As a rapid prototyping technology,three-dimensional (3D) printing is widely used in diagnosis and treatment of cardiovascular diseases.There are variable methods of 3D printing,and different forming methods have their respective advantages and disadvantages.3D printing plays an important role in congenital heart disease,valvular heart disease,aorta disease and arrhythmia.The application and the research progresses of 3D printing based on medical imaging in diagnosis and treatment of cardiovascular diseases were reviewed in this article.

Objective To analyze cardiac function of patients with first onset acute myocardial infarction (AMI)by speckle tracking imaging (STI).With clinical data of long-term follow-up,to explored the prognostic value of left ventricular functional reservation and damage after AMI.Methods Seventy-eight patients with first onset AMI were enrolled in the study.Dynamic images were acquired before primary percutaneous coronary intervention for the analyses of longitudinal peak systolic strain (LPSS), radial peak systolic strain (RPSS)and circumferential peak systolic strain (CPSS).Clinical data of long-term follow-up,results of electrocardiogram and coronary angiography were used for the evaluation of the recurrence risk of cardiac events and cardiac death after AMI.All the baseline clinical data and parameters of echocardiography were compared between patients with and without cardiac events and cardiac death during follow-up.Results Baseline clinical data of electrocardiogram and coronary angiography didn't show significant differences for the comparison of AMI patients with and without cardiac events and cardiac death during long-term follow-up.Compared to patients without cardiac events during follow-up,LPSS and CPSS (P <0.001)of patients with cardiac events were relatively lower and the prognostic value of CPSS (HR=1 .4096)for the recurrence risk of cardiac events was better.For the risk prediction of cardiac death,LPSS ( P <0.001,HR=1.5735)was relatively better.Conclusions Left ventricular functional reservation and damage after AMI were accurately assessed by STI,which helped predicted the recurrence risk of cardiac events and cardiac death of AMI patients.CPSS and LPSS were optimal indicators for the prediction of cardiac events and cardiac death,respectively.

Objective To explore the value of echocardiography in percutaneous left atrial appendage (LAA)closure for stroke prevention in patients with nonvalvular atrial fibrillation during procedure and for short-term follow-up.Methods Twenty patients were enrolled to undergo percutaneous LAA closure with the LAmbre device.Rheumatic valvular diseases were excluded by transthoracic echocardiography (TTE) and transesophageal echocardiography(TEE)before the closure procedure.TEE was performed during the procedure for the trans-septal puncture and the release of the closure device.Combined TEE with angiographic measurements,guidance for the optimal device size was provided.The closure effect and procedure-related complications were observed immediately by TEE and also evaluated by TTE at 1-day and 1-month follow-up.Results All patients underwent LAA occlusion successfully.TEE color Doppler evaluation have shown nine patients with complete closure immediately,one with a ≤ 1 mm residual LAA leak,and ten with a 1 -3 mm jet.There were no other complications during the procedure.One day after the closure,small pericardial effusions were observed for three patients while two of the three were free of the pericardial effusion at the 1-month follow-up.During the short-term follow-up,no damage was found at any anatomical structures near LAA due to the closure process,and there was no significant difference of cardiac function before and after the procedure.Conclusions With the guidance of TEE,the successful rate of percutaneous LAA closure procedure was preferable and the occurrence rate of compliance was acceptable. And TTE played an important role in patients'short-term follow-up.

Objective To evaluate the right ventricular function in patients with congestive heart failure (CHF) after cardiac resynchronization therapy (CRT) by 2-dimensional speckle imaging (2D-STI).Methods 46 patients with CHF were divided into responders to CRT and non-responders to CRT according the standard of a decline in LV end-systolic volume ≥ 10％.All the patients received echocardiography examination 1-3 days before CRT and 6 month after CRT.Tissue Doppler imaging (TDI) indices included SD of time to peak velocity in systole (Ts-SD) among 12 segments.Right ventricular diameters included RV basal transverse diameter (D1),RV middle transverse diameter (D2) and RV longitudinal diameter (D3) in apical four views.2D-STI indices included systolic strain (S) and stain rate (SR) of basal or middle segment of RV free wall.Results Compared with before CRT,LVEDd,LVEDV,LVESV and Ts-SD significantly decreased,LVEF significantly increased in responders 6 months after CRT.Before CRT,compared with nonresponders,there was no significant difference of D1,D2 and D3 in responders,while S and SR in basal or middle segment of RV free wall were higher than non-responders.Compared with before CRT,D1,D2 and D3 in responders decreased significantly,S and SR in basal or middle segment of RV free wall increased significantly,while there was no difference in non-responders.There were significant negative correlation between S and SR in basal or middle segment of RV free wall and Ts-SD in responders.Conclusions The remodeling and systolic function of RV are improved after CRT.It may help for improving the efficacy of CRT when takes RV function data into account before CRT.

