Reference values of the mitral annular peak systolic velocity (Sm) in 690 healthy pediatric patients, calculation of Z-score values, and comparison to the mitral annular Plane systolic excursion (MAPSE).

BACKGROUND: The mitral annular peak systolic velocity (Sm) is an echocardiographic measurement using tissue Doppler imaging to assess longitudinal left ventricular (LV) systolic function in children and adults. We determined growth-related changes in Sm to establish reference values for the entire pediatric age group. METHODS AND RESULTS: A prospective study was conducted in a group of 690 healthy pediatric patients (age: 1 day-18 years). We determined the effects of age, sex, and body surface area (BSA) on the Sm values. Regression analysis was used to estimate Sm from age, BSA, and sex. In addition, a correlation of normal Sm with normal age-matched values of the M-mode parameter mitral annular plane systolic excursion (MAPSE) was measured. The Sm ranged from a mean of 5.8 cm/sec (Z-score ±2: 3.6-8.0 cm/sec) in the newborn to 11.8 cm/sec (Z-score ±2: 8.5-15.1 cm/sec) in the 18-year-old adolescent. The Sm values showed a positive correlation with age and BSA with a nonlinear course. There was no significant difference in Sm values between females and males. A significant correlation was found between Sm and MAPSE values. CONCLUSION: Z-scores of Sm values were calculated and percentile charts were established to serve as reference data in patients with congenital heart diseases.

Left ventricular long-axis function: reference values of the mitral annular plane systolic excursion in 558 healthy children and calculation of z-score values.

BACKGROUND: Longitudinal myocardial function has gained more interest in the last years. The mitral annular plane systolic excursion (MAPSE) is an echocardiographic measurement to assess left ventricular (LV) long-axis function in adults. The aim of this study was to evaluate MAPSE values in a healthy pediatric population and to propose reference values. METHODS: A prospective study was conducted in a group of 558 healthy children and adolescents (age day 1 to 18 years) (body surface area [BSA] 0.18-2.21 m(2)). We determined the effects of age and BSA on MAPSE values and a possible correlation of MAPSE values with LV ejection fraction values. RESULTS: The MAPSE ranged from a mean of 0.57 cm (z-score ±2: 0.38-0.76 cm) in neonates to 1.63 cm (z-score ±2: 1.31-1.95 cm) in 18-year-old adolescents. The MAPSE values showed a positive correlation with age (r = 0.87, P < .001) and BSA (r = 0.89, P < .001) with a nonlinear course. There was no significant difference in MAPSE values between females or males. A positive correlation was found between MAPSE values and LV ejection fraction values (r = 0.28, P < .001). CONCLUSIONS: Z-scores of MAPSE values were calculated, and percentile charts were established to serve as reference data in patients with congenital heart disease or heart failure in the future.

Regional oxygen saturation of the brain during birth transition of term infants: comparison between elective cesarean and vaginal deliveries.

OBJECTIVE: To evaluate differences in regional oxygen saturation of the brains of term infants of vaginal or cesarean deliveries. STUDY DESIGN: Vaginal delivery (n = 63) and elective cesarean delivery infants were prospectively evaluated for the first 10 minutes after delivery. Peripheral arterial oxygen saturation (SpO(2)) and heart rate were measured on the right hand using pulsoximetry with near infrared spectroscopy. Regional oxygen saturation of the brain (rSO(2)brain) was measured. Fractional tissue oxygen extraction was calculated for each minute. RESULTS: From 4 to 8 minutes, SpO(2) values for cesarean delivery infants were significantly lower than for vaginally delivered infants. Heart rate of the cesarean delivery infants was significantly lower throughout the whole observation period. There was no difference between groups in rSO(2)brain. Fractional tissue oxygen extraction only differed at minute 10. CONCLUSIONS: Although SpO(2) and heart rate were significantly lower in cesarean-delivered infants, there were no differences in rSO(2)brain with respect to mode of delivery.

Phospholipid content, expression and support of thrombin generation of neonatal platelets.

