The role of the autopsy: 1) Whether the death is ascribable to a natural or unnatural cause and when natural, if cardiac or extra-cardiac;2) The nosology of the cardiac diseases and the mechanism of cardiac death, whe...The role of the autopsy: 1) Whether the death is ascribable to a natural or unnatural cause and when natural, if cardiac or extra-cardiac;2) The nosology of the cardiac diseases and the mechanism of cardiac death, whether arrhythmic or mechanical;3) If the cardiac disease is inherited, screening and counselling of the next of kin is required. About 30% of sudden deaths is ascribable to genetically determined morbid entities, mostly transmissible with the autosomal dominant pattern of inheritance, so that 50% of the first degree relatives are genetically affected (“carriers”) and exposed at risk;4) If toxic or illicit drug abuse was involved.展开更多
The influences of dipole-dipole interaction and detuning on the entanglement between two atoms with different initial tripartite entangled W-like states in the Tavis Cummings model have been investigated by means of W...The influences of dipole-dipole interaction and detuning on the entanglement between two atoms with different initial tripartite entangled W-like states in the Tavis Cummings model have been investigated by means of Wootters' concurrence, respectively. The results show that the entanglement between the two atoms can be enhanced via appropriately tuning the strength of dipole-dipole interaction of two atoms or the detunings between atom and cavity, and the so-called sudden death effect can he weakened simultaneously.展开更多
We investigate the properties of entanglement between an isolated atom and a Jaynes-Cummings atom in the presence of transient effects. These effects are due to the modulation of the atom-field coupling whose explicit...We investigate the properties of entanglement between an isolated atom and a Jaynes-Cummings atom in the presence of transient effects. These effects are due to the modulation of the atom-field coupling whose explicit time-dependence is considered for the case of the linear sweep. We show that the sudden death of entanglement can be controlled by the transient effects. These effects can suppress the sudden death of entanglement in time.展开更多
In this paper, we investigate the entanglement of two qubits coupled collectively to a common thermal environment and find that the the collective decay can lead to a revival of the entanglement that has already been ...In this paper, we investigate the entanglement of two qubits coupled collectively to a common thermal environment and find that the the collective decay can lead to a revival of the entanglement that has already been destroyed. We also show that the ability of the system to revival entanglement relies on the mean photon number of the thermal environment and the degree of entanglement of the initial state.展开更多
In this paper, we investigate the dynamical behaviour of entanglement in terms of concurrence in a bipartite system subjected to an external magnetic field under the action of dissipative environments in the extended ...In this paper, we investigate the dynamical behaviour of entanglement in terms of concurrence in a bipartite system subjected to an external magnetic field under the action of dissipative environments in the extended Werner-like initial state. The interesting phenomenon of entanglement sudden death as well as sudden birth appears during the evolution process. We analyse in detail the effect of the purity of the initial entangled state of two qubits via Heisenberg XY interaction on the apparition time of entanglement sudden death and entanglement sudden birth. Furthermore, the conditions on the conversion of entanglement sudden death and entanglement sudden birth can be generalized when the initial entangled state is not pure. In particular, a critical purity of the initial mixed entangled state exists, above which entanglement sudden birth vanishes while entanglement sudden death appears. It is also noticed that stable entanglement, which is independent of different initial states of the qubits (pure or mixed state), occurs even in the presence of decoherence. These results arising from the combination of the extended Werner-like initial state and dissipative environments suggest an approach to control and enhance the entanglement even after purity induced sudden birth, death and revival.展开更多
Sudden unexpected death in epilepsy (SUDEP) is the most important direct epilepsy-related cause of death. Additionally, potential pathomechanisms for SUDEP is unknown, but it is very probable that cardiac arrhythmia...Sudden unexpected death in epilepsy (SUDEP) is the most important direct epilepsy-related cause of death. Additionally, potential pathomechanisms for SUDEP is unknown, but it is very probable that cardiac arrhythmia during and between seizures, electrolyte disturbances, arrhythmogenic drugs or transmission of epileptic activity via the autonomic nervous system to the heart may play a potential role. Quite interestingly, clinical and experimental data have shown that physical activity can decrease seizure frequency, as well as lead to improved cardiovascular health in patients with epilepsy. Based on these facts, the purpose of this article is to review the body of literature of the possible contribution of physical exercise to the SUDEP prevention in a comprehensive manner.展开更多
