Left and right ventricular myocardial performance index (Tei index) in very-low-birth-weight infants

Comparing the tissue Doppler-derived left ventricular myocardial performance index before and after recovery from respiratory distress in neonates: A prospective observational study

Background and Objective

Respiratory distress is the most common cause requiring neonatal intensive care unit admission. As respiratory and cardiac functions are closely interrelated, some cardiac dysfunction is expected in respiratory distress. The myocardial performance index (MPI) is an index to assess global myocardial function, easily measurable by bedside echocardiography and reliable. Here, we conducted this study to determine the change in cardiac function in neonates with respiratory distress before initiating respiratory support and after weaning from the support.

Methodology

The study was carried out in 92 neonates with a gestational age of more than 32 weeks who required invasive or noninvasive respiratory support. The tissue Doppler left ventricular MPI (LV MPI) was calculated before the initiation of respiratory support and after weaning from respiratory support. The data were analyzed using a paired t-test and a Wilcoxon signed-rank test.

Results

This study comprised 92 neonates with a median (interquartile range) LV MPI value of 0.56 (0.10) before initiation of respiratory support and 0.47 (0.04) after weaning from respiratory support with P < 0.001. The isovolumetric contraction time, isovolumetric relaxation time, and ejection time increased after weaning from respiratory support (all P < 0.0001). The severity of respiratory distress determined by invasive mode of ventilation and longer duration of respiratory support caused higher initial LV MPI before initiation of respiratory support compared with recovery and P < 0.001, suggesting subclinical ventricular dysfunction with respiratory distress in neonates.

Conclusion

LV MPI was higher in neonates with respiratory distress and normalized after weaning from respiratory support, which indicates that neonates requiring respiratory support may have subclinical ventricular dysfunction and should be followed up carefully.

Right ventricular function indices and platelet parameters for early prediction value of bronchopulmonary dysplasia: a retrospective study

BACKGROUND

To examine the value of early echocardiographic indices for the right ventricular function combined with platelet(PLT) parameters for predicting bronchopulmonary dysplasia (BPD) in preterm infants.

METHODS

This retrospective study included infants with gestational age (GA) below 32 weeks, who were admitted to the neonatal intensive care unit(NICU). The detection rate of tricuspid regurgitation jet velocity (TRVJ), ventricular septal flattening, pulmonary artery widening, right ventricular dilation, and right atrial enlargement on the 7th day of life (DOL 7) were compared between BPD and non-BPD infants. Echocardiographic indices of the right ventricular function including tricuspid annular plane systolic excursion (TAPSE) and right ventricular index of myocardial performance (RIMP) were measured on 1 day of life (DOL 1)、on DOL 7 and on 14 day of life (DOL 14) respectively. The PLT parameters including the PLT count, mean platelet volume (MPV), platelet hematocrit (PCT) level, and platelet distribution width (PDW) were measured on the DOL 1,DOL 7, and DOL 14. Multivariate logistic regression was used to analyze the relationship between these parameters and BPD. Receiver operating characteristic curve analysis was performed to assess the predictive value of the right ventricular function indices and PLT parameters for BPD.

RESULTS

A total of 220 preterm infants were included in this study, and of these, 85 infants developed BPD among them. The RIMP of the BPD group on DOL 14 was higher than that of the non-BPD group (P < 0.05). The TAPSE of the BPD group on DOL 14 was lower than that of the non-BPD group (P < 0.05). The PLT count of the BPD group on DOL 1 was lower than that of the non-BPD group (P < 0.05), and the MPV of the BPD group on DOL 1 was higher than that of the non-BPD group (P < 0.05). Using multivariate logistic regression, GA、invasive mechanical ventilation duration ≥ 7 days、 PLT、 MPV、 TAPSE and RIMP were found to be independent risk factors for BPD. The area under the receiver operating characteristic curve was 0.846 (95CI: 0.794∼0.899), which improved when using right ventricular function indices combined with platelet parameters.

CONCLUSION

TAPSE and RIMP combined with PLT count and MPV can help identify preterm infants at an increased risk of developing BPD.

Right ventricular myocardial performance index (Tei) in premature infants

OBJECTIVE

The objective of this study was to evaluate the right ventricular myocardial performance index) based on echocardiography in very low birth weight premature neonates, close to hospital discharge.

