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.

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.

Calculation of left ventricular diastolic time constant(Tau) in dogs with aortic regurgitation using continuous-wave Doppler spectra

OBJECTIVE To investigate a new noninvasive method for calculating left ventricular diastolic time constant(Tau) through a continuous-wave aortic regurgitation Doppler spectrum.METHODS According to ultrasound guidance, twenty-four animal models(beagles) of aortic regurgitation and acute ischemic left ventricular diastolic dysfunction were created. The left ventricular diastolic function was manipulated with dobutamine or esmolol and fifty-nine hemodynamic stages were achieved. Raw audio signals of the continuous-wave Doppler spectra were collected, and new aortic regurgitation Doppler spectra were built after reprocessing by a personal computer. The updating time of the spectral line was 0.3 ms. The new Doppler spectra contour line was automated using MATLAB(MATrix LABoratory, MathWorks, Natick, MA, USA), and two time intervals,(t2–t1) and(t3–t1) were measured on the ascending branch of the aortic regurgitation Doppler spectrum. Then, the two time intervals were substituted into Bai's equations, and Doppler-derived Tau(Tau-D)was resolved and compared with catheter-derived Tau(Tau-c).RESULTS There is no significant difference between Tau-D and Tau-c(45.95 ± 16.90 ms and 46.81 ± 17.31 ms, respectively;P >0.05). Correlation analysis between Tau-c and Tau-D suggested a strong positive relationship(r = 0.97, P = 0.000). A Bland-Altman plot of Tau-c and Tau-D revealed fair agreement.CONCLUSIONS This new calculation method is simple, convenient, and shows a strong positive relationship and fair agreement with the catheter method.

The Hidden Value of Assessing Right Ventricular Performance with Exercise in Hypertensive Patients with Left Ventricular Diastolic Dysfunction

Background: Right ventricular (RV) dysfunction could develop during exercise in patients with both hypertension and left ventricular diastolic dysfunction and may contribute to the patient symptoms. The objective is to assess RV function, both at rest and during exercise in patients with hypertension and left ventricular diastolic dysfunction. Methods: We included 30 patients with hypertension and resting LV diastolic dysfunction. The systolic function of the right ventricle was assessed by TAPSE (Tricuspid Annular Plane Systolic Excursion) and S, while E/A ratio, annular lateral E’, E/E’ and E’/A’ were used to measure diastolic function. The global function of the right ventricle was assessed by measuring the right indexed myocardial performance. The dimensions and pulmonary pressures were also measured. Results: The following parameters of RV systolic function were increased significantly with exercise: TAPSE (P = 0.0054), S’ (P = 0.0045). Moreover, the following diastolic parameters of the RV increased significantly with exercise: E/E’ (P = 0.05), A’ (P = 0.04). The global RV function showed also a significant increase (P = 0.0011). The three RV dimensions as well as the pulmonary artery pressures also increased during exercise (P = 0.000004, 0.001, and 0.00000064 respectively). In addition, the presence of resting LV grade II DD predicted significantly higher pulmonary pressures during exercise (P = 0.006). The advanced resting grade of LVDD predicted significantly the presence of advanced grade of RVDD with exercise (P = 0.037). Conclusions: Some patients who have both hypertension and LV diastolic dysfunction showed structural and functional changes of the right ventricle at rest. However, all patients had RV functional changes during exercise.

Prognostic value of the echocardiographic right/left ventricular end-diastolic diameter ratio in patients with idiopathic pulmonary arterial hypertension

Background Previous studies have shown that an echocardiographic right/left ventricular end-diastolic diameter ratio(RV/LV ratio)≥0.9 is an independent predictor of poor prognosis in patients with acute pulmonary embolism. The prognostic value of the RV/LV ratio in patients with idiopathic pulmonary arterial hypertension(IPAH) is still unknown. Methods We retrospectively enrolled 95 consecutive patients with newly diagnosed IPAH and 16 of them were reevaluated by echocardiography at 3-12 months following targeted therapy.Follow-up data were obtained by telephone interviews and review of the patients’ records.Results The RV/LV ratio was in parallel with the severity of World Health Orgnization(WHO) functional class and mean right atrial pressure.The RV/LV ratio was positively correlated with total pulmonary resistance(P P P 2 saturation(P P = 0.001),weight and absence of targeted therapy were independent predictors of death.No significant changes in the RV/LV ratio before and after targeted therapy were observed. A baseline RV/LV ratio≥0.84 or a further increase in the RV/LV ratio during targeted therapy indicated a poor prognosis. Conclusions The RV/LV ratio helps to assess the severity of IPAH and serves as an independent predictor of prognosis in patients with IPAH.

