This work proposes to design a fuzzy proportional-integral derivative (FPID) controller for dual-sensor cardiac pacemaker systems, which can automatically control the heart rate to accurately track a desired preset pr...This work proposes to design a fuzzy proportional-integral derivative (FPID) controller for dual-sensor cardiac pacemaker systems, which can automatically control the heart rate to accurately track a desired preset profile. The combination of fuzzy logic and conventional PID control approaches is adopted for the controller design based on dual-sensors. This controller offers good adaptation of the heart rate to the physiological needs of the patient under different states (rest and walk). Through comparing with the conventional fuzzy control algorithm, FPID provides a more suitable control strategy to determine a pacing rate in order to achieve a closer match between actual heart rate and a desired profile. To assist the heartbeat recovery, the stimuli with adjustable pacing rate is generated by the pacemaker according to the FPID controller, such actual heart rate may track the preset heart rate faithfully. Simulation results confirm that this proposed control design is effective for heartbeat recovery and maintenance. This study will be helpful not only for the analysis and treatment of bradycardias but also for improving the performance of medical devices.展开更多
Cardiovascular disease is defined as a heart rate that is less than 60 bpm. Implantable cardiac devices such as pacemakers are widely used nowadays. In this paper, design and implementation of the heart model can be c...Cardiovascular disease is defined as a heart rate that is less than 60 bpm. Implantable cardiac devices such as pacemakers are widely used nowadays. In this paper, design and implementation of the heart model can be controlled to be the heart of a patient suffering from a decrease in heart rate (Bradycardia). A system is designed to sense and calculate the heart rate per minute and it is considered as an input to the controller. The design and implementation of Mamdani fuzzy controller to generate electric pulses that mimic the natural pacing system of the heart maintains an adequate heart rate by delivering controlled, rhythmic electrical stimuli to the chambers of the patient heart. The proposed controller is tested by using Matlab/Simulink program.展开更多
BACKGROUND Esophagogastric varices are a common complication of cirrhosis with portal hypertension and endoscopic treatment has been recognized as a primary preventive and therapeutic option for such patients;however,...BACKGROUND Esophagogastric varices are a common complication of cirrhosis with portal hypertension and endoscopic treatment has been recognized as a primary preventive and therapeutic option for such patients;however,it should be noted that bradyarrhythmia is regarded as one of the contraindications to endoscopic examination.Meanwhile,acute variceal bleeding may result in a high mortality rate in cirrhotic patients with portal hypertension accompanied by bradyarrhythmia.At present,there is an absence of reports concerning the treatment of such group of patients who underwent transjugular intrahepatic portosystemic shunt(TIPS).The present report details the case of a cirrhotic patient with acute variceal bleeding accompanied by bradyarrhythmia who underwent TIPS under temporary pacemaker protection.CASE SUMMARY We report the case of a 64-year-old male patient who was confirmed with bradyarrhythmia by ambulatory electrocardiogram 24 h before the operation.The patient was successfully treated by TIPS under temporary pacemaker protection.CONCLUSION In terms of cirrhotic patients with abnormal cardiac electrophysiological conduction,TIPS may be effective in reducing the complications of portal hypertension following the exclusion of severe pulmonary hypertension and heart failure,showing moderate feasibility in clinical applications.展开更多
The usability assessment of a pacemaker is a complex task where the dedicated programmer for testing programmed algorithms is necessary.This paper provides the outcomes of development and complex testing of the artifi...The usability assessment of a pacemaker is a complex task where the dedicated programmer for testing programmed algorithms is necessary.This paper provides the outcomes of development and complex testing of the artificial cardiac system to evaluate the pacemaker’s functionality.In this work,we used the modular laboratory platform ELVIS II and created graphical user interface in LabVIEW programming environment.The electrical model of the heart allows signals generation(right atrium,right ventricle)and the monitoring of the stimulation pulses.The LabVIEW user interface allows to set the parameters of the generated signals and the simulation of the cardiac rhythm disorders as well as the monitoring and visualization of the pacemaker behavior in real-time.The results demonstrate the capability of proposed system to evaluate the paced and sensed pulses.The proposed solution allows the scientists to test the behavior of any cardiac pacemaker for its pre-programmed settings and pacing mode.In addition,the proposed system can simulate various disorders and test cardiac pacemakers in different working modes.展开更多
Objective: To inquire into the effect of systematic family nursing guidance on improving the Quality of Life for elderly patients with implanted cardiac pacemaker. Methods: 41 elderly patients in accordance with the c...Objective: To inquire into the effect of systematic family nursing guidance on improving the Quality of Life for elderly patients with implanted cardiac pacemaker. Methods: 41 elderly patients in accordance with the corresponding requirements were studied after offering systematic family nursing guidance and surveyed through the questionnaires about the QOL (quality of life) respectively 1 month, 3 months and 6 months after leaving hospital. Results: Compared with that of 1 month and 3 months after the operation, the questionnaire scores for 6 months after the operation were found to have significant improvement, and the differences were statistically significant. Conclusion: Systematic family nursing guidance can effectively improve the QOL for elderly patients with implanted cardiac pacemaker, which makes them spend their old age in comfort and happiness.展开更多
