B-flow/spatiotemporal image correlation M-mode ultrasound provides novel method to quantify spiral artery remodeling during normal human pregnancy.

OBJECTIVES: During human pregnancy, placental extravillous trophoblasts replace vascular smooth muscle and elastic tissue within the walls of the uterine spiral arteries, thereby remodeling them into distensible low-resistance vessels to promote placental perfusion. The present study determined whether B-flow/spatiotemporal image correlation (STIC) M-mode ultrasonography provides an in-vivo imaging method able to digitally quantify spiral artery luminal distensibility as a physiological index of spiral artery remodeling during the advancing stages of normal human pregnancy. METHODS: A prospective, longitudinal, observational study was conducted to quantify spiral artery distensibility (i.e. vessel luminal diameter at systole minus diameter at diastole) by B-flow/STIC M-mode ultrasonography during the first, second and third trimesters in 290 women exhibiting a normal pregnancy. Maternal serum levels of placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1), growth factors that modulate important events in spiral artery remodeling, were quantified in a subset of the women in the first, second and third trimesters of pregnancy. RESULTS: Median (interquartile range (IQR)) spiral artery distensibility increased progressively between the first (0.17 (0.14-0.21) cm), second (0.23 (0.18-0.28) cm) and third (0.26 (0.21-0.35) cm) trimesters of pregnancy (P < 0.0001 for all). Median (IQR) spiral artery volume flow increased progressively between the first (2.49 (1.38-4.99) mL/cardiac cycle), second (3.86 (2.06-6.91) mL/cardiac cycle) and third (7.79 (3.83-14.98) mL/cardiac cycle) trimesters (P < 0.001 for all). In accordance with the elevation in spiral artery distensibility, the median (IQR) ratio of serum PlGF/sFlt-1 × 103 levels increased between the first (7.2 (4.5-10.0)), second (22.7 (18.6-42.2)) and third (56.2 (41.9-92.5)) trimesters (P < 0.001 for all). CONCLUSIONS: The present study shows that B-flow/STIC M-mode ultrasonography provides an in-vivo imaging technology to quantify digitally the structural and physiological expansion of the walls of the spiral arteries during the cardiac cycle as a consequence of their transformation into compliant vessels during advancing stages of normal human pregnancy. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Assessment of fetal cardiac function in pregnant women with anemia: prospective case-control study.

OBJECTIVE: To compare fetal cardiac function in pregnant women with iron deficiency anemia (IDA) vs healthy pregnant controls. METHODS: This was a single-center, prospective, case-control study conducted in a tertiary hospital between November 2022 and September 2023. Women diagnosed with IDA who attended as outpatients at the pregnancy follow-up clinic at 30-34 weeks' gestation or who were hospitalized for intravenous iron treatment owing to profound anemia were included. The control group consisted of randomly selected gestational-age-matched pregnant women with no obstetric complications or comorbidities and who did not have anemia. Patients underwent two-dimensional imaging, followed by pulsed-wave Doppler and M-mode and tissue Doppler imaging (TDI) to evaluate fetal cardiac function. A fetal cardiac score was calculated using systolic, diastolic and global hemodynamic function parameters, and was compared between patients with IDA and those without. The fetal cardiac score was also assessed according to the severity of anemia in the IDA group. RESULTS: A total of 150 patients, comprising 50 patients with IDA and 100 healthy pregnant women at 30-34 weeks' gestation, were included in the study. Of the patients with IDA, 20 had mild, 18 had moderate and 12 had severe anemia. The fetal myocardial performance index and isovolumetric relaxation time were significantly higher in the IDA group compared with the control group (P < 0.0001 for both), while isovolumetric contraction time was similar. Among the fetal tricuspid and mitral valve diastolic parameters, the E, A and E/A values were significantly lower in the IDA group (P < 0.05 for all). Mitral (MAPSE) and tricuspid (TAPSE) annular plane systolic excursions were significantly lower in the IDA group (P < 0.05 for both). The IDA group also had significantly lower values for the TDI parameters mitral and tricuspid E', A', S' and E'/A' ratio and a significantly higher E/E' ratio (P < 0.05 for all). Among the IDA subgroups, a significant decrease was observed in the tricuspid and mitral A, E and E/A ratio in fetuses whose mothers had severe anemia (P = 0.001). M-mode Doppler analysis revealed significantly lower fetal TAPSE and MAPSE in the patient group with severe maternal anemia (P = 0.001 for both). According to the subgroup comparison of TDI findings, the fetuses of mothers with severe anemia had significantly lower tricuspid and mitral E', A', S' and E'/A' ratio values and a significantly higher E/E' ratio (P < 0.05 for all). The fetal cardiac score was significantly higher in the maternal IDA group compared with the control group (P < 0.001). A significant negative correlation was found between maternal hemoglobin level and fetal cardiac score (P < 0.001). CONCLUSIONS: We observed differences in fetal systolic and diastolic cardiac function in pregnancies with maternal IDA. Fetal cardiac function was affected more among patients with severe anemia. This study found an increased E/E' ratio in the fetuses of pregnant women with IDA, suggesting decreased fetal heart maturation. Prenatal fetal cardiac evaluation, especially in women with severe anemia, can facilitate a more seamless transition to the postnatal period for these newborns. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Tricuspid Annular Plane Systolic Excursion (TAPSE) for the Assessment of Right Ventricular Function in Adult and Pediatric Cardiac Surgery: Modified Two-dimensional and M-mode TAPSE by Transesophageal Echocardiography Compared to M-mode TAPSE by Transthoracic Echocardiography.

