Coronary angiography (CAG) as a typical imaging modality for the diagnosis of coronary diseases hasbeen widely employed in clinical practices. For CAG-based computer-aided diagnosis systems, accurate vessel segmentation plays a fundamental role. However, patients with bradycardia usually have a pacemaker which frequently interferes the vessel segmentation. In this case, the segmentation of vessels will be hard. To mitigate interferences of pacemakers and then extract main vessels more effectively in CAG images, we propose an approach. At first, a pseudo CAG (pCAG) image is generated through a part of a CAG sequence, in which the pacemaker exists. Then, a local feature descriptor is employed to register the relative location of pacemaker between the pCAG image and the target CAG image. Finally, combining the registration result and segmentation results of main vessels and pacemaker, interferences of pacemaker are removed and the segmentation of main vessels is improved. The proposed method is evaluated based on 11 CAG images with pacemakers acquired in clinical practices. An optimization ratio of the Dice coefficient is 12.04%, which demonstrates that our method can remove overlapping pacemakers and achieve the improvement of main vessel segmentation in CAG images.Our method can further become a helpful component in a CAG-based computer-aided diagnosis system, improving its diagnosis accuracy and efficiency.
目的 调查安置永久性人工心脏起搏器的老年患者术前焦虑状况，为制订护理对策提供依据。 方法 2004年7月-2008年7月收治需安置永久性人工心脏起搏器的心脏病患者78例，术前采用焦虑自评量表（SAS）对其进行问卷调查，并采用自制一般情况问卷调查了解情况。 结果 植入永久性心脏起搏器的老年患者术前SAS得分高于国内常模（Plt;0.05）。根据自制调查问卷结果，差异有统计学意义（Plt;0.05）的项目:老年患者随年龄增长焦虑量表评分降低；丧偶者焦虑评分高于有配偶者；完全公费、部分公费、自费的焦虑量表评分依次增高；老年患者对起搏器知识了解程度越少，焦虑评分越高；无家人陪伴者比有家人陪伴者焦虑评分高。而性别、文化水平差异无统计学意义。 结论 植入永久性起搏器的老年患者术前多数存在焦虑情绪，且焦虑与年龄、婚姻、费用支付方式、有无家人陪伴、相关知识等有一定关系，医护人员应针对性地做好患者术前护理，帮助患者面对现实，以积极的心态接受手术治疗。
ObjectiveTo compare and analyze the clinical effects of two kinds of frame design valves after transcatheter aortic valve replacement (TAVR).MethodsWe retrospectively reviewed 124 patients who underwent TAVR and were followed up for 1 year. There were 71 males and 53 females aged 75.57±6.21 years. These patients were treated with Venus-A or Edwards Sapien aortic valves. The hemodynamics and cardiac function of these two kinds of transcatheter aortic valves (THV) were evaluated by echocardiography. The 30-day mortality and 1-year clinical effect of the patients were calculated.ResultsEight-one patients used Venus-A valve and 43 patients used Edwards Sapien valve. The aortic valve transaortic pressure gradient was reduced and the rate of perivalvular leakage was low (both 2.6%) in both groups, and there was no statistical difference between the two groups. The implantation rate of permanent pacemaker was 17.3% and 11.6%, respectively. The 1-month survival (94.0% and 93.0%) and 1-year survival (94.0% and 91.0%) rates were not statistically different.ConclusionThe two groups of THV with different stent structures have good short-term clinical effect and low implantation rate of permanent pacemaker.