Starting from famous Schrodinger equation within the framework of semi-c/assicai theory of light-matter interaction, we firstly obtain the anaiytical non-resonant solutions of the driven bipartite system's entangleme...Starting from famous Schrodinger equation within the framework of semi-c/assicai theory of light-matter interaction, we firstly obtain the anaiytical non-resonant solutions of the driven bipartite system's entanglement dynamics in independent and coherent double pathways. Numerical simulations show that under non-resonant condition, entanglement sudden death and revival between these transition patterns behave quite differently, indicating the utmost importance of transition pathways' interference. Furthermore, the laser pulse's area and detuning exert significant but quite distinct influences on the entanglement dynamics. Our analyses are helpful in manipulating entanglement in current experimental technology.展开更多
Sudden Infant Death Syndrome (SIDS) is an unexpected death of infants under one year old. SIDS is the most common cause of death for infants after the first month of birth, commonly between two and four months. MEMS...Sudden Infant Death Syndrome (SIDS) is an unexpected death of infants under one year old. SIDS is the most common cause of death for infants after the first month of birth, commonly between two and four months. MEMS (Micro-Electro-Mechanical Systems) technology can be very useful to help us to avoid this horrible tragedy. In the present work, using a MEMS technology, an intelligent pacifier is designed to alarm any unusual changes in breathing during sleeping. A PZT (Piezoelectric) sensor is utilized to detect the force generated by breathing and convert it to a measurable voltage and alarm the risky breathing during infant's sleeping. This voltage can subsequently drive some simple alarm and make parents aware of hazard.展开更多
Objective To find the pathogenesis of sudden infant death syndrome (SIDS) from changes of pulmonary surfactant. Methods By means of thin layer chromatography technique, surfactant in whole lung specimens of 10 inf...Objective To find the pathogenesis of sudden infant death syndrome (SIDS) from changes of pulmonary surfactant. Methods By means of thin layer chromatography technique, surfactant in whole lung specimens of 10 infants with SIDS and 10 control infants without SIDS (dead of nonrespiratory diseases) were examined qualitatively and quantitatively. Results Eleven components in pulmonary surfactant were examined qualitatively, including lysophosphatidylcholine, sphingomyelin, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidic acid, cholesterol and neutral lipids. Quantitative examination showed that the amount of surfactant of whole lung specimens in sudden death group [(8.9±1.0) mg/g wet lung weight] was significantly less than that in control group [(12.6±1.4) mg/g wet lung weight, P<0.01]. Qualitative variance showed that the percentages of phosphatidylcholine (49.4%±2.0%) and phosphatidylglycerol (2.6%±0.7%) decreased markedly in sudden death group compared with those in control group (61.5%±3.0% and 4.3%±1.5%, P<0.01). Conclusion Before death there is serious defect on metabolism of pulmonary surfactant in sudden death infants, with the amount decreasing and the ratio of its components being disturbed, which is one of the important pathogenies of SIDS.展开更多
Most heart failure (HF) related mortality is due to sudden cardiac death (SCD) and worsening HF, particularly in the case of reduced ejection fraction. Predicting and preventing SCD is an important goal but most w...Most heart failure (HF) related mortality is due to sudden cardiac death (SCD) and worsening HF, particularly in the case of reduced ejection fraction. Predicting and preventing SCD is an important goal but most works include no or few patients with advanced age, and the prevention of SCD in elderly patients with HF is still controversial. A recent reduction in the annual rate of SCD has been recently described but it is not clear if this is also true in advanced age patients. Age is associated with SCD, although physicians frequently have the perception that elderly patients with HF die mainly of pump failure, underestimating the importance of SCD. Other clinical variables that have been associated to SCD are symptoms, New York Heart Association functional class, ischemic cause, and comorbidities (chronic obstructive pulmonary disease, renal dysfunction and diabetes). Some test results that should also be considered are left ventricular ejection fraction and diameters, natriuretic peptides, non-sustained ventricular tachycardias and autonomic abnormalities. The combination of all these markers is probably the best option to predict SCD. Different risk scores have been described and, although there are no specific ones for elderly populations, most include age as a risk predictor and some were developed in populations with mean age 〉 65 years. Finally, it is important to stress that these scores should be able to predict any type of SCD as, although most are due to tachyarrhythmias, bradyarrhythmias also play a role, particularly in the case of the elderly.展开更多