METHODS

This was a prospective cross-sectional study that included premature neonates with birth weight <1,500 g and gestational age <37 weeks at the Intermediate Neonatal Unit of Bonsucesso Federal Hospital from July 2005 to July 2006. The infants underwent two-dimensional color Doppler echocardiography, being the right ventricular myocardial performance index evaluated close to hospital discharge. We compared the neonatal and echocardiographic variables in neonates with and without bronchopulmonary dysplasia.

RESULTS

A total of 81 exams were analyzed. The mean birth (standard deviation) weight and gestational age were 1,140 (235) g and 30 (2.2) weeks, respectively. The incidence of bronchopulmonary dysplasia was 32%. The mean right ventricle myocardial performance index (standard deviation) of the sample was 0.13 (0.06). We found a significant difference in aortic diameter [non-bronchopulmonary dysplasia 0.79 (0.07) vs. bronchopulmonary dysplasia 0.87 (0.11) cm, p=0.003], left ventricle in diastole [non-bronchopulmonary dysplasia 1.4 (0.19) vs. bronchopulmonary dysplasia 1.59 (0.21) cm, p=0.0006], ventricular septal thickness [non-bronchopulmonary dysplasia 0.23 (0.03) vs. bronchopulmonary dysplasia 0.26 (0.05) cm, p=0.032], and "a" measurement [(= sum of the isovolumetric contraction time, ejection time, and isovolumetric relaxation time) when calculating the myocardial performance index (p=0.01)].

CONCLUSION

Higher "a" interval in neonates with bronchopulmonary dysplasia suggests right ventricle diastolic dysfunction. We conclude that the right ventricle myocardial performance index is an important indicator both of ventricular function and for serial follow-up testing of very low birth weight premature neonates, especially those with bronchopulmonary dysplasia.

Tissue Doppler, speckling tracking and four-dimensional echocardiographic assessment of right ventricular function in children with dilated cardiomyopathy

BACKGROUND

Right ventricular (RV) function is frequently overlooked during dilated cardiomyopathy (DCM) evaluation.

AIM

To evaluate RV function in children with idiopathic DCM using relatively recent echocardiographic modalities.

METHODS

We prospectively studied the cardiac function in 50 children with idiopathic DCM and 50 healthy children as a control group, using four-dimensional echocardiography (4-DE), Tissue Doppler Imaging (TDI), and two-dimensional-speckles tracking echocardiography (2-D-STE). RV EF was measured by 4-DE.

RESULTS

The auto left (LV) ejection fractions (EF) measured by 2-D-STE were significantly lower in the patients' group than in the control. The sphericity index was also significantly lower in children with DCM than in the control. RV EF measured by 4-DE was significantly lower in the patient's group than the control. RV S wave, e´/a' ratio, myocardial performance index (MPI), and tricuspid annular plane systolic excursion (TAPSE) were significantly impaired in children with DCM than in control. Both LV and RV global longitudinal strains (GLS) were significantly reduced in children with DCM than in control. RVGLS was significantly associated with the duration since diagnosis, tricuspid annulus S wave, RV MPI, and TAPSE, but not with the age of the patients, RV EF, or e´/a' ratio.

CONCLUSION

There was impairment of the RV LGS and other systolic and diastolic parameters in children with DCM. STE and TDI can help to detect the early decline of RV function.

Fetal and Neonatal Modified Myocardial Performance Indices in Preeclamptic versus Normotensive Pregnancies: A Prospective Cohort Study

Objective

To compare fetal and neonatal cardiac functions in terms of global, systolic, and diastolic function between the preeclampsia and normotensive blood pressure of pregnancies.

Methods

A prospective cohort study was conducted at a university hospital in Northeast Thailand. Twenty-nine pregnancies diagnosed as preeclampsia with or without severe features were compared with 29 normotensive pregnancies. Global cardiac, systolic, and diastolic function were assessed at prenatal and postnatal periods, by a professionally trained obstetrician and pediatric cardiologist, respectively.