Objective To evaluate the value of selecting and locating coronary artery severe stenosis by the segmental longitudinal strain imaging diastolic indexes (LSI-DI).Methods 94 subjects with left ventricular ejection function (LVEF) ≥50％ and without regional wall motion abnormalities (RWMA) were divided into A group (coronary artery sever stenosis),B group (coronary artery light or mid stenosis) and C group (normal control) using coronary angiography.Some indexes were measured such as early diastolic mitral annulus velocity of septum (e),diastolic peak flow velocity of mitral valve (E,A) and E/e ratio.Using two-dimensional speckle tracking,indexes were measured such as segmental peak systolic longitudinal strain (PSLS),segmental longitudinal strain imaging diastolic indexes (LSI-DI) and global peak systolic longitudinal strain (GPSLS),global longitudinal strain imaging diastolic indexes (GLSI-DI).Compared these indexes among the three groups,the most valuabe segments were obtained and the optimal values were found out by ROC curve.Results There were no significant differences about GPSLS among the three groups.Coronary artery severe stenosis group were significantly lower than the other two groups on GLSI-DI (P ＜0.05);GLSI-DI of B group was lower than that of normal control group but the difference was not significant(P ＞0.05).The optimal cutoff values of LSI-DI were 45.5％ in the middle anteroseptal segment for detecting left anterior descending (LAD) artery severe stenosis (sensitivity 81.8％,specificity 84.2％),44.8％ in the basal anterolateral segment for detecting left circumflex (LCX) artery stenosis (sensitivity 87.3％,specificity 85.3％),and 48.3 ％ in the basal inferior segment for detecting right coronary (RCA) artery stenosis (sensitivity 79.6％,specificity 86.9 ％).Conclusions Patients with coronary artery severe stenosis can be screened by LSI-DI among patients with LVEF ≥50％ and without RWMA through conventional echocardiography.The middle anteroseptal segment,the basal anterolateral segment and the basal inferior segment can better locate the branches of coronary artery severe stenosis and the cutoff values were separately 45.5 ％,44.8 ％ and 48.3 ％.

Objective To measure left atrial appendage (LAA)in patients with atrial fibrillation using Flexi Slice imaging by real time 3D transesophageal echocardiography (TEE),and compare with common multiplane TEE.Methods Forty-six patients with atrial fibrillation were performed 2D and real time 3D TEE.Zero degree,45°,90° and 135° plane were acquired by 2D TEE and Flexi Slice remolding. Maximum and minimum values of ostium of left atrial appendage were acquired in the short axis view of LAA by Flexi Slice remolding.Results Compared with 2D TEE,values acquire by Flexi Slice in measurement of LAA ostium showed no significant difference(P >0.05).The depth measurement by Flexi Slicein 45° and 90° plane showed significant difference with 2D TEE (P-values were successively 0.045, 0.002),and in 0 and 135° plane showed no difference.All values measured by 2D TEE and Flexi Slices showed significant correlation.Bland-Altman plot showed that 94.29% of plots were among limits of agreement,which was (-2.5 mm,2.9 mm).The maximum values of LAA ostium values ranged from 30° to 160°,among which 87% (40/46 cases)distributed between 90° and 1 50°,and minimum values ranged from 0°to 160°,among which 85%(39/46 cases)distributed between 0°and 60°.Conclusions Measurement of LAA can be well achieved by Flexi Slice imaging,which showed significant advantage compared with 2D TEE.

Objective To evaluate left ventricular systolic synchronicity in patients with dilated cardiomyopathy by V-plane imaging and compare with clinical commonly used tissue Doppler imaging (TDI),evaluate the relevance and consistency between these two parameters.Methods 20 patients diagnosed with DCM and 20 healthy controls were enrolled,2D images,V-plane imaging and TDI waveform were acquired.Time to peak velocity of left ventricular 12 segments were measured by TDI and the standard deviation (TDI_SD) were calculated.Displacement time to peak were measured by V-plane and the standard deviation (V-plane_SD) were calculated.Results Compared with control group,TDI_SD and V-plane_SD increased significantly (P ＜ 0.01),TDI time to peak increased and V-plane time to peak decreased significantly(P ＜0.01).In the two group,12 segment time to peak measured by V-plane were significantly higher than TDI(P ＜ 0.01).There was a significant correlation between TDI_SD and V-plane_SD (r =0.925,P ＜0.001).Bland-Altman plot showed that 95％ plots of ratio of TDI_SD and V-plane_SD were among limits of agreement,which was (0.50,1.36).Conclusions Left ventricular systolic synchronicity in DCM patients can be observed by V-plane imaging.V-plane has significant relevance and consistency with TDI,and can overcome the limitations of TDI that 12 segments can not be displayed in the same cardiac cycle.

