Hypertrophic cardiomyopathy(HCM)is a hereditary cardiomyopathy characterized with obvious myocardial hypertrophy and complex intracardiac hemodynamics.Vector flow mapping(VFM)could be used to accurately detect blood flow status in heart cavity,acquire important data such as cardiac blood flow direction,energy loss and eddy current,hence providing incremental information for understanding the complex blood flow status in heart cavity in HCM patients.The application progresses of VFM in HCM were reviewed in this article.

Hypertrophic cardiomyopathy(HCM)is a hereditary cardiomyopathy characterized with obvious myocardial hypertrophy and complex intracardiac hemodynamics.Vector flow mapping(VFM)could be used to accurately detect blood flow status in heart cavity,acquire important data such as cardiac blood flow direction,energy loss and eddy current,hence providing incremental information for understanding the complex blood flow status in heart cavity in HCM patients.The application progresses of VFM in HCM were reviewed in this article.

Objective:To evaluate the clinical efficacy of percutaneous intramyocardial septal radiofrequency ablation (PIMSRA) in the treatment of obstructive hypertrophic cardiomyopathy (HOCM) with mild septal hypertrophy.Methods:Forty-five HOCM patients with mild septal hypertrophy (the maximal left ventricular wall thickness is 15-19 mm) who were treated with PIMSRA between November 2016 to February 2021 in the Hypertrophic Cardiomyopathy Center of Xijing Hospital of Air Force Military Medical University were enrolled, and their clinical datas were collected and analyzed. The clinical symptoms and NYHA functional class before operation, 6 months and 1 year after operation were collected. Interventricular septum thickness, left ventricular outflow tract pressure gradient, left ventricular outflow tract diameter, mitral regurgitation, left ventricular systolic and diastolic function were evaluated by transthoracic echocardiography before operation, 6 months and 1 year after operation, intraoperative complications were monitored and recorded. Postoperative arrhythmias were monitored by routine 12 lead ECG and 24-hour ambulatory ECG.Results:All patients successfully completed PIMSRA procedure.No clinical adverse events such as death, bleeding and stroke occurred during and around the operation.No left bundle branch block, complete atrioventricular block and malignant arrhythmia occurred after the operation. All patients did not need permanent pacemaker implantation.NYHA functional class and clinical symptoms of patients were significantly improved after 6 months compared with values before operation (all P<0.001, respectively), it remained stable for 1 year after operation; Anterior interventricular septum, posterior interventricular septum, maximal left ventricular wall thickness all significantly decreased (all P<0.001, respectively), left ventricular outflow tract diameter widened ( P<0.001), continuous improvement 1 year after operation; left ventricular outflow tract gradient and provoked left ventricular outflow tract gradient all significantly decreased, mitral regurgitation decreased and SAM classification reduced after 6 months compared with values before operation (all P<0.001, respectively); left ventricular end-diastolic diameter widened and left atrial diameter decreased (all P<0.001, respectively), it remained stable for 1 year after operation. Left atrial volume index decreased ( P<0.001), with continuous improvement 1 year after operation; The ratio of early diastolic mitral valve velocity to early diastolic mitral annulus velocity (E/e′) decreased ( P=0.001), it remained stable for 1 year after operation. There were no significant differences in left ventricular end diastolic volume, left ventricular end systolic volume and left ventricular ejection fraction among the three groups (all P>0.05). Conclusions:PIMSRA is effective in the treatment of obstructive hypertrophic cardiomyopathy with mild ventricular septal hypertrophy.

Objective:To investigate the effect of percutaneous intramyocardial septal radiofrequency ablation (PIMSRA) guided by echocardiography on the Lown classification of ventricular arrhythmias in patients with hypertrophic obstructive cardiomyopathy (HOCM).Methods:A total of 85 patients with HOCM who received PIMSRA treatment at Xijing Hospital of Air Force Military Medical University from May 2017 to October 2019 were retrospectively selected. All patients underwent 24-hour Holter examinations before and 1 year after PIMSRA to obtain parameters related to Lown classification. The changes in Lown grades after PIMSRA were analyzed. The patients were divided into improved group and unimproved group according to whether there was significant improvement in Lowen′s grades, and the difference of the parameters related were compared. The influencing factors of the changes in Lown classification were analyzed.Results:Compared with before PIMSRA, there was a significant improvement in the Lown classification after PIMSRA ( P=0.001). The patients with Lown grade Ⅰ increased significantly ( P=0.001), and the patients with grade Ⅲ decreased significantly ( P=0.005). There were no significant changes in patients with Lown grades 0, Ⅱ, and Ⅳ (all P>0.05). The proportion of patients with family history of hypertrophic cardiomyopathy (HCM), the baseline Lown classes, the reduction rate of the maximum left ventricular wall thickness and the reduction rate of the provocative left ventricular outflow tract gradient (LVOTG) were higher in the improved group than the unimproved group (all P<0.05). Multivariate Logistic regression results showed that HCM family history ( OR=3.95, 95% CI=1.34-11.64, P=0.013), baseline Lown classes ( OR=2.01, 95% CI=1.25-3.22, P=0.004) and the reduction rate of the provocative LVOTG gradient ( OR=1.02, 95% CI=1.00-1.04, P=0.041) were independent factors of postoperative Lown classification improvement. Conclusions:The Lown classes of HOCM patients after PIMSRA is significantly improved.HCM family history, the baseline Lown classes, and the reduction rate of postoperative provocative LVOTG are independent influencing factors for the improvement of Lown grade.