Results

The fetal left modified myocardium performance index (Mod-MPI) in preeclampsia and normotensive blood pressure were 0.60±0.08 and 0.59±0.08 (p-value=0.341), respectively, while fetal right Mod-MPI were 0.57±0.16 and 0.54±0.21 (p-value=0.861), respectively. There were no statistically significant differences in terms of fetal isovolumic contraction time (ICT), isovolumic relaxation time (IRT), ejection time (ET), aortic peak systolic velocity (Ao PSV), pulmonary artery peak systolic velocity (PA PSV), mitral valve (MV) E:A ratio, or tricuspid valve (TV) E:A ratios between the two groups. Neonatal mitral valve E peak systolic velocity (MV-E PV) in preeclamptic and normotensive blood pressure groups were significantly different at 51.1±8.02 cm/s and 43.56±5.21cm/s (p-value=0.036), respectively, whereas neonatal left Mod-MPI, mitral valve A peak systolic velocity (MV-A PV), MV E:A ratio, and Ao PSV were not significantly different (p-value=0.436, 0.119, 0.379, and 0.709), respectively.

Conclusion

Neonatal MV-E PV of the preeclampsia group was significantly higher than the normotensive blood pressure group, while there were no statistically significant differences in terms of global cardiac and diastolic functions during the fetal period between two groups.

The role of very low birth weight and prematurity on cardiovascular disease risk and on kidney development in children: a pilot study

BACKGROUND

Cardiovascular and renal disease are nowadays among the leading cause of morbidity and mortality in Western Countries. Low birth weight has been recently considered a key factor in determining cardiovascular disease and long-term renal disease in adulthood.

METHODS

In our study we analyzed, through echocardiography, eco color Doppler of carotid arteries, ultrasound of abdominal aorta and kidneys, morphological characteristics of cardiovascular and renal system, in a group of children born preterm with very low birth weight, (birth weight<1500 grams) and in a group of children, age and sex matched, born at term with weight appropriate for gestational age. Fifteen children born very low birth weight preterm (cases), aged from 3 to 5 years, and 15, age and sex matched children, born appropriate for gestational age at term (controls) were enrolled in the study.

RESULTS

The two groups were homogeneous for interventricular septum diameter, left ventricular end-systolic diameter, left atrial diameter, and ejection fraction. Left ventricular end diastolic diameter was higher in case compared to controls (P=0.04), while aortic diameter root smaller (P=0.005). E and A waves peak velocities and E/A ratio resulted lower in cases compared to controls (P=0.02, P<0.001and P<0.001, respectively). Tei index, S, e' and a' waves velocities were similar in the two groups, while E/e' ratio was higher in cases (P=0.046). Intima-media thickness and antero-posterior diameter of abdominal aorta values did not differ in cases versus controls. Longitudinal diameters of both kidneys were reduced in cases compared to controls (P<0.05).

CONCLUSIONS

Although limited by the small sample size, our study highlighted an increased size of the left ventricle and altered left ventricular diastolic function in children born very low birth weight preterm, but no long-term consequences on systolic performance and vascular structure have been found. The finding of smaller kidneys in ex-preterm very low birth weight children could explain their higher susceptibility to develop renal disease in adulthood.

Cesarean section predominantly affects right ventricular diastolic function during the early transitional period

BACKGROUND

Although the mode of delivery is well known to affect pulmonary function, the effects of a cesarean delivery on postnatal changes in cardiac mechanics have not been clearly defined.

METHODS

To evaluate whether delivery mode influences cardiac function in the early transitional period, 42 infants delivered by cesarean section (CS) and 110 by vaginal delivery (VD) were enrolled, and they underwent serial echocardiography at 0, 1, 2, and 5 days of age. Longitudinal changes in ejection fraction (EF), fractional area change (FAC), mitral annular plane systolic excursion (MAPSE), tricuspid annular plane systolic excursion (TAPSE), Tei index, ratio of peak early diastolic flow velocity (E) to peak early diastolic annular velocity (e') (E/e'), and deceleration time (DcT) were compared between the two groups.

RESULTS

FAC and DcT of both ventricles increased during the first week, whereas Tei index of each chamber decreased irrespective of delivery mode. E/e's of both ventricles were significantly higher and MAPSE was significantly lower in the CS than VD group throughout the observation period. After adjustment for the effects of birth weight, gestational age, and oxygen administration by multivariate analysis, right ventricular E/e', which reflects diastolic function of the right ventricle, was most affected by delivery mode.

