Evaluation of Right Ventricular Volume and Systolic Function by Real-time Three-dimensional Echocardiography

The optimal plane for measurement of the right ventricular (RV) volumes by real-time three-dimensional echocardiography (RT3DE) was determined and the feasibility and accuracy of RT3DE in studying RV systolic function was assessed. RV “Full volume” images were acquired by RT3DE in 22 healthy subjects. RV end-diastolic volumes (RVEDV) and end-systolic volumes (RVESV) were outlined using apical biplane, 4-plane, 8-plane, 16-plane offline separately. RVSV and RVEF were calculated. Meanwhile tricuspid annual systolic excursion (TASE) was measured by M-mode echo. LVSV was outlined by 2-D echo according to the biplane Simpson's rule. The results showed: (1) There was a good correlation between RVSV measured from series planes and LVSV from 2-D echo (r=0.73; r=0.69; r=0.63; r=0.66, P<0.25—0.0025); (2) There were significant differences between RVEDV in biplane and those in 4-, 8-, 16-plane (P<0.001). There was also difference between RV volume in 4-plane and that in 8-plane (P<0.05), but there was no significant difference between RV volume in 8-plane and that in 16-plane (P>0.05); (3) Inter-observers and intro-observers variability analysis showed that there were close agreements and relations for RV volumes (r=0.986, P<0.001; r=0.93, P<0.001); (4) There was a significantly positive correlation of TASE to RVSV and RVEF from RT3DE (r=0.83; r=0.90). So RV volume measures with RT3DE are rapid, accurate and reproducible. In view of RV's complex shape, apical 8-plane method is better in clinical use. It may allow early detection of RV systolic function.

Left Ventricular Regional Systolic Function in Patient with Hypertrophic Cardiomyopathy by Quantitative Tissue Velocity Imaging

The left ventricular regional systolic functions in patients with hypertrophic cardiomyopathy （HCM） were assessed by using quantitative tissue velocity imaging （QTVI）. Left ventricular （LV） regional myocardial velocity along long- and short-axis in 31 HCM patients and 20 healthy subjects were analyzed by QTVI, and the regional myocardial systolic peak velocities （MVS） were measured. Mean MVS at each level including mitral annular, basal, middle and apical segments were calculated. The ratio of MVS along long-axis to that along short-axis （Ri） at basal and middle segments of the LV posterior wall and ventricular septum were calculated. The results showed that mean MVS was slower at each level including mitral annular, basal, middle and apical segments in the HCM patients than that in the healthy subjects （P〈0.01）. There were no significant differences in mean MVS between obstructive and non-obstructive groups in HCM patients. MVS of all regional myocardial segments along long-axis in the HCM patients were significantly slower than that in the healthy subjects （P〈0.05）, but there was no significant difference in MVS of all regional myocardial segments along long-axis between hypertrophied and non-hypertrophied group in the HCM patients. Ri was significantly lower in the HCM patients than that in the healthy subjects. The LV regional myocardial contractility along long-axis was impaired not only in the hypertrophied wall but also in the non-hypertrophied one in patients with HCM, suggesting that QTVI can assess accurately LV regional systolic function in patient with HCM and provides a novel means for an early diagnosis before and independent of hypertrophy.

Quantitative Assessment of Right Ventricular Systolic Function by the Analysis of Right Ventricular Contrast Time-intensity Curve

Summary: To study reliability and reliable indices of quantitative assessment of right ventricular systolic function by time-intensity curve (TIC) with right ventricular contrast, 5 % sonicated human albumin was injected intravenously at a does of 0.08 ml/kg into 10 dogs at baseline status and cardiac insufficiency. Apical four-chamber view was observed for washin and washout of contrast agent from right ventricle. The parameters of TIC were obtained by curve fitting. The differences of parameters were analyzed in different states of cardiac functions. Among the parameters derived from TIC, the time constant (k) was decreased significantly with decline of cardiac function (P<0.001). But half-time of decent of peak intensity (HT) and mean-transit-time (MTT) of washout were increased significantly (P<0.001). The k was strongly related to cardiac output of right ventricle (CO) and ejection fraction (EF) of left ventricle and fractional shortening (FS) of left ventricle. Right ventricular systolic function could be assessed reliably by the parameters derived from TIC with right ventricular contrast echocardiography. The k, HT and MTT are reliable indices for quantitative assessment of right ventricular systolic function.

