Under the acceptable hypothesis that cardiac rhythm is an approximately deterministic process with a small scale noise component, an available way is provided to construct a model that can reflect its prominent dynami...Under the acceptable hypothesis that cardiac rhythm is an approximately deterministic process with a small scale noise component, an available way is provided to construct a model that can reflect its prominent dynamics of the deterministic component. When applied to the analysis of 19 heart rate data sets, three main findings are stated. The obtained model can reflect prominent dynamics of the deterministic component of cardiac rhythm; cardiac chaos is stated in a reliable way; dynamical noise plays an important role in the generation of complex cardiac rhythm.展开更多
Objectives: To describe the epidemiological, clinical and etiological aspects of rhythmic emergencies at the University Hospital of Brazzaville. Patients and Methods: This was a retrospective descriptive study conduct...Objectives: To describe the epidemiological, clinical and etiological aspects of rhythmic emergencies at the University Hospital of Brazzaville. Patients and Methods: This was a retrospective descriptive study conducted in the cardiology and internal medicine department of the University Hospital of Brazzaville from January 1, 2014 to June 30, 2016. Were included, all patients admitted for a severe rhythm disorder diagnosed on the surface electrocardiogram. Rhythmic emergency was defined as a severe rhythm disorder of abrupt onset and required rapid management. Data entry and analysis were performed with Epi Info software version 3.5.1. Results: During the study period, 2269 patients were hospitalized, including 138 for a rhythmic emergency. The frequency of rhythmic emergencies was 6.1%. The patients were divided into 76 women and 62 men (sex ratio = 0.81). The mean age of the patients was 63.1 ± 16.9 years (extremes: 17 and 91 years). The socio-economic level was low for 103 patients (74.6%), medium for 26 (17.7%), and high for nine (6.6%). The average time to consultation was 13.7 ± 12.3 days. On admission, the signs were: heart failure (103 cases;74.6%) including 22 acute cases;dyspnea (94 cases;68%);palpitations (38 cases;27.5%);functional impotence (13 cases;9.4%);collapse (nine cases;6.5%);chest pain (two cases;1.4%). The type of rhythmic emergency was: rapid atrial fibrillation (103 cases;74.6%), ventricular tachycardia (14 cases;10.1%), junctional tachycardia (10 cases;7.2%), rapid atrial flutter (10 cases;7.2%), tachysystole (one case;0.7%). The context of occurrence was: hypokalemia (8 cases;5.8%), drunkenness (two cases;1.4%), acute gastroenteritis (one case;0.7%). Cardiovascular risk factors were: hypertension (62 cases;45.2%), smoking (17 cases;12.1%), dyslipidemia (12 cases;8.7%), diabetes (11 cases;8%), obesity (10 cases;7.2%). Underlying heart disease was: dilated cardiomyopathy (40 cases;29%), hypertensive cardiomyopathy (26 cases;18.8%), valvulopathy (24 cases;17.4%). Ischemic heart disease, chronic pulmonary heart disease, and cardiothyreosis were noted equally (n = 5;3.6%). No heart disease was noted in 24 patients (17.4%). Conclusion: Rhythmic emergencies are frequent in Brazzaville. They are dominated by atrial fibrillation and often occur on heart disease.展开更多
Hyperpolarization-activated cyclic-nucleotide-gated (HCN) channels in the heart modulate cardiac automaticity via the hyperpolarization-activated cation current ( named Ⅰf, Ⅰh, or Ⅰq). Recent studies have unveiled ...Hyperpolarization-activated cyclic-nucleotide-gated (HCN) channels in the heart modulate cardiac automaticity via the hyperpolarization-activated cation current ( named Ⅰf, Ⅰh, or Ⅰq). Recent studies have unveiled the molecular identity of HCN (HCN1-4) channels. HCN isoforms are unevenly expressed in the heart, even in the sinoatrial node. Features of HCN currents have been characterized in cardiac and other types of cells or in cell lines transfected with the HCN isoforms. The factors modulating Ih and the physiological significance of HCN channels in the heart have been extensively investigated in recent years. The hypothesis for transplanting and/or creating biological pacemakers to replace diseased sinoatrial and/or atrioventricular nodes has been postulated and tested in animal models. Local overexpression of HCN2 channels in the left atrium or in the left conductive bundle branch of the left ventricle via gene delivery induced significant Ⅰh and escape rhythms during vagal stimulation in canines. In addition, implantation of human mesenchymal stem cells with overexpression of HCN2 channels to the canine left ventricular wall was associated with formation of spontaneous escape rhythms of left-sided origin during vagal-stimulation-induced sinus arrest. This preliminary data suggest that the use of HCN channels may hold great promise in,the development of biological pacemakers.展开更多