Objective:To investigate the effect of 12-lead electrocardiogram and 24-hour dynamic electrocardiogram in detecting pacemaker dysfunction and changes in cardiac function indexes in patients with pacemaker implantation...Objective:To investigate the effect of 12-lead electrocardiogram and 24-hour dynamic electrocardiogram in detecting pacemaker dysfunction and changes in cardiac function indexes in patients with pacemaker implantation.Methods:A total of 136 patients with pacemaker implantation in the First Clinical Medical College of Three Gorges University,Institute of Cardiovascular Disease of Three Gorges University and Yicang Central People’s Hospital from January 2023 to December 2024 were selected as the research objects.All patients received 12-lead electrocardiogram and 24-hour holter 3–14 days after implantation.Results:The overall detection rate of various types of pacemaker dysfunction by Holter was significantly higher than that by conventional ECG(27.21%vs.5.15%,χ^(2)=24.402,P<0.001).The overall arrhythmia detection rate of Holter was significantly higher than that of conventional electrocardiogram(57.35%vs.10.29%,χ^(2)=67.277,P<0.001).The time domain indexes of heart rate variability obtained by 24-hour continuous monitoring of Holter were significantly improved compared with those of conventional electrocardiogram(P<0.05).Conclusions:Compared with 12-lead electrocardiogram,24-hour holter monitoring can more accurately detect pacemaker dysfunction and arrhythmia in patients with pacemaker implantation,and provide more comprehensive data of heart rate variability,which is helpful for clinicians to better evaluate the cardiac function of patients and adjust treatment plans.展开更多
BACKGROUND Autoimmune myocarditis(AM)associated with autoimmune diseases can cause complete atrioventricular block(CAVB),but the related autoantigens and the underlying mechanisms are unclear.Anti-SSA/Ro antibodies ma...BACKGROUND Autoimmune myocarditis(AM)associated with autoimmune diseases can cause complete atrioventricular block(CAVB),but the related autoantigens and the underlying mechanisms are unclear.Anti-SSA/Ro antibodies may play an important role in this process,but cases of AM with positive anti-SSA/Ro antibodies are rare.In addition,arrhythmias,such as atrioventricular block,are very common in patients with autoimmune diseases,but severe atrioventricular block requiring permanent pacemaker implantation is extremely rare.CASE SUMMARY The patient in this case had AM with anti-SSA/Ro antibody positivity,which was associated with connective tissue disease,and the patient subsequently developed CAVB.After intensive immunosuppressive therapy,the antibody test results became negative,and pulmonary hypertension significantly improved.However,the outcome of permanent pacemaker implantation did not change.CONCLUSION In clinical practice,the awareness of adult AM associated with autoimmune diseases combined with CAVB should be strengthened in clinicians,and anti-SSA/Ro antibodies may play a role in this process.Therefore,improving the detection of antibodies and early intervention,such as active immunosuppression therapy,may be very important for improving disease prognosis.For patients who do not respond to immunosuppressive therapy,implantation of a permanent pacemaker may become an essential treatment option.展开更多
Objective To retrospectively identify risk factors and the prognosis for new-onset atrial fibrillation (AF)after implantation of dual-chamber pacemakers in elderly patients.Methods Consecutive patients aged >65year...Objective To retrospectively identify risk factors and the prognosis for new-onset atrial fibrillation (AF)after implantation of dual-chamber pacemakers in elderly patients.Methods Consecutive patients aged >65years who underwent their first implantation of a dual-chamber permanent pacemaker in Beijing Anzhen Hospital from October 2013to May 2016were enrolled.Their complete program- ming and follow-up data were recorded.Follow-up end points included new-onset AF and major adverse cardiovascular and cerebrovascular events.Restdts Altogether,322patients were enrolled,with new-onset AF observed in 79(24.5%)during their follow-up.Multivariable analysis identified four independent predictors of new-onset AF in elderly patients after pacemaker implantation:hypertension (HR =3.040, 95%CI:1.09-3.05,P =0.00),age (HR =1.966,95%CI:1.57-3.68,P =0.01);left atrial enlargement (HR =1.645,95%CI:1.05-1.25,P = 0.03);high ventricular pacing rate (HR =1.137,95%CI:1.01-1.06,P =0.01).Univariable analysis indicated that the CHA2DS2-VASc score was also a risk factor for AF (HR =1.368,95%CI:1.178-1.589,P =0.002),whereas multivariable regression analysis did not. Kaplan-Meier survival analysis showed that the risk for ischemic stroke was significantly higher in the new-onset AF group than in the non-AF group (P <0.05).Conclusion Hypertension,age,left atrial enlargement,and high ventricular pacing rate were independent predictors of new-onset AF in elderly patients after implantation of a permanent pacemaker.New-onset AF increased the risk for ischemic stroke.展开更多
Objective To assess the prevalence of the bleeding complications in pacemaker implanted patients receiving different antiplatelet regimens, and the influence of each regimen on hospital stays after device implantation...Objective To assess the prevalence of the bleeding complications in pacemaker implanted patients receiving different antiplatelet regimens, and the influence of each regimen on hospital stays after device implantation. Methods We prospectively enrolled 364 patients receiving the cardiac rhythm device implantations in Fuwai Hospital from July 2012 to December 2013. Bleeding complications including pocket hematoma, hemothorax, cardiac tamponade and blood transfusion requirement were measured as endpoints. Post operation hospital stay was also included in the endpoints. Results Bleeding complications were detected in 15 patients （14 with hematoma, one with hemothorax） out of all 364 patients （4.12%）. Dual antiplatelet therapy （DAT） significantly increased hematoma （19.3%） compared with aspi- fin treatment （ASA） （3.2%, P = 0.001） and no antiplatelet therapy （1.9%, P 〈 0.001）. There was no significant difference in incidence of pocket hematoma between the ASA group and the control group （P = 0.45）. The post procedure hospital stay was longer in DAT group （5.45 ± 2.01 days） compared to those in the ASA group （3.65 ± 1.37 days, P 〈 0.05） or control group （3.99 ± 2.27 days, P 〈 0.05）. Pocket hema- toma was considered an independent predictor of hospital stay prolongation （OR： 5.26; 95% CI： 1.56-16.64; P = 0.007）. Conclusions Among the Chinese patients undergoing device implantation in this study, the use of dual antiplatelet agents significantly increased the risk of pocket hematoma complications and led to a longer hospital stay. Use of aspirin alone did not increase the risk.展开更多