OBJECTIVES: To compare transesophageal echocardiography-guided 2-dimensional and M-mode tricuspid annular plane systolic excursion (TAPSE) to transthoracic echocardiography (TTE)-guided M-mode TAPSE in terms of accuracy, interobserver, and intra-observer variability. DESIGN: A prospective, observational study. SETTING: Adult and pediatric operating rooms. PARTICIPANTS: Adult and pediatric patients (42 each) undergoing cardiac surgeries. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Modified midesophageal (Mod-ME), deep transgastric, and transgastric TAPSEs were analyzed for reliability and were compared to TTE TAPSE in both adult and pediatric groups. Modified ME TAPSE showed good method agreement with TTE TAPSE (bias = -0.97, p = 0.08 (adult); bias = 0.17, p = 0.71 [pediatric]), and showed a moderate correlation with right ventricular (RV) fractional area change (FAC) (r = 0.41, p = 0.006, [adult]; r = 0.57, p < 0.001, [pediatric]), with acceptable interobserver variability (percentage error =10.56 [adult]; 4.42 [pediatric]) and intraobserver variability (percentage error = 13.1 [adults]; 12.24 [pediatric]). Transgastric TAPSE poorly agreed with TTE TAPSE and had higher interobserver and intraobserver variability. Deep transgastric TAPSE had good method agreement with TTE TAPSE and had acceptable interobserver and intra-observer variability. CONCLUSIONS: Modified ME TAPSE is a reliable and reproducible measure of RV function before pericardiotomy in both adult and pediatric cardiac surgery. Right ventricular FAC values reflected the RV systolic function better than TAPSE after pericardiotomy. Deep transgastric TAPSE is reliable and reproducible but is less accurate than Mod-ME TAPSE.

The Importance of Tissue Doppler Imaging and M-Mode Ultrasonography in Fetuses With Preterm Premature Rupture of Membranes: A Case-Control Study.

OBJECTIVE: To compare the cardiac functions of fetuses with preterm premature rupture of membranes (PPROM) between their control groups and investigate its relationship with perinatal outcomes. METHODS: This prospective study was conducted with 102 pregnant women. Pregnant women with PPROM were divided into two subgroups Group A, between 26 and 30 weeks, and Group B, between 30 and 34 weeks. A control group was formed by randomly including one healthy pregnant woman for each study patient. Sociodemographic, obstetric data, tissue Doppler imaging, and M-mode imaging results were compared. The relationship between echocardiographic parameters and perinatal outcomes was also investigated. RESULTS: Tricuspid annular plane systolic excursion (TAPSE), S', and ET' of systolic cardiac parameters were shortened in both groups compared with their controls. Diastolic function indicator E'/A', and global function indicator myocardial performance index' increased in both groups. Isovolumetric contraction time' did not change between groups. A correlation was found between myocardial performance index', and the length of neonatal intensive care unit stay in Group A and TAPSE and duration of respiratory support and length of neonatal intensive care unit stay in Group B. CONCLUSIONS: The fetal cardiac function seems to be affected by PPROM, and these changes are associated with neonatal outcomes. Therefore, administering fetal cardiac function evaluation in pregnancies complicated by PPROM may help physicians establish more appropriate clinical management protocols in this special population.

