Effect of assessing velocity time integral at different locations across ventricular outflow tracts when calculating cardiac output in neonates.

This study aims to evaluate the effect of assessing velocity time integral at different locations across ventricular outflow tracts for calculating cardiac output (CO) in neonates. Velocity time integral (VTI) and CO were measured at 3 different locations across right and left ventricular outflow tracts using transthoracic echocardiography in healthy term neonates without any major congenital heart disease. ANOVA with Bonferroni correction was used to determine the differences between the VTI and CO sampled at these three locations. Forty-one neonates met inclusion criteria with mean gestational age of 38.6 ± 1 weeks and mean birth weight of 3155 ± 463 g. The median hours after birth when echocardiography was obtained was 23 h (range 11-68 h after birth). Left CO were 121 ± 30 mL/kg/min, 155 ± 38 mL/kg/min, and 176 ± 36 mL/kg/min measured below the valve, hinges of the valve, and tip of the valve, respectively. Right CO were 197 ± 73 mL/kg/min, 270 ± 83 mL/kg/min, and 329 ± 104 mL/kg/min measured below the valve, hinges of the valve, and tip of the valve, respectively. A statistically significant difference (P < 0.001) was found in the VTI and CO measured at the 3 different locations across both left and right ventricular outflow tracts.     Conclusions: There is a significant difference in measurements of VTI and CO depending on the location of Doppler gate sampling across the ventricular outflow tracts. Consistency and precision in Doppler gate location are essential for measuring VTI and calculating CO while assessing changes in hemodynamic status in critically ill infants. What is Known: • Targeted Neonatal Echocardiography is increasingly applied to measure cardiac output in critically ill neonates and serial assessments are performed to assess the trend in changes in cardiac output. • Noninvasive measurement using velocity time integral to calculate cardiac output is commonly performed. However, location of Doppler sample gate to measure ventricular outflow tract velocity time integral is not consistent. What is New: • Statistically significant changes in measured velocity time integral and cardiac output are noted based on the location of Doppler gate sampling. • To monitor the cardiac output for trending, it is important to be consistent with regards to the location of the Doppler sample gate to assess changes in cardiac output in critically ill newborns.

Outcomes of patent foramen ovale greater than 3 mm at birth in extremely low birthweight infants.

BACKGROUND: Foramen ovale (FO) is an obligate fetal shunt that typically resolves after birth, although patency throughout life is not uncommon. The natural history of patent FO (PFO) is known in term infants, but less is known about its course in extremely preterm infants. We describe the echocardiographic changes in FO size from birth to discharge in extremely low birth weight (ELBW) infants in this retrospective study. METHODS: Cohort was divided based on size of FO at birth. Size of FO at discharge was measured and evaluated relative to postnatal weight gain. Demographics and clinical outcomes were compared between the two groups. RESULTS: Of the 54 ELBW infants, 50 were born with FO less than 3 mm in diameter (small), and 4 were born with FO greater than 3 mm (large). Of small defects, the majority (44/50, 88%) did not increase in size with weight gain, and minority (6/50, 12%) increased in size, and three of these 6 patients, FO grew to be slightly larger than 3 mm. In contrast, all large defects (4 of 4, 100%) nearly doubled in size with postnatal growth. These 4 ELBW infants with enlargement of FO had a flap valve evident on echocardiogram obtained prior to discharge, and subsequently closed on outpatient follow-up echocardiograms, although time to resolution was variable (6 months - 3 years). One infant had presumptive resolution because of the presence of flap valve. CONCLUSION: No maternal or neonatal demographic characteristics were predictive of FO enlargement, although, demonstrable flap valve on discharge echocardiogram correlated with resolution of FO on outpatient follow-up echocardiogram. Therefore, based on our data, we recommend that ELBW infants born with large FO should have echocardiographic re-evaluation of the atrial septal opening prior to discharge, to specify the presence of a flap valve or lack thereof, which is an important detail that can help a neonatologist determine the need for outpatient cardiac follow-up.