AIM To investigate the effects of a water extract of Hwangryunhaedok-tang(HHTE) on the pacemaker potentials of mouse interstitial cells of Cajal(ICCs).METHODS We dissociated ICCs from small intestines and cultured. IC...AIM To investigate the effects of a water extract of Hwangryunhaedok-tang(HHTE) on the pacemaker potentials of mouse interstitial cells of Cajal(ICCs).METHODS We dissociated ICCs from small intestines and cultured. ICCs were immunologically identified using an antic-kit antibody. We used the whole-cell patch-clamp configuration to record the pacemaker potentials generated by cultured ICCs under the current clamp mode(I = 0). All experiments were performed at 30 ℃-32 ℃RESULTS HHTE dose-dependently depolarized ICC pacemaker potentials. Pretreatment with a 5-HT_3 receptor anta-gonist(Y25130) or a 5-HT_4 receptor antagonist(RS39604) blocked HHTE-induced pacemaker potential depolarizations, whereas pretreatment with a 5-HT7 receptor antagonist(SB269970) did not. Intracellular GDPβS inhibited HHTE-induced pacemaker potential depolarization and pretreatment with a Ca^(2+)-free solution or thapsigargin abolished the pacemaker potentials. In the presence of a Ca^(2+)-free solution or thapsigargin, HHTE did not depolarize ICC pacemaker potentials. In addition, HHTE-induced pacemaker potential depolarization was unaffected by a PKC inhibitor(calphostin C) or a Rho kinase inhibitor(Y27632). Of the four ingredients of HHT, Coptidis Rhizoma and Gardeniae Fructus more effectively inhibited pacemaker potential depolarization.CONCLUSION These results suggest that HHTE dose-dependently depolarizes ICC pacemaker potentials through 5-HT_3 and 5-HT_4 receptors via external and internal Ca^(2+) regulation and via G protein-, PKC-and Rho kinase-independent pathways.展开更多
AIM:To determine if there were any interactions between cardiac devices and small bowel capsules secondary to electromagnetic interference (EMI) in patients who have undergone small bowel capsule endoscopy (SBCE).METH...AIM:To determine if there were any interactions between cardiac devices and small bowel capsules secondary to electromagnetic interference (EMI) in patients who have undergone small bowel capsule endoscopy (SBCE).METHODS:Authors conducted a chart review of 20 patients with a cardiac pacemaker (CP) or implantable cardioverter defibrillator (ICD) who underwent continuous electrocardiographic monitoring during their SBCE from 2003-2008.authors searched for unexplained electrocardiogram (ECG) findings,changes in CP andICD set parameters,any abnormality in transmitted capsule data,and adverse clinical events.RESULTS:There were no adverse events or hemodynamically significant arrhythmias reported.CP and ICD set parameters were preserved.The majority of ECG abnormalities were also found in pre-or post-SBCE ECG tracings and the CP behavior during arrhythmias appeared appropriate.Two patients seemed to have episodes of undersensing by the CP.However,similar findings were documented in ECGs taken outside the time frame of the SBCE.One patient was observed to have a low signal encountered from the capsule resulting in lack of localization,but no images were lost.CONCLUSION:Capsule-induced EMI remains a possibility but is unlikely to be clinically important.CPinduced interference of SBCE is also possible,but is infrequent and does not result in loss of images transmitted by the capsule.展开更多
BACKGROUND: This study aims to investigate whether small balloon aortic valvuloplasty(BAV) reduces the need for permanent pacemaker implantation (PPMI) after transcatheter aortic valveimplantation (TAVI).METHODS: This...BACKGROUND: This study aims to investigate whether small balloon aortic valvuloplasty(BAV) reduces the need for permanent pacemaker implantation (PPMI) after transcatheter aortic valveimplantation (TAVI).METHODS: This was a retrospective analysis using data from our local TAVI database. SmallBAV was defined as a small balloon size (=18 mm) pre-dilatation. Normal BAV was defined as aballoon size >18 mm. The primary endpoint was the incidence of new PPMI.RESULTS: Of 99 consecutive TAVI patients, five patients were excluded due to pre-existingpermanent pacemaker. Patients in the small BAV group (n=57) had a signifi cantly lower PPMI ratecompared with the normal BAV group (n=37) (3.5% vs. 18.9%, P=0.026). Moderate or severe aorticvalve regurgitation post-procedure was similar between the small BAV and normal BAV groups (5.3%vs. 8.1%, P=0.480);likewise, the mean aortic gradient post-procedure did not differ significantly(11.5±5.2 mmHg vs. 12.2±7.3 mmHg, 1 mmHg=0.133 kPa, P=0.580) between the groups. Devicesuccess rates were also similar (94.7% vs. 91.8%, P=0.680). In multivariable analysis, small BAV(P=0.027), the ratio of prosthesis diameter to annulus diameter (P=0.048), and mean aortic gradientby echo in the basement (P=0.021) were independent predictors of PPMI.CONCLUSIONS: The small BAV strategy is associated with a low rate of permanentpacemaker implantation after transcatheter self-expanding valve implantation in this single-centerobservational study.展开更多