Advancing Lung Ultrasound: The Development and Application of the Anatomical M-Mode Evaluation for Lung Swings (AMLES) Technique in Respiratory Assessment.

Exploring the frontiers of lung ultrasound, this document details a groundbreaking technique for lung function evaluation using anatomical M-mode, also known as angle-independent M-mode. The method, termed AMLES (Anatomical M-Mode Evaluation for Lung Swings), quantifies the displacement of the lung curtain observed at the bilateral costophrenic recesses. This approach translates lung curtain movements into graphical data, offering insights into respiratory mechanics and enhancing the assessment of lung ventilation in emergency settings.

The evaluation of fetal interventricular septum with M-mode and spectral tissue Doppler imaging in gestational diabetes mellitus: a case-control study.

OBJECTIVES: To demonstrate possible functional changes in the frequently affected fetal interventricular septum (IVS) with spectral tissue Doppler imaging (TDI) and M-mode imaging to compare gestational diabetes mellitus (GDM) and control groups. METHODS: A total of 63 pregnant women with GDM, 30 on diet (A1 GDM) and 33 on treated with insulin (A2 GDM), and 63 healthy pregnant women randomly selected and matched to the case group in the control group were included. RESULTS: The GDM fetuses had significantly thickened IVS, increased early diastole (E'), atrial contraction (A'), systole (S'), higher myocardial performance index (MPI'), prolonged isovolumetric relaxation time (IVRT'), shortened ejection time (ET'), and decreased septal annular plane systolic excursion (SAPSE) than the controls. The A2 GDM group fetuses had significantly thickened IVS, increased S' and shortened ET' than the A1 GDM group. In the GDM group, we found a significantly positive low correlation between glycated hemoglobin levels and maternal serum fasting glucose and one-hour postprandial glucose with fetal IVS thickness. We demonstrated a significantly negative low correlation between maternal serum one-hour postprandial glucose, glycated hemoglobin levels, and gestational weight gain with fetal IVS ET'. CONCLUSIONS: Fetal IVS diastolic and systolic functions were altered in the GDM group compared to controls, and systolic functions were altered in A2 GDM compared to A1 GDM. This may alert clinicians to possible cardiovascular diseases in the postnatal life, and early preventive strategies and long-term lifestyle changes may provide protection in fetuses with GDM.

Comprehensive ultrasound imaging of right ventricular remodeling under surgically induced pressure overload in mice.

This study reports a new methodology for right heart imaging by ultrasound in mice under right ventricular (RV) pressure overload. Pulmonary artery constriction (PAC) or sham surgeries were performed on C57BL/6 male mice at 8 wk of age. Ultrasound imaging was conducted at 2, 4, and 8 wk postsurgery using both classical and advanced ultrasound imaging modalities including electrocardiogram (ECG)-based kilohertz visualization, anatomical M-mode, and strain imaging. Based on pulsed Doppler, the PAC group demonstrated dramatically enhanced pressure gradient in the main pulmonary artery (MPA) as compared with the sham group. By the application of advanced imaging modalities in novel short-axis views of the ventricles, the PAC group demonstrated increased thickness of RV free wall, enlarged RV chamber, and reduced RV fractional shortening compared with the sham group. The PAC group also showed prolonged RV contraction, asynchronous interplay between RV and left ventricle (LV), and passive leftward motion of the interventricular septum (IVS) at early diastole. Consequently, the PAC group exhibited prolongation of LV isovolumic relaxation time, without change in LV wall thickness or systolic function. Significant correlations were found between the maximal pressure gradient in MPA measured by Doppler and the RV systolic pressure by catheterization, as well as the morphological and functional parameters of RV by ultrasound.NEW & NOTEWORTHY The established protocol overcomes the challenges in right heart imaging in mice, thoroughly elucidating the changes of RV, the dynamics of IVS, and the impact on LV and provides new insights into the pathophysiological mechanism of RV remodeling.

Effect of glycemic control on fetal hearts of pregestational diabetic women by tissue doppler and M-mode imaging.