A NUMERICAL MODEL OF LEFT VENTRICLE AND AORTIC VALVE FUNCTION OF ITS AFTERLOAD(Ⅰ)

Due to the study of the function of heart and aoritic valve, we set up a physicalmodel of left ventricle, aortic valve and afterload and derive theoretical equation of each part from the model. Then we calculate the hasic equations within phystology and impair parameters. Bwsed on this, we will discus fully in the next paper the effectofleyt ventricular afterloadon valve opining, ejection and valve Jumction .etc

Left ventricular systolic function assessment in patients with dilated heart failure using cardiovascular magnetic resonance

Cardiovascular magnetic resonance (CMR) has become a reference standard for the measure-ment of cardiac volumes, function, and mass. This study aims to reconstruct three dimen-sional modeling of the left ventricle (LV) in pa-tients with heart failure (HF) using CMRtools and thereby derive the LV functional indices. CMR images were acquired in 41 subjects (6 females) with heart failure (HF) and 12 normal controls (4 females). Five comparisons were made (i) nor-mal and dilated heart failure subjects, (ii) male and female normal heart, (iii) male and female dilated heart, (iv) male normal and dilated heart failure and (v) female normal and dilated heart failure. In HF, a significant higher values of EDV (320 刡 79 vs. 126 刡 22 ml, P&amp;amp;amp;amp;amp;lt;0.0001), ESV (255 刡 68 vs. 54 刡 12 ml, P&amp;amp;amp;amp;amp;lt;0.00001) and lower values of EF (20 刡 7 vs. 58 刡 5 %) were found compared that of normal control. There were significant difference on LV EDV and ESV between sex in both normal and HF subjects.

A very high frequency index of heart rate variability for evaluation of left ventricular systolic function and prognosis in chronic heart failure patients using five-minute electrocardiogram

Objective A novel index based on fi-equency-domain analysis of heart rate variability （HRV） was tested on patients with reduced left ventricular systolic function. This index, namely VHFI, was defined as the very high frequency （VHF） component of the power spectrum normalized to represent its relative value in proportion to the total power minus the very low frequency component. Methods Patients （n = 130） were divided into a study group, consisting 66 patients with decreased left ventricular systolic function, and a control group, consisting 64 patients with normal heart structure and function and without severe coronary artery stenosis （〈 50%）. Results VHFI in the study group was significantly higher than that in the control group （19.17 ± 13.35 vs 11.37 ± 10.77, P 〈 0.001）. Cardiac events occurred in 18 patients during follow-up （33.34 i 3.26 months）. Defining the positive test as VHFI =15 and negative test as VHFI 〈15, achieved a sensitivity of 57.58% and a specificity of78.13% for predicting decreased left ventricular systolic function, and achieved a sensitivity of 66.67% and a specificity of 64.29% for predicting cardiac events. Univariate Cox regression analysis showed that positive VHFI test was an independent variable in predictive cardiac events. Conclusions The results suggest that VHFI is a useful tool for quick evaluation of left ventricular systolic function and prediction of prognosis

MAX (dk/dt)──A NEW DOPPLER-DERIVED INDEX OF VENTRICULAR SYSTOLIC FUNCTION

Objective This study attempted to seek a new Doppler-derived index for estimating ventricularsystolic function. Methods With custom - made software the aortic and pulmonic flow profiles were digitized andconverted to their 4V2 curves, their maximum value of the first derivative, max (dk/dt) were obtained separately in23 and 25patients with congenital heart disease (mean age 4.5 years). Aortic max(dk/dt) and pulmonic max(dk/dt)measured by Doppler were compared with left ventricular max(dp/dt) and right ventricular max(dp/dt) measuredby cardiac catheterization. Results Aortic max(dk/dt) correlated well with LV max(dp/dt) (r=0.817, P<0.001).An excellent correlation of pulmonic max(dk/dt) with RV max(dp/dt) was established (r=0.926, P<0.0001). Therewas a significant correlation between RVSP and RV max(dp/dt) (r= 0.839, P<0.0001). Conclusion Doppler - derived aortic max(dk/dt) and pulmonic max(dk/dt) could be reliable index of left ventricular contractility and rightventricular contractility respectively. When max(dp/dt) is used for assessing RV systolic function, the impact ofRVSP on that should be taken into consideration.