Background Permanent pacing is the therapy of choice for treating severe and/or symptomatic bradyarrhythmias. The number of very elderly patients receiving pacemakers is increasing and little is known about survival i...Background Permanent pacing is the therapy of choice for treating severe and/or symptomatic bradyarrhythmias. The number of very elderly patients receiving pacemakers is increasing and little is known about survival in this specific subgroup. This study is aimed at assessing the actual survival of patients requiring pacing therapy at age > 85 years and investigating variables associated with death. Methods Between 2010 and 2017, 572 patients aged ≥ 85 years underwent pacemaker implantation for conventional bradycardia indications in Department of Cardiology, S. Chiara Hospital, Italy. Results Thirty percent of patients were ≥ 90-year-old and comorbidities were frequent. Fifty-seven percent of patients required pacing for prognostic reasons(acquired atrioventricular block), and the remaining for relief of bradycardia symptoms. A dual-chamber pacemaker was implanted in 34% of patients. The 5-year survival was 45%(standard error: 3%), and the 8-year survival was 26%(standard error: 4%). The risk of death was similar in patients who received pacemaker for symptom relief and for prognostic reasons in the overall population(HR = 1.19, 95% CI: 0.93–1.52, P = 0.156), as well as in the ≥ 90-year-old group(HR = 1.39, 95% CI: 0.92–2.11, P = 0.102). At multivariate analysis, following variables were associated with death: higher age, lower ejection fraction, dementia/dysautonomia and diagnosis of cancer. The pacing indication and the implantation of a single chamber pacemaker were not associated with worse prognosis. Conclusions This study showed a good life expectancy in patients aged ≥ 85 years who received a pacemaker. Strong risk factors for all-cause death were non-cardiac. Pacemaker therapy seems a clinically effective therapeutic option to improve survival and to control bradyarrhythmia-related symptoms in very elderly patients.展开更多
To investigate the mechanisms of microwave induced pacemaker cell injuries, Wistar rats and the primary pacemaker cells of newborn Wistar rats were exposed to microwave at average power density of 50 mW/cm2. Slower sp...To investigate the mechanisms of microwave induced pacemaker cell injuries, Wistar rats and the primary pacemaker cells of newborn Wistar rats were exposed to microwave at average power density of 50 mW/cm2. Slower spontaneous beating rate, intercellular Ca2＋ aggregation and cell membrane perforation were detected immediately after the exposure. Moreover, hyperpolarizationactivated cyclic nucleotide-gated cation channel 4 （HCN4） was down-regulated immediately after the exposure and up-regulated at 12 h after the exposure. In the sinoatrial node （SAN） of the rats,展开更多
Atrial fibrillation(AF)is the most common sustained cardiac arrhythmia,increasing in prevalence with age.Catheter ablation is recommended to symptomatic paroxysmal AF refractory or intolerant to at least one Class I o...Atrial fibrillation(AF)is the most common sustained cardiac arrhythmia,increasing in prevalence with age.Catheter ablation is recommended to symptomatic paroxysmal AF refractory or intolerant to at least one Class I or III antiarrhythmic medication.[1]Main current catheter ablation of AF with radiofrequency can give priority to,other include freezing,ultrasonic and laser ablation etc.Recent studies provides substantial information regarding the efficacy and safety of novel cryoballoon technology in creating pulmonary vein(PV)isolation.[2,3]Processed in cyroballoon ablation,some AF patients implanted with double chamber pacemaker are difficult to puncture atrial septal,because of the atrial electrode.My case report was as follows.展开更多
The end-stage renal disease population poses a challenge for obtaining venous access required for life-saving invasive cardiac procedures. In this case report, we describe an adult patient with end-stage renal disease...The end-stage renal disease population poses a challenge for obtaining venous access required for life-saving invasive cardiac procedures. In this case report, we describe an adult patient with end-stage renal disease in whom the hepatic vein was the only available access to implant a single-lead permanent cardiac pacemaker. A 63-year-old male with endstage renal disease on maintenance hemodialysis and permanent atrial fibrillation/atrial flutter presented with symptomatic bradycardia. Imaging studies revealed all traditional central venous access sites to be occluded/non-accessible. With the assistance of vascular interventional radiology, a trans-hepatic venous catheter was placed. This was then used to place a right ventricular pacing lead with close attention to numerous technical aspects. The procedure was completed successfully with placement of a single-lead permanent cardiac pacemaker.展开更多
Pacemaking dysfunction has become a significant disease that may contribute to heart rhythm disorders,syncope,and even death.Up to now,the best way to treat it is to implant electronic pacemakers.However,these have ma...Pacemaking dysfunction has become a significant disease that may contribute to heart rhythm disorders,syncope,and even death.Up to now,the best way to treat it is to implant electronic pacemakers.However,these have many disadvantages such as limited battery life,infection,and fixed pacing rate.There is an urgent need for a biological pacemaker(bio-pacemaker).This is expected to replace electronic devices because of its low risk of complications and the ability to respond to emotion.Here we survey the contemporary development of the bio-pacemaker by both experimental and computational approaches.The former mainly includes gene therapy and cell therapy,whilst the latter involves the use of multi-scale computer models of the heart,ranging from the single cell to the tissue slice.Up to now,a bio-pacemaker has been successfully applied in big mammals,but it still has a long way from clinical uses for the treatment of human heart diseases.It is hoped that the use of the computational model of a bio-pacemaker may accelerate this process.Finally,we propose potential research directions for generating a bio-pacemaker based on cardiac computational modeling.展开更多