Preliminary Clinical Study of Real-time Three-dimensional Echo-cardiographic Volume-time Curve in Evaluating Left Ventricular Diastolic Function

The volume-time curve change in patients with normal left ventricular （LV） diastolic function and diastolic dysfunction was evaluated by real-time three-dimensional echocardiography （RT3DE）. LV diastolic dysfunction was defined by E＇〈A＇ in pulse-wave tissue Doppler for inter-ventricular septal （IVS） of mitral annulus. In 24 patients with LV diastolic dysfunction, including 12 patients with delayed relaxation （delayed relaxation group） and 12 patients with pseudo-normal function （pseudo-normal group） and 24 normal volunteers （control group）, data of full-volume image were acquired by real-time three-dimensional echocardiography and subjected to volume-time curve analysis. EDV （end-diastolic volume）, ESV （end-systolic volume）, LVEF （left ventricular ejection fraction）, PER （peak ejection rate）, PFR （peak filling rate） from RT3DE were examined in the three groups. Compared to the control group, PFR （diastolic filling index of RT3DE） was significantly reduced in the delayed relaxation group and pseudo-normal group （P〈0.05）. There were no significant differences in EDV, ESV, LVEE PER （P〉0.05）. It is concluded that PFR, as a diastolic filling index of RT3DE, can reflect the early diastolic function and serve as a new non-invasive, quick and accurate tool for clinical assessment of LV diastolic function.

Effect of exercise on left and right ventricular ejection fraction and wallmotion in patients with coronary artery disease: an ultrafast computed tomography study

To measure the response of left and right ventricular ejection fraction and wall motion to exercise in eighteen patients with angiogl’aphically documented coronary artery disease (CAD) and in twenty-two patients with angiographicallynormal coronary arteries using ultrafast computed tomography(UFCT). Methods: Angiography and UFCT exercise cine studieswere performed for the evaluation of chest pain in all 40 cases, including 18 CAD patients and 22 patients with normal coronary arteries. Results: Of the 18 patients with CAD, 14(78% ) had a≥5% decrease in left ventricular ejection fraction (LVEF) duringexercise by UFCT (P< 0 .001), and 14 (78%) had an abnormal response in left ventricular wall motion during exercise, (aworsened or newly-developed reginal RV wall motion abnormality (RVWMA)) during exercise. In the 22 normal patients, onlyone had a decrease in LVEF > 5%; none had an abnormal response in LV wall motion during peak exercise or a RVWMA at restor during stress. Using a decrease of ≥5 % in LVEF or a LVWMA or RVWMA during stress as a criterion for identifying patientswith CAD, the accuracy was 88% (35/40) with LVEF, 90% (36/40) with LVWMA, and 92% (37/40) with a combination ofLVEF, LVWMA and RVWMA. The sensitivity of RVWMA alone in detecting right coronary artery disease (RCAD) was 60%(6/10) and the specificity was 78% (7/9). Conclusion: Our study suggests that exercise-UFCT appears to be a useful tool for thedetection of CAD in patients with chest pain. The abnormal response of LVEF and exercise-induced LVWMA and RVWMA as determined by UFCT were important predictors CAD. Both LVWMA and RVWMA of important value in identifying patientswith CAN from those with normal coronary arteries, as is RVWMA in defining the existence of RCAD in patients with CAD.

Real-time Three-dimensional Echocardiographic Assessment of Left Ventricular Remodeling Index in Patients with Hypertensive Heart Disease and Coronary Artery Disease

Left ventricular remodeling index （LVRI） was assessed in patients with hypertensive heart disease （HHD） and coronary artery disease （CAD） by real-time three-dimensional echocardiography （RT3DE）. RT3DE data of 18 patients with HHD, 20 patients with CAD and 22 normal controis （NC） were acquired. Left ventricular end-diastolic volume （EDV） and left ventricular end-diastolic epicardial volume （EDVepi） were detected by RT3DE and two-dimensional echocardiography Simpson biplane method （2DE）. LVRI （left ventricular mass/EDV） was calculated and compared. The results showed that LVRI measurements detected by RT3DE and 2DE showed significant differences inter-groups （P〈0.01）. There was no significant difference in NC group （P〉0.05）, but significant difference in HHD and CAD intra-group （P〈0.05）. There was good positive correlations between LVRI detected by RT3DE and 2DE in NC and HHD groups （t=0.69, P〈0.01; r=0.68, P〈0.01）, but no significant correlation in CAD group （r=0.30, P〉0.05）. It was concluded that LVRI derived from RT3DE as a new index for evaluating left ventricular remodeling can provide more superiority to LVRI derived from 2DE.