Pulmonary hemorrhage in extremely low birth weight infants: Significance of the size of left to right shunting through a valve incompetent patent foramen ovale.

OBJECTIVE: Pulmonary hemorrhage is a rare but severe complication of extremely low birth weight (ELBW) infants. The association of hemodynamically significant patent ductus arteriosus (hsPDA) and the diameter of the foramen ovale (FO) with pulmonary hemorrhage has not been reported. STUDY DESIGN: Case control study of ELBW infants with and without pulmonary hemorrhage. Each ELBW infant with an echocardiogram within 48 h of pulmonary hemorrhage was analyzed. RESULT: 16 infants with pulmonary hemorrhage were matched with 32 controls by birth weight and gestational age. Echocardiogram showed hsPDA in all infants and those with pulmonary hemorrhage had significantly smaller patent FO [PFO] (1 vs 2.4 mm, p < 0.01) (OR 0.007; 95% CI 0.00007, 0.67 p = 0.03). Incidence of pulmonary hemorrhage was 8.9%. CONCLUSION: ELBW infants with hsPDA who experienced pulmonary hemorrhage had a significantly restricted or closed FO. Evaluation of FO should be considered with serial echocardiograms when evaluating for hsPDA.

Effectiveness of Simulation Training in Acquiring Echocardiography Skills among Neonatology Care Providers.

OBJECTIVE: The objective of this study was to test the hypothesis that simulation training improves echocardiography skills. STUDY DESIGN: In this prospective study, 43 participants (16 neonatologists, 26 neonatology fellows, and 1 nurse practitioner) were tested on the simulator after 4 hours of didactic sessions on topographical cardiac anatomy and standard echocardiographic views. Participants were given 20 minutes to obtain and save the standard views. After the simulation hands-on training for 8 hours over 3 days, they were tested again. Each image was scored from 0 to 3 based on the image quality. Pre- and postsimulator training data were compared using both automated and visual scoring methods. RESULTS: After the hands-on simulator training, the automated median (interquartile) score for the quality of acquired images increased from 36 (22, 43) to 55 (48, 58), p < 0.0001. The increase was similar using visual scoring. The number of views with acceptable or good image quality (scores of 2 or 3) increased from 11 (6, 16) to 20 (17, 21), p < 0.0001. The neonatology fellows and faculty, as well as those with or without prior echocardiography experience, demonstrated significant improvement. CONCLUSIONS: Echocardiography simulation is an effective tool in improving echocardiography skills among neonatology care providers. KEY POINTS: · Simulation is effective in acquiring echocardiography skills among neonatology care providers.. · Simulation improves image acquisition in those with and without prior echocardiography experience.. · Effectiveness of simulation in retaining the acquired echocardiography skill should be investigated..

Development and validation of an automated assessment tool of echocardiography skills acquired on a neonatal simulator.

INTRODUCTION: Simulators are increasingly used for training in echocardiography. However, there is no objective method to assess the skills acquired. Our objective was to develop and test an automated method to assess echocardiography skills. METHODS: To automate the image quality evaluation, we expanded our previously developed neonatal echocardiography simulator to enable recording of images of the 26 standard cuts and process the image quality. We then compared the automated and visual methods in scoring image quality of the echocardiograms obtained by 22 trainees. RESULTS: Each echocardiographic image representing a slice of a three-dimensional volume possesses 3 axes (X, Y, and Z) that correspond to the roll, pitch, and yaw angles of the transducer, respectively. Therefore, if the placement and orientation of the transducer are correct, the acquired image represents the appropriate cardiac window with the desired orientation in all 3 axes. The automated system gives a score of 0 if the transducer is not in the appropriate cardiac window. A score of 1, 2, or 3 is given if the image falls within the range of one, two, or three angles, respectively. There was no difference in the image quality score between automated and visual assessment methods (46.0 ± 13.0 vs 45.1 ± 14.4, P = .19). The two methods had excellent correlation (r = .95). The bias and precision were 0.9 and 8.8, respectively. CONCLUSIONS: The automated method is comparable to visual method for assessment of image quality. The automated process allows for instantaneous feedback and has the potential to standardize assessment of echocardiography skills of trainees.

