Despite advances in intelligent medical care,difficulties remain.Due to its complicated governance,designing,planning,improving,and managing the cardiac system remains difficult.Oversight,including intelligent monitor...Despite advances in intelligent medical care,difficulties remain.Due to its complicated governance,designing,planning,improving,and managing the cardiac system remains difficult.Oversight,including intelligent monitoring,feedback systems,and management practises,is unsuccessful.Current platforms cannot deliver lifelong personal health management services.Insufficient accuracy in patient crisis warning programmes.No frequent,direct interaction between healthcare workers and patients is visible.Physical medical systems and intelligent information systems are not integrated.This study introduces the Advanced Cardiac Twin(ACT)model integrated with Artificial Neural Network(ANN)to handle real-time monitoring,decision-making,and crisis prediction.THINGSPEAK is used to create an IoT platform that accepts patient sensor data.Importing these data sets into MATLAB allows display and analysis.A myocardial ischemia research examined Health Condition Tracking’s(HCT’s)potential.In the case study,75%of the training sets(Xt),15%of the verified data,and 10%of the test data were used.Training set feature values(Xt)were given with the data.Training,Validation,and Testing accuracy rates were 99.9%,99.9%,and 99.9%,respectively.General research accuracy was 99.9%.The proposed HCT system and Artificial Neural Network(ANN)model gather historical and real-time data to manage and anticipate cardiac issues.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
Artificial intelligence(AI)is the process of having a computational program that can perform tasks of human intelligence by mimicking human thought processes.AI is a rapidly evolving transdisciplinary field which inte...Artificial intelligence(AI)is the process of having a computational program that can perform tasks of human intelligence by mimicking human thought processes.AI is a rapidly evolving transdisciplinary field which integrates many elements to develop algorithms that aim to simulate human intuition,decision-making,and object recognition.The overarching aims of AI in cardiovascular medicine are threefold:To optimize patient care,improve efficiency,and improve clinical outcomes.In cardiology,there has been a growth in the potential sources of new patient data,as well as advances in investigations and therapies,which position the field well to uniquely benefit from AI.In this editorial,we highlight some of the main research priorities currently and where the next steps are heading us.展开更多
The deleterious effects of long-term right ventricular pacing necessitated the search for alternative pacing sites which could prevent or alleviate pacinginduced cardiomyopathy.Until recently,biventricular pacing(BiVP...The deleterious effects of long-term right ventricular pacing necessitated the search for alternative pacing sites which could prevent or alleviate pacinginduced cardiomyopathy.Until recently,biventricular pacing(BiVP)was the only modality which could mitigate or prevent pacing induced dysfunction.Further,BiVP could resynchronize the baseline electromechanical dssynchrony in heart failure and improve outcomes.However,the high non-response rate of around 20%-30%remains a major limitation.This non-response has been largely attributable to the direct non-physiological stimulation of the left ventricular myocardium bypassing the conduction system.To overcome this limitation,the concept of conduction system pacing(CSP)came up.Despite initial success of the first CSP via His bundle pacing(HBP),certain drawbacks including lead instability and dislodgements,steep learning curve and rapid battery depletion on many occasions prevented its widespread use for cardiac resynchronization therapy(CRT).Subsequently,CSP via left bundle branch-area pacing(LBBP)was developed in 2018,which over the last few years has shown efficacy comparable to BiVP-CRT in small observational studies.Further,its safety has also been well established and is largely free of the pitfalls of the HBP-CRT.In the recent metanalysis by Yasmin et al,comprising of 6 studies with 389 participants,LBBPCRT was superior to BiVP-CRT in terms of QRS duration,left ventricular ejection fraction,cardiac chamber dimensions,lead thresholds,and functional status amongst heart failure patients with left bundle branch block.However,there are important limitations of the study including the small overall numbers,inclusion of only a single small randomized controlled trial(RCT)and a small follow-up duration.Further,the entire study population analyzed was from China which makes generalizability a concern.Despite the concerns,the meta-analysis adds to the growing body of evidence demonstrating the efficacy of LBBP-CRT.At this stage,one must acknowledge that the fact that still our opinions on this technique are largely based on observational data and there is a dire need for larger RCTs to ascertain the position of LBBPCRT in management of heart failure patients with left bundle branch block.展开更多