OBJECTIVE: To determine whether changes in fetal heart function according to glycemic control in pregnant women with Type 1 and Type 2 diabetes using spectral tissue Doppler imaging (TDI) and M-mode imaging. METHODS: This study included 68 pregestational diabetic women (DM) at 30-32 gestational weeks. All participants were divided into two groups: type 1(n = 17) and type 2(n = 51), and then these groups were divided into the subgroups as well-controlled and poorly controlled, according to fasting glucose (FG) and 1-h postprandial glucose (PPG) values. Cardiac parameters were compared for well- and poorly-controlled groups with TDI and M-mode imaging. The correlation of cardiac parameters with FG, PPG, and HbA1c values was evaluated. Their roles in predicting neonatal outcomes were also assessed. RESULTS: Thickness measurements, early diastolic annular peak velocity (E'), late diastolic annular peak velocity (A'), tissue isovolumetric relaxation time (IRT'), and tissue myocardial performance index (MPI') were increased in both poorly controlled groups. Tissue ejection time (ET') was significantly reduced in the poorly controlled groups, while tissue isovolumetric contraction time (ICT') was not significantly changed in any group. Tricuspid, mitral, and septal annular plane excursions (TAPSE, MAPSE, and SAPSE, respectively) were significantly decreased in all poorly controlled subgroups. E', E'/A', MPI', IRT', ET', and M-mode imaging parameters significantly correlated with FG notably. CONCLUSION: Maternal hyperglycemia leads to subtle changes in systolic and diastolic functions both in the interventricular septum and ventricles, so it is essential to ensure glycemic control in both Type 1 and Type 2 DM.

Functional assessment of atrial wall excursion and foramen ovale flap tracings in 3rd trimester as predictor of short-term hemodynamic stability in congenital heart defects fetuses.

OBJECTIVES: Right atrium and left atrium of the fetal heart play a fundamental role in fetal heart circulatory physiology. METHODS: Excursion of fetal atria walls and tracings of foramen ovale (FO) flap movement were analyzed by M-mode echocardiography by new FO index to determine fetal and neonatal outcome in the first week and month of life in various congenital heart defects. The study group was divided into 3 subgroups: group A: neonates stable after birth (all on I.V. prostaglandin infusion) for at least 7 days, group B: neonates unstable after birth (despite I.V. prostaglandin infusion) requiring catheterization procedure or early cardiac surgery <6th day of life and group C: fetuses with in utero demise. RESULTS: The average values of FO index: group A - 32, group B - 20, group C - 12.Schaffe test showed statistical difference of FO index between group A and B (p=0.029) and group A and C (p=0.001), but no difference between group B and C (p=0.24) The FO index of stability was determined by ROC curve analysis. Cut-off point distinguishing between postnatal stability and postnatal instability + in utero demise constituted FO index=25 (specificity 82%; sensitivity 90%). CONCLUSIONS: Prenatal features of atrial M-mode echocardiography shortly before birth might be helpful to predict the short term prognosis of fetal hemodynamic stability or instability shortly after birth regardless of the type of congenital heart defects (CHD).

Echocardiographic measurements and cardiac anatomy in healthy Western hognose snakes (Heterodon nasicus).

This study aims to describe the most important cardiac structures in the Heterodon nasicus through echocardiography and anatomical dissection. Echocardiographic and echo-Doppler measurements were performed on twenty healthy adult Heterodon nasicus (10.10). The values of the ventricular length, aortic diameter, pulmonary trunk diameter, the mean thickness of the interventricular septum, and thicknesses of the wall of the cavum pulmonale (Cav. P) and cavum arteriosum (Cav. A), were measured. The aortic flow and pulmonary trunk flow were recorded. Two dead specimens (1.1) were dissected. The male's pulmonary trunk diameter was bigger compared to the female's in both the long and short axis. The reproductive ecology of Heterodon nasicus has yet to be fully elucidated upon, however, male territorialism and dispersal from the hibernacula, and multiple male courtships toward a single female were described, hence, the more active reproductive activity of the male and the consequent sexual selection toward a higher aerobic performance can be hypothesised. A moderate interventricular right to left shunt was noticed in the Cav. V of all the specimens, which is considered normal and should not confuse the clinician. Congenital defects, cardiomyopathies, valvulopathies, and pericardial diseases are known to occur in ophidians and other reptiles. Reliable data and profound knowledge of the anatomy and physiology of the ophidian heart are fundamental for the in vivo diagnosis of cardiac diseases in snakes.

B-flow/spatiotemporal image correlation M-mode: novel ultrasound method that detects decrease in spiral artery luminal diameter in first trimester in primate model of impaired spiral artery remodeling.