Systemic to Pulmonary Collaterals in Extremely Low Birth Weight Infants: Incidence, Clinical Significance, and Hemodynamic Features.

OBJECTIVE: This study aimed to determine the incidence of systemic to pulmonary collaterals (SPCs) in extremely low birth weight infants and to assess its clinical and hemodynamic significance beyond the neonatal period. STUDY DESIGN: Retrospective cohort study was conducted on 61 infants with echocardiogram performed at the time of discharge to determine the presence of SPC and to measure the right and left ventricular outputs and left atrium to aortic ratio. We compared two groups: small or no SPC (Group 1) to moderate or large SPC (Group 2) on demographics, clinical outcomes, and echocardiographic parameters. RESULTS: Sixty-one infants were included. The incidence of SPC was 57%; 21% of infants had moderate or large shunts and 31% had small SPC. Demographics, clinical outcomes, and echocardiographic parameters were not significantly different between small or no SPC and moderate to large SPC. CONCLUSION: More than half of the infants had SPC. The size of the shunt did not affect the clinical outcomes nor the echocardiographic parameters measured. All infants had cardiac output above the normative mean.

Pulmonary Venous Congestion and Pulmonary Hemorrhage in an Extremely Premature Neonate With a Large Patent Ductus Arteriosus and Closed Patent Foramen Ovale: A Case Report.

We describe a case of an extremely low birthweight infant with a large patent ductus arteriosus and closed foramen ovale resulting in markedly increased pulmonary blood flow, pulmonary venous congestion, and pulmonary hemorrhage.

Association of high level of hs-CRP with in-stent restenosis: A case-control study.

BACKGROUND: In-stent restenosis (ISR) is one adverse outcome of coronary stent implantation. Although using drug-eluting stents has reduced the rate of ISR, it remains a major problem. Here, we have investigated the relationship between several patient characteristics including serum high sensitive C-reactive protein (hs-CRP) and ISR. METHODS: This was a case-control study comprising 104 individuals with ISR and 202 patients without. Baseline characteristics were collected using a questionnaire. Fasting blood glucose (FBG), serum triglycerides (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C) and serum high sensitivity C-reactive protein (hs-CRP) were measured using commercial kits on an auto-analyzer. Data were analyzed using SPSS software and a p value ≤ 0.05 was considered significant. RESULTS: Diabetes mellitus (p < 0.001), stent type (p = 0.005), serum hs-CRP (p = 0.006), FBG (p = 0.038) and serum TG (p = 0.039) were significantly associated with ISR. The association between hs-CRP and ISR remained significant after adjustment for stent type and DM. For patients with a serum hs-CRP <2.64 mg/dL, ISR was only associated with diabetes mellitus (p = 0.016); while for individuals with a serum hs-CRP ≥2.64 mg/dL, ISR was also associated with the presence of diabetes mellitus, serum triglycerides and stent type. CONCLUSION: Higher levels of serum hs-CRP were significantly associated with the occurrence of ISR.

Virtual Neonatal Echocardiographic Training System (VNETS): An Echocardiographic Simulator for Training Basic Transthoracic Echocardiography Skills in Neonates and Infants.