Objective:To evaluate the left ventricular myocardial strain in patients with light chain cardiac amyloidosis (AL-CA) with normal left ventricular ejection fraction (LVEF) by three-dimensional speckle tracking imaging(3D-STI), and to explore the clinical value of 3D-STI in predicting the prognosis of AL-CA patients with normal LVEF.Methods:A total of 80 patients with AL-CA and LVEF≥50% were retrospectively analyzed in the Xijing Hospital of Air Force Military Medical University from October 2014 to May 2020.According to whether the patients had endpoint events, they were divided into endpoint event group and non-endpoint event group. The clinical data, conventional echocardiographic parameters, 3D-STI related parameters and follow-up results were collected. Cox regression proportional hazards model was used to analyze the survival status of AL-CA patients with univariate and multivariate regression analyses, in order to find the relevant indicators of conventional echocardiography and 3D-STI to predict adverse events.Results:All patients were followed up for 20(7.3, 40.8) months. At the end of follow-up, 25 patients had all-cause deaths. Compared with the non-endpoint group, the endpoint event group had significantly increased left ventricular end diastolic maximum wall thickness (MLVWT), peak early diastolic flow velocity/peak early diastolic velocity at mitral annulus(E/e′) (all P<0.05), and decreased LVEF, left ventricular global longitudinal strain (GLS) and basal segment longitudinal strain (LS) (all P<0.05). Multivariate cox regression analysis after adjusting for age and gender showed that basal segment LS ( HR=0.812, 95% CI=0.675-0.976, P=0.026) was an independent predictor of end-point events in patients with AL-CA. Kaplan-Meier survival curve showed that AL-CA patients with basal segment LS≤13.07% were more likely to have endpoint events. Conclusions:Basal segment LS can be used as a predictor of endpoint events in patients with AL-CA.

Objective:To investigate the safety and efficacy of echocardiography-guided trans-right-ventricular percutaneous intramyocardial septal radiofrequency ablation (PIMSRA) in a healthy sheep model, and to observe the pathological changes of myocardium in ablation area one year later.Methods:Twelve sheep were divided into PIMSRA group ( n=6) and sham group ( n=6). In PIMSRA group, a radiofrequency (RF) electrode was inserted to the interventricular septum (IVS) with maximum power of 80 Watts for 5 minutes. In the sham group, RF electrode tip was positioned in IVS segment but without the RF power delivery. Electrocardiogram (ECG), echocardiography, myocardial contrast echocardiography(MCE) were performed to assess the efficacy of PIMSRA at postoperative immediately, 2-week, 1-month, 2-month, 3-month, 6-month and 12-month during the follow-up. The following parameters were recorded, including the thickness of ablation area, the systolic wall thickening rate and amplitude of movement of the ablated region, left ventricular outflow tract pressure gradient (LVOT PG), and left ventricular ejection fraction (LVEF), mitral valve early diastolic peak velocity(E), late diastolic peak velocity(A) and the E/A ratio, peak velocity of early diastolic mitral annular motion(E′), peak velocity of late diastolic mitral annular motion(A′), and the E′/A′ ratio.For both groups, the myocardial biomarkers of troponin I, myoglobin and isoenzymes of creatine kinase were tested before the ablation and 3 h after the ablation, and again after 2 weeks. Tissue pathology examinations were performed at the end of study. Results:None of the animals in both groups was observed to have pericardial tamponade during perioperative period.Immediately after the procedure, septal hypokinesis was seen in all PIMSRA group animals, the systolic wall thickening rate and amplitude of movement of the ablated region were significantly decreased ( P<0.001), which was sustained until 12 months.In Sham group, there were no significant differences in the wall thickening rate and amplitude of movement of the operated region(all P>0.05).The thickness of the ablation area in the PIMSRA group was significantly increased immediately after the procedure( P<0.001), decreased to baseline level at 1-week ( P=0.931), and significantly increased at 3-month ( P<0.001).In the Sham group, the IVS thickness was significantly increased immediately after the procedure( P=0.005), decreased to baseline level at 1-week ( P=0.027), then has no further significant changes.There were no significant differences in LVEF, E/A, E′/A′ between PIMSRA and Sham group(all P>0.05).MCE showed the thickness of the ablation area was significantly decreased in the PIMSRA group 12 months after the operation.In both groups, troponin I increased significantly 3 h after the operation(all P<0.005), which decreased to baseline level 2 weeks later(all P>0.05). ECG showed that all the sheep had normal sinus rhythm. Pathological examinations revealed the tissue in the ablation area was fibrotic, having clear boundary with the surrounding normal tissue and no carbonization was observed 1 year later. Conclusions:Echocardiography-guided trans-right-ventricular PIMSRA produced precisely ablated myocardial tissues, reduced the IVS thickness significantly, preserved the global left ventricular function. All the sheep had normal sinus rhythm and without pericardial tamponade in 1 year follow-ups. Echocardiography-guided trans-right-ventricular PIMSRA is a safe and effective minimally invasive treatment for septal reduction therapy.