With the widespread application of artificial permanent pacemakers in clinical practice,there have been new changes in the indications for pacemaker implantation.The current clinical indications include high atriovent...With the widespread application of artificial permanent pacemakers in clinical practice,there have been new changes in the indications for pacemaker implantation.The current clinical indications include high atrioventricular block,sick sinus syndrome,cardiac resynchronization therapy for heart failure,and implantation of cardioverter defibrillators for ventricular arrhythmias.The implantation of a pacemaker can improve the quality of life and prognosis of patients with arrhythmia.In the past,permanent pacemaker implantation was performed in clinical practice,and the right ventricular pacing electrode was often fixed at the apex of the right ventricle,which belongs to non physiological pacing.Through long-term clinical follow-up,it was found that apex pacing can easily cause abnormal depolarization of the left ventricle,asynchronous contraction of the myocardium,and ultimately lead to myocardial fibrosis,which has adverse effects on the patient's cardiac function and psychological state.In recent years,Scholars have found that pacing in the right ventricular outflow tract septum is closer to the atrioventricular node and closer to the His bundle Purkinje fibers.The pacing impulse almost simultaneously expands towards both ventricles,closer to the physiological pacing state,thereby reducing the occurrence of cardiovascular events in patients.This article explores the impact of pacing in different parts of the heart on the cardiac function and psychological state of patients based on clinical data from the past three years.展开更多
The case report presented in this edition by Mu et al.The report presents a case of atrial septal defect(ASD)associated with electrocardiographic changes,noting that the crochetage sign resolved after Selective His Bu...The case report presented in this edition by Mu et al.The report presents a case of atrial septal defect(ASD)associated with electrocardiographic changes,noting that the crochetage sign resolved after Selective His Bundle Pacing(S-HBP)without requiring surgical closure.The mechanisms behind the appearance and resolution of the crochetage sign remain unclear.The authors observed the dis-appearance of the crochetage sign post-S-HBP,suggesting a possible correlation between these specific R waves and the cardiac conduction system.This editorial aims to explore various types of ASD and their relationship with the cardiac con-duction system,highlighting the diagnostic significance of the crochetage sign in ASD.展开更多
The right atrial appendage (RAA) and right ventricular apex (RVA) have been widely considered as conventional sites for typical dual-chamber atrio-ventricular cardiac (DDD) pacing. Unfortunately conventional RAA pacin...The right atrial appendage (RAA) and right ventricular apex (RVA) have been widely considered as conventional sites for typical dual-chamber atrio-ventricular cardiac (DDD) pacing. Unfortunately conventional RAA pacing seems not to be able to prevent atrial fibrillation in DDD pacing for tachycardia-bradycardia syndrome, and the presence of a left bundle branch type of activation induced by RVA pacing can have negative effects. A new technology with active screw-in leads permits a more physiological atrial and right ventricular pacing. In this review, we highlight the positive effects of pacing of these new and easily selected sites. The septal atrial lead permits a shorter and more homogeneous atrial activation, allowing better prevention of paroxysmal atrial fibrillation. The para-Hisian pacing can be achieved in a simpler and more reliable way with respect to biventricular pacing and direct Hisian pacing. We await larger trials to consider this "easy and physiological pacing" as a first approach in patients who need a high frequency of pacing.展开更多
