Real Time Three-Dimensional Echocardiographic Evaluations of Fetal Left Ventricular Stroke Volume, Mass, and Myocardial Strain: In Vitro and In Vivo Experimental Study

Evaluation of right ventricular volume and systolic function in normal fetuses using intelligent spatiotemporal image correlation

BACKGROUND

Heart defects are the most common congenital malformations in fetuses. Fetal cardiac structure and function abnormalities lead to changes in ventricular volume. As ventricular volume is an important index for evaluating fetal cardiovascular development, an effective and reliable method for measuring fetal ventricular volume and cardiac function is necessary for accurate ultrasonic diagnosis and effective clinical treatment. The new intelligent spatiotemporal image correlation (iSTIC) technology acquires high-resolution volumetric images. In this study, the iSTIC technique was used to measure right ventricular volume and to evaluate right ventricular systolic function to provide a more accurate and convenient evaluation of fetal heart function.

AIM

To investigate the value of iSTIC in evaluating right ventricular volume and systolic function in normal fetuses.

METHODS

Between October 2014 and September 2015, a total of 123 pregnant women received prenatal ultrasound examinations in our hospital. iSTIC technology was used to acquire the entire fetal cardiac volume with off-line analysis using QLAB software. Cardiac systolic and diastolic phases were defined by opening of the atrioventricular valve and the subsequent closure of the atrioventricular valve. The volumetric data of the two phases were measured by manual tracking and summation of multiple slices and recording of the right ventricular end-systolic volume and the right ventricular end-diastolic volume. The data were used to calculate the right stroke volume, the right cardiac output, and the right ejection fraction. The correlations of changes between the above-mentioned indices and gestational age were analyzed. The right ventricular volumes of 30 randomly selected cases were measured twice by the same sonographer, and the intra-observer agreement measurements were calculated.

RESULTS

Among the 123 normal fetuses, the mean right ventricular end-diastolic volume increased from 0.99 ± 0.34 mL at 22 wk gestation to 3.69 ± 0.36 mL at 35⁺⁶ wk gestation. The mean right ventricular end-systolic volume increased from 0.43 ± 0.18 mL at 22 wk gestation to 1.36 ± 0.22 mL at 35⁺⁶ wk gestation. The mean right stroke volume increased from 0.62 ± 0.29 mL at 22 wk gestation to 2.33 ± 0.18 mL at 35⁺⁶ wk gestation. The mean right cardiac output increased from 92.23 ± 40.67 mL/min at 22 wk gestation to 335.83 ± 32.75 mL/min at 35⁺⁶ wk gestation. Right ventricular end-diastolic volume, right ventricular end-systolic volume, right stroke volume, and right cardiac output all increased with gestational age and the correlations were linear (P < 0.01). Right ejection fraction had no apparent correlation with gestational age (P > 0.05).

CONCLUSION

Fetal right ventricular volume can be quantitatively measured using iSTIC technology with relative ease and high repeatability. iSTIC technology is expected to provide a new method for clinical evaluation of fetal cardiac function.

Four-Dimensional Ultrasound for Evaluating Newborn Cardiac Output: A Pilot Study of Healthy Infants

BACKGROUND

There is currently no reliable non-invasive method of measuring cardiac output in neonatal intensive care. Spatiotemporal image correlation (STIC) is a novel four-dimensional (4D) ultrasound technique that was developed to assess the foetal heart, and it may be a useful way to assess neonatal haemodynamics.

OBJECTIVE

This study aimed to evaluate the feasibility and reproducibility of determining neonatal cardiac output using STIC ultrasound in newborn infants.

DESIGN

Infants were recruited opportunistically from a neonatal intensive care unit and then examined by 2 independent observers. STIC was used to obtain images of the heart. End-diastolic and end-systolic ventricular volumes were measured using virtual organ computer-aided analysis (VOCAL) and used to calculate cardiac output. Reproducibility was assessed with intraclass correlation coefficients (ICC) and agreement with Bland-Altman analysis.

RESULTS

Twenty-four clinically stable infants of 34-43 weeks corrected gestational age were assessed. Both observers successfully acquired 4D STIC volumes in all infants. Left ventricular output showed good reproducibility, with an intra-observer ICC of 0.86 (0.69-0.94) and inter-observer ICC of 0.87 (0.70-0.95). Right ventricular output also showed good reproducibility, with an intra-observer ICC of 0.88 (0.70-95) and inter-observer ICC of 0.84 (0.63-0.93).

CONCLUSIONS

Determining cardiac output using 4D STIC ultrasound is feasible and reproducible in well newborn infants. With further evaluation, this technique may provide valuable information about haemodynamic status in newborn infants requiring intensive care.