ObjectiveTo investigate the new-onset conduction block after transcatheter aortic valve replacement (TAVR) and summarize the relevant experience. Methods The perioperative data of TAVR patients in the Second Hospital of Hebei Medical University from January 2016 to February 2023 were collected, and the new-onset incidence of conduction block after TAVR was analyzed retrospectively. Results Finally 352 patients were included, including 225 males and 127 females, with an average age of (67.2±5.1) years, among whom 256 patients were treated with Venus-A valves, 69 patients with Vita-Flow valves, and 27 patients with J-Valve valves. There were 38 (10.8%) patients of new-onset postoperative block. There were 6 (1.7%) patients of new-onset postoperative grade Ⅲ atrioventricular block, including 5 (2.0%) patients of Venus-A and 1 (1.4%) patient of Vita-Flow. Conduction function was restored in 2 patients within 14 days after surgery, and failed to be restored in 4 patients, who then received permanent pacemaker implantation in the Department of Cardiology. There were 27 (7.7%) patients of new left bundle branch block after surgery, including 22 (8.6%) patients of Venus-A, 4 (5.8%) patients of Vita-Flow and 1 (3.7%) patient of J-Valve; and conduction function was restored within 7 days after surgery in 23 patients, and 5 (1.4%) patients developed new right bundle branch blocks after surgery including 4 (1.5%) patients of Venus-A and 1 (1.4%) patient of Vita-Flow. Conclusion New-onset conduction block is a common complication after TAVR, and the new-onset rate of left bundle branch block is the highest, followed by the grade Ⅲ atrioventricular block. Mastering reasonable methods and applying appropriate strategies can effectively reduce the new-onset rate of postoperative conduction block and improve the overall success rate of TAVR surgery.
Objective To construct the expression short hairpin RNA （shRNA） targeting gene kir2. 1 in rat myocardial cells, named pEGFP6 kir2. 1, and to observe the effects on the expression of messenger RNA（mRNA） and protein of gene kir2. 1 as well as the changes of myocardial beating rates. Methods Five RNA interference （RNAi） sites targeting the rat kir2. 1 gene was selected, designed and synthesized five pairs of oligonucleotides fragments ,annealed them to double-strand, then cloned them into the vectors containing U6 promoter,obtained the vector expressing five aim genes. Rat myocardial cells were divided into three groups： Experimental group, negative plasmid control group and normal control group. Reverse transcription-polymerase chain reaction（RT PCR） and Western-blot were carried out to detect the expression of the mRNA and protein of gene kir2.1 and the beating rates of myocardial cells were observed after 72 h. Results The expression of mRNA and protein of gene kir2. 1 of experimental group were markedly lower than that of other two control groups after 72 h（P〈0.01）. There was no statistically significant between two control groups. The beating rate in experimental group was much faster than other two control groups （P〈0.01）, remained unchanged in both negative plasmid control group and normal control group. Conclusion Plasmid pEGFP6-kir2.1 could suppress the expression of the mRNA and protein of kir2.1 and increase the rat cardiac muscle cell beats.
ObjectiveTo explore the efficacy of an innovative approach of follow-up in patients implanted with permanent pacemaker (DDD). MethodsA total of 400 patients who underwent permanent pacemaker (DDD) implantation between June 2011 and June 2013 were included in the present study. Patients were randomly assigned to the innovative and conventional follow-up groups in a 1：1 manner (200 patients in each group). The baseline characteristics were well balanced with no statistically significant differences in the mean age, proportion of male sex, prevalence of hypertension, position of the electrode or the device used between the two groups. At the end of the follow-up, patient outcomes were compared between the two groups. ResultsThe outcomes of patients were better in the innovative follow-up group, with higher degree of satisfaction, better state of health, lower incidence of complications, and less frequent readmission and follow-up visits (all P<0.05). ConclusionThe innovative approach of follow-up considerably improves patient outcomes, and can be useful in future clinical practice.
ObjectiveTo analyze the impact of balloon post-dilation on cardiac conduction in patients undergoing transcatheter aortic valve replacement (TAVR). MethodsFrom June 2021 to December 2022, patients with severe aortic valve stenosis or regurgitation who underwent TAVR surgery using domestically produced valves at Xijing Hospital, Air Force Military Medical University were selected. The occurrence of intraoperative and postoperative cardiac conduction block was recorded. According to whether balloon post-dilation was performed during the surgery, patients were divided into the post-dilation group and the non-post-dilation group. The baseline data, postoperative cardiac conduction block occurrence, and cardiac function of the two groups were analyzed. ResultsA total of 126 patients were included, including 83 males and 43 females, with an average age of (66.6±7.6) years. There were 30 patients in the post-dilation group and 96 patients in the non-post-dilation group. On the first day after TAVR, the average QRS intervals in the post-dilation group and the non-post-dilation group were (105.6±13.8) ms and (125.9±28.2) ms, respectively (P=0.017). At discharge, the average PR intervals in the two groups were (168.7±36.8) ms and (192.1±44.2) ms, respectively (P=0.024). After TAVR, 9 (7.1%) patients developed new atrioventricular block, 5 (4.0%) patients developed new complete right bundle branch block, and 33 (26.2%) patients developed new complete left bundle branch block. During hospitalization, 2 (1.6%) patients received permanent cardiac pacemakers, both of whom were in the non-post-dilation group. There was no statistical difference in postoperative left ventricular structure and function between the two groups (P>0.05). ConclusionPostoperative expansion using domestically produced interventional valves for TAVR do not increase the incidence of early atrioventricular block and permanent cardiac pacemaker implantation after valve implantation, and there are no significant changes in cardiac structure and function in patients with conduction block in the short term after surgery.