Simultaneous ramp right heart catheterization and echocardiography in a Reliant Heart left ventricular assist device

Many clinicians caring for patients with continuous flow left ventricular assist devices(CF-LVAD) use ramp right heart catheterization(RHC) studies to optimize pump speed and also to troubleshoot CF-LVAD malfunction. An investigational device,the Reliant Heart Heart Assist 5(Houston,TX),provides the added benefit of an ultrasonic flow probe on the outflow graft that directly measures flow through the CF-LVAD. We performed a simultaneous ramp RHC and echocardiogram on a patient who received the above CF-LVAD to optimize pump parameters and investigate elevated flow through the CF-LVAD as measured by the flow probe. We found that the patient's hemodynamics were optimized at their baseline pump speed,and that the measured cardiac output via the Fick principle was lower than that measured by the flow probe. Right heart catheterization may be useful to investigate discrepancies between flow measured by a CF-LVAD and a patient's clinical presentation,particularly in investigational devices where little clinical experience exists. More data is needed to elucidate the correlation between the flow measured by an ultrasonic probe and cardiac output as measured by RHC.

Left Ventricular Pseudoaneurysm Caused by a Left Ventricular Venting Catheter via the Right Superior Pulmonary Vein during Thoracic Aortic Surgery: A Case Report

A left ventricular (LV) pseudoaneurysm is one of the complications of acute myocardial infarction. It is also reported after chest trauma, cardiac surgery, and endocarditis. We report a rare case of an LV pseudoaneurysm induced by an LV venting catheter through the right superior pulmonary vein during thoracic aortic surgery. A 77-year-old man was referred for surgical repair of a distal aortic arch aneurysm. He underwent total aortic arch reconstruction with the frozen elephant trunk technique. The early postoperative period was uneventful. Postoperative contrast computed tomography and transthoracic echocardiography (TTE) revealed a pseudoaneurysm with a narrow neck at the apex of the LV that had sub-clinically progressed. Because of the risk of spontaneous rupture, an urgent aneurysmectomy was performed via a repeat sternotomy. Under cardioplegic arrest, the pseudoaneurysm was opened and the small orifice, which communicated with the LV, was confirmed. No myocardial ischemic changes were observed around the orifice. The pseudoaneurysm was thought to be induced by endocardial laceration by the tip of the venting catheter. The pseudoaneurysm was closed by linear repair reinforced with felt strips. The patient recovered well and was discharged 18 days after the second surgery. TTE showed no recurrence of LV aneurysm at the last follow-up.

A Case of Premature Ventricular Complexes from the Proximal Left Bundle Branch Successfully Ablated from the Right Coronary Cusp

Background:Premature ventricular complexes(PVCs)from the proximal left bundle branch(LBB)can be ablated in the left ventricular outflow tract but can easily damage normal conduction bundles.Here,we report a case of successful ablation of PVCs from the proximal LBB within the right coronary cusp(RCC).Case presentation:Our patient was a 70-year-old woman with PVCs from the proximal LBB that were successfully ablated via the RCC through radiofrequency catheter ablation with a 3D mapping system;she had a complication of incomplete right bundle branch block(RBBB)and remained asymptomatic during follow-up.Conclusion:The RCC provides an alternative approach for ablating PVCs originating from the proximal LBB,ow-ing to the close relationship between the RCC and proximal LBB.

Right Ventricular Failure Following Left Ventricular Assist Device Implantation

Left ventricular assist device (LVAD) is being used increasingly in recent years for end stage heart failure as a bridge to transplant (BTT) and also as a destination therapy (DT). Patients with end stage heart failure have some degree of elevated pulmonary capillary wedge pressure, causing right ventricular hypertrophy which in due course leads to decreased dilatation of the RV and fall in cardiac output & severe tricuspid regurgitation (TR) presenting with features of RV failure (RVF). Implantation of LVAD improves left heart function at the cost of right ventricular output with an incidence of 25%-30%. RVF may lead to impaired LVAD flow, difficulty in weaning from cardio-pulmonary bypass (CPB), decreased tissue perfusion and multi-organ failure. In this article we comprehended the pathophysiology leading to RVF post LVAD implantation and its preoperative predictors and the various treatment modalities for managing RVF post LVAD implantation.