Evaluation of the Effect of Sigmoid-Shaped Interventricular Septum on Left Ventricular Systolic Function in Patients with Essential Hypertension by Two-Dimensional Speckle Tracking Echocardiography

Objective: To evaluate left ventricular regional and global systolic function by measuring left ventricular longitudinal strain (LS) in hypertensive patients with sigmoid-shaped interventricular septum (SIS) by two-dimensional speckle tracking (2D-STE);in order to explore whether the sigmoid-shaped interventricular septum affects the left ventricular systolic function in patients with hypertension. Methods: Routine echocardiographic parameters were measured in 30 hypertensive patients with SIS (SIS group) and 30 hypertensive patients without SIS (non-SIS group). The left ventricular segments and global LS were measured by 2D-STE, and the two sets of parameters were compared. Results: The value of the thickness of the basal segment of the interventricular septum (IVSBT), the thickness of the middle segment of the interventricular septum (IVSMT) and the ratio of the basal segment of the ventricular septum to the middle segment of the interventricular septum (IVSBT/IVSMT) in SIS group was higher than that in non-SIS group. However, the value of left ventricular outflow tract diameter (LVOTD) in SIS group was lower than that in non-SIS group. There was a significant difference between the two groups (all P Conclusion: SIS affects left ventricular regional systolic function of patients with hypertension. 2D-STE can early evaluate left ventricular longitudinal systolic function in hypertensive patients with SIS.

Ultrasonic evaluation of fetal ventricular systolic function in hypertensive disorder complicating pregnancy and its correlation with the expression of placental hypoxia-related genes

Objective: To discuss the ultrasonic evaluation of fetal ventricular systolic function in hypertensive disorder complicating pregnancy and its correlation with the expression of placental hypoxia-related genes. Methods: A total of 98 late pregnant women with hypertensive disorder complicating pregnancy who were treated in the hospital between December 2014 and February 2017 were selected as hypertensive disorder complicating pregnancy group and 100 normal late pregnant women who received physical examination in the hospital during the same period were selected as normal control group. The ultrasonic parameters of fetal ventricular systolic function in two groups of pregnant women were detected before delivery, and the expression of hypoxia-related genes in placental tissue was detected by fluorescence quantitative PCR. Pearson test was used to assess the correlation between the parameters of fetal ventricular systolic function and placental hypoxia in hypertensive disorder complicating pregnancy. Results: The fetal left ventricular fractional shortening and right ventricular fractional shortening levels of hypertensive disorder complicating pregnancy group were lower than those of normal control group. Angiogenesis-related genes VEGF, netrin-1 and XIAP mRNA expression in placental tissue of hypertensive disorder complicating pregnancy group were lower than those in placental tissue of normal control group while HIF-1α mRNA expression was higher than that in placental tissue of normal control group;oxidative stress-related genes Nrf2, TAC3 and PrxⅡ mRNA expression in placental tissue were lower than those in placental tissue of normal control group;apoptosis genes Fas, p53 and caspase-9 mRNA expression in placental tissue were higher than those in placental tissue of normal control group while Bcl-2 and SFRP2 mRNA expression were lower than those in placental tissue of normal control group. Pearson test showed that the ultrasonic parameter levels of fetal ventricular systolic function in hypertensive disorder complicating pregnancy were directly correlated with the degree of placental hypoxia. Conclusion:Ultrasonic testing of fetal ventricular systolic function in hypertensive disorder complicating pregnancy can be used as a reliable method to measure the degree of placental hypoxia.