Background Super-responders (SRs) are defined as patients who show crucial cardiac function improvement after cardiac resynchro- nization therapy (CRT). The purpose of this study is to identify and validate predic...Background Super-responders (SRs) are defined as patients who show crucial cardiac function improvement after cardiac resynchro- nization therapy (CRT). The purpose of this study is to identify and validate predictors of SRs after CRT. Methods This study enrolled 201 patients who underwent CRT during the period from 2010 to 2014. Clinical and echocardiographic evaluations were conducted before CRT and 6 months after. Patients with a decrease in New York Heart Association (NYHA) fimctional class 〉 1, a decrease in left ventricular end-systolic volume (LVESV) ≥ 15%, and a final left ventricular ejection fraction (LVEF) ≥ 45% were classified as SRs. Results 29% of the 201 patients who underwent CRT were identified as SRs. At baseline, SRs had significantly smaller left atrial diameter (LAD), LVESV, left ventricular end-diastolic volume (LVEDV) and higher LVEF than the non-super-responders (non-SRs). The percentage of patients using angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (ACEI/ARB) was higher in SRs than non-SRs. Most SRs had Biventricular (BiV) pacing percentage greater than 98% six months after CRT. In the multivariate logistic regression analysis, the independ- ent predictors of SRs were lower LVEDV [odd ratios (OR): 0.93; confidence intervals (CI): 0.90-0.97], use of ACEI/ARB (OR: 0.33; CI: 0.13~3.82) and BiV pacing percentage greater than 98% (OR: 0.29; CI: 0.16~.87). Conclusion Patients with a better compliance of ACEI/ARB and a less ectatic ventricular geometry before CRT tends to have a greater probability of becoming SRs. Higher percentage of BiV pacing is essential for becoming SRs.展开更多
Objective To evaluate left univentricular (LUV) pacing for cardiac resynchronization therapy (CRT) using a rate-adaptive atrioven- tricular delay (RAAVD) algorithm to track physiological atrioventricular delay ...Objective To evaluate left univentricular (LUV) pacing for cardiac resynchronization therapy (CRT) using a rate-adaptive atrioven- tricular delay (RAAVD) algorithm to track physiological atrioventricular delay (AVD). Methods A total of 72 patients with congestive heart failure (CHF) were randomized to RAAVD LUV pacing versus standard biventricular (BiV) pacing in a 1 : 1 ratio. Echocardiography was used to optimize AVD for both groups. The effects of sequential BiV pacing and LUV pacing with optimized A-V (right atrio-LV) delay using an RAAVD algorithm were compared. The standard deviation (SD) of the S/R ratio in lead VI at five heart rate (HR) segments (Rs/R-SD5), defined as the "tracking index," was used to evaluate the accuracy of the RAAVD algorithm for tracking physiological AVD. Results TheQRS complex duration (132 ± 9.8 vs. 138± 10ms, P 〈 0.05), the time required for optimization (21 ±5 vs. 50±8min, P〈 0.001), the mitral regurgitant area (1.9 ± 1.1 vs. 2.5 ± 1.3 em2, P 〈 0.05), the interventricular mechanical delay time (60.7 ± 13.3 ms vs. 68.3 ± 14.2 ms, P 〈 0.05), and the average annual cost (13,200 ± 1000 vs. 21,600 ± 2000 RMB, P 〈 0.001) in the RAAVD LUV pacing group were significantly less than those in the standard BiV pacing group. The aortic valve velocity-time integral in the RAAVD LUV pacing group was greater than that in the standard BiV pacing group (22.7 ± 2.2 vs. 21.4 ± 2.1 cm, P 〈 0.05). The Rs/R-SD5 was 4.08 ± 1.91 in the RAAVD LUV pacing group, and was significantly negatively correlated with improved left ventricular ejection fraction (LVEF) (ALVEF, Pearson's r = -0.427, P = 0.009), and positively correlated with New York Heart Association class (Spearman's r - 0.348, P 0.037). Conclusions RAAVD LUV pacing is as effective as standard BiV pacing, can be more physiological than standard BiV pacing, and can de- crease the average annual cost of CRT.展开更多
Cardiac pacing is a medical device to help human to overcome arrhythmia and to recover the regular beats of heart. A helical configuration of electrode tip is a new type of cardiac pacing lead distal tip. The helical ...Cardiac pacing is a medical device to help human to overcome arrhythmia and to recover the regular beats of heart. A helical configuration of electrode tip is a new type of cardiac pacing lead distal tip. The helical electrode attaches itself to the desired site of heart by screwing its helical tip into the myocardium. In vivo experiments on anesthetized dogs were carried out to measure the acute interactions between helical electrode and myocardium during screw-in and pull-out processes. These data would be helpful for electrode tip design and electrode/myocardium adherence safety evaluation. They also provide reliability data for clinical site choice of human heart to implant and to fix the pacing lead. A special design of the helical tip using strain gauges is instrumented for the measurement of the screw-in and pull-out forces. We obtained the data of screw-in torques and pull-out forces for five different types of helical electrodes at nine designed sites on ten canine hearts. The results indicate that the screw-in torques increased steplike while the torque-time curves presente saw-tooth fashion. The maximum torque has a range of 0.3-1.9 Nmm. Obvious differences are observed for different types of helical tips and for different test sites. Large pull-out forces are frequently obtained at epicardium of left ventricle and right ventricle lateral wall, and the forces obtained at right ventricle apex and outflow tract of right ventricle are normally small. The differences in pull-out forces are dictated by the geometrical configuration of helix and regional structures of heart muscle.展开更多