AIM: Newborns have, despite low clotting factors and poor in vitro platelet function, a well functioning haemostasis. We investigated whether phospholipids (PL) in neonatal platelets differ from those in adult platelets in their exposure on the platelet surface, and their effect on thrombin generation. METHODS: The effect of newborn and adult platelets on thrombin generation (TG) was measured by means of calibrated automated thrombography (CAT), and in a purified system. In addition, clotting times were measured. Phosphatidylserine (PS)-exposure was measured by flow cytometry. The amount of PL was determined by means of mass-spectrometry (Materials and Methods section in Supporting Information online). RESULTS: In comparison with adults the clotting times in platelet-rich plasma of newborns were less shortened by adding calciumionophore. No differences in the support of TG between neonatal and adult platelets were found by means of CAT. In the purified system, TG was increased by ionophor-stimulated platelets but no difference was evident between newborn and adult platelets. Flow cytometric analysis showed no difference between adult and newborn platelets. Results of mass-spectrometry showed a very similar pattern of phospholipid-content of adult and newborn platelets. CONCLUSION: Our results do not provide any evidence that a different phospholipid-expression of neonatal platelets may alter TG in neonates.

Increased shear stress- and ristocetin-induced binding of von Willebrand factor to platelets in cord compared with adult plasma.

Multiple indications do exist that the extensive neonatal platelet adhesion and aggregation, and the shorter closure time of neonatal compared with adult whole blood in the platelet function analyzer 100 are attributable to the physiological high plasma concentrations and high concentrations of unusually large von Willebrand factor (vWf) multimers in neonates. However, to date the direct experimental evidence is lacking. Therefore, we compared in the present study the ability of neonatal vWf to bind to platelets to that of adult vWf. Platelet-poor plasma of neonatal or adult origin, containing antibody-stained vWf, was incubated with neonatal or adult platelet suspension. Subsequently, vWf-platelet interaction was induced by exposing the mixture to shear stress by means of a cone/plate measuring system or by incubating the mixture with ristocetin. Finally, samples were analyzed in a FACScan flow cytometer. Detected fluorescence intensities directly correlate with the amount of vWf attached to the platelet surface. We found that significantly higher amounts of neonatal vWf were attached to platelets in the presence of shear stress or ristocetin. This efficient neonatal vWf-platelet interaction is an effect intrinsic to the neonatal vWf, and not to the neonatal platelet: the amount of neonatal vWf attached to neonatal platelets was not different from the amount of neonatal vWf attached to adult platelets. Furthermore, decreasing the vWf content in cord plasma to adult level resulted in significantly suppressed vWf-platelet attachment in the presence of ristocetin, indicating that the high neonatal vWf level contributes to the efficient vWf-platelet binding in neonates.

Combined effects of melagatran and eptifibatide on platelet aggregation inhibition but not thrombin generation inhibition.

The aim of our study was to investigate the combined in vitro effects of melagatran and eptifibatide on platelet aggregation and thrombin generation under low and high coagulant challenge in tissue-factor-activated, platelet-rich plasma. Increasing amounts of melagatran dose-dependently decreased prothrombin fragment 1.2 and activated factor X values, and dose-dependently prolonged the lag phase until the onset of platelet aggregation. Eptifibatide exerted a dose-dependent anti-aggregating effect under both high and low coagulant challenge. The combination of melagatran and eptifibatide resulted in significant additive prolongation of the lag phase until the onset of platelet aggregation, which was more pronounced under low coagulant challenge. Under low, but not under high, coagulant challenge, the combination of melagatran and eptifibatide had a significant additive inhibitory effect on platelet aggregation. No additive effects on decreasing prothrombin fragment 1.2 and activated factor X values were observed with combined administration of the drugs. The present study demonstrates the additive effect of melagatran and eptifibatide on platelet aggregation inhibition and on prolongation of the lag phase until the onset of platelet aggregation.

Reference values of the right ventricular outflow tract systolic excursion in 711 healthy children and calculation of z-score values.