OBJECTIVE: To determine if B-flow/spatiotemporal image correlation (STIC) M-mode ultrasonography detects a decrease in spiral artery luminal diameter and volume flow during the first trimester in a non-human primate model of impaired spiral artery remodeling (SAR). METHODS: Pregnant baboons were treated daily with estradiol benzoate on days 25-59 of the first trimester (term, 184 days), or remained untreated. On day 60 of gestation, spiral artery luminal diameter (in seven untreated and 12 estradiol-treated baboons) and volume flow (in four untreated and eight estradiol-treated baboons) were quantified by B-flow/STIC M-mode ultrasonography. In addition, in 15 untreated and 18 estradiol-treated baboons, the percent of spiral arteries remodeled by extravillous trophoblasts was quantified ex vivo by immunohistochemical image analysis on placental basal plate tissue collected via Cesarean section on day 60. Findings were compared between treated and untreated animals. The correlation between spiral artery luminal diameter and percent of SAR was assessed in three untreated and six estradiol-treated baboons which underwent both B-flow/STIC M-mode ultrasound and quantification of SAR. RESULTS: The proportion of spiral arteries greater than 50 µm in diameter remodeled by extravillous trophoblasts was 70% lower in estradiol-treated baboons than in untreated animals (P = 0.000001). Spiral artery luminal diameter in systole and diastole, as quantified by B-flow/STIC M-mode in the first trimester of pregnancy, was 31% (P = 0.014) and 50% (P = 0.005) lower, respectively, and volume flow was 85% lower (P = 0.014), in SAR-suppressed baboons compared with untreated animals. There was a significant correlation between spiral artery luminal diameter as quantified by B-flow/STIC M-mode ultrasonography and the percent of SAR (P < 0.05). CONCLUSION: B-flow/STIC M-mode ultrasonography provides a novel real-time non-invasive method to detect a decrease in uterine spiral artery luminal diameter and volume flow during the cardiac cycle, reflecting decreased distensibility of the vessel wall, in the first trimester in a non-human primate model of defective SAR. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Passively scanned, single-fiber optical coherence tomography probes for gastrointestinal devices.

BACKGROUND/OBJECTIVES: Optical coherence tomography (OCT) uses low coherence interferometry to obtain depth-resolved tissue reflectivity profiles (M-mode) and transverse beam scanning to create images of two-dimensional tissue morphology (B-mode). Endoscopic OCT imaging probes typically employ proximal or distal mechanical beam scanning mechanisms that increase cost, complexity, and size. Here, we demonstrate in the gastrointestinal (GI) tracts of unsedated human patients, that a passive, single-fiber probe can be used to guide device placement, conduct device-tissue physical contact sensing, and obtain two-dimensional OCT images via M-to-B-mode conversion. MATERIALS AND METHODS: We designed and developed ultrasmall, manually scannable, side- and forward-viewing single fiber-optic probes that can capture M-mode OCT data. Side-viewing M-mode OCT probes were incorporated into brush biopsy devices designed to harvest the microbiome and forward-viewing M-mode OCT probes were integrated into devices that measure intestinal potential difference (IPD). The M-mode OCT probe-coupled devices were utilized in the GI tract in six unsedated patients in vivo. M-mode data were converted into B-mode images using an M-to-B-mode conversion algorithm. The effectiveness of physical contact sensing by the M-mode OCT probes was assessed by comparing the variances of the IPD values when the probe was in physical contact with the tissue versus when it was not. The capacity of forward- and side-viewing M-mode OCT probes to produce high-quality B-mode images was compared by computing the percentages of the M-to-B-mode images that showed close contact between the probe and the luminal surface. Passively scanned M-to-B-mode images were qualitatively compared to B-mode images obtained by mechanical scanning OCT tethered capsule endomicroscopy (TCE) imaging devices. RESULTS: The incorporation of M-mode OCT probes in these nonendoscopic GI devices safely and effectively enabled M-mode OCT imaging, facilitating real-time device placement guidance and contact sensing in vivo. Results showed that M-mode OCT contact sensing improved the variance of IPD measurements threefold and side-viewing probes increased M-to-B-mode image visibility by 10%. Images of the esophagus, stomach, and duodenum generated by the passively scanned probes and M-to-B-mode conversion were qualitatively superior to B-mode images obtained by mechanically scanning OCT TCE devices. CONCLUSION: These results show that passive, single optical fiber OCT probes can be effectively utilized for nonendoscopic device placement guidance, device contact sensing, and two-dimensional morphologic imaging in the human GI tract in vivo. Due to their small size, lower cost, and reduced complexity, these M-mode OCT probes may provide an easier avenue for the incorporation of OCT functionality into endoscopic/nonendoscopic devices.