Relationship between left ventricular diastolic dyssynchrony and systolic dyssynchrony in hypertrophic cardiomyopathy by single-cardiac real-time three-dimensional ultrasonography

The relationship between left ventricular diastolic and systolic dyssynchrony in hypertrophic cardiomyopathy (HCM) was investigated by single-cardiac real-time three-dimensional ultrasonography. A total of 52 patients with HCM were selected in Jining No. 1 People's Hospital from July 2016 to June 2017. Additionally, a total of 52 healthy people were selected to serve as the control group. All participants received real-time two- and three-dimensional ultrasonography to evaluate left ventricular morphology, function and systolic and diastolic function. The relevant parameters included left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular ejection fraction (LVEF), end-systolic/diastolic sphericity index (ESSI/EDSI), systolic dyssynchrony index (SDI), diastolic dyssynchrony index (DDI), dispersion end systole (DISPES), diastolic dyssynchrony index-late (DDI-late) and dispersion end diastole (DISPED-late). The LVEF of observation group was significantly lower than that of the control group, while LVEDV, LVESV, E/A and E/Ea were significantly higher than those in control group (P<0.05); EDSI, DDI-late and DISPED-late were significantly higher in observation than in control group (P<0.05); ESSI, SDI and DISPES in observation were significantly higher than those in control group (P<0.05); The 16-segment time-volume curve of observation group was disordered without synchronization, while the curve of control group was regular and smooth with synchronization; Pearson's correlation analysis showed that SDI and DDI were positively correlated (P<0.05). In conclusion, three-dimensional ultrasonography can be used to effectively evaluate left ventricular diastolic and systolic dyssynchrony in HCM. The severity of diastolic is positively correlated with systolic dyssynchrony.

Assessment of left ventricular function in chronic alcoholics by real-time three-dimensional echocardiography

Chronic alcohol consumption may lead to progressive cardiac dysfunction. The aim of this study was to evaluate the feasibility of using real-time 3-dimensional echocardiography (3DE) on assessing left ventricular (LV) function in chronic alcoholics.We classified 92 male alcoholics into mild, moderate, and severe groups; 30 age-matched controls were also recruited. LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), LV ejection fraction (LVEF), LV mass (LVM), LV mass index (LVMI), and systolic dyssynchrony index (SDI) were measured by 3DE and 2-dimensional echocardiography (2DE).Compared to the control group, LV volume and mass were higher in the moderate and severe alcoholic groups (P < 0.05). The severe alcoholic (symptomatic) group demonstrated decreased LVEF and increased SDI (detected by 3DE) (P < 0.05).Real-time 3DE can detect the increases of LV volumes and mass in asymptomatic alcoholics, and the changes of LVEF and systolic synchrony index in symptomatic alcoholics.

Cardiac Mechanics in Isolated Bicuspid Aortic Valve Disease With Normal Ejection Fraction: A Study of Various Valvular Lesion Types

Aortic stenosis (AS) and aortic regurgitation (AR) are associated with congenital isolated bicuspid aortic valve (BAV) disease. The chronic pressure overload of AS and the volume overload of AR are known to impair the left ventricular function. This study assessed whether two-dimensional speckle tracking echocardiography (2D-STE) is capable of detecting the myocardial dysfunction associated with BAV caused by various aortic valve lesions in patients retaining normal ejection fraction (EF).Thirty-two isolated BAV patients and 20 healthy tricuspid aortic valve (TAV) volunteers were recruited. BAV patients were divided into 4 subgroups based on aortic valvular lesion types: normal function (NF) group, isolated AS group, isolated AR group, and a group who had both AS&AR. Myocardial strain and degree of twist were analyzed and compared between the BAV and TAV groups, as well as between valvular lesion groups and the NF group.Compared with healthy TAV controls, global radial strain (GRS), global circumferential strain (GCS), global longitudinal strain (GLS), and twist angle absolute values were lower in the BAV group (P < 0.05). The AS, AR, and AS&AR groups all demonstrated a significant decrease in GRS and GCS when compared with the TAV group. The AS and AS&AR groups demonstrated lower GLS than the TAV group, and the smallest degree of twist was detected in the AR group. There were no significant differences between the NF and TAV groups. The AR and AS&AR groups demonstrated significant differences in multiple parameters of cardiac mechanics compared with the NF group.2D-STE is able to detect altered cardiac mechanics associated with aortic lesion types in BAV patients with normal EF compared with normal TAV controls, and so can provide valuable information for clinical decision-making.