1 Introduction Over one million cardiac pacemakers are implanted every year worldwide,[11 of which approximately 200,000 are implanted in the United States alone.121 Combined with an aging population and increasing p...1 Introduction Over one million cardiac pacemakers are implanted every year worldwide,[11 of which approximately 200,000 are implanted in the United States alone.121 Combined with an aging population and increasing pacing indications, these numbers are expected to grow. Since the first pacemaker implantation in 1950s, cardiac pacemaker technology has rapidly advanced. Reduction in generator size, increased battery longevity, quality of pacemaker leads, algorithmic and rate responsive programming-all have revolutionized and transformed the implantation and management of transvenous cardiac pacemaker （TV-PPM）.展开更多
Objectives:We aim to compare the major complications between leadless pacemakers and traditional pacemakers.Background:Leadless pacemakers,which are increasingly used in clinical practice,have several advantages compa...Objectives:We aim to compare the major complications between leadless pacemakers and traditional pacemakers.Background:Leadless pacemakers,which are increasingly used in clinical practice,have several advantages compared with traditional pacemakers in avoiding pocket-and lead-related complications.However,the clinical effect of leadless pacemakers remains controversial.Methods:PubMed,Embase,the Cochrane Central Register of Controlled Trials(CENTRAL),the CNKI database,and the Wanfang database were searched from July 2013 to December 2019.Studies comparing leadless pacemakers and traditional pacemakers were included.The primary end point was major complications.The secondary end points were cardiac perforation/pericardial effusion,device revision or extraction,loss of device function,and death.Results:Six studies fulfi lled the inclusion criteria.Only four of the six studies reported data on major complications.Leadless pacemakers were associated with a lower incidence of major complications(risk ratio 0.33,95%confi dence interval 0.25–0.44,P<0.00001,I²=49%).We extracted data on cardiac perforation/pericardial effusion,device revision or extraction,loss of device function,and death from six studies.Our meta-analysis showed that leadless pacemakers have a higher risk of cardiac perforation or pericardial effusion(risk ratio 4.28,95%confi dence interval 1.66–11.08,P=0.003,I²=0%).No statistically signifi cant differences were found for mortality,device revision or extraction,and loss of device function.Conclusion:Compared with traditional pacemakers,leadless pacemakers have a signifi cantly decreased risk of major complications,but have a higher risk of cardiac perforation or pericardial effusion.展开更多
Background: The Nanostim {trade mark, serif} Leadless Cardiac Pacemaker (LCP) has been shown to be safe and effective in human clinical trials. Since there is little information on the effect of implant location on LC...Background: The Nanostim {trade mark, serif} Leadless Cardiac Pacemaker (LCP) has been shown to be safe and effective in human clinical trials. Since there is little information on the effect of implant location on LCP performance, the aim of this study was to determine whether anatomic position affects the long-term pacing performance of the LCP. Methods: Patients who enrolled in the Leadless II IDE Clinical Trial and had finished 6 months follow up (n = 479) were selected for the study. The implanting investigators determined the LCP final position under fluoroscope, which was categorized into three groups: RV apex (RVA, n = 174), RV apical septum (RVAS, n = 101), and RV septum (RVS, n = 204) (Figure 1). Data on capture threshold (at a 0.4 ms pulse width), R-wave amplitude and impedance were analyzed at implant, hospital discharge and 2 weeks, 6 weeks, 3 months and 6 months post-implant. Results: At implant, the mean capture thresholds in the RVA, RVAS and RVS were 0.77 ± 0.45, 0.81 ± 0.61 and 0.78 ± 0.59 volts, respectively. R-wave amplitudes were 8.0 ± 3.0 mV, 7.7 ± 2.9 mV and 7.6 ± 2.9 mV, respectively. Impedance values were 727 ± 311, 765 ± 333, and 677 ± 227 respectively. There were no differences among the 3 implant locations in capture threshold or R-wave amplitudes at 6 months (P > 0.06);however, all 3 performance parameters significantly improved over time (P < 0.001). Conclusions: The LCP implant location does not affect capture thresholds or R-wave amplitudes at 6 months, and there is little effect on impedance. Although implant location does not appear to be a predictor of electrical performance, additional long-term data will help guide optimal implant location.展开更多