Longitudinal functional assessment of atrial M-mode in dextro- transposition of the great arteries fetus may help to predict the necessity for urgent neonatal Rashkind procedure.

Six fetal echocardiographic examinations were analyzed and presented with special emphasis on atrial M-mode in one case of fetal isolated dextro- transposition of the great arteries. The only significant changes were seen based on analysis of the new index of foramen ovale (FO) flap movement. Emergency Rashkind procedure on the first day of postnatal life was predicted based on fetal atrial M-mode.

Ultrasound imaging of diaphragmatic motion.

The diaphragm is the key muscle of respiration, especially in infants. Diaphragmatic dysfunction and paralysis can have significant implications for medical management and treatment, and they can be challenging to diagnose by clinical parameters alone. Multiple imaging modalities are useful for assessing the diaphragm, but US - specifically M-mode US - offers several distinct advantages and few limitations compared to fluoroscopy, radiography, CT and MRI. The purpose of this manuscript is to discuss the pathophysiology of the diaphragm, review common indications for dynamic diaphragmatic US, describe optimal imaging technique, and discuss how to avoid imaging pitfalls.

Automated quantitative evaluation of fetal atrioventricular annular plane systolic excursion.

OBJECTIVES: The primary aim of this study was to evaluate the feasibility of automated measurement of fetal atrioventricular (AV) plane displacement (AVPD) over several cardiac cycles using myocardial velocity traces obtained by color tissue Doppler imaging (cTDI). The secondary objectives were to establish reference ranges for AVPD during the second half of normal pregnancy, to assess fetal AVPD in prolonged pregnancy in relation to adverse perinatal outcome and to evaluate AVPD in fetuses with a suspicion of intrauterine growth restriction (IUGR). METHODS: The population used to develop the reference ranges consisted of women with an uncomplicated singleton pregnancy at 18-42 weeks of gestation (n = 201). The prolonged-pregnancy group comprised women with an uncomplicated singleton pregnancy at ≥ 41 + 0 weeks of gestation (n = 107). The third study cohort comprised women with a singleton pregnancy and suspicion of IUGR, defined as an estimated fetal weight < 2.5th centile or an estimated fetal weight < 10th centile and umbilical artery pulsatility index > 97.5th centile (n = 35). Cineloops of the four-chamber view of the fetal heart were recorded using cTDI. Regions of interest were placed at the AV plane in the left and right ventricular walls and the interventricular septum, and myocardial velocity traces were integrated and analyzed using an automated algorithm developed in-house to obtain mitral (MAPSE), tricuspid (TAPSE) and septal (SAPSE) annular plane systolic excursion. Gestational-age specific reference ranges were constructed and normalized for cardiac size. The correlation between AVPD measurements obtained using cTDI and those obtained by anatomic M-mode were evaluated, and agreement between these two methods was assessed using Bland-Altman analysis. The mean Z-scores of fetal AVPD in the cohort of prolonged pregnancies were compared between cases with normal and those with adverse outcome using Mann-Whitney U-test. The mean Z-scores of fetal AVPD in IUGR fetuses were compared with those in the normal reference population using Mann-Whitney U-test. Inter- and intraobserver variability for acquisition of cTDI recordings and offline analysis was assessed by calculating coefficients of variation (CV) using the root mean square method. RESULTS: Fetal MAPSE, SAPSE and TAPSE increased with gestational age but did not change significantly when normalized for cardiac size. The fitted mean was highest for TAPSE throughout the second half of gestation, followed by SAPSE and MAPSE. There was a significant correlation between MAPSE (r = 0.64; P < 0.001), SAPSE (r = 0.72; P < 0.001) and TAPSE (r = 0.84; P < 0.001) measurements obtained by M-mode and those obtained by cTDI. The geometric means of ratios between AVPD measured by cTDI and by M-mode were 1.38 (95% limits of agreement (LoA), 0.84-2.25) for MAPSE, 1.00 (95% LoA, 0.72-1.40) for SAPSE and 1.20 (95% LoA, 0.92-1.57) for TAPSE. In the prolonged-pregnancy group, the mean ± SD Z-scores for MAPSE (0.14 ± 0.97), SAPSE (0.09 ± 1.02) and TAPSE (0.15 ± 0.90) did not show any significant difference compared to the reference ranges. Twenty-one of the 107 (19.6%) prolonged pregnancies had adverse perinatal outcome. The AVPD Z-scores were not significantly different between pregnancies with normal and those with adverse outcome in the prolonged-pregnancy cohort. The mean ± SD Z-scores for SAPSE (-0.62 ± 1.07; P = 0.006) and TAPSE (-0.60 ± 0.89; P = 0.002) were significantly lower in the IUGR group compared to those in the normal reference population, but the differences were not significant when the values were corrected for cardiac size. The interobserver CVs for the automated measurement of MAPSE, SAPSE and TAPSE were 28.1%, 17.7% and 15.3%, respectively, and the respective intraobserver CVs were 33.5%, 15.0% and 17.9%. CONCLUSIONS: This study showed that fetal AVPD can be measured automatically by integrating cTDI velocities over several cardiac cycles. Automated analysis of AVPD could potentially help gather larger datasets to facilitate use of machine-learning models to study fetal cardiac function. The gestational-age associated increase in AVPD is most likely a result of increasing cardiac size, as the AVPD normalized for cardiac size did not change significantly between 18 and 42 weeks. A decrease was seen in TAPSE and SAPSE in IUGR fetuses, but not after correction for cardiac size. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Right ventricular free wall contractility in subcostal views: A proof-of-concept study to assess right ventricular systolic function.