The endocardial electrodes were placed in endoventriculus beside bed withoutfluoroscopy in 9 patients who required temporary cardiac pacing and theresults were satisfactory.The manipulatory points are below:operatingc...The endocardial electrodes were placed in endoventriculus beside bed withoutfluoroscopy in 9 patients who required temporary cardiac pacing and theresults were satisfactory.The manipulatory points are below:operatingcarefully with lightly and softly handling,noticing hand’s feeling,tryingagain by roling the electrode and/or changing its top’s direction whenmeeting with venous valves or branches.Judging the position of electrode’stop according to the right ventricular luminal electrogram.As comparedwith the setting of electrode under X ray,our method is superior in savingtime and requires less instrumente,the patients needn’t be moved,bothphysicans and patients are avoided X radiation’s injury.展开更多
Background: Heart failure is a major public health challenge in sub-Saharan Africa. In patients with chronic Heart Failure and cardiac desynchrony, studies have suggested that cardiac resynchronization, can improve ca...Background: Heart failure is a major public health challenge in sub-Saharan Africa. In patients with chronic Heart Failure and cardiac desynchrony, studies have suggested that cardiac resynchronization, can improve cardiac function and the quality of life of patients. However, in Sub-Saharan Africa, very few studies have been done on cardiac resynchronization which is in its infancy. The aim of this study is to report the local data from our hospital. Method: It was a transversal, descriptive and analytical study conducted from November 2019 to September 2022 at the Cardiology Department of the Principal Hospital of Dakar. Results: Twelve patients were implanted for Cardiac Resynchronization Therapy (CRT). The sex ratio was 8 males/4 females. The average age was 67 ± 11 years. Ten patients had non-ischemic heart disease and the two others had ischemic one. All of them had NYHA III or IV scores before CRT. The Quality of Life (QOL) was judged as poor by all of the patients. The average duration of QRS was 156 ± 9 ms. 27.9% ± 5% was the mean Left Ventricular ejection fraction (LVEF). Complications occur in 3/12 patients (25%). It was one CS vein dissection, one micro LV lead dislodgement and one phrenic nerve stimulation. Nine patients, who were considered as responders, had an improvement of QOL and NYHA, the LVEF increased and the end-diastolic dimension, and the duration of the QRS interval all decreased. Two patients do not respond and one (1) who had permanent atrial fibrillation, was a secondary responder after an atrioventricular junction ablation. Conclusion: Cardiac resynchronization is a therapy that improves the QOL of patients, the LVEF and reduces the duration of the QRS interval. However, this procedure is not without risk of complications. In sub-Saharan Africa, the major challenge is to improve the financial accessibility of this therapy for the population.展开更多
文摘Despite advances in intelligent medical care,difficulties remain.Due to its complicated governance,designing,planning,improving,and managing the cardiac system remains difficult.Oversight,including intelligent monitoring,feedback systems,and management practises,is unsuccessful.Current platforms cannot deliver lifelong personal health management services.Insufficient accuracy in patient crisis warning programmes.No frequent,direct interaction between healthcare workers and patients is visible.Physical medical systems and intelligent information systems are not integrated.This study introduces the Advanced Cardiac Twin(ACT)model integrated with Artificial Neural Network(ANN)to handle real-time monitoring,decision-making,and crisis prediction.THINGSPEAK is used to create an IoT platform that accepts patient sensor data.Importing these data sets into MATLAB allows display and analysis.A myocardial ischemia research examined Health Condition Tracking’s(HCT’s)potential.In the case study,75%of the training sets(Xt),15%of the verified data,and 10%of the test data were used.Training set feature values(Xt)were given with the data.Training,Validation,and Testing accuracy rates were 99.9%,99.9%,and 99.9%,respectively.General research accuracy was 99.9%.The proposed HCT system and Artificial Neural Network(ANN)model gather historical and real-time data to manage and anticipate cardiac issues.