Objective:To quantitatively evaluate myocardial microcirculation perfusion changes after percutaneous intracardiac septal radiofrequency ablation (PIMSRA, Liwen procedure) in patients with obstructive hypertrophic cardiomyopathy (HOCM) using myocardial contrast echocardiography (MCE) and to further establish the effect of the procedure and predict the long-term prognosis of patients.Methods:A total of 45 patients with HOCM treated by the Liwen procedure in the First Affiliated Hospital of Air Force Medical University (Xijing Hospital) from July 2019 to June 2020 were included. MCE was performed before and 6 months after surgery, respectively. Time-intensity perfusion curve analysis was performed using QLab 10.8 offline software to obtain quantitative parameters of myocardial microcirculation perfusion including myocardial blood volume (A value), myocardial blood flow velocity (β value), and myocardial blood flow (A×β value), then the changes in parameters before and after the procedure were compared.Results:After the Liwen procedure, the mean septal thickness and mean left ventricular free wall thickness were significantly reduced, accompanied by a significant reduction in the left ventricular outflow tract pressure gradient (LVOT-PG) and mitral regurgitation length, and a significant improvement in mitral systolic antegrade motion (SAM) (all P<0.001). In addition, the left ventricular ejection fraction (LVEF) did not deteriorate significantly ( P=0.560) and the E/e′ ratio decreased after the procedure ( P=0.015). Besides, the A values of both the ventricular septum and the left ventricular free wall were not significantly changed compared to those before procedure ( P>0.05), whereas the β values and A×β values were obviously increased ( P<0.05). Conclusions:Myocardial blood velocity and myocardial blood flow in the septum and left ventricular free wall were significantly increased in patients with HOCM after the Liwen procedure, suggesting a significant improvement in myocardial microcirculation perfusion. MCE provides a non-invasive quantitative evaluation parameters of myocardial microcirculation perfusion for the Liwen procedure for the treatment of HOCM.

Purpose To evaluate the myocardial perfusion in diabetes mellitus (DM) rats with insulin intervention at different times by myocardial contrast echocardiography (MCE) so as to explore the value of MCE in evaluating the treatment of diabetic cardiomyopathy (DCM).Materials and Methods In this prospective study,90 rats were randomly divided into normal control (NC) group,DM group and insulin intervention (INS) group,with 30 rats in each group.After the DM models were established,the INS group was then divided into three subgroups of A,B and C treated with insulin intervention at 0,4 and 8 weeks respectively and further treated continuously for 12 weeks.The NC and DM groups were also randomly divided into three subgroups and fed synchronously just as the INS group but without insulin intervention.At the end of 12,16 and 20 weeks after modeling,the rats in each subgroup were examined by MCE.The changes of myocardial blood volume (A),blood velocity (β) and blood flow (A×β) were analyzed,and the myocardial tissues were also collected for pathological examination.Results A,β and A×β were increased in INS group compared with DM group (P＜0.05).Compared with NC group,the values of INS group including A×β in A subgroup,A and A×β in B subgroup,A,β and A×β in C subgroup were decreased (all P＜0.05).In INS group,there was no difference in the three values of myocardial blood between A and B subgroup (P＞0.05),but A and A×β were lower in C subgroup than those in A subgroup (P＜0.05).On pathology,the thickness of capillary basement membrane of INS group improved compared with DM group;the capillary density of INS group increased compared with DM group,but there was significant difference only inA subgroup (P＜0.05).Conclusion Early insulin intervention can improve myocardial microvascular structure and increase myocardial blood flow.MCE can be used to evaluate the myocardial microcirculation of DCM rats sensitively and accurately,which can be used as an important method for early diagnosis and dynamic monitoring of DCM with clinical significance.