BACKGROUND There is a high risk for sudden cardiac death(SCD) in certain patient groups that would not meet criteria for implantable cardioverter defibrillator(ICD) therapy.In conditions such as hypertrophic cardiomyo...BACKGROUND There is a high risk for sudden cardiac death(SCD) in certain patient groups that would not meet criteria for implantable cardioverter defibrillator(ICD) therapy.In conditions such as hypertrophic cardiomyopathy(HCM) there are clear risk scores that help define patients who are high risk for SCD and would benefit from ICD therapy. There are however many areas of uncertainty such as certain patients post myocardial infarction(MI). These patients are high risk for SCD but there is no clear tool for risk stratifying such patients.AIM To assess risk factors for sudden cardiac death in major cardiac disorders and to help select patients who might benefit from Wearable cardiac defibrillators(WCD).METHODS A literature search was performed looking for risk factors for SCD in patients post-MI, patients with left ventricular systolic dysfunction(LVSD), HCM, long QT syndrome(LQTS). There were 41 studies included and risk factors and the relative risks for SCD were compiled in table form.RESULTS We extracted data on relative risk for SCD of specific variables such as age,gender, ejection fraction. The greatest risk factors for SCD in post MI patients was the presence of diabetes [Hazard ratio(HR) 1.90-3.80], in patient with LVSD was ventricular tachycardia(Relative risk 3.50), in LQTS was a prolonged QTc(HR36.53) and in patients with HCM was LVH greater than 20 mm(HR 3.10). A proportion of patients currently not suitable for ICD might benefit from a WCDCONCLUSION There is a very high risk of SCD post MI, in patients with LVSD, HCM and LQTS even in those who do not meet criteria for ICD implantation. These patients may be candidates for a WCD. The development of more sensitive risk calculators to predict SCD is necessary in these patients to help guide treatment.展开更多
In this paper the so-called sudden death effect of entanglement is investigated in a quantum model. The results show that one can expect the resurrection of the original entanglement to occur in a periodic way followi...In this paper the so-called sudden death effect of entanglement is investigated in a quantum model. The results show that one can expect the resurrection of the original entanglement to occur in a periodic way following each sudden death event. The length of the time interval for the zero entanglement depends not only on the degree of entanglement of the initial state but also on the initial state.展开更多
Sudden cardiac death threats ischaemic and dilated cardiomyopathy patients. Anti- arrhythmic protection may be provided to these patients with implanted cardiac defibrillators(ICD), after an efficient risk stratificat...Sudden cardiac death threats ischaemic and dilated cardiomyopathy patients. Anti- arrhythmic protection may be provided to these patients with implanted cardiac defibrillators(ICD), after an efficient risk stratification approach. The proposed risk stratifier of an impaired left ventricular ejection fraction has limited sensitivity meaning that a significant number of victims will remain undetectable by this risk stratification approach because they have a preserved left ventricular systolic function. Current risk stratification strategies focus on combinations of non invasive methods like T wave alternans, late potentials, heart rate turbulence, deceleration capacity and others, with invasive methods like the electrophysiologic study. In the presence of an electrically impaired substrate with formed post myocardial infarction fibrotic zones, programmed ventricular stimulation provides important prognostic information for the selection of the patients expected to benefit from an ICD implantation, while due to its high negative predictive value, patients at low risk level may also be detected. Clustering evidence from different research groups and electrophysiologic labs support an electrophysiologic testing guided risk stratification approach for sudden cardiac death.展开更多
An increased cardiovascular morbidity and mortality, including the risk of sudden cardiac death(SCD), has been shown in patients with rheumatoid arthritis(RA). Abnormalities in autonomic markers such as heart rate var...An increased cardiovascular morbidity and mortality, including the risk of sudden cardiac death(SCD), has been shown in patients with rheumatoid arthritis(RA). Abnormalities in autonomic markers such as heart rate variability and ventricular repolarization parameters, such as QTc interval and QT dispersion, have been associated with sudden death in patients with RA. The interplay between these parameters and inflammation that is known to exist with RA is of growing interest. In this article, we review the prevalence and predictors of SCD in patients with RA and describe the potential underlying mechanisms, which may contribute to this. We also review the impact of biologic agents on arrhythmic risk as well as cardiovascular morbidity and mortality.展开更多