Objective To evaluate the usefulness of speckle tracking imaging(STI) for assessment of left ventricular(LV) and right ventricular (RV) functions in patients with isolated disease of right coronary artery.Methods 45 cases were diagnosed as single right coronary lesions given echocardiography,30 cases had chest pain but coronary angiography had not seen the obvious narrow as a comparison.The twodimensional loop-cinec were obtained in apical 4-chamber view,apical 2-chamber view and long axis of LV view.Eighteen segments of LV longitudinal peak systolic strain,global peak systolic strain of each view and three segments of RV free wall were measured by two-dimensional strain software.Results In the patients who had right coronary lesions but did not happen myocardial infarction,the strain(S) values in the base,mid and apex segmental of LV post wall,the base and mid segmental of LV inferior wall and the base and mid segmental of LV septum were significantly lower( P ＜0.05).The S values in the mid segment of RV free wall was lower( P ＜0.05).In the patients who had right coronary lesions and myocardial infarction,the S values in the base,mid segmental of LV antsept,the apex segmental of LV anterior wall,the base,mid and apex segmental of LV post wall,the base and mid segmental of LV inferior wall and the base and mid segmental of LV septum were significantly lower( P ＜0.05).The S values in the mid and apex segments of RV free wall were lower ( P ＜0.05).And the LV global longitudinal strains were lower in the two groups (P ＜0.05).Conclusions STI is a new and useful technology for assessment ventricular functions in patients with isolated disease of right coronary artery,and there are multiple segments impaired.

Objective To assess the left ventricular systolic function after renal sympathetic denervation(RSD) in beagles with heart failure by layer-specific two-dimensional speckle tracking imaging.Methods Twenty-three beagles were randomly divided into control group (8 dogs),URSD group (8 dogs)and RSD group (7 dogs).Control group was implanted with pacemakers without pacing,URSD group was implanted with pacemakers and underwent 3 weeks of rapid right ventricular pacing,and RSD group underwent catheter-based RSD bilaterally and was simultaneously implanted with pacemakers.All standard measurements were obtained from the left ventricular short-axis views at the levels of mitral annulus,papillary muscle and apex,and apical four-chamber,two-chamber,and long-axis views.The peak systolic longitudinal strain and circumferential strain of each layer of the left ventricle were measured by layerspecific two-dimensional speckle tracking imaging.Results After 3 weeks,all of the dogs in both the URSD and RSD groups showed lower left ventricular diastolic and systolic function compared with those in the control group,however,the dogs in the RSD group had a higher LV ejection fraction (LVEF) than the dogs in the URSD group(P ＜ 0.05).Compared with the control group,the global longitudinal strain,circumferential strain and radial strain all decreased significantly in URSD and RSD groups.The longitudinal strain of endo-and mid-cardium and the circumferential strain in endo-cardium were significantly higher in RSD group than those in URSD group(P ＜0.05).Conclusions Myocardial systolicfunction is impaired in dogs with heart failure,layer-specific two-dimensional speckle tracking imaging can provide effective tools to assess the left ventricular systolic function.Renal sympathetic denervation can improve the myocardial systolic function in dogs with heart failure.

Objective To create an left atrial appendage(LAA) occlusion preoperative simulation system by three dimensional transesophageal echocardiography(3DTEE) and three dimensional printing (3DP),and simulate the process of LAA occlusion including the selection and deployment of devices,leaks around devices and the compression rate of the devices in vitro.Methods Fifteen cases of LAA occlusion in patients with atrial fibrillation were selected in this study. Preoperative and intraoperative TEE was performed to acquire the volume data of LAA.Replicas of LAAs were created by 3DP.Then the simulation system was created by 3DTEE and the models.The models were scanned by 3DTEE to evaluate the accuracy of models,leaks around devices and the compression rate of the devices.The results were compared with intraoperative measurements.Results 3DP models of 15 patients were created based on the 3DTEE data.There was no significant difference in the values of measurements between models and cases in vivo by 3DTEE and there were agreements between these two methods.The compression rate of devices was higher in models than in case(P =0.04).Compression rate in models correlated with that in cases (r =0.949, P < 0.01).Four cases were observed with leaks in 3DP models and 6 cases were observed with leaks intraoperatively,the Kappa value of agreement was 0.706. Conclusions Preoperative exercise and evaluation of LAA occlusion can be acquired by the preoperative simulation system based on 3DTEE and 3DP,which can be an important supplement for preoperative preparation.