There is a great need for training in pediatric echocardiography. In addition to physicians being trained in pediatric cardiology and echocardiography technologists, neonatologist, pediatric intensivists, and other health care professionals may be interested in such training. Since, there is limited opportunity of training on live patients, echocardiographic simulators may be of help. No simulator with complete range of echocardiographic modalities is available for neonates and infants. The aim of this project was to develop a mannequin-based echocardiographic simulator capable of simulating full range of pediatric 2D, color flow Doppler, spectral Doppler, and M-mode echocardiograms. A mannequin, a laptop computer, a magnetic tracking device, and a six-degree freedom (6DOF) sensor incorporated in a dummy transducer serve as the hardware platform of the simulator. We obtained six to seven 4D echocardiographic datasets in DICOM format through five acoustic windows from each infant along with a complete set of 2D video clips of color flow, Doppler, and M-mode. The 4D datasets are sliced into 3D slices using the visualization toolkit and are displayed as 2D echocardiograms through the information obtained by the 6DOF sensor. The coordinates from specific 3D slices triggers display of video clips of color flow, M-mode, and Doppler echocardiogram. Software written in C++ programming language controls the basic function of the program. The main simulator screen displays the full range of 2D echocardiograms including color flow Doppler, spectral Doppler, and M-mode from each acoustic window, whereas the side screen display the position and motion of the cutting planes through a 3D heart model. The system includes a software module to perform hemodynamic measurements from specific video clips images. Our hybrid, mannequin-based pediatric echocardiography simulator provides full range of pediatric echocardiography training experience. This simulator may help training in pediatric echocardiography for which there is a growing demand in clinical medicine.

Anomalous Left Coronary Artery from the Pulmonary Artery Presenting with Atypical Chest Pain in an Adult: A Case Report.

The anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital anomaly. The usual clinical course is severe left-sided heart failure and mitral valve insufficiency presenting during the first months of life. However, in some cases, the collateral blood supply from the right coronary artery is sufficient and symptoms may be subtle or even absent. We describe a 49-year-old woman presenting with atypical chest pain during physical exertion. The exercise tolerance test and then coronary angiography by indication revealed an anomalous origin of the left coronary artery. The patient underwent surgical treatment, whereby a pulmonary artery tube graft from the aorta to the left coronary artery was created and the main pulmonary artery was reconstructed with a bovine pericardial patch. The patient was discharged from the hospital without any chest pain and dyspnea and was symptom free during a follow-up period of 18 months. Clinicians should consider ALCAPA as a differential diagnosis in adults with presentations similar to exercise-related asthma.

Evaluation of natural radioactivity content in high-volume surface water samples along the northern coast of Oman Sea using portable high-resolution gamma-ray spectrometry.

Portable high-resolution gamma-ray spectrometry was carried out to determine the natural radioactivity levels in high volume surface water samples of the northern coast of Oman Sea, covering the coastal strip from Hormoz strait to Goatr seaport, for the first time. The water samples from 36 coastal and near shore locations were collected for analysis. Analyses on the samples collected were carried out to determine (226)Ra, (232)Th and (40)K contents. The concentration of (226)Ra, (232)Th and (40)K in surface water samples ranged between 2.19 and 2.82 Bq/L, 1.66-2.17 Bq/L and 132.6-148.87 Bq/L, respectively. The activity profile of radionuclides shows low activity across the study area. The study also examined some radiation hazard indices. The external hazard index was found to be less than 1, indicating a low dose. The results of measurements will serve as background reference level for Oman Sea coastlines.

The mechanical PR interval in fetuses of women with intrahepatic cholestasis of pregnancy.

OBJECTIVE: The purpose of this study was to evaluate the fetal mechanical PR interval in intrahepatic cholestasis of pregnancy (ICP). STUDY DESIGN: Fetal echocardiography was performed for women with ICP and control subjects. Clinical characteristics, total bile acids, and liver profile tests were compared between groups. RESULTS: Fourteen women with ICP and 7 control subjects were enrolled. Total bile acids (28.3 vs 6.2 µmol/L; P < .001), aspartate aminotransferase (53 vs 23 IU/L; P = .002), alanine aminotransferase (63 vs 19 IU/L; P = .002), and the PR interval (124 vs 110 msec; P = .006) were significantly higher in fetuses with ICP than in control fetuses. On multivariable linear regression analysis, only the presence of ICP was associated significantly with an increase in the PR interval (95% confidence interval, 4-24 msec; P = .01). CONCLUSION: The fetal cardiac conduction system is altered in ICP. Further investigation is needed to determine whether fetal echocardiography can help to predict which fetuses are at risk for death that is associated with ICP.