Early detection of sudden cardiac death may be used for surviving the life of cardiac patients. In this paper we have investigated an algorithm to detect and predict sudden cardiac death, by processing of heart rate v...Early detection of sudden cardiac death may be used for surviving the life of cardiac patients. In this paper we have investigated an algorithm to detect and predict sudden cardiac death, by processing of heart rate variability signal through the classical and time-frequency methods. At first, one minute of ECG signals, just before the cardiac death event are extracted and used to compute heart rate variability (HRV) signal. Five features in time domain and four features in frequency domain are extracted from the HRV signal and used as classical linear features. Then the Wigner Ville transform is applied to the HRV signal, and 11 extra features in the time-frequency (TF) domain are obtained. In order to improve the performance of classification, the principal component analysis (PCA) is applied to the obtained features vector. Finally a neural network classifier is applied to the reduced features. The obtained results show that the TF method can classify normal and SCD subjects, more efficiently than the classical methods. A MIT-BIH ECG database was used to evaluate the proposed method. The proposed method was implemented using MLP classifier and had 74.36% and 99.16% correct detection rate (accuracy) for classical features and TF method, respectively. Also, the accuracy of the KNN classifier were 73.87% and 96.04%.展开更多
The dynamics of distillability entanglement between qutrit-qutrit systems interacting with a thermal reservoir is investigated in this paper. We discovered an interesting phenomenon that under a thermal reservoir cert...The dynamics of distillability entanglement between qutrit-qutrit systems interacting with a thermal reservoir is investigated in this paper. We discovered an interesting phenomenon that under a thermal reservoir certain initially prepared free=entangled states become bound-entangled states in a finite time, which is called distillability sudden death (DSD). We use a realignment criterion to measure the nine-dimensional density matrix of the entanglement. Moreover, we analyze some other parameters to investigate the effects to the systems. Explanations are then given.展开更多
Tis paper demonstrates that multipartite Bell-inequality violations can be fully destroyed in a finite time in three- qubit states coupled to a general XY spin-chain with a three-site interaction environment. The Merm...Tis paper demonstrates that multipartite Bell-inequality violations can be fully destroyed in a finite time in three- qubit states coupled to a general XY spin-chain with a three-site interaction environment. The Mermin Ardehali- Belinksii-Klyshko inequality is used to detect the degree of nonlocality, as measured by the extent of their violations. The effects of system-environment couplings, the size of degrees of freedom of the environment and the strength of the three-site interaction on the Bell-inequality violations are given. The results indicate that the Bell-inequality violations of the tripartite states will be completely destroyed by decoherence under certain conditions for the GHZ state. The decoherence-free subspaces of our model are identified and the entanglement of quantum states is also discussed.展开更多
Background: The potential benefits of implantable cardioverter-defibrillator (ICD) therapy in patients with sudden cardiac death (SCD) treated with therapeutic hypothermia (TH) have not been well studied. Methods: Inc...Background: The potential benefits of implantable cardioverter-defibrillator (ICD) therapy in patients with sudden cardiac death (SCD) treated with therapeutic hypothermia (TH) have not been well studied. Methods: Incidence of recurrent non-sustained ventricular arrhythmia, ICD therapy, and death were ascertained in 64 consecutive survivors of SCD due to ventricular fibrillation or tachycardia, who were treated with TH. Follow-up was 31.5 +/- 3.3 months in 41 ICD recipients and 36.3 +/- 3.9 months in 23 patients who did not receive an ICD due to the presence of a reversible cause of cardiac arrest, an acute myocardial infarction in 87%. Results: Combined incidence of ventricular arrhythmia, ICD therapy, or death in patients who underwent ICD placement (21.9%) were similar to overall mortality in the patients who did not receive an ICD (21.7%, p = 0.752). ICD placement was associated with a significant mortality benefit;95.1% survival in ICD recipients vs. 78.3% in the no-ICD group (p = 0.038). Electrocardiographic findings of ST segment elevation on admission were associated with increased event rate in ICD recipients (p = 0.039) and increased mortality in SCD patients who did not receive an ICD (p Conclusions: SCD survivors treated with TH are at increased risk for recurrent arrhythmic events and derive significant mortality benefit from ICD implantation. Increased mortality in revascularized SCD patients with acute coronary syndrome, thought to have a reversible cause of cardiac arrest, calls for prospective trials investigating utility of ICD in this vulnerable patient population.展开更多