A Heterozygous Phospholamban Variant(p.R14del)Leads to Left Ventricular Involvement and Heart Failure Phenotypes in Arrhythmogenic Right Ventricular Cardiomyopathy

This study aimed to determine the prevalence and clinical features of Arrhythmogenic Right Ventricular Cardiomyopathy(ARVC)caused by pathogenic mutations in the Phospholamban(PLN)gene.The study included 170 patients who had a confrmed diagnosis of ARVC and underwent PLN genetic screening using next-generation sequencing.The fndings of this study provide valuable insights into the association between PLN mutations and ARVC,which can aid in the development of more efective diagnostic and treatment strategies for ARVC patients.Out of the patients evaluated,six had a rare pathogenic mutation in PLN with the same p.R14del variant.Family screening revealed that heterozygous carriers of p.R14del exhibited a defnite ARVC phenotype.In clinical studies,individuals with the p.R14del mutation experienced a similar rate of malignant arrhythmia events as those with classic desmosome mutations.After adjusting for covariates,individuals with PLN mutations had a two point one seven times greater likelihood of experiencing transplant-related risks compared to those who did not possess PLN mutations(95%CI 1.08–6.82,p=0.035).The accumulation of left ventricular fat and fbers is a pathological marker for ARVC patients with p.R14del mutations.In a cohort of 170 Chinese ARVC patients,three point fve percent of probands had the PLN pathogenic variant(p.R14del)and all were female.Our data shows that PLN-related ARVC patients are at high risk for ventricular arrhythmias and heart failure,which requires clinical diferentiation from classic ARVC.Furthermore,carrying the p.R14del mutation can be an independent prognostic risk factor in ARVC patients.

Right ventricular septal pacing: Safety and efficacy in a long term follow up

AIM: To evaluate the safety and efficacy of the permanent high interventricular septal pacing in a long term follow up, as alternative to right ventricular apical pacing. METHODS: We retrospectively evaluated:(1) 244 patients(74 ± 8 years; 169 men, 75 women) implanted with a single(132 pts) or dual chamber(112 pts) pacemaker(PM) with ventricular screw-in lead placed at the right ventricular high septal parahisian site(SEPTAL pacing);(2) 22 patients with permanent pacemaker and low percentage of pacing(< 20%)(NO pacing);(3) 33 patients with high percentage(> 80%) right ventricular apical pacing(RVA). All patients had a narrow spontaneous QRS(101 ± 14 ms). We evaluated New York Heart Association(NYHA) class, quality of life(Qo L), 6 min walking test(6MWT) and left ventricular function(end-diastolic volume, LV-EDV; end-systolic volume, LVESV; ejection fraction, LV-EF) with 2D-echocardiography. RESULTS: Pacing parameters were stable duringfollow up(21 mo/patient). In SEPTAL pacing group we observed an improvement in NYHA class, Qo L score and 6MWT. While LV-EDV didn't significantly increase(104 ± 40 m L vs 100 ± 37 m L; P = 0.35), LV-ESV slightly increased(55 ± 31 m L vs 49 ± 27 m L; P = 0.05) and LV-EF slightly decreased(49% ± 11% vs 53% ± 11%; P = 0.001) but never falling < 45%. In the RVA pacing control group we observed a worsening of NYHA class and an important reduction of LV-EF(from 56% ± 6% to 43% ± 9%, P < 0.0001).CONCLUSION: Right ventricular permanent high septal pacing is safe and effective in a long term follow up evaluation; it could be a good alternative to the conventional RVA pacing in order to avoid its deleterious effects.

The Prevalence and Short-Term Outcomes of Ventricular Dyssynchrony after Right Ventricular Pacing

