus arteriosus (PDA) is believed to be a contributing factor in the etiopathogenesis of bronchopulmonary dysplasia (BPD). We studied the effects of early dexamethasone therapy on persistent ductal patency and the role of PDA in the etiopathogenesis of BPD during the course of a randomized double-blind trial of dexamethasone to prevent BPD. Infants, who weighed between 700 and 999 g, had severe RDS, and had been given surfactant, were randomized to receive a 12-day course of dexamethasone (n= 13) or placebo (n= 17) starting within the first 12 hours of postnatal life. The diagnosis of PDA was made clinically and was confirmed by cardiac ultrasound. The incidence of clinically significant ductus in infants who weighed less than 1000 g was 23% in the dexamethasone-treated group, as compared with 59% in infants who were given placebo. This difference was marginally significant, p= 0.05, odds ratio 0.21, 95% confidence interval 0.04–1.05. None of the infants in the dexamethasone group had recurrence of PDA after indomethacin therapy as compared with three infants in the placebo group. Dexamethasone significantly reduced the number of days infants required ventilator and supplemental oxygen as compared with infants who received placebo. Dexamethasone, as compared with placebo, also reduced the incidence of BPD, p= 0.025, odds ratio 0.08, 95% confidence interval 0.01–0.58. Dexamethasone may reduce the incidence of PDA in premature infants who weigh less than 1000 g at birth and thereby reduce the incidence of BPD.     

Early nasal continuous positive airway pressure treatment reduces the need for intubation in very low birth weight infants

Nasal continuous positive airway pressure (CPAP) applied shortly after birth is said to be an effective treatment of respiratory distress in very low birth weight infants (VLBW). We tested the hypothesis that the use of early nasal CPAP (applied as soon as signs of respiratory distress occurred, usually within 15 min after birth) reduces the need for intubation, the duration of intermittent mandatory ventilation and the incidence of bronchopulmonary dysplasia. All liveborn VLBW infants (birth weight < 1500 g) admitted to our tertiary neonatal intensive care unit in 1990 (historical controls) and in 1993 (early nasal CPAP group) entered the study. The intubation rate was significantly lower after introduction of nasal CPAP (30% vs 53%, P = 0.016). Median duration of intubation was 4.5 days (interquartile range 3–7 days) before versus 6.0 days (2.8–9 days) after nasal CPAP was introduced (P = 0.73). The incidence of bronchopulmonary dysplasia was not reduced significantly (32% vs 30%, P = 0.94). Survival until discharge was 89.5% before versus 92.9% after introduction of nasal CPAP (P = 0.54). Conclusion Early nasal CPAP is an effective treatment of respiratory distress in VLBW infants, significantly reducing the need for intubation and intermittent mandatory ventilation, without worsening other stan dard measures of neonatal outcome. We found no significant decrease in the incidence of bronchopulmo nary dysplasia. Received: 5 February 1996 and in revised form: 12 September 1996 / Accepted: 23 October 1996     

Changes in left ventricular volume and systolic function before and after the closure of ductus arteriosus in full-term infants

Using echocardiographic techniques, the change in left ventricular (LV) volume and its effect on systolic function were studied before and after the closure of ductus arteriosus in 18 full-term infants. Examinations were performed twice in each infant, within 6 h after birth and on day 5, and the patency of the ductus with left-to-right shunt was confirmed at the first examination by Doppler echocardiography. A biplane Simpson's rule method was used for volume measurements. The LV end-diastolic volume, stroke volume, and cardiac output were more than 1.3-fold before the ductal closure, and the ejection fraction showed the similar change. However, the mean normalized systolic ejection rate, an index of contractility, and heart rate showed no significant difference. The Frank-Starling curve was obtained from the relationship between the LV end-diastolic and stroke volumes, and the LV performance was operated at a higher level on that curve when the ductus was open. Our data indicated that LV cardiac output was significantly higher during the patency of the ductus arteriosus and that this high cardiac performance might depend more on the Frank-Starling response to the volume load through the ductus arteriosus than on the increase of LV contractility and heart rate.     

Isolated Congenital Left Ventricular Diverticulum with Perinatal Dysrhythmia: A Case Report and Review of the Literature

We report a case of isolated congenital left ventricular diverticulum (LVD) with perinatal dysrhythmia, which disappeared spontaneously 1 week after birth. The LVD arose from the lateral wall of the LV, and the contraction of the LVD was synchronous with the kinetics of the main LV chamber. The LVD changed very little in size during the first 30 months after birth, and its relative size to the growing LV main chamber decreased. The patient had neither any symptoms nor complications during this time. The available literature on prenatal and neonatal cases with isolated LVD or LV aneurysm is also reviewed.     