BACKGROUND: Normal right ventricular (RV) function has been traditionally assessed from the apical window. However, in several patients the subcostal window is the only available acoustic. METHODS: Given the intricate functional and mechanical inter-dependence between longitudinal tricuspid annular (TA) displacement and RV free wall contractility (RVFW), we studied the utility of RVFW inward motion using both M-mode and velocity with tissue Doppler imaging (TDI) from the subcostal transthoracic view. RESULTS: If a TAPSE value ≥ 2 cm is used to identify normal RV function, an RVFW M-mode value > .8 cm, TA TDI s' velocity > .06 cm/s and TA TDI e' velocity value > .05 cm/s identify normal RV systolic function. Furthermore, ROC curve analysis for the RVFW M-mode showed an area under the curve (AUC) of .753 (95% CI: .604-.868) with a cut-off value > .8, sensitivity 75% and specificity 73%; for TA TDI s' AUC at .822 (95% CI: .681-.919) with a cut-off value > .06, sensitivity 75% and specificity 77% and for TA TDI e' the AUC was .771 (95% CI: .624-.882) with a cut-off value > .05, sensitivity 90% and specificity 46%. Reproducibility of repeat RVFW M-mode, TDI s' and e' measurements was good with strong inter-rater agreement (Kappa > .8). CONCLUSIONS: The subcostal window appears useful for assessing RV systolic function. Additional studies are now required to prospectively use these measures in the routine evaluation of RV systolic function particularly in patients with suboptimal apical windows.

Tracheal, Lung, and Diaphragmatic Applications of M-Mode Ultrasonography in Anesthesiology and Critical Care.

Today, proficiency in cardiopulmonary ultrasound is considered essential for anesthesiologists and critical care physicians. Conventional 2-dimensional images, however, do not permit optimal characterization of specific conditions (eg, diaphragmatic paralysis, major atelectasis, and pneumothorax) that may have relevant clinical implications in critical care and perioperative settings. By contrast, M-mode (motion-based) ultrasonographic imaging modality offers the highest temporal resolution in ultrasonography; this modality, therefore, can provide important information in ultrasound-driven approaches performed by anesthesiologists and intensivists for diagnosis, monitoring, and procedural guidance. Despite its practicability, M-mode has been progressively abandoned in echocardiography and is often underused in lung and diaphragmatic ultrasound. This review describes contemporary applications of M-mode ultrasonography in the practice of critical care and perioperative medicine. Information presented for each clinical application includes image acquisition and interpretation, evidence-based clinical implications in critically ill and surgical patients, and main limitations. The article focuses on tracheal, lung, and diaphragmatic ultrasound. It reviews tracheal ultrasound for procedural guidance during endotracheal intubation, confirmation of correct tube placement, and detection of esophageal intubation; lung ultrasound for the confirmation of endotracheal and endobronchial (selective) intubation and for the diagnosis of pneumothorax, alveolar-interstitial syndrome (cardiogenic v noncardiogenic pulmonary edema), pulmonary consolidation (pneumonia v major atelectasis) and pleural effusion; and diaphragmatic ultrasound for the diagnosis of diaphragmatic dysfunction and prediction of extubation success.

Point-of-Care Echocardiography: A Useful Tool for Assessing Complex Arrhythmias in the Pediatric Intensive Care Unit.