OBJECTIVE: Quantitative determination of right ventricular (RV) function has gained more interest over the last years. The RV outflow tract systolic excursion (RVOT SE) has been recently proposed as an echocardiographic tool to assess RV systolic function in adults. We aimed to determine growth-related changes of RVOT SE in children and to establish references values. STUDY DESIGN: A prospective study was conducted in a group of 711 healthy paediatric patients (age: 1 day to 18 years). We determined the effects of age and body surface area (BSA) on RVOT SE values. RVOT SE values were further correlated with the established RV systolic function parameters tricuspid annular plane systolic excursion (TAPSE) and tricuspid annular peak systolic velocity (S'). RESULTS: The RVOT SE ranged from a mean of 3.4 mm in neonates to 9.5 mm in 18-year-old adolescents. The RVOT SE values showed a positive correlation with age (r = 0.90, P < 0.001) and BSA (r = 0.91, P < 0.001). A significant positive correlation was seen between RVOT SE and TAPSE (r = 0.93, P < 0.001) and also between RVOT SE and S' (r = 0.86, P < 0.001) in our patients. CONCLUSION: RVOT SE provides a simple measure and, in combination with long-axis excursion parameters TAPSE and S', a comprehensive assessment of RV systolic function. Z-scores of RVOT SE values were calculated, and percentile charts were established to serve as reference data.

Longitudinal systolic ventricular interaction in pediatric and young adult patients with TOF: a cardiac magnetic resonance and M-mode echocardiographic study.

Aim of this prospective study was to evaluate longitudinal systolic left ventricular (LV)-right ventricular (RV) interaction using M-mode compared to magnetic resonance imaging (MRI) data in 146 pediatric and adults with operated tetralogy of Fallot (TOF). We determined biventricular measures of longitudinal M-mode echocardiography [i.e., tricuspid annular plane systolic excursion (TAPSE); the mitral annular plane systolic excursion (MAPSE)] compared to longitudinal function parameters using MRI. M-mode data were compared to established normal z-score values. We found a good correlation between MAPSE and LVEF values (r = 0.788; p < 0.001). Correlations between MRI derived MAPSE and M-mode guided MAPSE (r = 0.879, p < 0.001), and between MRI derived TAPSE and M-mode guided TAPSE were significant (r = 0.780, p < 0.001). While the LVEF was normal in patients with a normal RVEF, the LVEF was decreased in patients with significantly reduced RVEF. Patients with a significantly dilated RV (RVEDVi > 150 ml/m(2)) showed a significantly reduced mean MAPSE of 1.30 ± 0.26 cm. LV longitudinal function decreases below -2 SD of normal MAPSE z-score values after a mean of 22 postoperative years. Our data confirm progressive adverse RV-LV interaction in the long-term follow-up of TOF. We show that simple M-mode measurement of the longitudinal LV function (i.e. MAPSE) is a sufficient surrogate for estimation of LVEF. Therefore determination of the MAPSE is a helpful additional tool for LV systolic function assessment late after TOF repair.

Regional cerebral oxygen saturation in newborn infants in the first 15 min of life after vaginal delivery.

The objective of this study was to evaluate regional oxygen saturation of the brain during immediate transition after birth, and to correlate it with pre-ductal arterial oxygen saturation in newborn infants. The prospective observational study including newborn infants in the first 15 min after spontaneous vaginal delivery and uncomplicated transitional period was undertaken. Regional cerebral oxygen saturation (rSO(2)brain) was measured using near-infrared spectroscopy. Arterial oxygen saturation (SpO(2)) and heart rate (HR) were measured on the right wrist by pulse oximetry. rSO(2)brain, SpO(2) and HR measurements were started immediately after birth and were performed in the first 15 min of life. Cerebral fractional tissue oxygen extraction (FTOE) was calculated for each minute. Of 145 newborn infants, 16 were included and the gender allocation was 31 females (49.2%) and 32 males (50.8%). rSO(2)brain increased rapidly from 39% (2 min) to 69% (5 min), SpO(2) increased from 72% (2 min) to 96% (14 min) and FTOE showed a significant decrease from minute 2 (0.47) until minute 4 (0.30) and an increase between 8 to 13 min. rSO(2)brain increased rapidly after vaginal delivery. Although SpO(2) increased within the first 14 min after delivery, rSO(2)brain showed no further significant changes after 5 min. FTOE decreased in the first 4 min and reached standard values subsequently.

Reference values of tricuspid annular peak systolic velocity in healthy pediatric patients, calculation of z score, and comparison to tricuspid annular plane systolic excursion.