The possibility of rats mesenchymal stem cells (MSCs) modified with murine hyperpolarization-activated cyclic nucleotide-gated 2 (mHCN2) gene as biological pacemakers in vitro was studied. The cultured MSCs were trans...The possibility of rats mesenchymal stem cells (MSCs) modified with murine hyperpolarization-activated cyclic nucleotide-gated 2 (mHCN2) gene as biological pacemakers in vitro was studied. The cultured MSCs were transfected with pIRES2-EGFP plasmid carrying enhanced green fluorescent protein (EGFP) gene and mHCN2 gene. The identification using restriction enzyme and sequencing indicated that the mHCN2 gene was inserted to the pIRES2-EGFP. Green fluorescence could be seen in MSCs after transfection for 24–48 h. The expression of mHCN2 mRNA and protein in the transfected cells was detected by RT-PCR and Western blot, and the quantity of mHCN2 mRNA and protein expression in transfected MSCs was 5.31 times and 7.55 times higher than that of the non-transfected MSCs respectively (P<0.05, P<0.05). IHCN2 was recorded by whole-cell patch clamp method. The effect of Cs+, a specific blocker of pacemaker current, was measured after perfusion by patch clamp. The results of inward current indicated that there was no inward current recording in non-transfected MSCs and a large voltage-dependent inward and Cs+-sensitive current activated on hyperpolarizations presented in the transfected MSCs. IHCN2 was fully activated around–140 mV with an activation threshold of –60 mV. The midpoint (V50) was –95.1±0.9 mV (n=9). The study demonstrates that mHCN2 mRNA and protein can be expressed and the currents of HCN2 channels can be detected in genetically modified MSCs. The gene-modified MSCs present a novel method for pacemaker genes into the heart or other electrical syncytia.展开更多
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
文摘This work proposes to design a fuzzy proportional-integral derivative (FPID) controller for dual-sensor cardiac pacemaker systems, which can automatically control the heart rate to accurately track a desired preset profile. The combination of fuzzy logic and conventional PID control approaches is adopted for the controller design based on dual-sensors. This controller offers good adaptation of the heart rate to the physiological needs of the patient under different states (rest and walk). Through comparing with the conventional fuzzy control algorithm, FPID provides a more suitable control strategy to determine a pacing rate in order to achieve a closer match between actual heart rate and a desired profile. To assist the heartbeat recovery, the stimuli with adjustable pacing rate is generated by the pacemaker according to the FPID controller, such actual heart rate may track the preset heart rate faithfully. Simulation results confirm that this proposed control design is effective for heartbeat recovery and maintenance. This study will be helpful not only for the analysis and treatment of bradycardias but also for improving the performance of medical devices.
文摘Cardiovascular disease is defined as a heart rate that is less than 60 bpm. Implantable cardiac devices such as pacemakers are widely used nowadays. In this paper, design and implementation of the heart model can be controlled to be the heart of a patient suffering from a decrease in heart rate (Bradycardia). A system is designed to sense and calculate the heart rate per minute and it is considered as an input to the controller. The design and implementation of Mamdani fuzzy controller to generate electric pulses that mimic the natural pacing system of the heart maintains an adequate heart rate by delivering controlled, rhythmic electrical stimuli to the chambers of the patient heart. The proposed controller is tested by using Matlab/Simulink program.
文摘BACKGROUND Esophagogastric varices are a common complication of cirrhosis with portal hypertension and endoscopic treatment has been recognized as a primary preventive and therapeutic option for such patients;however,it should be noted that bradyarrhythmia is regarded as one of the contraindications to endoscopic examination.Meanwhile,acute variceal bleeding may result in a high mortality rate in cirrhotic patients with portal hypertension accompanied by bradyarrhythmia.At present,there is an absence of reports concerning the treatment of such group of patients who underwent transjugular intrahepatic portosystemic shunt(TIPS).The present report details the case of a cirrhotic patient with acute variceal bleeding accompanied by bradyarrhythmia who underwent TIPS under temporary pacemaker protection.CASE SUMMARY We report the case of a 64-year-old male patient who was confirmed with bradyarrhythmia by ambulatory electrocardiogram 24 h before the operation.The patient was successfully treated by TIPS under temporary pacemaker protection.CONCLUSION In terms of cirrhotic patients with abnormal cardiac electrophysiological conduction,TIPS may be effective in reducing the complications of portal hypertension following the exclusion of severe pulmonary hypertension and heart failure,showing moderate feasibility in clinical applications.
基金Thework and the contributions were supported by the project SV4502261/SP2022/98‘Biomedical Engineering systems XVIII’.
文摘The usability assessment of a pacemaker is a complex task where the dedicated programmer for testing programmed algorithms is necessary.This paper provides the outcomes of development and complex testing of the artificial cardiac system to evaluate the pacemaker’s functionality.In this work,we used the modular laboratory platform ELVIS II and created graphical user interface in LabVIEW programming environment.The electrical model of the heart allows signals generation(right atrium,right ventricle)and the monitoring of the stimulation pulses.The LabVIEW user interface allows to set the parameters of the generated signals and the simulation of the cardiac rhythm disorders as well as the monitoring and visualization of the pacemaker behavior in real-time.The results demonstrate the capability of proposed system to evaluate the paced and sensed pulses.The proposed solution allows the scientists to test the behavior of any cardiac pacemaker for its pre-programmed settings and pacing mode.In addition,the proposed system can simulate various disorders and test cardiac pacemakers in different working modes.
文摘Objective: To inquire into the effect of systematic family nursing guidance on improving the Quality of Life for elderly patients with implanted cardiac pacemaker. Methods: 41 elderly patients in accordance with the corresponding requirements were studied after offering systematic family nursing guidance and surveyed through the questionnaires about the QOL (quality of life) respectively 1 month, 3 months and 6 months after leaving hospital. Results: Compared with that of 1 month and 3 months after the operation, the questionnaire scores for 6 months after the operation were found to have significant improvement, and the differences were statistically significant. Conclusion: Systematic family nursing guidance can effectively improve the QOL for elderly patients with implanted cardiac pacemaker, which makes them spend their old age in comfort and happiness.