CONCLUSION

CS affected diastolic function of the right ventricle in the 2nd day after giving birth and did not persist. Delayed adaptation of the neonatal myocardium and/or persistence of pulmonary hypertension might explain the hemodynamic changes in neonates born by CS.

Myocardial Function Maturation in Very-Low-Birth-Weight Infants and Development of Bronchopulmonary Dysplasia

Background: Myocardial function in very-low-birth-weight infants (VLBWIs) develops during early postnatal life, but different patterns of temporal evolution that might be related to the development of bronchopulmonary dysplasia (BPD) are not completely understood. Methods: A prospective cohort study including VLBWIs admitted to our NICU from January 2015 to 2017 was conducted. Plasma N-terminal pro B type natriuretic peptide (NTproBNP) levels were measured, and echocardiograms were performed at 24 and 72 h of life and weekly thereafter until 36 weeks of postmenstrual age (PMA). We measured the tricuspid annular plane systolic excursion (TAPSE) by M-mode; the lateral tricuspid E', A', and S' waves; and the myocardial performance index (MPI) by tissue doppler imaging (TDI). The subjects were divided into non-BPD and BPD groups. Results: We included 101 VLBWIs. The TAPSE and E', A', and S' waves increased while MPI-TDI decreased over time. Birth gestational age (GA) and postnatal PMA impacted these parameters, which evolved differently in those who developed BPD compared to those in the non-BPD group. The NTproBNP levels at 14 days of life and different echocardiographic parameters were associated with the development of BPD in different multivariate models. Conclusion: TAPSE and TDI values depend on GA and PMA and follow a different temporal evolution that is related to the later development of BPD. Combined biochemical and echocardiographic biomarkers can help identify which VLBWIs are at higher risk of developing BDP.

Post-transitional adaptation of the left heart in uncomplicated, very preterm infants

BACKGROUND

The postnatal period in preterm infants involves multiple physiological changes occurring immediately after birth and continuing for days or weeks. To recognise and treat compromise, it is important to measure cardiovascular function. The aim of this study was to describe longitudinal left ventricular function using conventional and novel echocardiography techniques in preterm infants who did not experience significant antenatal or postnatal complications and treatments.

METHODS

We prospectively obtained cardiac ultrasound images at days 3, 7, 14, 21, and 28 in 25 uncomplicated, preterm infants <30 weeks of gestation. Speckle tracking analysis of the four chambers and short-axis images provided parameters of left ventricular volume, deformation, and basal myocardial velocities. The patent ductus arteriosus, cardiac dimensions, and atrial volume were also measured.

RESULTS

Stroke volume increased by 24% during the study period (1.05-1.30 ml/kg, p<0.05). Cardiac length, diameter, and systolic basal myocardial velocity increased with unchanged wall stress and deformation parameters. Diastolic function parameters resembled that of the fetus with predominance of atrial contraction compared with early diastolic velocities. Blood pressure and estimates of left ventricular filing pressure increased, suggesting that left ventricular compliance did not change in this period.

CONCLUSION

Stroke volume increased in the first 28 days after preterm birth. The preterm heart adapted by increasing its size, while maintaining systolic and atrial function, independent of early diastolic maturation. Longitudinal deformation of the left ventricle remained unchanged, suggesting relatively preserved function with maturation.

Echocardiographic evaluation of right ventricular function in preterm infants with bronchopulmonary dysplasia

AIM

To evaluate right ventricular function in preterm infants with and without bronchopulmonary dysplasia.

METHODS

Eighty-nine preterm infants (<32 weeks) were divided into three groups: (1) no-bronchopulmonary dysplasia (n=32); (2) mild-bronchopulmonary dysplasia (n=35); (3) severe-bronchopulmonary dysplasia (n=15). Right ventricular echocardiographic parameters included the following: (1) pulsed-wave Doppler through the tricuspid valve (E/A ratio), pulmonary artery acceleration time, right ventricular ejection time, right ventricular velocity-time integral; (2) tissue Doppler measurements of myocardial velocities and atrioventricular conduction times; (3) pulsed-wave Doppler and tissue Doppler evaluation of myocardial performance index and E/E' ratio; and (4) M-mode detection of right ventricular end-diastolic wall diameter.