BACKGROUND: To evaluate the outcome of cardiopulmonary resuscitation(CPR) in out-ofhospital cardiac arrests(OHCA) in India and factors infl uencing the outcome.METHODS: The outcome and related factors like demographic...BACKGROUND: To evaluate the outcome of cardiopulmonary resuscitation(CPR) in out-ofhospital cardiac arrests(OHCA) in India and factors infl uencing the outcome.METHODS: The outcome and related factors like demographics, aspects of the OHCA event, return of spontaneous circulation(ROSC) and survival to discharge, among the 80 adult patients presenting to emergency department experiencing OHCA considered for resuscitation between January 2014 to April 2015, were analyzed, according to the guidelines of the Utstein consensus conference.RESULTS: The survival rate to hospital admission was 32.5%, the survival rate to hospital discharge was 8.8% and with good cerebral performance category(CPC1) neurological status was 3.8%. Majority of OHCA was seen in elderly individuals between 51 to 60 years, predominately in males. Majority of OHCA were witnessed arrests(56.5%) with 1.3% bystander CPR rate, 92.5% arrests occurred at home, 96% presented with initial non-shockable rhythm and 92.5% with presumed cardiac etiology but survival was better in those who experienced OHCA at public place, in witnessed arrests, in patients who had shockable presenting rhythm and in those where CPR duration was ≤20 minutes.CONCLUSION: Witnessed arrests, early initiation of CPR by bystanders, CPR duration ≤20 minutes, initial presenting shockable rhythm, OHCA with non-cardiac etiology are associated with a good outcome. To improve the outcome of CPR and the low survival rates after an OHCA event in India, focused strategies should be designed to set up an emergency medical system(EMS), to boost the rates of bystander CPR and education of the lay public in basic CPR.展开更多
Recent developments of the wireless sensor network will revolutionize the way of remote monitoring in dif-ferent domains such as smart home and smart care, particularly remote cardiac care. Thus, it is challenging to ...Recent developments of the wireless sensor network will revolutionize the way of remote monitoring in dif-ferent domains such as smart home and smart care, particularly remote cardiac care. Thus, it is challenging to propose an energy efficient technique for automatic ECG diagnosis (AED) to be embedded into the wireless sensor. Due to the high resource requirements, classical AED methods are unsuitable for pervasive cardiac care (PCC) applications. This paper proposes an embedded real-time AED algorithm dedicated to PCC sys-tems. This AED algorithm consists of a QRS detector and a rhythm classifier. The QRS detector adopts the linear time-domain statistical and syntactic analysis method and the geometric feature extraction modeling technique. The rhythm classifier employs the self-learning expert system and the confidence interval method. Currently, this AED algorithm has been implemented and evaluated on the PCC system for 30 patients in the Gabriel Monpied hospital (CHRU of Clermont-Ferrand, France) and the MIT-BIH cardiac arrhythmias da-tabase. The overall results show that this energy efficient algorithm provides the same performance as the classical ones.展开更多
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 69735101 and 69872009).
文摘Under the acceptable hypothesis that cardiac rhythm is an approximately deterministic process with a small scale noise component, an available way is provided to construct a model that can reflect its prominent dynamics of the deterministic component. When applied to the analysis of 19 heart rate data sets, three main findings are stated. The obtained model can reflect prominent dynamics of the deterministic component of cardiac rhythm; cardiac chaos is stated in a reliable way; dynamical noise plays an important role in the generation of complex cardiac rhythm.
文摘Objectives: To describe the epidemiological, clinical and etiological aspects of rhythmic emergencies at the University Hospital of Brazzaville. Patients and Methods: This was a retrospective descriptive study conducted in the cardiology and internal medicine department of the University Hospital of Brazzaville from January 1, 2014 to June 30, 2016. Were included, all patients admitted for a severe rhythm disorder diagnosed on the surface electrocardiogram. Rhythmic emergency was defined as a severe rhythm disorder of abrupt onset and required rapid management. Data entry and analysis were performed with Epi Info software version 3.5.1. Results: During the study period, 2269 patients were hospitalized, including 138 for a rhythmic emergency. The frequency of rhythmic emergencies was 6.1%. The patients were divided into 76 women and 62 men (sex ratio = 0.81). The mean age of the patients was 63.1 ± 16.9 years (extremes: 17 and 91 years). The socio-economic level was low for 103 patients (74.6%), medium for 26 (17.7%), and high for nine (6.6%). The average time to consultation was 13.7 ± 12.3 days. On admission, the signs were: heart failure (103 cases;74.6%) including 22 acute cases;dyspnea (94 cases;68%);palpitations (38 cases;27.5%);functional impotence (13 cases;9.4%);collapse (nine cases;6.5%);chest pain (two cases;1.4%). The type of rhythmic emergency was: rapid atrial fibrillation (103 cases;74.6%), ventricular tachycardia (14 cases;10.1%), junctional tachycardia (10 cases;7.2%), rapid atrial flutter (10 cases;7.2%), tachysystole (one case;0.7%). The context of occurrence was: hypokalemia (8 cases;5.8%), drunkenness (two cases;1.4%), acute gastroenteritis (one case;0.7%). Cardiovascular risk factors were: hypertension (62 cases;45.2%), smoking (17 cases;12.1%), dyslipidemia (12 cases;8.7%), diabetes (11 cases;8%), obesity (10 cases;7.2%). Underlying heart disease was: dilated cardiomyopathy (40 cases;29%), hypertensive cardiomyopathy (26 cases;18.8%), valvulopathy (24 cases;17.4%). Ischemic heart disease, chronic pulmonary heart disease, and cardiothyreosis were noted equally (n = 5;3.6%). No heart disease was noted in 24 patients (17.4%). Conclusion: Rhythmic emergencies are frequent in Brazzaville. They are dominated by atrial fibrillation and often occur on heart disease.