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Artificial intelligence(AI)is the process of having a computational program that can perform tasks of human intelligence by mimicking human thought processes.AI is a rapidly evolving transdisciplinary field which integrates many elements to develop algorithms that aim to simulate human intuition,decision-making,and object recognition.The overarching aims of AI in cardiovascular medicine are threefold:To optimize patient care,improve efficiency,and improve clinical outcomes.In cardiology,there has been a growth in the potential sources of new patient data,as well as advances in investigations and therapies,which position the field well to uniquely benefit from AI.In this editorial,we highlight some of the main research priorities currently and where the next steps are heading us.
文摘The deleterious effects of long-term right ventricular pacing necessitated the search for alternative pacing sites which could prevent or alleviate pacinginduced cardiomyopathy.Until recently,biventricular pacing(BiVP)was the only modality which could mitigate or prevent pacing induced dysfunction.Further,BiVP could resynchronize the baseline electromechanical dssynchrony in heart failure and improve outcomes.However,the high non-response rate of around 20%-30%remains a major limitation.This non-response has been largely attributable to the direct non-physiological stimulation of the left ventricular myocardium bypassing the conduction system.To overcome this limitation,the concept of conduction system pacing(CSP)came up.Despite initial success of the first CSP via His bundle pacing(HBP),certain drawbacks including lead instability and dislodgements,steep learning curve and rapid battery depletion on many occasions prevented its widespread use for cardiac resynchronization therapy(CRT).Subsequently,CSP via left bundle branch-area pacing(LBBP)was developed in 2018,which over the last few years has shown efficacy comparable to BiVP-CRT in small observational studies.Further,its safety has also been well established and is largely free of the pitfalls of the HBP-CRT.In the recent metanalysis by Yasmin et al,comprising of 6 studies with 389 participants,LBBPCRT was superior to BiVP-CRT in terms of QRS duration,left ventricular ejection fraction,cardiac chamber dimensions,lead thresholds,and functional status amongst heart failure patients with left bundle branch block.However,there are important limitations of the study including the small overall numbers,inclusion of only a single small randomized controlled trial(RCT)and a small follow-up duration.Further,the entire study population analyzed was from China which makes generalizability a concern.Despite the concerns,the meta-analysis adds to the growing body of evidence demonstrating the efficacy of LBBP-CRT.At this stage,one must acknowledge that the fact that still our opinions on this technique are largely based on observational data and there is a dire need for larger RCTs to ascertain the position of LBBPCRT in management of heart failure patients with left bundle branch block.
文摘With the widespread application of artificial permanent pacemakers in clinical practice,there have been new changes in the indications for pacemaker implantation.The current clinical indications include high atrioventricular block,sick sinus syndrome,cardiac resynchronization therapy for heart failure,and implantation of cardioverter defibrillators for ventricular arrhythmias.The implantation of a pacemaker can improve the quality of life and prognosis of patients with arrhythmia.In the past,permanent pacemaker implantation was performed in clinical practice,and the right ventricular pacing electrode was often fixed at the apex of the right ventricle,which belongs to non physiological pacing.Through long-term clinical follow-up,it was found that apex pacing can easily cause abnormal depolarization of the left ventricle,asynchronous contraction of the myocardium,and ultimately lead to myocardial fibrosis,which has adverse effects on the patient's cardiac function and psychological state.In recent years,Scholars have found that pacing in the right ventricular outflow tract septum is closer to the atrioventricular node and closer to the His bundle Purkinje fibers.The pacing impulse almost simultaneously expands towards both ventricles,closer to the physiological pacing state,thereby reducing the occurrence of cardiovascular events in patients.This article explores the impact of pacing in different parts of the heart on the cardiac function and psychological state of patients based on clinical data from the past three years.
基金Supported by Guangzhou Municipal Science and Technology Bureau's 2024 Basic and Applied Basic Research Topic,China,No.2024A04J4491,and No.2024A04J4254the Scientific Research Project of Guangdong Provincial Bureau of Traditional Chinese Medicine,China,No.2022ZYYJ01the Soft Science Research Program of Luohu District,Shenzhen,China,No.LX202402016.