RESULTS

The severe-bronchopulmonary dysplasia group had higher mean right ventricular myocardial performance index (on the 28th day of life by pulsed-wave Doppler) than the no-bronchopulmonary dysplasia (P=.014) or mild-bronchopulmonary dysplasia (P=.031) groups; no differences were found between no-bronchopulmonary dysplasia and mild-bronchopulmonary dysplasia groups (P=.919). A reduction in right ventricular myocardial performance index at later time points was observed in all three groups (P<.05). We found no differences between preterm infants with differing bronchopulmonary dysplasia severity in other right ventricular echocardiographic parameters.

CONCLUSION

Right ventricular myocardial performance index measured by pulsed-wave Doppler indicates impaired right ventricular function in preterm infants with severe bronchopulmonary dysplasia.

Vascular Function and Myocardial Performance Indices in Children Born Small for Gestational Age

BACKGROUND

Small-for-gestational-age (SGA) children have increased cardiovascular risk, but the mediating factors are poorly understood. We hypothesized that birth size could affect the cardiovascular system since childhood in the absence of other risk factors. We investigated endothelial and myocardial function in SGA children with regular catch-up growth.

METHODS AND RESULTS

Biochemical markers, blood pressure, flow-mediated vasodilation (FMD), common carotid intima-media thickness (cIMT), anteroposterior diameter of the infrarenal abdominal aorta (APAO) and echocardiographic parameters of left and right ventricular (LV and RV) function were studied in 27 SGA and 25 appropriate-for-gestational-age (AGA) subjects. SGA subjects had a higher homeostasis model assessment index than controls (2.61±1.27 vs. 1.56±0.40, P=0.01), higher cIMT (0.51±0.04 mm vs. 0.45±0.07 mm, P=0.007) and APAO (1.31±1.35 cm vs. 1.30±0.16 cm, P=0.005), and lower FMD (10.11±4.17% vs. 12.34±4.28, P=0.04) than controls. On echocardiography SGA had higher Tei index both at LV and RV than controls (P=0.001). Reduced RV systolic function was also observed in SGA subjects.

CONCLUSIONS

SGA subjects had vascular morphological and function abnormalities compared with AGA, which increase their cardiovascular risk profile. Furthermore, a subtle cardiac alteration in both RV and LV functions was seen in SGA patients compared with AGA.

Right ventricular function in preterm and term neonates: reference values for right ventricle areas and fractional area of change

BACKGROUND

Right ventricular (RV) fractional area of change (FAC) is a quantitative two-dimensional echocardiographic measurement of RV function. RV FAC expresses the percentage change in the RV chamber area between end-diastole (RV end-diastolic area [RVEDA]) to end-systole (RV end-systolic area [RVESA]). The objectives of this study were to determine the maturational (age- and weight-related) changes in RV FAC and RV areas and to establish reference values in healthy preterm and term neonates.

METHODS

A prospective longitudinal study was conducted in 115 preterm infants (23-28 weeks' gestational age at birth, 500-1,500 g). RV FAC was measured at 24 hours of age, 72 hours of age, and 32 and 36 weeks' postmenstrual age (PMA). The maturational patterns of RVEDA, RVESA, and RV FAC were compared with those in 60 healthy full-term infants in a cross-sectional study (≥37 weeks, 3.5 ± 1 kg), who underwent echocardiography at birth (n = 25) and 1 month of age (n = 35). RVEDA and RVESA were traced in the RV-focused apical four-chamber view, and FAC was calculated using the formula 100 × [(RVEDA - RVESA)/RVEDA)]. Premature infants who developed chronic lung disease or had clinically and hemodynamically significant patent ductus arteriosus were excluded (n = 55) from the reference values. Intra- and interobserver reproducibility analysis was performed.

