Objective To investigate clinical features and treatment strategy of cardiac complications caused by permanent pacemaker （PPM） implantation.?Methods?We retrospectively reviewed clinical records of 10 patients with cardiac complications caused by PPM who received surgical treatment in General Hospital of People’s Liberation Army from January 2003 to May 2010. There were seven males and three females with an average age of 62.9 years. One patient had an Atrial demand inhibited pacemaker （AAI） PPM and the other nine patients had a DDD PPM. Cardiac complications included infective endocarditis （IE） in 5 patients, tricuspid insufficiency （TI） in 4 patients and pulmonary artery thrombosis in one patient. According to their respective situation, these patients underwent different surgical treatment such as tricuspid valve plasty （TVP）， tricuspid valve replacement and/or removal of PPM lead and vegetations as part of intensive debridement of the infected area.?Results?Postoperatively， all the patients were successfully discharged. Five patients whose PPM lines and leads were preserved in the surgery had normal PPM function. Three PPM-dependent patients whose PPM leads were removed in the surgery received a PPM reimplantation later. Nine patients were followed up for an average of 5.5 months and all these patients had a significantly improved quality of life. One patient after TVP had mild TI during follow-up. Conclusion Surgical treatment should be performed as early as possible when infection is too severeto control in patients with IE caused by PPM. PPM-induced TI may be hard to be diagnosed preoperatively, and transesophageal echocardiography or surgical exploration should be considered to establish the diagnosis. Measures should be taken to protect PPM if PPM lines and leads are preserved during operation. Patients whose PPM lines and leads are removed during the surgery need to choose a suitable time for PPM reimplantation.
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.
Objective To review the current status and problems in developing cardiac biological pacemaker(CBP) by cell transplantation. Methods The l iterature over the past decade concerning CBP constructed through celltransplantation was reviewed and summarized. Results Experiments in vivo testified that the cell transplantation was feasible for CBP construction, and the transplantation of sinus atrial node cell and stem cell was still the predominant method for constructing CBP. However, such problems as difficult ampl ification of transferred cardio muscle cell, low success rate of CBP construction as well as unstable function of CBP make it lag behind the tremendous cl inical demands. The gene transfection technology might be one of the approaches to resolve these issues. Conclusion As one feasible method for CBP construction, the cell transplantation has a bright future in the cl inical appl ication and is worthy of further study.
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.
The early cardiac biological pacemaker studies were mostly around HCN channel, and how to build a biological pacemaker through the enhanced If current. In recent years, however, people found that the genes of Tbx3 could play an important role in the development of cardiac conduction system, especially in processes of the maturity of the sinoatrial node and maintenance of its function. And the Tbx3 can further optimize the biological pacemaker. Therefore, it could be a new therapeutic focus in biological pacemaker and treatment of cardiac conduction system disease. This paper summarizes some of the latest research progress of the Tbx3 in biological pacemaker in recent years. We hope that this review could provide theoretical basis for the clinical applications of Tbx3.
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.
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.
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.
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.
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 2016 to 2023 were collected, and the new-onset incidence of conduction block after TAVR was analyzed retrospectively. ResultsThere were 352 patients of TAVR operation (256 patients of Venus-A, 69 patients of Vita-Flow, 27 patients of J-Valve), among whom 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%) 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 block is a common complication after TAVR, 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 also effectively reduce the new rate of postoperative conduction block and improve the overall success rate of TAVR surgery.