Objective: Long-term right ventricular pacing has been associated with an increased risk of heart failure and cardiomyopathy. The pathophysiology of cardiomyopathy associated with right ventricular pacing remains unclear. We aim to evaluate the burden and short-term outcomes of ventricular dyssynchrony after immediate permanent pacemaker implantation. Materials and Methods: This prospective cohort study examined consecutive patients who had permanent pacemaker implantation at Vajira Hospital in 2019. Left ventricular systolic function, specifically left ventricular ejection fraction (LVEF) and echocardiographic ventricular dyssynchrony parameters were assessed. The endpoints included the prevalence of ventricular dyssynchrony, new-onset cardiomyopathy, heart failure, and death. The correlation between QRS complex duration, the burden of ventricular pacing, and echocardiographic ventricular dyssynchrony was measured. Results: Thirty-six consecutive patients underwent pacemaker implantation. The prevalence of mechanical ventricular dyssynchrony was 22.2% using the interventricular conduction delay method, 41.7% using LV pre-ejection period method, and 11.1% using the septal posterior wall motion abnormality method. Electrical ventricular dyssynchrony was 86.1% and new-onset cardiomyopathy was 17.1% after 3 months of permanent pacemaker implantation. The right ventricular pacing of more than 20% was significantly associated with cardiomyopathy (p < 0.022) and heart failure (log-rank, p = 0.049) within 3 months. But heart failure was not associated with mechanical ventricular dyssynchrony parameters (log-rank, p = 0.610;hazard ratio [HR], 1.53;95% confidence interval [CI], 0.29 - 7.96;p = 0.613 for IVMD and log-rank, p = 0.398;HR, 0.04;95% CI, 0.01 - 3316.7 for SPWMD). Conclusion: Mechanical and electrical ventricular dyssynchrony are common findings in right ventricular pacing. High-burden right ventricular pacing after 3 months of permanent pacemaker implantation is often associated with cardiomyopathy and heart failure, but mechanical and electrical ventricular dyssynchrony does not predict a short-term decline in left ventricular systolic function and heart failure.

Ⅰ导联R/(R+S)对胸前V3导联移行流出道室性心律失常起源部位的鉴别价值

目的:探索鉴别胸前V3导联移行流出道室性心律失常(OT-VA)起源部位的体表心电图指标。方法:连续选择2017年1月至2022年8月行导管射频消融术的胸前V3导联移行OT-VA患者65例。比较左室流出道起源组(LVOT组)和右室流出道起源组(RVOT组)室性心律失常发作时体表心电图QRS波振幅及相关指标的差异,选择差异有统计学意义的指标,绘制ROC曲线评价所选取指标鉴别OT-VA起源部位的效能。结果:LVOT组11例,RVOT组54例,两组间差异有统计学意义且ROC曲线下面积(AUC)最大的指标为Ⅰ导联R波/(R+S)波振幅比[R/(R+S)],其鉴别OT-VA起源部位的AUC(95%CI)为0.949(0.894~1.000),截断值为0.50。Ⅰ导联R/(R+S)<0.50诊断胸前V3导联移行LVOT起源OT-VA的敏感度、特异度和准确度分别为0.909、0.944和0.938。结论:Ⅰ导联R/(R+S)<0.50可准确鉴别LVOT起源的胸前V3导联移行OT-VA。

Validation of real-time three-dimensional echocardiography for quantifying left and right ventricular volumes:an experimental study

Background Assessment of the left ventricular (LV) and the right ventricular (RV) volumes and their functions is important for prognostic prediction and clinical decision making. We compared the accuracy for quantifying the LV and the RV volumes in vitro between conventional two-dimensional echocardiography (2DE) and real-time three-dimensional echocardiography (RT3DE) Methods The volumes of 37 rubber-models (10 regularly shaped to simulate normal LV, 7 shaped to simulate LV with symmetric aneurysm, 8 shaped to simulate LV with asymmetric aneurysm, and 12 irregularly shaped to simulate normal RV) and 10 excised canine hearts were measured by RT3DE and 2DE On RT3DE 'full volume' imaging, the inner-surfaces of the rubber-models and canine LV and RV were outlined and the volumes were measured using 2-, 4-, 8- and 16-plane methods with the RT3DE analysis software On 2DE imaging, the volumes were measured by the Simpson method The LV and RV volumes measured by drained water were served as reference values, with which we compared RT3DE and 2DE data Results In rubber models mimicking normal LV and LV with symmetric aneurysms, RT3DE results were strongly correlated with reference values ( r =0 795-0 998) and there was a good correlation between 2DE estimates and reference values ( r =0 715-0 729) There were no significant differences between RT3DE estimates, 2DE results and reference values ( P >0 05) In rubber models mimicking the RV and LV with asymmetric aneurysm, RT3DE strongly correlated with reference values ( r =0 765-0 988), but 2DE weakly correlated with reference values ( r =0 518-0 592) There were no differences between RT3DE and reference values ( P >0 05), but a significant difference between 2DE and reference values occurred ( P <0 05) For excised canine hearts, there was a strong correlation between RT3DE and reference values ( r =0 728-0 914), while 2DE showed a less obvious correlation ( r =0 502-0 615) Again, there were no significant differences between RT3DE and reference values ( P >0 05), but there was a significant difference between 2DE and reference values ( P <0 05) Conclusions RT3DE can accurately quantify LV and RV volumes and provides a new tool to evaluate LV and RV function For LV and RV measurements by RT3DE, 8-plane strategy is the optimum choice for accuracy and convenience