RESULTS

RV FAC ranged from 26% at birth to 35% by 36 weeks' PMA in preterm infants (n = 60) and increased almost 2 times faster in the first month of age compared with healthy term infants (n = 60). Similarly, RVEDA and RVESA increased throughout maturation in both term and preterm infants. RV FAC and RV areas were correlated with weight (r = 0.81, P < .001) but were independent of gestational age at birth (r = 0.3, P = .45). RVEDA and RVESA were correlated with PMA in weeks (r = 0.81, P < .001). RV FAC trended lower in preterm infants with bronchopulmonary dysplasia (P = .04) but was not correlated with size of patent ductus arteriosus (P = .56). There was no difference in RV FAC based on gender or need for mechanical ventilation.

CONCLUSIONS

This study establishes reference values of RV areas (RVEDA and RVESA) and RV FAC in healthy term and preterm infants and tracks their maturational changes during postnatal development. These measures increase from birth to 36 weeks' PMA, and this is reflective of the postnatal cardiac growth as a contributor to the maturation of cardiac function These measures are also linearly associated with increasing weight throughout maturation. This study suggests that two-dimensional RV FAC can be used as a complementary modality to assess global RV systolic function in neonates and facilitates its incorporation into clinical pediatric and neonatal guidelines.

Serial assessment of right ventricular function using tissue Doppler imaging in preterm infants within 7 days of life

BACKGROUND

We aimed to evaluate right ventricular (RV) function longitudinally using tissue Doppler imaging (TDI) echocardiography in preterm infants.

METHODS

We selected 101 very-low-birth-weight (VLBW) infants for the study. Echocardiographic examinations including TDI were performed serially within 7days of life. Pulsed-Doppler TDI waveforms were recorded at the tricuspid valve annulus, and peak systolic velocities (Sa), early diastolic velocities (Ea), and late diastolic velocities (Aa) were measured.

RESULTS

Sa, Ea and Aa were all reduced significantly from 3h to 12h, and then increased gradually thereafter. These three velocities also increased with gestational age in the early neonatal period. The ratio of Ea to Aa (Ea/Aa) did not change significantly within the first week of life. The ratio of E to Ea (E/Ea) in VLBW infants also seemed to remain stable from birth to day 7. The values of Sa appeared to be associated with cardiac output in the early neonatal period. Both Sa and Aa in intubated infants were significantly higher than in non-intubated infants.

CONCLUSION

RV TDI velocities of preterm infants in the early neonatal period are influenced by gestational age, postnatal age, and respiratory status, although the RV E/Ea ratio appears to be almost stable throughout the neonatal period. Our findings may provide some basis for assessment of RV function in critically ill preterm infants.

Serial assessment of left-ventricular function using tissue Doppler imaging in premature infants within 7 days of life

Although many echocardiographic parameters can assess cardiac function noninvasively in preterm infants, it has not been determined what indices are the best. We assessed left-ventricular performance in 101 very low-birth weight (VLBW) infants using tissue Doppler imaging (TDI) echocardiography. Echocardiographic examinations, including TDI, were performed serially within 7 days of life. Pulsed-Doppler TDI waveforms were recorded at the mitral valve annulus, and peak systolic velocities (Sa), early diastolic velocities (Ea), and late diastolic velocities (Aa) were measured. Sa and Aa velocities were both decreased significantly from 3 to 12 h and then gradually increased. Ea velocities showed no significant, longitudinal changes, but Ea values in premature groups appeared to be significantly lower than those in mature groups. The ratio of E to Ea (E/Ea) of VLBW infants seemed to be almost stable from birth to day 7, and this also showed no significant differences between different gestational age groups. E/Ea values in infants with patent ductus arteriosus (PDA) appeared to be greater than those in non-PDA infants. Our present findings suggest that TDI assessment in the early neonatal period might be useful in detecting latent systolic/diastolic failure of critically ill preterm infants.

Umbilical cord milking stabilizes cerebral oxygenation and perfusion in infants born before 29 weeks of gestation

OBJECTIVE

To investigate the effects of umbilical cord milking at birth on cerebral perfusion and systemic perfusion in very low birth weight (VLBW) infants.

STUDY DESIGN

Cerebral tissue oxygenation index and cerebral fractional tissue oxygen extraction were monitored in 50 stable VLBW infants (gestational age <29 weeks, birth weight <1250 g), with 26 allocated to the milked group and 24 to the control group. We used near-infrared spectroscopy 3-6, 12, 18, 24, 36, 48, and 72 hours after birth. Left ventricular end-diastolic dimension, left ventricular ejection fraction, left ventricle (LV) Tei index (measurement of left ventricular systolic and diastolic function), left ventricular cardiac output, and superior vena cava flow were measured concurrently using echocardiography.