Hemodynamic changes after low-dosage hydrocortisone administration in vasopressor-treated preterm and term neonates.

OBJECTIVE: We sought to investigate whether the increase in blood pressure and decrease in vasopressor support after hydrocortisone administration are associated with changes in systemic hemodynamics in neonates who receive high-dosage dopamine to maintain blood pressure at the lowest acceptable levels. METHODS: In this prospective, observational study, preterm and term neonates who required dopamine > or = 15 microg/kg per minute to maintain minimum acceptable blood pressure received intravenous hydrocortisone 2 mg/kg followed by up to 4 doses of 1 mg/kg every 12 hours. Fifteen preterm and 5 term neonates without a patent ductus arteriosus composed the study population. Echocardiograms and vascular Doppler studies were performed immediately before the first dose of hydrocortisone and at 1, 2, 6 to 12, 24, and 48 hours thereafter. RESULTS: In the 15 preterm infants, during the first 12 hours of hydrocortisone treatment, the 28% increase in blood pressure paralleled that in the systemic vascular resistance without changes in stroke volume or cardiac output, whereas dopamine dosage decreased. By 24 hours, the dosage of dopamine continued to decrease, whereas stroke volume increased without additional changes in systemic vascular resistance. By 48 hours, dopamine dosage decreased by 72%; blood pressure and stroke volume increased by 31% and 33%, respectively; and systemic vascular resistance and cardiac output tended to be higher (14% and 21%, respectively) compared with baseline. Contractility, global myocardial function, and Doppler indices of blood flow in the middle cerebral and renal artery remained normal and unchanged. The findings in the 5 term infants showed a similar pattern for changes in cardiac function, systemic hemodynamics, and organ blood flow after hydrocortisone administration. CONCLUSIONS: In preterm and term neonates who require high-dosage dopamine to maintain blood pressure at the lowest acceptable levels, hydrocortisone improves blood pressure without compromising cardiac function, systemic perfusion, or cerebral and renal blood flow.

Cardiac abnormalities in children with sickle cell anemia.

Sickle cell anemia (SCA) results in chronic volume overload of the heart due to hemodilution. Previous echocardiographic studies of cardiac function in children with SCA have not accounted for these abnormal loading conditions. The objectives of this study were to (1) determine how the degree of anemia and transfusion status relate to cardiac findings and (2) evaluate cardiac function using load-independent parameters of function. We evaluated 77 patients with SCA, ages 2 to 22 years (mean +/- SD = 11.7 +/- 4.7), using physical examination, electrocardiography, and echocardiography. We compared two groups of patients. Group 1 consisted of 57 non-transfused patients, and Group 2 consisted of 20 patients on a chronic transfusion protocol. Group 1 patients exhibited a significantly lower hemoglobin, higher cardiac output, and larger left ventricular (LV) end-diastolic dimension and LV mass than groups 2 (P < 0.05). However, the velocity of circumferential fiber shortening-wall stress index (a load-independent measure of systolic function) was normal and not statistically different between the two groups. Conversely, the LV myocardial performance index (a measure of combined systolic and diastolic function) was significantly higher in Group 2 (P < 0.001), possibly indicating impaired myocardial diastolic function. SCA in children results in a volume-overloaded heart with a significant increase in LV dimensions and mass, both proportional to the degree of anemia. Despite these abnormal loading conditions, systolic function is preserved. Patients on a chronic transfusion protocol may develop diastolic dysfunction despite iron chelation therapy.

A rare presentation of Pompe disease with massive hypertrophic cardiomyopathy at birth.

We report a term infant with Pompe disease presenting in the immediate newborn period. The infant was born at 40 weeks' gestation, weighing 3600 g to a 32 year-old black female. Infant presented at delivery with massive hypertrophic cardiomyopathy and pulmonary hypertension. Diagnosis was confirmed by low alpha-glucosidase activity. The histopathology and electron microscopic findings were consistent with Pompe disease. This is the second reported case of Pompe disease presenting at delivery.