The tricuspid annular peak systolic velocity (TAPSV) is an echocardiographic measurement assessing right ventricular systolic function in children and adults. We determined the growth-related changes of the TAPSV to establish the references values for the entire pediatric age group. A prospective study was conducted of a group of 860 healthy pediatric patients (age 1 day to 18 years; body surface area [BSA] 0.14 to 2.30 m(2)). We determined the effects of age, gender, and BSA on the TAPSV values. Stepwise linear multiple regression analysis was used to estimate the TAPSV from the age, BSA, and gender. A correlation of normal TAPSV with normal tricuspid annular plane systolic excursion values was performed. The TAPSV ranged from a mean of 7.2 cm/s (z score ± 2: 4.8 to 9.5 cm/s) in the newborn to 14.3 cm/s (z score ± 2: 10.6 to 18.6 cm/s) in the 18-year-old adolescent. The TAPSV values showed a positive correlation with age and BSA, with a nonlinear course. No significant difference was found in the TAPSV values according to gender. A significant correlation was found between the TAPSV and tricuspid annular plane systolic excursion values in our pediatric population. In conclusion, the z scores of the TAPSV values were calculated, and percentile charts were established to serve as reference data for patients with congenital heart disease.

Tricuspid annular peak systolic velocity (S') in children and young adults with pulmonary artery hypertension secondary to congenital heart diseases, and in those with repaired tetralogy of Fallot: echocardiography and MRI data.

BACKGROUND: Tricuspid annular peak systolic velocity (S'), as an echocardiographic index to assess right ventricular (RV) systolic function, has not been investigated thoroughly in children and young adults with repaired tetralogy of Fallot (TOF) and pulmonary artery hypertension secondary to congenital heart disease (PAH-CHD). METHODS: S' values in patients with TOF (n = 183) and PAH-CHD (n = 55) were compared with those in normal subjects. S' values were compared with RV ejection fraction and RV end-diastolic volume index (RVEDVi) determined by magnetic resonance imaging. RESULTS: S' values became significantly reduced in PAH-CHD patients after 10.4 years of age and after 13.6 years of age in patients with TOF compared with the lower boundary of the ±2-SD interval of normal subjects. Significant positive correlations between S' and RV ejection fraction were seen in patients with TOF (r = 0.66, P < .001) and those with PAH-CHD (r = 0.82, P < .001). Significant negative correlations between S' and RVEDVi were also seen in patients with repaired TOF (r = -0.29, P = .002) and in those with PAH-CHD (r = -0.59, P < .001). CONCLUSIONS: Although initially preserved, in this prospective study, impaired S' values with increasing age were found in patients with repaired TOF and PAH-CHD. Persistent pressure overload in patients with PAH-CHD as well as volume overload in those with repaired TOF might lead to systolic RV functional impairment and increased RVEDVi. The validity of S' data was supported by magnetic resonance imaging data (RVEDVi and RV ejection fraction).

First experience with the Prismaflex HF 20 set in four infants.

PURPOSE: Renal replacement therapy (RRT) in infants is challenging due to a lack of widely available technology that is specific to this patient population. We present our initial experience with the newly developed Prismaflex HF20 disposable set used on the Prismaflex device in infants with renal failure. PATIENTS: Four infants, age 5 to 24 months, were enrolled. Overall 120 treatment sessions were performed over 300 patient-days. Treatment monitoring included patient weight change and fluid balance, treatment efficacy, number of interventions, and alarms. RESULTS: Desired fluid balance according to the prescribed weight loss was achieved in all patients (R²=0.86, p<0.0001). Treatment efficacy was monitored by blood urea nitrogen (BUN) and serum creatinine values at the start of RRT (59 ± 17 mg/dL and 5.1 ± 1.1 mg/dL) and their decrease after 4 hours of RRT (23 ± 7 mg/dL and 2.2 ± 0.6 mg/dL). Measured urea and creatinine clearances for the HF20 filter were 23 ± 7 ml/min and 19 ± 4 ml/min, respectively. No complications occurred. CONCLUSION: This is the first report on the use of the Prismaflex HF20 set in infants. No adverse events were observed, treatments were well tolerated in all patients, and flow rate adaptability to infants' needs was good.