RESULTS

There were no significant differences in gestational age and birth weight between the 2 groups. Hematocrit, left ventricular end-diastolic dimension, left ventricular cardiac output, and superior vena cava flow were higher in the milked group than in the control group, with improvement in the LV Tei index despite the absence of left ventricular ejection fraction changes within 24 hours after birth. Tissue oxygenation index increased and cerebral fractional tissue oxygen extraction decreased in the milked group within 24 hours after birth.

CONCLUSION

Umbilical cord milking stabilized cerebral oxygenation and perfusion in VLBW infants by improving LV diastolic function by increasing LV preload.

Transthoracic echocardiography in children and young adults with congenital heart disease

Transthoracic echocardiography (TTE) is the first-line tool for diagnosis and followup of pediatric and young adult patients with congenital heart disease (CHD). Appropriate use of TTE can reduce the need for more invasive modalities, such as cardiac catheterization and cardiac magnetic resonance imaging. New echocardiographic techniques have emerged more recently: tissue Doppler imaging, tissue tracking (strain and strain rate), vector velocity imaging (VVI), myocardial performance index, myocardial acceleration during isovolumic acceleration (IVA), the ratio of systolic to diastolic duration (S/D ratio), and two dimensional measurements of systolic right ventricular (RV) function (e.g., tricuspid annular plane systolic excursion, TAPSE). These may become valuable indicators of ventricular performance, compliance, and disease progression. In addition, three-dimensional (3D) echocardiography when performed for the assessment of valvular function, device position, and ventricular volumes is being integrated into routine clinical care. In this paper, the potential use and limitations of these new echocardiographic techniques in patients with CHD are discussed. A particular focus is on the echocardiographic assessment of right ventricular (RV) function in conditions associated with increased right ventricular volume (e.g., pulmonary regurgitation after tetralogy of Fallot repair) or pressure (e.g., pulmonary hypertension) in children and young adults.

Persistently elevated right ventricular index of myocardial performance in preterm infants with incipient bronchopulmonary dysplasia

OBJECTIVES

Elevated pulmonary vascular resistance occurs during the first days after birth in all newborn infants and persists in infants at risk for bronchopulmonary dysplasia (BPD). It is difficult to measure in a non-invasive fashion. We assessed the usefulness of the right ventricular index of myocardial performance (RIMP) to estimate pulmonary vascular resistance in very low birth weight infants.

STUDY DESIGN

Prospective echocardiography on day of life (DOL) 2, 7, 14, and 28 in 121 preterm infants (median [quartiles] gestational age 28 [26]-[29] weeks, birth weight 998 [743-1225] g) of whom 36 developed BPD (oxygen supplementation at 36 postmenstrual weeks).

RESULTS

RIMP derived by conventional pulsed Doppler technique was unrelated to heart rate or mean blood pressure. RIMP on DOL 2 was similar in infants who subsequently did (0.39 [0.33-0.55]) and did not develop BPD (0.39 [0.28-0.51], p = 0.467). RIMP declined steadily in non-BPD infants but not in BPD infants (DOL 7: 0.31[0.22-0.39] vs. 0.35[0.29-0.48], p = 0.014; DOL 14: 0.23[0.17-0.30] vs. 0.35[0.25-0.43], p<0.001; DOL 28: 0.21[0.15-0.28] vs. 0.31 [0.21-0.35], p = 0.015).

CONCLUSIONS

In preterm infants, a decline in RIMP after birth was not observed in those with incipient BPD. The pattern of RIMP measured in preterm infants is commensurate with that of pulmonary vascular resistance.