Left Ventricle Postinfarction Pseudoaneurysm: Anatomical Forms and Surgical Management

Introduction: Left Ventricle Postinfarction Pseudoaneurysm (LVPS)—false aneurysm occurs after a free-wall rupture contained by the adjacent pericardium. LVPS lacks the normal structure of the ventricular wall and disrupts the normal chamber anatomy. However, the natural history, clinical presentation and surgical outcome are still unclear. For that reason, it is necessary to describe the most relevant anatomical characteristics of LVPS and the appropriate surgical strategies currently applied. Methods: We reviewed the anatomical characteristics of several patients diagnosed of LVPS and the surgical technique performed. In this work two different anatomical types of LVPS are described in detail, with the surgical and structural implications for left ventricle reconstruction. Results: There are two different anatomical forms of LVPS: 1) Typical pseudoaneurysm, with a small gateway neck between the Left Ventricle and the false aneurysm chamber (Figure 1(A));2) Atypical pseudoaneurysm, in which the anatomical defect is bigger, without well-defined edges, extends over a large segment of infarcted and thinned myocardial tissue. In both cases, the therapeutics targets and the surgical techniques used were directed to restore the normal geometry of Left Ventricle, keeping the optimal mitral valve function. Conclusions: The surgical key-step is to preserve or to remodel the ventricular chamber anatomy. This fact restores the ventricular geometry, not only removing the wall discontinuity that generated the pseudoaneurysm. Nevertheless, final prognosis depends on the underlying ischemic cardiomyopathy and mechanical complications, such us mitral regurgitation or ventricular septal defect.

Evaluation of Sub Clinical Myocardial Systolic Dysfunction Using 2D Global Longitudinal Strain Assessment in Type 2 Diabetes Patients in Sub-Saharan Africa

Background: Heart failure is the commonest cardiovascular complication in type 2 diabetes mellitus. However, subclinical left ventricular dysfunction can’t be detected using 2D echocardiography which is routinely used for cardiac evaluation of diabetic patients. We aimed to determine the prevalence and factors associated to left ventricular global longitudinal strain (LV GLS) impairment in type 2 diabetes Cameroonians patients. Methods: We conducted a cross-sectional study from January 2019 to June 2019, including type 2 diabetes patients with preserved left ventricle ejection fraction. Clinical and echocardiographic data were collected, and LV GLS was assessed using speckle tracking technique, a value ≤ -16% been considered as normal value. Results: We recruited 95 patients, with a mean age of 57.4 ± 11.8 years old and median diabetes duration of 5 [2 - 12] years. Echocardiographic evaluation found 56.3% of left ventricle remodelling, 51.6% of left ventricle diastolic dysfunction and mean left ventricle ejection of 63.3% ± 6.6%. LV GLS impairment was present in 43.2% (95% CI: 32.6 - 53.7) of the participants. After adjustment to all significantly associated factors, Obesity (aOR: 4;95% CI: 1.5 - 10.6) and diastolic dysfunction (aOR: 3.1;95% CI: 1.2 - 8.2) were independent factors associated with LV GLS. Conclusions: Subclinical systolic dysfunction assessed by LV GLS impairment is frequent in diabetic patients. Further research should be carried out more extensively to integrate LV GLS in the type 2 diabetes patients’ routine follow up for a better prognostic outcome, especially in low-incomes countries.