文摘Objective:To investigate the effect of 12-lead electrocardiogram and 24-hour dynamic electrocardiogram in detecting pacemaker dysfunction and changes in cardiac function indexes in patients with pacemaker implantation.Methods:A total of 136 patients with pacemaker implantation in the First Clinical Medical College of Three Gorges University,Institute of Cardiovascular Disease of Three Gorges University and Yicang Central People’s Hospital from January 2023 to December 2024 were selected as the research objects.All patients received 12-lead electrocardiogram and 24-hour holter 3–14 days after implantation.Results:The overall detection rate of various types of pacemaker dysfunction by Holter was significantly higher than that by conventional ECG(27.21%vs.5.15%,χ^(2)=24.402,P<0.001).The overall arrhythmia detection rate of Holter was significantly higher than that of conventional electrocardiogram(57.35%vs.10.29%,χ^(2)=67.277,P<0.001).The time domain indexes of heart rate variability obtained by 24-hour continuous monitoring of Holter were significantly improved compared with those of conventional electrocardiogram(P<0.05).Conclusions:Compared with 12-lead electrocardiogram,24-hour holter monitoring can more accurately detect pacemaker dysfunction and arrhythmia in patients with pacemaker implantation,and provide more comprehensive data of heart rate variability,which is helpful for clinicians to better evaluate the cardiac function of patients and adjust treatment plans.
文摘BACKGROUND Autoimmune myocarditis(AM)associated with autoimmune diseases can cause complete atrioventricular block(CAVB),but the related autoantigens and the underlying mechanisms are unclear.Anti-SSA/Ro antibodies may play an important role in this process,but cases of AM with positive anti-SSA/Ro antibodies are rare.In addition,arrhythmias,such as atrioventricular block,are very common in patients with autoimmune diseases,but severe atrioventricular block requiring permanent pacemaker implantation is extremely rare.CASE SUMMARY The patient in this case had AM with anti-SSA/Ro antibody positivity,which was associated with connective tissue disease,and the patient subsequently developed CAVB.After intensive immunosuppressive therapy,the antibody test results became negative,and pulmonary hypertension significantly improved.However,the outcome of permanent pacemaker implantation did not change.CONCLUSION In clinical practice,the awareness of adult AM associated with autoimmune diseases combined with CAVB should be strengthened in clinicians,and anti-SSA/Ro antibodies may play a role in this process.Therefore,improving the detection of antibodies and early intervention,such as active immunosuppression therapy,may be very important for improving disease prognosis.For patients who do not respond to immunosuppressive therapy,implantation of a permanent pacemaker may become an essential treatment option.
文摘Objective To retrospectively identify risk factors and the prognosis for new-onset atrial fibrillation (AF)after implantation of dual-chamber pacemakers in elderly patients.Methods Consecutive patients aged >65years who underwent their first implantation of a dual-chamber permanent pacemaker in Beijing Anzhen Hospital from October 2013to May 2016were enrolled.Their complete program- ming and follow-up data were recorded.Follow-up end points included new-onset AF and major adverse cardiovascular and cerebrovascular events.Restdts Altogether,322patients were enrolled,with new-onset AF observed in 79(24.5%)during their follow-up.Multivariable analysis identified four independent predictors of new-onset AF in elderly patients after pacemaker implantation:hypertension (HR =3.040, 95%CI:1.09-3.05,P =0.00),age (HR =1.966,95%CI:1.57-3.68,P =0.01);left atrial enlargement (HR =1.645,95%CI:1.05-1.25,P = 0.03);high ventricular pacing rate (HR =1.137,95%CI:1.01-1.06,P =0.01).Univariable analysis indicated that the CHA2DS2-VASc score was also a risk factor for AF (HR =1.368,95%CI:1.178-1.589,P =0.002),whereas multivariable regression analysis did not. Kaplan-Meier survival analysis showed that the risk for ischemic stroke was significantly higher in the new-onset AF group than in the non-AF group (P <0.05).Conclusion Hypertension,age,left atrial enlargement,and high ventricular pacing rate were independent predictors of new-onset AF in elderly patients after implantation of a permanent pacemaker.New-onset AF increased the risk for ischemic stroke.
文摘Objective To assess the prevalence of the bleeding complications in pacemaker implanted patients receiving different antiplatelet regimens, and the influence of each regimen on hospital stays after device implantation. Methods We prospectively enrolled 364 patients receiving the cardiac rhythm device implantations in Fuwai Hospital from July 2012 to December 2013. Bleeding complications including pocket hematoma, hemothorax, cardiac tamponade and blood transfusion requirement were measured as endpoints. Post operation hospital stay was also included in the endpoints. Results Bleeding complications were detected in 15 patients （14 with hematoma, one with hemothorax） out of all 364 patients （4.12%）. Dual antiplatelet therapy （DAT） significantly increased hematoma （19.3%） compared with aspi- fin treatment （ASA） （3.2%, P = 0.001） and no antiplatelet therapy （1.9%, P 〈 0.001）. There was no significant difference in incidence of pocket hematoma between the ASA group and the control group （P = 0.45）. The post procedure hospital stay was longer in DAT group （5.45 ± 2.01 days） compared to those in the ASA group （3.65 ± 1.37 days, P 〈 0.05） or control group （3.99 ± 2.27 days, P 〈 0.05）. Pocket hema- toma was considered an independent predictor of hospital stay prolongation （OR： 5.26; 95% CI： 1.56-16.64; P = 0.007）. Conclusions Among the Chinese patients undergoing device implantation in this study, the use of dual antiplatelet agents significantly increased the risk of pocket hematoma complications and led to a longer hospital stay. Use of aspirin alone did not increase the risk.