BACKGROUND Dextroversion is defined as the presence of dextrocardia with situs solitus,dextroloop ventricles,and normally related great arteries.Dextrocardia can pose technical challenges when interventional treatment...BACKGROUND Dextroversion is defined as the presence of dextrocardia with situs solitus,dextroloop ventricles,and normally related great arteries.Dextrocardia can pose technical challenges when interventional treatments are required.However,the challenges posed by dextroversion can be amplified due to the disruption of typical anatomical relationships,the unpredictable positioning and boundaries of cardiac structures resulting from the shift,and the pathological processes influencing rotation.CASE SUMMARY A 73-year-old woman with cardiac dextroversion suffered from a recurrence of atrial fibrillation after her radiofrequency catheter ablation and Despite the cessation of antiarrhythmic medications,there were episodes of sinus pauses and symptomatic bradycardia,with heart rates dropping as low as 28 beats per minute.CONCLUSION Dextroversion makes the implantation of leadless pacemakers more challenging,and appropriate adjustments in fluoroscope angles may be crucial for intracardiac operations.Additionally,when advancing delivery systems,attention should be paid to rotational direction during valve-crossing procedures;changes in the perspective of posture angle between normal cardiac position and dextroversion can serve as references.展开更多
In many industries,there is a growing demand for semiconductor pressure sensors capable of operating in harsh environments with extremely high and low temperatures and high vibrations.Utilizing the piezoresistive effe...In many industries,there is a growing demand for semiconductor pressure sensors capable of operating in harsh environments with extremely high and low temperatures and high vibrations.Utilizing the piezoresistive effect of heavily doped N-type 4H-SiC,we proposed a family design of eight pressure sensor chip structures featuring different diaphragm shapes of circles and squares,along with different piezoresistor configurations.The 4H-SiC piezoresistive pressure sensor was developed using micro-electromechanical systems(MEMS)technology and encapsulated in a leadless package structure via low-stress connection achieved by glass frit sintering.The 4H-SiC pressure sensor demonstrates impressive performance,exhibiting an accuracy of 0.18%FSO and a temperature tolerance range from−50 to 600°C,with a temperature coefficient of zero output as low as 0.08%/°C at 600°C.Furthermore,the developed sensor shows remarkable stability under conditions of high-temperature vibration coupling.The advancement of this family of 4H-SiC pressure sensors provides a promising solution for pressure measurement in harsh industrial environments.展开更多
文摘1 Introduction Over one million cardiac pacemakers are implanted every year worldwide,[11 of which approximately 200,000 are implanted in the United States alone.121 Combined with an aging population and increasing pacing indications, these numbers are expected to grow. Since the first pacemaker implantation in 1950s, cardiac pacemaker technology has rapidly advanced. Reduction in generator size, increased battery longevity, quality of pacemaker leads, algorithmic and rate responsive programming-all have revolutionized and transformed the implantation and management of transvenous cardiac pacemaker （TV-PPM）.
文摘Objectives:We aim to compare the major complications between leadless pacemakers and traditional pacemakers.Background:Leadless pacemakers,which are increasingly used in clinical practice,have several advantages compared with traditional pacemakers in avoiding pocket-and lead-related complications.However,the clinical effect of leadless pacemakers remains controversial.Methods:PubMed,Embase,the Cochrane Central Register of Controlled Trials(CENTRAL),the CNKI database,and the Wanfang database were searched from July 2013 to December 2019.Studies comparing leadless pacemakers and traditional pacemakers were included.The primary end point was major complications.The secondary end points were cardiac perforation/pericardial effusion,device revision or extraction,loss of device function,and death.Results:Six studies fulfi lled the inclusion criteria.Only four of the six studies reported data on major complications.Leadless pacemakers were associated with a lower incidence of major complications(risk ratio 0.33,95%confi dence interval 0.25–0.44,P<0.00001,I²=49%).We extracted data on cardiac perforation/pericardial effusion,device revision or extraction,loss of device function,and death from six studies.Our meta-analysis showed that leadless pacemakers have a higher risk of cardiac perforation or pericardial effusion(risk ratio 4.28,95%confi dence interval 1.66–11.08,P=0.003,I²=0%).No statistically signifi cant differences were found for mortality,device revision or extraction,and loss of device function.Conclusion:Compared with traditional pacemakers,leadless pacemakers have a signifi cantly decreased risk of major complications,but have a higher risk of cardiac perforation or pericardial effusion.