BENEFICIAL EFFECTS OF NTG ON LEFT VENTRICULAR VOLUMES AND SYSTOLIC FUNCTION IN PATIENTS WITH MYOCARDIAL INFARCTION

The effect of sublingual administration and intravenous drip of nitroglycerin (SLNTG and IVNTG) on left ventricular volumes (LVVs) were studied and systolic function was quantitatively assessed with two-dimensional echocardiography (2DE) in 28 patients with myocardial infarction (MI), including 13 cases without heart failure (MI-NHF) in one group and 15 with heart failure (MI-HF) in another. The results showed that after SLNTG and IVNTG in both groups the heart rate (HR) increased significantly (P< 0.05-0.001); the systolic blood pressure (SBP) decreased significantly (P< 0.05-0.001); the diastolic blood pressure (DBP) was not significantly changed (all P>0.05); the left ventricular end-diastolic and end-systolic volumes (EDV and ESV) both significantly reduced [EDV: decreased by 5.8-11.6% (-13.2-19.0 ml), P< 0.05-0.001; ESV: decreased by 9.6-16.6% (-8.6-17.3 ml), P< 0.05-0.001)1; the left ventricular ejection fraction (LVEF) all significantly elevated (increased by 6.6%-9.4% (3.2%-3.4%), P < 0.05-0.001] except in MI-NHF group after IVNTG; the segmental EF of normal and hypokinetic segments also significantly increased (P<0.05-0.001). The results suggest that NTG could beneficially reduce left ventricular EDV and ESV; and improve or strengthen its global and segmental systolic function in MI patients, particularly noticeable in patients with heart failure.

Quantification of Regional Left Ventricular Systolic Dysfunction in Patients With Coronary Artery Disease by Strain Rate Imaging

Objectives To detect and compare the systolic strain rate (SR) and strain in the infarct and ischemic myocardium by strain rate imaging (SRI), in order to explore the clinical value of SRI in evaluating regional left ventricular systolic dysfunction. Methods Patients with coronary artery disease were divided into angina pectoris (11 cases) and myocardial infarction (21 cases) groups. Twenty age-matched normal subjects served as the control group. Septal, lateral, anterior, inferior, anteroseptal and posterior walls of the left ventricle were respectively scanned using color tissue Doppler imaging (TDI). Then SR and strain curves were derived from TDI for basal, middle and apical segments of each wall. SRI parameters were: Systolic SR (SRsys), systolic strain (εsys) and maximum strain (εmax). Results Compared with normal segments, SRsys, εsys and εmax decreased significantly in the infarct and ischemic segments (P<0.01). Compared with ischemic segments, SRsys, εsys and εmax decreased significantly in the infarct segments (P<0.05). Conclusions SRsys, εsys and εmax measured by SRI can be used to quantitatively analyze regional left ventricular systolic dysfunction in patients with coronary artery disease, and aid in differentiating infarct from ischemic myocardium.

Surgical outcomes of functional single ventricle with total anomalous pulmonary venous connection

Background The surgical outcomes have been greatly improved over the past four decades for functional single ventricle(FSV). However,the repair for coexistence of FSV and total anomalous pulmonary venous connection(TAPVC),especially obstructed TAPVC,has remained a clinical challenge. Little is known about the results of surgical treatment for patients with FSV-TAPVC in China. Methods Forty consecutive patients with FSV-TAPVC undergoing initial surgical palliation(median age:16.8 months;body weight:8.25 kg)were retrospectively enrolled from 2006 to 2016 in a specialized cardiovascular institute. TAPVC was repaired in 30 patients. The mean follow-up period was 49 months. Results All of the 7 patients with preoperative pulmonary vein obstruction(PVO)underwent repair of TAPVC at the first operation and survived. When a systemic to pulmonary(S-P)shunt or pulmonary artery banding(PAB)was necessary,patients with concomitant TAPVC repair had lower mortality(30.0%)and higher total cavopulmonary connection completion rate(20.0%)than those without TAPVC repair[75.0% and 0%,respectively],although with no statistical significance(Fisher test,P=0.505 and P=0.245). The overall survival rates for the cohort at 1,3 and 5 years after the initial surgical intervention were 80.0%,77.1% and 77.1%,respectively. Multivariate COX regression analysis detected that SP shunt(adjusted odds ratio:6.51;95%CI:1.26-33.71,P=0.030)is the only risk factor for survival. The reintervention rate for postoperative PVO was higher in patients with preoperative PVO than those without(57.1%vs. 4.3%,Log Rank:P=0.006). Conclusion The mid-term results of surgical repair of FSV-TAPVC are still challenging. When PVO exists,surgical repair for TAPVC is suggested as soon as possible. Repair for TAPVC should also be considered when S-P shunt or PAB is necessary. Further study with larger population are warranted to support our finding.