基金Supported by the National Research Foundation of Korea Grant funded by the Korea Government(MSIP),No.2014R1A5A2009936
文摘AIM To investigate the effects of a water extract of Hwangryunhaedok-tang(HHTE) on the pacemaker potentials of mouse interstitial cells of Cajal(ICCs).METHODS We dissociated ICCs from small intestines and cultured. ICCs were immunologically identified using an antic-kit antibody. We used the whole-cell patch-clamp configuration to record the pacemaker potentials generated by cultured ICCs under the current clamp mode(I = 0). All experiments were performed at 30 ℃-32 ℃RESULTS HHTE dose-dependently depolarized ICC pacemaker potentials. Pretreatment with a 5-HT_3 receptor anta-gonist(Y25130) or a 5-HT_4 receptor antagonist(RS39604) blocked HHTE-induced pacemaker potential depolarizations, whereas pretreatment with a 5-HT7 receptor antagonist(SB269970) did not. Intracellular GDPβS inhibited HHTE-induced pacemaker potential depolarization and pretreatment with a Ca^(2+)-free solution or thapsigargin abolished the pacemaker potentials. In the presence of a Ca^(2+)-free solution or thapsigargin, HHTE did not depolarize ICC pacemaker potentials. In addition, HHTE-induced pacemaker potential depolarization was unaffected by a PKC inhibitor(calphostin C) or a Rho kinase inhibitor(Y27632). Of the four ingredients of HHT, Coptidis Rhizoma and Gardeniae Fructus more effectively inhibited pacemaker potential depolarization.CONCLUSION These results suggest that HHTE dose-dependently depolarizes ICC pacemaker potentials through 5-HT_3 and 5-HT_4 receptors via external and internal Ca^(2+) regulation and via G protein-, PKC-and Rho kinase-independent pathways.
文摘AIM:To determine if there were any interactions between cardiac devices and small bowel capsules secondary to electromagnetic interference (EMI) in patients who have undergone small bowel capsule endoscopy (SBCE).METHODS:Authors conducted a chart review of 20 patients with a cardiac pacemaker (CP) or implantable cardioverter defibrillator (ICD) who underwent continuous electrocardiographic monitoring during their SBCE from 2003-2008.authors searched for unexplained electrocardiogram (ECG) findings,changes in CP andICD set parameters,any abnormality in transmitted capsule data,and adverse clinical events.RESULTS:There were no adverse events or hemodynamically significant arrhythmias reported.CP and ICD set parameters were preserved.The majority of ECG abnormalities were also found in pre-or post-SBCE ECG tracings and the CP behavior during arrhythmias appeared appropriate.Two patients seemed to have episodes of undersensing by the CP.However,similar findings were documented in ECGs taken outside the time frame of the SBCE.One patient was observed to have a low signal encountered from the capsule resulting in lack of localization,but no images were lost.CONCLUSION:Capsule-induced EMI remains a possibility but is unlikely to be clinically important.CPinduced interference of SBCE is also possible,but is infrequent and does not result in loss of images transmitted by the capsule.
基金supported by National Key R & D Plan(2017YFC1104202).
文摘BACKGROUND: This study aims to investigate whether small balloon aortic valvuloplasty(BAV) reduces the need for permanent pacemaker implantation (PPMI) after transcatheter aortic valveimplantation (TAVI).METHODS: This was a retrospective analysis using data from our local TAVI database. SmallBAV was defined as a small balloon size (=18 mm) pre-dilatation. Normal BAV was defined as aballoon size >18 mm. The primary endpoint was the incidence of new PPMI.RESULTS: Of 99 consecutive TAVI patients, five patients were excluded due to pre-existingpermanent pacemaker. Patients in the small BAV group (n=57) had a signifi cantly lower PPMI ratecompared with the normal BAV group (n=37) (3.5% vs. 18.9%, P=0.026). Moderate or severe aorticvalve regurgitation post-procedure was similar between the small BAV and normal BAV groups (5.3%vs. 8.1%, P=0.480);likewise, the mean aortic gradient post-procedure did not differ significantly(11.5±5.2 mmHg vs. 12.2±7.3 mmHg, 1 mmHg=0.133 kPa, P=0.580) between the groups. Devicesuccess rates were also similar (94.7% vs. 91.8%, P=0.680). In multivariable analysis, small BAV(P=0.027), the ratio of prosthesis diameter to annulus diameter (P=0.048), and mean aortic gradientby echo in the basement (P=0.021) were independent predictors of PPMI.CONCLUSIONS: The small BAV strategy is associated with a low rate of permanentpacemaker implantation after transcatheter self-expanding valve implantation in this single-centerobservational study.