文摘The case report presented in this edition by Mu et al.The report presents a case of atrial septal defect(ASD)associated with electrocardiographic changes,noting that the crochetage sign resolved after Selective His Bundle Pacing(S-HBP)without requiring surgical closure.The mechanisms behind the appearance and resolution of the crochetage sign remain unclear.The authors observed the dis-appearance of the crochetage sign post-S-HBP,suggesting a possible correlation between these specific R waves and the cardiac conduction system.This editorial aims to explore various types of ASD and their relationship with the cardiac con-duction system,highlighting the diagnostic significance of the crochetage sign in ASD.
文摘The right atrial appendage (RAA) and right ventricular apex (RVA) have been widely considered as conventional sites for typical dual-chamber atrio-ventricular cardiac (DDD) pacing. Unfortunately conventional RAA pacing seems not to be able to prevent atrial fibrillation in DDD pacing for tachycardia-bradycardia syndrome, and the presence of a left bundle branch type of activation induced by RVA pacing can have negative effects. A new technology with active screw-in leads permits a more physiological atrial and right ventricular pacing. In this review, we highlight the positive effects of pacing of these new and easily selected sites. The septal atrial lead permits a shorter and more homogeneous atrial activation, allowing better prevention of paroxysmal atrial fibrillation. The para-Hisian pacing can be achieved in a simpler and more reliable way with respect to biventricular pacing and direct Hisian pacing. We await larger trials to consider this "easy and physiological pacing" as a first approach in patients who need a high frequency of pacing.
文摘Background Super-responders (SRs) are defined as patients who show crucial cardiac function improvement after cardiac resynchro- nization therapy (CRT). The purpose of this study is to identify and validate predictors of SRs after CRT. Methods This study enrolled 201 patients who underwent CRT during the period from 2010 to 2014. Clinical and echocardiographic evaluations were conducted before CRT and 6 months after. Patients with a decrease in New York Heart Association (NYHA) fimctional class 〉 1, a decrease in left ventricular end-systolic volume (LVESV) ≥ 15%, and a final left ventricular ejection fraction (LVEF) ≥ 45% were classified as SRs. Results 29% of the 201 patients who underwent CRT were identified as SRs. At baseline, SRs had significantly smaller left atrial diameter (LAD), LVESV, left ventricular end-diastolic volume (LVEDV) and higher LVEF than the non-super-responders (non-SRs). The percentage of patients using angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (ACEI/ARB) was higher in SRs than non-SRs. Most SRs had Biventricular (BiV) pacing percentage greater than 98% six months after CRT. In the multivariate logistic regression analysis, the independ- ent predictors of SRs were lower LVEDV [odd ratios (OR): 0.93; confidence intervals (CI): 0.90-0.97], use of ACEI/ARB (OR: 0.33; CI: 0.13~3.82) and BiV pacing percentage greater than 98% (OR: 0.29; CI: 0.16~.87). Conclusion Patients with a better compliance of ACEI/ARB and a less ectatic ventricular geometry before CRT tends to have a greater probability of becoming SRs. Higher percentage of BiV pacing is essential for becoming SRs.
文摘Objective To evaluate left univentricular (LUV) pacing for cardiac resynchronization therapy (CRT) using a rate-adaptive atrioven- tricular delay (RAAVD) algorithm to track physiological atrioventricular delay (AVD). Methods A total of 72 patients with congestive heart failure (CHF) were randomized to RAAVD LUV pacing versus standard biventricular (BiV) pacing in a 1 : 1 ratio. Echocardiography was used to optimize AVD for both groups. The effects of sequential BiV pacing and LUV pacing with optimized A-V (right atrio-LV) delay using an RAAVD algorithm were compared. The standard deviation (SD) of the S/R ratio in lead VI at five heart rate (HR) segments (Rs/R-SD5), defined as the "tracking index," was used to evaluate the accuracy of the RAAVD algorithm for tracking physiological AVD. Results TheQRS complex duration (132 ± 9.8 vs. 138± 10ms, P 〈 0.05), the time required for optimization (21 ±5 vs. 50±8min, P〈 0.001), the mitral regurgitant area (1.9 ± 1.1 vs. 2.5 ± 1.3 em2, P 〈 0.05), the interventricular mechanical delay time (60.7 ± 13.3 ms vs. 68.3 ± 14.2 ms, P 〈 0.05), and the average annual cost (13,200 ± 1000 vs. 21,600 ± 2000 RMB, P 〈 0.001) in the RAAVD LUV pacing group were significantly less than those in the standard BiV pacing group. The aortic valve velocity-time integral in the RAAVD LUV pacing group was greater than that in the standard BiV pacing group (22.7 ± 2.2 vs. 21.4 ± 2.1 cm, P 〈 0.05). The Rs/R-SD5 was 4.08 ± 1.91 in the RAAVD LUV pacing group, and was significantly negatively correlated with improved left ventricular ejection fraction (LVEF) (ALVEF, Pearson's r = -0.427, P = 0.009), and positively correlated with New York Heart Association class (Spearman's r - 0.348, P 0.037). Conclusions RAAVD LUV pacing is as effective as standard BiV pacing, can be more physiological than standard BiV pacing, and can de- crease the average annual cost of CRT.