OBJECTIVE: To demonstrate that the analysis of the atrioventricular, intraventricular, and interventricular asynchrony by point-of-care ultrasound (POCUS) could be an alternative tool for assessing complex arrhythmias in pediatric patients with congenital heart diseases, mainly when an epicardial register or electrophysiology study is not available. DESIGN: Descriptive, retrospective case series study. SETTING: The pediatric intensive care unit of a university-affiliated tertiary hospital in Spain. PATIENTS: The authors included 12 patients with congenital heart disease younger than 18 years admitted to the authors' pediatric intensive care unit (PICU) from January 2018 to December 2019, with complex arrhythmias after surgery, managed by performing a bedside echocardiography when an electrophysiology test or epicardial auriculogram was unavailable. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The authors included a total of 14 complex arrhythmias in 12 postsurgical patients in whom a comprehensive transthoracic electrocardiogram was not conclusive. The presence of atrioventricular, intraventricular, or interventricular asynchrony was assessed in standard echo views by performing M-mode and Doppler mitral inflow analysis, checking the heart motion. The final POCUS diagnoses were atrial flutter (n = 5), postsurgical atrioventricular block (n = 4), asynchrony induced by pacemaker (n = 2), junctional ectopic tachycardia (n = 1), nodal rhythm plus ventricular extrasystole (n = 1), and supraventricular tachycardia (n = 1). In all patients, regardless of the type of arrhythmia, detecting motion asynchrony was crucial for making the correct diagnosis. Offline cardiologist analysis of the POCUS scans showed full agreement. CONCLUSIONS: POCUS is a useful tool for initial diagnosis and management of complex arrhythmias in the PICU, mainly when epicardial auriculogram or electrophysiology studies are unavailable.

A Realistic and Inexpensive Ultrasound Phantom for Teaching M-Mode Measurement of Fetal Heart Rate.

BACKGROUND: M-mode ultrasound is frequently used to measure a fetal heart rate. Phantoms are used to simulate clinical conditions for teaching ultrasound-related skills. This is particularly important in the case of early pregnancy, when it is not ethical to use a live fetus in utero for teaching purposes. OBJECTIVES: To date, no phantom has been created to model the beating heart of an intrauterine pregnancy. Our goal was to create such a model for use in teaching M-mode ultrasound. MATERIALS AND METHODS: The phantom is constructed using a toy fish, several balloons, and water-absorbing gel crystals. RESULTS: We have created a novel phantom for use in teaching M-mode measurements. The cost per phantom is around $20 and the phantom can be constructed in about 20 min. CONCLUSION: This phantom is easily constructed and cost-effective. It gives learners the opportunity to practice measuring an intrauterine fetal heart rate in a learning environment without exposing a live fetus to unnecessary ultrasound.

Echocardiographic evidence of left ventricular untwisting-filling interplay.

BACKGROUND: Left ventricular untwisting generates an early diastolic intraventricular pressure gradient (DIVPG) than can be quantified by echocardiography. We sought to confirm the quantitative relationship between peak untwisting rate and peak DIVPG in a large adult population. METHODS: From our echocardiographic database, we retrieved all the echocardiograms with a normal left ventricular ejection fraction, for whom color Doppler M-Mode interrogation of mitral inflow was available, and left ventricular untwisting rate was measurable using speckle tracking. Standard indices of left ventricular early diastolic function were assessed by Doppler (peaks E, e' and Vp) and speckle tracking (peak strain rate Esr). Load dependency of DIVPG and untwisting rate was evaluated using a passive leg raising maneuver. RESULTS: We included 154 subjects, aged between 18 to 77 years old, 63% were male. Test-retest reliability for color Doppler-derived DIVPG measurements was good, the intraclass correlation coefficients were 0.97 [0.91-0.99] and 0.97 [0.67-0.99] for intra- and inter-observer reproducibility, respectively. Peak DIVPG was positively correlated with peak untwisting rate (r = 0.73, P <  0.001). On multivariate analysis, peak DIVPG was the only diastolic parameter that was independently associated with untwisting rate. Age and gender were the clinical predictive factors for peak untwisting rate, whereas only age was independently associated with peak DIVPG. Untwisting rate and DIVPG were both load-dependent, without affecting their relationship. CONCLUSIONS: Color Doppler-derived peak DIVPG was quantitatively and independently associated with peak untwisting rate. It thus provides a reliable flow-based index of early left ventricular diastolic function.