Objective To analyze predictive factors, clinical implications and prognosis effects of new-onset conduction block after transcatheter aortic valve implantation (TAVI). Methods The clinical data of 86 patients who underwent TAVI through transfemoral approach from 2019 to 2021 in Fujian Provincial Hospital were retrospectively analyzed, including 59 males and 27 females with an average age of 72.9±8.0 years. The patients were divided into a normal group and a new-onset conduction block group according to whether there was new-onset conduction block after operation, and then the new-onset conduction block group was subdivided into a left bundle branch block (LBBB) group (28 patients) and a complete atrioventricular block (CAVB) group (11 patients). We compared the hemodynamics and TAVI-related complications between the postoperative and early follow-up periods, and used the multivariate logistic regression models to identify risk factors for the new-onset conduction block. Results The median EuroSCORE of all patients were 8 (2) points before the operation. In the postoperative and early follow-up periods, the hemodynamics and TAVI-related complications had no statistical difference between the new-onset conduction block group and the normal group (P>0.05). The incidence of permanent pacemaker implantation (81.8%, 9/11) and mortality due to cardiac causes (18.1%, 2/11) in the CAVB group were significantly higher than those in the normal group and theLBBB group (P<0.05). Female, severe calcification of the aortic valve, too large valve size and deep valve implants were the risk factors for new-onset conduction block after TAVI. ConclusionThe incidence of LBBB and CAVB is high after TAVI, however, both of them do not significantly effect the hemodynamics of the patients. Higher incidence of permanent pacemaker implantation is found in the CAVB group which affects the rate of rehospitalization and mortality. Female patients, severe calcification of the aortic valve, too large valve size and deep valve implants are the risk factors for the new-onset conduction block after TAVI.
The biological pacemaker has become a new strategy in the treatment of severe bradycardias, in which a kind of ideal pacemaker cells is a pivotal factor. Here we reviewed the progress in the differentiation of bone-marrow mesenchymal stem cells and adipose-derived stem cells into pacemaker-like cells by means of gene transfer, chemical molecules, co-culture with other cells and specific culture media, and we also analyzed the potential issues to be solved when they are used as seeding cells of biological pacemaker.
In order to improve the reliability of cardiac pacemaker contact-less power supply technology, this paper proposes a novel application of wireless feedback voltage stabilizing technology to adjust heart disease patients with inner power supply filter circuit output voltage and current control method, to keep the output voltage stability, and to ensure that the super capacitor and cardiac pacemaker to get a stable power supply. To implement the real-time accurate voltage control with considering the primary and secondary side inductance coupling coefficient changes, the change of the external power supply voltage and load, it is necessary to test thee real-time and accurate output voltage and current value after rectifying filtering. Therefore, based on the chaotic control theory, we adopted method of phase diagram on the basis of the quick observation after rectifying filtering, so that the method of voltage and current could improve the detection time of the circuit. The phase diagram of proposed control method can be divided into 8 segments, and we got 7 zero-extreme points. When these zero-extreme points are detected, according to extreme points of the zero instantaneous values, the corresponding average values of voltage and current were obtained. Simulation and experimental results showed that using the above method can shorten the response time to less than switch devices 1/2 switching cycles, thus validating the effectiveness and feasibility of the proposed detection algorithm.