Atrioventricular valve replacement in functional singleventricle patients

Background This article summarized the experience of atrioventricular valve replacement operation for func- tional single ventricle patients whose atrioventricular valve was insufficiency. The follow-up time of operation was arranged from early- to medium- tenn. Methods From July 2009 to July 2015, there were 40 patients of functional single ventricle receiving the operation of atrioventricular valve replacement, including 23 male and 17 female patients. The age at A-V valve replacement was ranged from 6 days to 32 years （the medium age of 9 years）, and the body weight ranged from 2.7 to 57 kg （the medium body weight of 21.5 kg）. Moreover, the atrio- ventricular valve replacement was performed on all patients under extracorporeal circulation. Results Atrioven- tricular valve replacement was performed on 40 patients with function single ventricle in hospital, of which eight （20.0%） died in hospital including two neonate and infant （age range： 6 days-2 years old） accounting for 25% （2/ 8）, Among them, seven patients died of low cardiac output syndrome two patients with repeated hypoxemia con- current infection after operation, and one with bilateral diaphragmatic paralysis and malignant arrhythmia. For the patients suffering the severe perivalvular leakage, there was a reoperation, and the cardiac function before the first operation was class 1W. One patient received heart transplantation finally for severe heart failure after AV valve replacement. For the rest of patients, their cardiac function recovered to class I - lI after operation. Conclusions For function single ventricle patients with atrioventricular valve regurgitation, the mortality rate of atrioventricular valve replacement can be accepted if the operation was indicated. For patients with severe atrio- ventricular value regurgitation, the result of the operation in the early and medium term was satisfying. Thus, the atrioventricular valve replacement served as a useful treatment for patients diagnosed of A-V valve regurgitation and functional single ventricle.

Left Ventricular Longitudinal Systolic Function in Septic Shock Patients with Normal Ejection Fraction： A Case-control Study

Background： Septic cardiomyopathy is a common finding in septic shock patients. The accepted definition of septic cardiomyopathy is often based on the left ventricular ejection traction （LVEF）. The aim of this study was to determine whether the left ventricular longitudinal systolic function was more sensitive than the LVEF in heart function appraisal of septic shock patients. Methods： This was a case-control study conducted at a 40-bed Intensive Care Unit （ICU） of Peking Union Medical College Hospital. Septic shock patients admitted to the ICU were consecutively enrolled in the study group from March I, 2016 to September 1,2016. The control group was selected from nonsepsis patients who were admitted to the ICU and were comparable to the study group. Transthoracic echocardiography was perfon-ned to obtain the LVEF measurement, mitral annular plane systolic excursion （MAPSE）, tissue Doppler velocity measurement of mitral annulus （Sa）, and tricuspid annular plane systolic excursion. Results： The study group consisted ot＇45 septic shock patients. Another 45 nonsepsis patients were selected as the control group. There was no difference in the LVEF between the two groups （64.6% vs. 67.2%, t = -1.426, P ： 0.161 ）. MAPSE in the study group was much lower than in the control group （1.2 cm vs. 1.5 cm, t - -4.945, P 〈 0.001）. Sa in the study group was also lower than in the control group （I0.2 cm/s vs. I 1.8 cm/s, t -2.796, P = 0.014）. Conclusions： Compared to the LVEF, longitudinal systolic function might be more sensitive in the detection of cardiac depression in septic shock patients. In the heart function appraisal of septic shock patients with a normal ejection fraction, more attention should be given to longitudinal function parameters such as MAPSE and Sa.