文摘Background Permanent pacing is the therapy of choice for treating severe and/or symptomatic bradyarrhythmias. The number of very elderly patients receiving pacemakers is increasing and little is known about survival in this specific subgroup. This study is aimed at assessing the actual survival of patients requiring pacing therapy at age > 85 years and investigating variables associated with death. Methods Between 2010 and 2017, 572 patients aged ≥ 85 years underwent pacemaker implantation for conventional bradycardia indications in Department of Cardiology, S. Chiara Hospital, Italy. Results Thirty percent of patients were ≥ 90-year-old and comorbidities were frequent. Fifty-seven percent of patients required pacing for prognostic reasons(acquired atrioventricular block), and the remaining for relief of bradycardia symptoms. A dual-chamber pacemaker was implanted in 34% of patients. The 5-year survival was 45%(standard error: 3%), and the 8-year survival was 26%(standard error: 4%). The risk of death was similar in patients who received pacemaker for symptom relief and for prognostic reasons in the overall population(HR = 1.19, 95% CI: 0.93–1.52, P = 0.156), as well as in the ≥ 90-year-old group(HR = 1.39, 95% CI: 0.92–2.11, P = 0.102). At multivariate analysis, following variables were associated with death: higher age, lower ejection fraction, dementia/dysautonomia and diagnosis of cancer. The pacing indication and the implantation of a single chamber pacemaker were not associated with worse prognosis. Conclusions This study showed a good life expectancy in patients aged ≥ 85 years who received a pacemaker. Strong risk factors for all-cause death were non-cardiac. Pacemaker therapy seems a clinically effective therapeutic option to improve survival and to control bradyarrhythmia-related symptoms in very elderly patients.
文摘To investigate the mechanisms of microwave induced pacemaker cell injuries, Wistar rats and the primary pacemaker cells of newborn Wistar rats were exposed to microwave at average power density of 50 mW/cm2. Slower spontaneous beating rate, intercellular Ca2＋ aggregation and cell membrane perforation were detected immediately after the exposure. Moreover, hyperpolarizationactivated cyclic nucleotide-gated cation channel 4 （HCN4） was down-regulated immediately after the exposure and up-regulated at 12 h after the exposure. In the sinoatrial node （SAN） of the rats,
文摘Atrial fibrillation(AF)is the most common sustained cardiac arrhythmia,increasing in prevalence with age.Catheter ablation is recommended to symptomatic paroxysmal AF refractory or intolerant to at least one Class I or III antiarrhythmic medication.[1]Main current catheter ablation of AF with radiofrequency can give priority to,other include freezing,ultrasonic and laser ablation etc.Recent studies provides substantial information regarding the efficacy and safety of novel cryoballoon technology in creating pulmonary vein(PV)isolation.[2,3]Processed in cyroballoon ablation,some AF patients implanted with double chamber pacemaker are difficult to puncture atrial septal,because of the atrial electrode.My case report was as follows.
文摘The end-stage renal disease population poses a challenge for obtaining venous access required for life-saving invasive cardiac procedures. In this case report, we describe an adult patient with end-stage renal disease in whom the hepatic vein was the only available access to implant a single-lead permanent cardiac pacemaker. A 63-year-old male with endstage renal disease on maintenance hemodialysis and permanent atrial fibrillation/atrial flutter presented with symptomatic bradycardia. Imaging studies revealed all traditional central venous access sites to be occluded/non-accessible. With the assistance of vascular interventional radiology, a trans-hepatic venous catheter was placed. This was then used to place a right ventricular pacing lead with close attention to numerous technical aspects. The procedure was completed successfully with placement of a single-lead permanent cardiac pacemaker.
基金Project supported by the National Natural Science Foundation of China(Nos.61572152,61601143,and 81770328)the Science Technology and Innovation Commission of Shenzhen Municipality(Nos.JCYJ20151029173639477 and JSGG20160229125049615)the China Postdoctoral Science Foundation(No.2015M581448)。
文摘Pacemaking dysfunction has become a significant disease that may contribute to heart rhythm disorders,syncope,and even death.Up to now,the best way to treat it is to implant electronic pacemakers.However,these have many disadvantages such as limited battery life,infection,and fixed pacing rate.There is an urgent need for a biological pacemaker(bio-pacemaker).This is expected to replace electronic devices because of its low risk of complications and the ability to respond to emotion.Here we survey the contemporary development of the bio-pacemaker by both experimental and computational approaches.The former mainly includes gene therapy and cell therapy,whilst the latter involves the use of multi-scale computer models of the heart,ranging from the single cell to the tissue slice.Up to now,a bio-pacemaker has been successfully applied in big mammals,but it still has a long way from clinical uses for the treatment of human heart diseases.It is hoped that the use of the computational model of a bio-pacemaker may accelerate this process.Finally,we propose potential research directions for generating a bio-pacemaker based on cardiac computational modeling.
文摘The possibility of rats mesenchymal stem cells (MSCs) modified with murine hyperpolarization-activated cyclic nucleotide-gated 2 (mHCN2) gene as biological pacemakers in vitro was studied. The cultured MSCs were transfected with pIRES2-EGFP plasmid carrying enhanced green fluorescent protein (EGFP) gene and mHCN2 gene. The identification using restriction enzyme and sequencing indicated that the mHCN2 gene was inserted to the pIRES2-EGFP. Green fluorescence could be seen in MSCs after transfection for 24–48 h. The expression of mHCN2 mRNA and protein in the transfected cells was detected by RT-PCR and Western blot, and the quantity of mHCN2 mRNA and protein expression in transfected MSCs was 5.31 times and 7.55 times higher than that of the non-transfected MSCs respectively (P<0.05, P<0.05). IHCN2 was recorded by whole-cell patch clamp method. The effect of Cs+, a specific blocker of pacemaker current, was measured after perfusion by patch clamp. The results of inward current indicated that there was no inward current recording in non-transfected MSCs and a large voltage-dependent inward and Cs+-sensitive current activated on hyperpolarizations presented in the transfected MSCs. IHCN2 was fully activated around–140 mV with an activation threshold of –60 mV. The midpoint (V50) was –95.1±0.9 mV (n=9). The study demonstrates that mHCN2 mRNA and protein can be expressed and the currents of HCN2 channels can be detected in genetically modified MSCs. The gene-modified MSCs present a novel method for pacemaker genes into the heart or other electrical syncytia.
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）.