Objective To assess whether strain parameters derived from three-dimensional speckle tracking imaging ( 3D-STI) could identify improvement of cardiac function and predict response of patients with immunoglobulin light-chain cardiac amyloidosis ( AL-CA) following chemotherapy . Methods Totally 13 patients with AL-CA [aged (58 .5 ± 8 .9)years;69％ males] were treated with melphalan or bortezomib-based regimens and by regular chemotherapy for 6 months .The clinical data was collected . Maximal left ventricular wall thickness (MLVWT) ,left ventricular mass index (LVMI) ,left ventricular ejection fraction ( LVEF) ,systolic mitral annular velocity ( s′) ,early diastolic mitral annular velocity echocardiography ( e′) , 3D-STI global longitudinal ,circumferential ,radial and area strain (GLS ,GCS ,GRS ,and GAS) ,the standard deviation of time to peak longitudinal strain among 16 left ventricular segments ( TS-SD_GLS ) were obtained by conventional echocardiography and 3D-STI . In addition ,serologic biomarkers including N-terminal pro-brain natriuretic peptide ( NT-proBNP) and free light chains ( FLC) were acquired at baseline and 6 months after chemotherapy . These patients were divided into two groups according to difference of FLC :complete response (CR) group and Non-CR group . The clinical data ,cardiac ultrasound parameters and serological parameters were compared between groups ,each group parameters at baseline and 6 months after chemotherapy were compared within the group.Results ①There were no significant differencein conventional echocardiographic parameters ,GCS ,GRS and GAS ,as well as TS-SD_GLS in either group between before and after chemotherapy . But GLS was improved only in CR group ( P = 0 .036) ,and its improvement was correlated with the decrease in NT-proBNP ( r = -0 .738 , P = 0 .037) . ② In baseline evaluation ,patients in Non-CR group had increased LVMI ,deteriorated e′ and GLS ,and longer Ts-SD as compared to those in CR group ( all P < 0 .05 ) . ③ ROC analysis revealed that these parameters had discriminative ability to forecast those with better therapeutic effectiveness ,esecially for AL-CA patients with baseline LVMI<96 .55 g/m2 ,e′>4 .7 cm/s ,absolute value of GLS>16 .6％ ,and TS-SD_GLS<35 .2 ms ,which may have better hematologic response to chemotherapy . Conclusions GLS can identify early improvement of cardiac function in AL-CA patients after chemotherapy . Moreover ,LVMI ,e′,GLS and TS-SD_GLS are sensitive measurements of pre-treatment ventricular impairment ,and may predict better response to chemotherapy .

Purpose Many studies have shown that subclinical left ventricular systolic dysfunction is seen in prediabetic patients.However,its relationship with prognosis is unclear.The purpose of this study is to investigate the prognostic value of subclinical left ventricular systolic dysfunction with prediabetes.Materials and Methods This was a prospective clinical cohort study.A total of 98 prediabetes patients with complete medical record and follow up data in the physical exam center and the clinic of Yan'an People's Hospital were chosen between January 2013 and January 2014.The biochemical data,echocardiography and left ventricular global longitudinal strain (GLS) in 2 years of follow up were collected.The subjects were grouped into diabetes if the diagnosis was confirmed during follow up,or non-diabetes group if not diagnosed.After follow up,the baseline parameters were compared to screen for risk factors to develop clinical diabetes.Results During the study,38 participants were diagnosed as clinical diabetes.Cox proportional hazard regression models show that obesity [hazard ratio (HR):2.662,95％ CI 1.374-5.159,P=0.004],waist-hip ratio (HR:1.917,95％ CI:1.012-3.492,P=0.001),mitral E/e'ratio (HR:1.661,95％ CI:1.336-2.065,P＜0.001),HbAlc (HR:2.029,95％ CI:1.047-3.932,P＜0.001),global longitudinal strain (HR:0.786,95％ CI:0.728-0.848,P＜0.001) were significant independent predictors for developing diabetes.Using GLS＜18％ as cutoff value,the area under receiver operating characteristic (ROC) curve to predict development of diabetes was 0.796 (95％ CI:0.704-0.888,P＜0.001),with sensitivity and specificity of 46.7％ and 89.5％,respectively.Conclusion Among modifiable risk factors in patients with prediabetes,subclinical left ventricular systolic dysfunction is an early indicator of progressing to diabetes.Early detection of left ventricular systolic dysfunction in prediabetes can provide the basis for early clinical intervention.