Effects of Lead on Systolic and Diastolic Cardiac Functions

In this paper, both systolic and diastolic cardiac functions were cvaluatcd in 54 lead exposed and 24 non-exposed workers by Doppler cchocardiography. With regard to systolic cardiac function, the results suggested that cardiac systolic function increased in exposed groups as a compensatory response for the effecl of lead on myocardium. To study left ventriculaf diastolic function, 2.5 MHz pulsed Doppler analyses of transmitral flow velocity were performed from apical four-chamber view. The results showed that timerelated parameters were comparable among all groups, but blood flow velocity through the mitral valve and Doppler area fractions changed significantly in lead-exposed groups as cvidenced by increased value A, decreased value E and E/A ratio. The decrease of diastolic cardiac function was more significant in lead intoxication group. It was also observed in this study that the activity in serum of thc MB isoenzyme of creatine phosphokinase (CPK-MB), one of the indices of myocardial damage, was significantly highcr in exposed group than that in control (P (0.05), and a positive correlation was found between CPK-MB activity and Pb-B. It denoted that the inereasing of lead burden leads to more release of CPK-MB from the myocardial cells and suggested the existence of slight myocardial damage, which, conceivably, might cause harm to diastolic cardiac function

Effect of remimazolam vs. propofol on hemodynamics during general anesthesia induction in elderly patients: Single-center, randomized controlled trial

The current study aimed to compare the effects between remimazolam and propofol on hemodynamic stability during the induction of general anesthesia in elderly patients.We used propofol at a rate of 60 mg/(kg·h)in the propofol group(group P)or remimazolam at a rate of 6 mg/(kg·h)in the remimazolam group(group R)for the induction.A processed electroencephalogram was used to determine whether the induction was successful and when to stop the infusion of the study drug.We measured when patients entered the operating room(T_(0)),when the induction was successful(T_(1)),and when before(T_(2))and 5 min after successful endotracheal intubation(T_(3)).We found that mean arterial pressure(MAP)was lower at T_(1–3),compared with T_(0) in both groups,but higher at T_(2) in the group R,whileΔMAP_(T0–T2) andΔMAP_(max) were smaller in the group R(ΔMAP_(T0–T2):the difference between MAP at time point T_(0) and T_(2),ΔMAP_(max):the difference between MAP at time point T_(0) and the lowest value from T_(0) to T_(3)).Cardiac index and stroke volume index did not differ between groups,whereas systemic vascular resistance index was higher at T_(1–3) in the group R.These findings show that remimazolam,compared with propofol,better maintains hemodynamic stability during the induction,which may be attributed to its ability to better maintain systemic vascular resistance levels.

左室收缩功能评估的超声新方法:心肌做功

心肌做功是一种无创评估左室收缩功能的超声新方法,其通过整合左室整体长轴应变和无创左室收缩压来评估心肌收缩功能。心肌做功能在心血管疾病的早期阶段评估左室整体和局部收缩功能,随访患者病情进展情况以及预后。为了让超声医师更好地理解和应用这一超声新方法,本文就心肌做功的概念、参数、正常参考值及临床应用做一评述。

Deep learning echocardiographic intelligent model for evaluation on left ventricular regional wall motion abnormality

Objective To observe the value of deep learning echocardiographic intelligent model for evaluation on left ventricular(LV)regional wall motion abnormalities(RWMA).Methods Apical two-chamber,three-chamber and four-chamber views two-dimensional echocardiograms were obtained prospectively in 205 patients with coronary heart disease.The model for evaluating LV regional contractile function was constructed using a five-fold cross-validation method to automatically identify the presence of RWMA or not,and the performance of this model was assessed taken manual interpretation of RWMA as standards.Results Among 205 patients,RWMA was detected in totally 650 segments in 83 cases.LV myocardial segmentation model demonstrated good efficacy for delineation of LV myocardium.The average Dice similarity coefficient for LV myocardial segmentation results in the apical two-chamber,three-chamber and four-chamber views was 0.85,0.82 and 0.88,respectively.LV myocardial segmentation model accurately segmented LV myocardium in apical two-chamber,three-chamber and four-chamber views.The mean area under the curve(AUC)of RWMA identification model was 0.843±0.071,with sensitivity of(64.19±14.85)%,specificity of(89.44±7.31)%and accuracy of(85.22±4.37)%.Conclusion Deep learning echocardiographic intelligent model could be used to automatically evaluate LV regional contractile function,hence rapidly and accurately identifying RWMA.