Clinical trial of vitamin A supplementation in infants susceptible to bronchopulmonary dysplasia

We conducted a randomized, double-blind, controlled trial to determine whether vitamin A supplementation from early postnatal life could reduce the morbidity associated with bronchopulmonary dysplasia in very low birth weight (VLBW) neonates. Forty VLBW neonates (700 to 1300 g birth weight, 26 to 30 weeks gestational age), who were oxygen dependent and required mechanical ventilation for at least 72 hours after birth, were given by the intramuscular route either supplemental vitamin A (retinyl palmitate 2000 IU) or 0.9% saline solution on postnatal day 4 and every other day thereafter for a total of 14 injections over 28 days. The study groups were comparable in gestational maturity, clinical characteristics, initial lung disease, and vitamin A status at entry into the trial. Vitamin A administration resulted in significantly higher mean plasma concentrations of vitamin A and retinol-binding protein in treated infants compared with controls. Bronchopulmonary dysplasia was diagnosed in nine of 20 infants given vitamin A supplement and in 17 of 20 control infants (P less than 0.008). Four of 19 infants in the vitamin A group and 11 of 20 in the control group required mechanical ventilation on study day 28 (P less than 0.029). The need for supplemental oxygen, mechanical ventilation, and intensive care was reduced in infants given vitamin A supplement compared with controls. Airway infection and retinopathy of prematurity were less frequent in the vitamin A group. We conclude that vitamin A supplementation at the dosage used in this trial in VLBW neonates not only improves their vitamin A status but also appears to promote regenerative healing from lung injury, as evidenced by a decrease in the morbidity associated with bronchopulmonary dysplasia.     

Effects of Transdermal Nitroglycerin in Children with Congestive Heart Failure: A Doppler Echocardiographic Study

The aim of this study was to evaluate by Doppler echocardiography whether administration of transdermal nitroglycerin (NTG) to children with congestive heart failure could modify mitral flow velocity profile with redistribution of left ventricular filling to late diastole, suggesting preload reduction of the left ventricle. Twelve children with congestive heart failure, aged from 6 months to 6 years (2.83 ± 2.24 years; mean ± SD), were recruited. Patients were randomly allocated either a NTG patch (study group; n= 6) or a placebo patch (control group; n= 6) in a double-blind procedure. The NTG patch was a 10-cm² patch releasing 5 mg of NTG per day. NTG patches were adjusted to a dose of 1 cm²/kg/day (0.5 mg/kg/day). Peak velocity and time–velocity integral (TVI) of E and A waves of transmitral flow, the ratio of the velocities of the A wave and E wave, and the ratio of the TVI of the A wave to the TVI of the E wave were measured. Doppler measurements were determined before treatment (H0) and 4 hours (H4) and 23 hours (H23) after the patch application. Relative changes of these parameters were not significantly different between these two groups. In the NTG group, mean NTG plasma concentration was 1.08 ± 0.47 μg Liter⁻¹ at H4 (n= 5) and 1.18 ± 0.81 μg Liter⁻¹ at H23 (n= 5). No patient had a NTG plasma concentration greater than 2 μg Liter⁻¹ either at H3 or at H24. These data suggest that 1 cm²/kg transdermal doses of NTG may have a limited bioavailability or a higher clearance and minimal hemodynamic effects in children with congestive heart failure already receiving other medications, implying that higher doses should be used.     

Response of skin blood volume, velocity and flow to local warming in newborns, measured by laser Doppler flowmetry

BACKGROUND: In order to know the response of the skin microcirculation to local warming, we determined changes in the skin blood volume (Vol), velocity (Vel) and flow (F) by using a new laser Doppler device on newborns. METHODS: The study subjects were 39 infants whose gestational age was 34.1 +/- 2.8 weeks and birth weight was 2189 +/- 572 g. The study was performed from 8 h postnatally to 28 postnatal days. We measured skin blood volume, velocity and flow at 36 degrees C (Vol36, Vel36, F36), and each value at 5 min (Vol44-5, Vel44-5, F44-5) and 10 min (Vol44-10, Vel44-10, F44-10) after local warming was applied at 44 degrees C and the response curve of each parameter was obtained. Subsequently, serial changes in the response of skin microcirculation to local warming were investigated in nine very low birth weight (VLBW) infants (28.3 +/- 0.9 weeks, 1150 +/- 148 g) and 12 low birth weight (LBW) infants (32.8 +/- 1.3 weeks, 1971 +/- 292 g). The F36, the increment rate of blood volume (delta Vol) and the increment rate of blood velocity (delta Vel) were obtained within 24 h, from day 1 to day 7 and from day 8 to day 30 in both VLBW and LBW infants and from day 31 to day 60 and at more than 61 days in VLBW infants. The F36, delta Vol and delta Vel were compared during the study periods in VLBW and LBW infants. All results were expressed as mean +/- SD. RESULTS: The results showed that F36/F44-10 and F44-5/F44-10, Vol36/Vol44-10 and Vol44-5/Vol44-10, Vel36/Vel44-10 and Vel44-5/Vel44-10 were 0.25 +/- 0.09 and 0.74 +/- 0.17, 0.58 +/- 0.14 and 0.94 +/- 0.08, 0.42 +/- 0.12 and 0.79 +/- 0.15, respectively. Different modes of delivery did not have a significant effect on this response. The F36 in VLBW infants was high during the early neonatal period and gradually decreased with postnatal age. The delta Vol was low in VLBW infants during the neonatal period and gradually increased. The F36 in VLBW1-7 was significantly higher than in LBW1-7 (P < 0.01) and full-term controls (P < 0.001). The delta Vol in VLBW1-7 was 0.26 +/- 0.23, which is significantly lower than in LBW1-7 (0.57 +/- 0.17, P < 0.001) and full-term controls (0.77 +/- 0.21, P < 0.001). The delta Vel in VLBW1-7 and LBW1-7 was significantly higher than in controls (P < 0.05). CONCLUSIONS: The skin blood flow increased continuously when local warming was applied at 44 degrees C. This high blood flow and limited potential of vasodilatation are the characteristics of the skin microcirculation in VLBW infants during the neonatal period.