文摘Hyperpolarization-activated cyclic-nucleotide-gated (HCN) channels in the heart modulate cardiac automaticity via the hyperpolarization-activated cation current ( named Ⅰf, Ⅰh, or Ⅰq). Recent studies have unveiled the molecular identity of HCN (HCN1-4) channels. HCN isoforms are unevenly expressed in the heart, even in the sinoatrial node. Features of HCN currents have been characterized in cardiac and other types of cells or in cell lines transfected with the HCN isoforms. The factors modulating Ih and the physiological significance of HCN channels in the heart have been extensively investigated in recent years. The hypothesis for transplanting and/or creating biological pacemakers to replace diseased sinoatrial and/or atrioventricular nodes has been postulated and tested in animal models. Local overexpression of HCN2 channels in the left atrium or in the left conductive bundle branch of the left ventricle via gene delivery induced significant Ⅰh and escape rhythms during vagal stimulation in canines. In addition, implantation of human mesenchymal stem cells with overexpression of HCN2 channels to the canine left ventricular wall was associated with formation of spontaneous escape rhythms of left-sided origin during vagal-stimulation-induced sinus arrest. This preliminary data suggest that the use of HCN channels may hold great promise in,the development of biological pacemakers.
基金partially supported by Moolch and Medcity,New Delhi,India
文摘BACKGROUND: To evaluate the outcome of cardiopulmonary resuscitation(CPR) in out-ofhospital cardiac arrests(OHCA) in India and factors infl uencing the outcome.METHODS: The outcome and related factors like demographics, aspects of the OHCA event, return of spontaneous circulation(ROSC) and survival to discharge, among the 80 adult patients presenting to emergency department experiencing OHCA considered for resuscitation between January 2014 to April 2015, were analyzed, according to the guidelines of the Utstein consensus conference.RESULTS: The survival rate to hospital admission was 32.5%, the survival rate to hospital discharge was 8.8% and with good cerebral performance category(CPC1) neurological status was 3.8%. Majority of OHCA was seen in elderly individuals between 51 to 60 years, predominately in males. Majority of OHCA were witnessed arrests(56.5%) with 1.3% bystander CPR rate, 92.5% arrests occurred at home, 96% presented with initial non-shockable rhythm and 92.5% with presumed cardiac etiology but survival was better in those who experienced OHCA at public place, in witnessed arrests, in patients who had shockable presenting rhythm and in those where CPR duration was ≤20 minutes.CONCLUSION: Witnessed arrests, early initiation of CPR by bystanders, CPR duration ≤20 minutes, initial presenting shockable rhythm, OHCA with non-cardiac etiology are associated with a good outcome. To improve the outcome of CPR and the low survival rates after an OHCA event in India, focused strategies should be designed to set up an emergency medical system(EMS), to boost the rates of bystander CPR and education of the lay public in basic CPR.
文摘Recent developments of the wireless sensor network will revolutionize the way of remote monitoring in dif-ferent domains such as smart home and smart care, particularly remote cardiac care. Thus, it is challenging to propose an energy efficient technique for automatic ECG diagnosis (AED) to be embedded into the wireless sensor. Due to the high resource requirements, classical AED methods are unsuitable for pervasive cardiac care (PCC) applications. This paper proposes an embedded real-time AED algorithm dedicated to PCC sys-tems. This AED algorithm consists of a QRS detector and a rhythm classifier. The QRS detector adopts the linear time-domain statistical and syntactic analysis method and the geometric feature extraction modeling technique. The rhythm classifier employs the self-learning expert system and the confidence interval method. Currently, this AED algorithm has been implemented and evaluated on the PCC system for 30 patients in the Gabriel Monpied hospital (CHRU of Clermont-Ferrand, France) and the MIT-BIH cardiac arrhythmias da-tabase. The overall results show that this energy efficient algorithm provides the same performance as the classical ones.