文摘Cardiac pacing is a medical device to help human to overcome arrhythmia and to recover the regular beats of heart. A helical configuration of electrode tip is a new type of cardiac pacing lead distal tip. The helical electrode attaches itself to the desired site of heart by screwing its helical tip into the myocardium. In vivo experiments on anesthetized dogs were carried out to measure the acute interactions between helical electrode and myocardium during screw-in and pull-out processes. These data would be helpful for electrode tip design and electrode/myocardium adherence safety evaluation. They also provide reliability data for clinical site choice of human heart to implant and to fix the pacing lead. A special design of the helical tip using strain gauges is instrumented for the measurement of the screw-in and pull-out forces. We obtained the data of screw-in torques and pull-out forces for five different types of helical electrodes at nine designed sites on ten canine hearts. The results indicate that the screw-in torques increased steplike while the torque-time curves presente saw-tooth fashion. The maximum torque has a range of 0.3-1.9 Nmm. Obvious differences are observed for different types of helical tips and for different test sites. Large pull-out forces are frequently obtained at epicardium of left ventricle and right ventricle lateral wall, and the forces obtained at right ventricle apex and outflow tract of right ventricle are normally small. The differences in pull-out forces are dictated by the geometrical configuration of helix and regional structures of heart muscle.
文摘The endocardial electrodes were placed in endoventriculus beside bed withoutfluoroscopy in 9 patients who required temporary cardiac pacing and theresults were satisfactory.The manipulatory points are below:operatingcarefully with lightly and softly handling,noticing hand’s feeling,tryingagain by roling the electrode and/or changing its top’s direction whenmeeting with venous valves or branches.Judging the position of electrode’stop according to the right ventricular luminal electrogram.As comparedwith the setting of electrode under X ray,our method is superior in savingtime and requires less instrumente,the patients needn’t be moved,bothphysicans and patients are avoided X radiation’s injury.
文摘Background: Heart failure is a major public health challenge in sub-Saharan Africa. In patients with chronic Heart Failure and cardiac desynchrony, studies have suggested that cardiac resynchronization, can improve cardiac function and the quality of life of patients. However, in Sub-Saharan Africa, very few studies have been done on cardiac resynchronization which is in its infancy. The aim of this study is to report the local data from our hospital. Method: It was a transversal, descriptive and analytical study conducted from November 2019 to September 2022 at the Cardiology Department of the Principal Hospital of Dakar. Results: Twelve patients were implanted for Cardiac Resynchronization Therapy (CRT). The sex ratio was 8 males/4 females. The average age was 67 ± 11 years. Ten patients had non-ischemic heart disease and the two others had ischemic one. All of them had NYHA III or IV scores before CRT. The Quality of Life (QOL) was judged as poor by all of the patients. The average duration of QRS was 156 ± 9 ms. 27.9% ± 5% was the mean Left Ventricular ejection fraction (LVEF). Complications occur in 3/12 patients (25%). It was one CS vein dissection, one micro LV lead dislodgement and one phrenic nerve stimulation. Nine patients, who were considered as responders, had an improvement of QOL and NYHA, the LVEF increased and the end-diastolic dimension, and the duration of the QRS interval all decreased. Two patients do not respond and one (1) who had permanent atrial fibrillation, was a secondary responder after an atrioventricular junction ablation. Conclusion: Cardiac resynchronization is a therapy that improves the QOL of patients, the LVEF and reduces the duration of the QRS interval. However, this procedure is not without risk of complications. In sub-Saharan Africa, the major challenge is to improve the financial accessibility of this therapy for the population.