Assessment of left ventricular systolic synchronicity by real-time three-dimensional echocardiography in patients with dilated cardiomyopathy

Background Recent advances in real-time three-dimensional echocardiography （RT3DE） offer the potential to assess the left ventricular （LV） dyssynchrony simultaneously by analyzing the 17 segments time-volume curves. The purpose of this study was to test the feasibility and accuracy of RT3DE for quantitative evaluation of left ventricular systolic synchronicity. Methods Twenty-four patients with dilated cardiomyopathy （DCM） and twenty-ftve healthy volunteers were enrolled in this study. Full volume RT3DE was performed by using Philips IE33 with X3-1 probe. The global and 17-segmental time-volume curves were obtained by the on-line Qlab software （version 4.2）. The time to minimal systolic volume in each segment （Tmsv） was taken to derive the following indexes of systolic asynchrony： Tmsv 16-SD, Tmsv 16-Dif, Tmsv 12-SD, Tmsv 12-Dif, Tmsv 6-SD and Tmsv 6-Dif, which meant the standard deviation or the maximal difference of Tmsv among the 16, 12 and 6 segments of the left ventricle respectively. The software also provided with each of the above parameters as a percentage of the cardiac cycle. Results Tmsv 16-SD, Tmsv 12-SD and Tmsv 6-SD were all significantly larger in the DCM group than those of the control group [Tmsv 16-SD： （52.9±40.6） ms vs （8.8±6.2） ms; Tmsv 12-SD： （29.5＋30.8） ms vs （6.9±4.0） ms; Tmsv 6-SD： （28.9±34.6） ms vs （7.0±4.7）ms, all P≤0.001]. Tmsv 16-Dif, Tmsv 12-Dif and Tmsv 6-Dif were also significantly larger in the DCM group. There were close negative relations between the LVEF determined by RT3DE and each of the indexes of systolic asynchrony, among which the indexes of Tmsv-16-SD% and Tmsv-16-Dif% correlated most closely （r=-0.703 and r=-0.701, respectively）. The DCM patients had significantly larger EDV and ESV, with significantly reduced LVEF compared with the healthy subjects. Conclusion RT3DE provides a simple, useful and unique approach to assess the systolic synchronicity of all the left ventricular segments simultaneously.

实时三维超声心动图及二维斑点追踪成像技术评估预激综合征患者左心室收缩同步性

目的:应用实时三维超声心动图(RT-3DE)及二维斑点追踪成像(2D-STI)技术评估预激综合征患者左心室收缩同步性临床应用价值。方法:选取芜湖市第二人民医院预激综合征患者35例为病例组,选取同期健康体检者35例为正常对照组。应用2D-STI计算左心室17节段圆周应变达峰时间标准差(Tcs-SD)、纵向应变达峰时间标准差(Tls-SD)、圆周应变率达峰时间标准差(Tcsr-SD)、纵向应变率达峰时间标准差(Tlsr-SD)参数水平值。应用RT-3DE记录左心室舒张末容积(LVEDV)、左心室收缩末容积(LVESV)、左心室射血分数(LVEF);分析17节段左心室容积-时间曲线(VTC),选取16节段最小收缩末容积时间差的标准差(Tmsv16-SD)、16节段最小收缩末容积时间差的最大时间差(Tmsv16-Dif)、校正后的16节段最小收缩末容积时间标准差(Tmsv16-SD%)、校正后的16节段最小收缩末容积时间最大时间差(Tmsv16-Dif%)进行同步记录分析。结果:①病例组Tcs-SD、Tls-SD、Tcsr-SD、Tlsr-SD均高于对照组(P<0.001)。②病例组LVEDV、LVESV均高于对照组(P<0.001),而两组间LVEF差异无统计学意义(P>0.05)。③病例组Tmsv16-SD、Tmsv16-Dif、Tmsv16-SD%、Tmsv16-Dif%水平均高于对照组(P<0.001)。结论:预激综合征患者左心室心肌存在收缩不同步运动,RT-3DE及2D-STI能够对预激综合征患者的左心室收缩功能进行量化,并且能够对其左心室收缩同步性进行有效评估。