Functional echocardiographic assessment of myocardial performance in anemic premature infants: a pilot study

This prospective observational study conducted in a neonatal intensive care unit aimed to evaluate echocardiographic changes provoked by anemia and transfusion of packed red blood cells (pRBCs) in premature infants. In this study, 32 anemic premature infants had serial echocardiographic assessment of left ventricular (LV) systolic performance, LV preload, and afterload immediately before, within 48 h, and up to 120 h after the transfusion of pRBCs. Pretransfusional evaluations also were compared with similar assessments of 71 nonanemic inpatient premature infants analogous for sex, gestational age at birth, and postnatal age. Left ventricular systolic performance was estimated from fractional shortening, LV output, and LV myocardial performance index (LVMPI). The LV preload was estimated from the LV end-diastolic dimension and the ratio of left atrium-to-aortic root dimension (LA/Ao ratio). The LV afterload was estimated from end-systolic wall stress. The LVMPI was found to decrease with increasing corrected gestational age in both the nonanemic (R = 0.173; p = 0.03) and anemic (R = 0.460; p = 0.007) infants. The LVMPI was the only index that changed after transfusion of pRBCs, decreasing in the younger anemic infants (p = 0.011) and increasing in the older anemic infants (p = 0.012). Finally, a significant inverse relationship between pre- and posttransfusional LVMPI values (R = 0.730; p < 0.001) was noted. The LVMPI may allow for identification of preterm infants more likely to be helped by transfusion of pRBCs.

Non-Invasive Imaging for Congenital Heart Disease: Recent Innovations in Transthoracic Echocardiography

Transthoracic echocardiography (TTE) is an important tool for diagnosis and follow-up of patients with congenital heart disease (CHD). Appropriate use of TTE can reduce the need for more invasive and complex modalities, such as cardiac catheterization and cardiac magnetic resonance imaging. New echocardiographic techniques have emerged for the assessment of ventricular systolic and diastolic function: Tissue Doppler imaging, tissue tracking, strain and strain rate imaging, vector velocity imaging (VVI), myocardial performance index, myocardial acceleration during isovolumic contraction (IVA), the ratio of systolic to diastolic duration (S/D ratio), and other measurements of systolic right ventricular (RV) function like tricuspid annular plane systolic excursion (TAPSE). These modalities may become valuable indicators of ventricular performance, compliance and disease progression, with the caveat of preload-dependency of the variables measured. In addition, three-dimensional (3D) echocardiography for the assessment of cardiac anatomy, valvular function, device position, ventricular volumes and ejection fraction is integrated into routine clinical care. In this review, we discuss the potential use and limitations of these new echocardiographic techniques in patients with CHD. A particular focus is on the echocardiographic assessment of right ventricular (RV) function by means of tissue Doppler imaging, tissue tracking, and three-dimensional imaging, in conditions associated with increased right ventricular volume or pressure load.

Relationship between Tei index of myocardial performance and left ventricular geometry in Nigerians with systemic hypertension

INTRODUCTION

Left ventricular geometry is associated with cardiovascular events and prognosis. The Tei index of myocardial performance is a combined index of systolic and diastolic dysfunction and has been shown to be a predictor of cardiovascular outcome in heart diseases. The relationship between the Tei index and left ventricular geometry has not been well studied. This study examined the association between the Tei index and left ventricular geometry among hypertensive Nigerian subjects.

METHODS

We performed echocardiography on 164 hypertensives and 64 control subjects. They were grouped into four geometric patterns based on left ventricular mass and relative wall thickness. The Tei index was obtained from the summation of the isovolumic relaxation time and the isovolumic contraction time, divided by the ejection time. Statistical analysis was done using SPSS 16.0.

RESULTS

Among the hypertensive subjects, 68 (41.4%) had concentric hypertrophy, 43 (26.2%) had concentric remodelling, 24 (14.6%) had eccentric hypertrophy, and 29 (17.7%) had normal geometry. The Tei index was significantly higher among the hypertensives with concentric hypertrophy (CH), concentric remodelling (CR) and eccentric hypertrophy (EH) compared to the hypertensives with normal geometry (0.83 ± 1.0, 0.71 ± 0.2, 0.80 ± 0.2 vs 0.61 ± 0.2, respectively). The Tei index was higher among hypertensives with CH and EH than those with CR. Stepwise regression analysis showed that the Tei index was related to ejection fraction, fractional shortening and mitral E/A ratio.

CONCLUSION

Among Nigerian hypertensives, LV systolic and diastolic functions (using the Tei index) were impaired in all subgroups of hypertensive patients according to their left ventricle geometry compared to the control group. This impairment was more advanced in patients with concentric and eccentric hypertrophy.