文摘Background: The Nanostim {trade mark, serif} Leadless Cardiac Pacemaker (LCP) has been shown to be safe and effective in human clinical trials. Since there is little information on the effect of implant location on LCP performance, the aim of this study was to determine whether anatomic position affects the long-term pacing performance of the LCP. Methods: Patients who enrolled in the Leadless II IDE Clinical Trial and had finished 6 months follow up (n = 479) were selected for the study. The implanting investigators determined the LCP final position under fluoroscope, which was categorized into three groups: RV apex (RVA, n = 174), RV apical septum (RVAS, n = 101), and RV septum (RVS, n = 204) (Figure 1). Data on capture threshold (at a 0.4 ms pulse width), R-wave amplitude and impedance were analyzed at implant, hospital discharge and 2 weeks, 6 weeks, 3 months and 6 months post-implant. Results: At implant, the mean capture thresholds in the RVA, RVAS and RVS were 0.77 ± 0.45, 0.81 ± 0.61 and 0.78 ± 0.59 volts, respectively. R-wave amplitudes were 8.0 ± 3.0 mV, 7.7 ± 2.9 mV and 7.6 ± 2.9 mV, respectively. Impedance values were 727 ± 311, 765 ± 333, and 677 ± 227 respectively. There were no differences among the 3 implant locations in capture threshold or R-wave amplitudes at 6 months (P > 0.06);however, all 3 performance parameters significantly improved over time (P < 0.001). Conclusions: The LCP implant location does not affect capture thresholds or R-wave amplitudes at 6 months, and there is little effect on impedance. Although implant location does not appear to be a predictor of electrical performance, additional long-term data will help guide optimal implant location.
基金Shanxi Provincial Health Commission“Four batch”Science and Technology Innovation Project of Medical Development,No.2021XM45Natural Science Foundation of Shanxi Province,No.20210302123346+1 种基金Scientific Research Incentive Fund of Shanxi Cardiovascular Hospital,No.XYS20220205Traditional Chinese Medicine research project of Shanxi Province,No.2023ZYYA028.
文摘BACKGROUND Dextroversion is defined as the presence of dextrocardia with situs solitus,dextroloop ventricles,and normally related great arteries.Dextrocardia can pose technical challenges when interventional treatments are required.However,the challenges posed by dextroversion can be amplified due to the disruption of typical anatomical relationships,the unpredictable positioning and boundaries of cardiac structures resulting from the shift,and the pathological processes influencing rotation.CASE SUMMARY A 73-year-old woman with cardiac dextroversion suffered from a recurrence of atrial fibrillation after her radiofrequency catheter ablation and Despite the cessation of antiarrhythmic medications,there were episodes of sinus pauses and symptomatic bradycardia,with heart rates dropping as low as 28 beats per minute.CONCLUSION Dextroversion makes the implantation of leadless pacemakers more challenging,and appropriate adjustments in fluoroscope angles may be crucial for intracardiac operations.Additionally,when advancing delivery systems,attention should be paid to rotational direction during valve-crossing procedures;changes in the perspective of posture angle between normal cardiac position and dextroversion can serve as references.
基金supported by the National Natural Science Foundation of China(62401451,62131017)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(GZB20230584)the China Postdoctoral Science Foundation(2024M762579)。
文摘In many industries,there is a growing demand for semiconductor pressure sensors capable of operating in harsh environments with extremely high and low temperatures and high vibrations.Utilizing the piezoresistive effect of heavily doped N-type 4H-SiC,we proposed a family design of eight pressure sensor chip structures featuring different diaphragm shapes of circles and squares,along with different piezoresistor configurations.The 4H-SiC piezoresistive pressure sensor was developed using micro-electromechanical systems(MEMS)technology and encapsulated in a leadless package structure via low-stress connection achieved by glass frit sintering.The 4H-SiC pressure sensor demonstrates impressive performance,exhibiting an accuracy of 0.18%FSO and a temperature tolerance range from−50 to 600°C,with a temperature coefficient of zero output as low as 0.08%/°C at 600°C.Furthermore,the developed sensor shows remarkable stability under conditions of high-temperature vibration coupling.The advancement of this family of 4H-SiC pressure sensors provides a promising solution for pressure measurement in harsh industrial environments.
