Assessment of fetal intraventricular diastolic fluid dynamics using ultrasound vector flow mapping.

OBJECTIVE: The purpose of this study was to investigate the feasibility of visualizing and quantifying the normal pattern of vortex formation in the left ventricle (LV) and right ventricle (RV) of the fetal heart during diastole using vector flow mapping (VFM). METHODS: A total of 36 healthy fetuses in the second trimester (mean gestational age: 23 weeks, 2 days; range: 22-24 weeks) were enrolled in the study. Color Doppler signals were recorded in the four-chamber view to observe the phase of the diastolic vortices in the LV and RV. The vortex area and circulation were measured, and parameters such as intraventricular pressure difference (IVPD), intraventricular pressure gradient (IVPG), and average energy loss (EL_AVG) were evaluated at different diastolic phases, including isovolumic relaxation (D1), early diastole (D2), and late diastole (D3). RESULTS: Healthy second-trimester fetal vortex formations were observed in both the LV and RV at the end of diastole, with the vortices rotating in a clockwise direction towards the outflow tract. There were no significant differences in vortex area and circulation between the two ventricles (p > 0.05). However, significant differences were found in IVPD, IVPG, and EL_AVG among the diastolic phases (D1, D2, and D3) (p < 0.05). Trends in IVPD, IVPG, and EL_AVG during diastole (D1-D2-D3) revealed increasing IVPD and EL_AVG values, as well as decreasing IVPG values. Furthermore, during D3, the RV exhibited significantly higher IVPD, IVPG, and EL_AVG compared to the LV (p > 0.05). CONCLUSION: VFM is a valuable technique for analyzing the formation of vortices in the left and right ventricles during fetal diastole. The application of VFM technology has the potential to enhance the assessment of fetal cardiac parameters.

Assessment of left ventricular function in patients with type 2 diabetes mellitus by non-invasive myocardial work.

Background: Diabetes mellitus (DM) is a chronic disease that poses a serious risk of cardiovascular diseases. Therefore, early detection of impaired cardiac function with non-invasive myocardial imaging is critical for improving the prognosis of patients with DM. Purpose: This study aimed to assess the left ventricular (LV) function in patients with type 2 diabetes mellitus (T2DM) by non-invasive myocardial work technique. Materials and methods: In all, 67 patients with T2DM and 28 healthy controls were included and divided into a DM group and a control group. Two-dimensional dynamic images of apical three-chamber view, apical two-chamber view, and apical four-chamber view were collected from all subjects, consisting of at least three cardiac cycles. LV myocardial strain parameters, including global longitudinal strain (GLS) and peak strain dispersion (PSD), as well as myocardial work parameters, including global constructive work (GCW), global wasted work (GWW), global work index (GWI), and global work efficiency (GWE), were obtained and analyzed. Results: A total of 15 subjects were randomly selected to assess intra-observer and inter-observer consistency of myocardial work parameters and strain parameters, which showed excellent results (intra-class correlation coefficients: 0.856 - 0.983, P<0.001). Compared with the control group, the DM group showed significantly higher PSD (37.59 ± 17.18 ms vs. 27.72 ± 13.52 ms, P<0.05) and GWW (63.98 ± 43.63 mmHg% vs. 39.28 ± 25.67 mmHg%, P<0.05), and lower GWE (96.38 ± 2.02% vs. 97.72 ± 0.98%, P<0.001). Furthermore, the PSD was positively correlated with GWW (r = 0.565, P<0.001) and negatively correlated with GWE (r = -0.569, P<0.001). Conclusion: Uncoordinated LV myocardial strain, higher GWW, and lower GWE in patients with T2DM may serve as indicators for the early assessment of cardiac impairment in T2DM.

Assessment of left ventricular energy loss in patients with mild coronary artery stenosis by using vector flow mapping combined with exercise stress echocardiography.

OBJECTIVES: To evaluate the left ventricular energy loss (EL), energy loss reserve (EL-r), and energy loss reserve rate in patients with mild coronary artery stenosis by using vector flow mapping (VFM) combined with exercise stress echocardiography. METHODS: A total of 34 patients (case group) with mild coronary artery stenosis and 36 sex and age matched patients (control group) without coronary artery stenosis according to coronary angiogram were prospectively enrolled. The total energy loss (ELt), basal segment energy loss (ELb), middle segment energy loss (ELm), apical segment energy loss (ELa), energy loss reserve (EL-r), and energy loss reserve rate were recorded in the isovolumic systolic period (S1), rapid ejection period (S2), slow ejection period (S3), isovolumic diastolic period (D1), rapid filling period (D2), slow filling period (D3), and atrial contraction period (D4). RESULTS: Compared with the control group, some of the EL in the resting case group were higher; some of the EL in the case group were lower after exercise, and those during D1 ELb and D3 ELb were higher. Compared with the resting state, the total EL and the EL within the time segment in the control group were higher after exercise, except during D2 ELb. In the case group, except for during D1 ELt, ELb and D2 ELb, the total and segmental EL of each phase was mostly higher after exercise (p < .05). Compared with the control group, most of the EL-r and EL reserve rates in the case group were lower (p < .05). CONCLUSION: The EL, EL-r, and energy loss reserve rate have a certain value in the evaluation of cardiac function in patients with mild coronary artery stenosis.

[Assessment of carotid plaque rotation angle using ultrasonic imaging].

OBJECTIVE: To demonstrate the abnormal intima rotation pattern of the carotid atherosclerosis plaque using velocity vector imaging, and to develop a new method for the clinical mechanical state assessment of the plaque intima. METHODS: The rotation movement and rotation angle on the serial dynamic ultrasonic short-axis gray scale views of 48 isolated atherosclerosis plaques (i. e., upstream, midstream, and downstream) and nearby reference segments of carotid artery in 46 patients were derived and analyzed using a dedicated velocity vector imaging workstation. The incidence of intima rotation movement and the rotation angle at different sections of the plaque and nearby reference segments before and after the standard grip stress test during systole and diastole respectively were counted and measured. RESULTS: Before and after the stress test, the intima rotation movement occurred at the majority of the short-axis sections of the plaque and the nearby reference segments during cardiac cycle. Before the stress test, the incidence of intima rotation movement at the upstream section of the plaque during systole was significantly higher than that of reference segment (P = 0.036) The reversal direction of the intima rotation at those sections and reference segment during systole and diastole was demonstrated. After the stress test, the incidence of intima rotation movement at the midstream section of the plaque during diastole was significantly lower than that of reference segment (P = 0.031). The incidence of the intima rotation movement changed at the sections of upstream, midstream, and downstream of the plaque before and after the stress test also were explored (i. e., increased in systole and decreased in diastole) except the reference segment intima. CONCLUSIONS: The intima rotation movement occurs at the majority of the isolated plaque and nearby reference segment, and the incidences of the intima rotation movement at the plaque is different from that of the reference segment during systole and diastole respectively. The abnormal pattern of intima rotation movement may be used to indicate the unstable mechanical state of the isolated plaque intima.