BACKGROUND:There have been numerous reports of sudden cardiac death attributable to the condition of commotio cordis. Primarily, these are reports from the USA. Although three Australian cases have been mentioned in ...BACKGROUND:There have been numerous reports of sudden cardiac death attributable to the condition of commotio cordis. Primarily, these are reports from the USA. Although three Australian cases have been mentioned in the published literature, the present case appears to be the first described Australian case. METHODS:A man was brought to the Emergency Department after sudden collapse while playing cricket. His medical history was suggestive of hitting by a cricket ball while batting. RESULTS:The epidemiology and mechanism of arrhythmia induction in commofio cordis are discussed. The emergency management of commotio cordis is outlined. CONCLUSIONS: Commofio cordis is rare in sports (and Emergency Medicine). However it has a high mortality rate, and rapid recognition of the condition allows early defibrillation, generally with a good outcome. The improvement of participant care is recommended at community and other sport events.展开更多
Brugada syndrome (BrS) is primary electrical disorder characterized by ST segment elevation with right bundle branch block morphology in patients with apparent structurally normal hearts, It predisposes affected in...Brugada syndrome (BrS) is primary electrical disorder characterized by ST segment elevation with right bundle branch block morphology in patients with apparent structurally normal hearts, It predisposes affected individuals to ventricular tachycardia/fibrillation (VT/VF) and sudden cardiac death (SCD).A number of studies have identified risk factors that are associated with a more malignant course of disease. These include male gender, syncope, a spontaneous type 1 ECG pattern, family history of SCD, family history of Brugada syndrome,展开更多
文摘The role of the autopsy: 1) Whether the death is ascribable to a natural or unnatural cause and when natural, if cardiac or extra-cardiac;2) The nosology of the cardiac diseases and the mechanism of cardiac death, whether arrhythmic or mechanical;3) If the cardiac disease is inherited, screening and counselling of the next of kin is required. About 30% of sudden deaths is ascribable to genetically determined morbid entities, mostly transmissible with the autosomal dominant pattern of inheritance, so that 50% of the first degree relatives are genetically affected (“carriers”) and exposed at risk;4) If toxic or illicit drug abuse was involved.
基金supported by the National Natural Science Foundation of China (Grant No 60667001)
文摘The influences of dipole-dipole interaction and detuning on the entanglement between two atoms with different initial tripartite entangled W-like states in the Tavis Cummings model have been investigated by means of Wootters' concurrence, respectively. The results show that the entanglement between the two atoms can be enhanced via appropriately tuning the strength of dipole-dipole interaction of two atoms or the detunings between atom and cavity, and the so-called sudden death effect can he weakened simultaneously.
文摘We investigate the properties of entanglement between an isolated atom and a Jaynes-Cummings atom in the presence of transient effects. These effects are due to the modulation of the atom-field coupling whose explicit time-dependence is considered for the case of the linear sweep. We show that the sudden death of entanglement can be controlled by the transient effects. These effects can suppress the sudden death of entanglement in time.
基金supported by the National Natural Science Foundation of China (Grant No.10374025)Hunan Provincial Natural Science Foundation of China (Grant No.06JJ4003)the Major Program for the Research Foundation of Education Bureau of Hunan Province,China (Grant No.08A015)
文摘In this paper, we investigate the entanglement of two qubits coupled collectively to a common thermal environment and find that the the collective decay can lead to a revival of the entanglement that has already been destroyed. We also show that the ability of the system to revival entanglement relies on the mean photon number of the thermal environment and the degree of entanglement of the initial state.
基金Project supported by the National Natural Science Foundation,China (Grant No.10904033)the Natural Science Foundation of Hubei Province,China (Grant No.2009CDA145)+1 种基金the Science Foundation of the Educational Commission of Hubei Province,China (Grant No.D20092204)the Postgraduate Programme of Hubei Normal University of China (Grant No.2007D20)
文摘In this paper, we investigate the dynamical behaviour of entanglement in terms of concurrence in a bipartite system subjected to an external magnetic field under the action of dissipative environments in the extended Werner-like initial state. The interesting phenomenon of entanglement sudden death as well as sudden birth appears during the evolution process. We analyse in detail the effect of the purity of the initial entangled state of two qubits via Heisenberg XY interaction on the apparition time of entanglement sudden death and entanglement sudden birth. Furthermore, the conditions on the conversion of entanglement sudden death and entanglement sudden birth can be generalized when the initial entangled state is not pure. In particular, a critical purity of the initial mixed entangled state exists, above which entanglement sudden birth vanishes while entanglement sudden death appears. It is also noticed that stable entanglement, which is independent of different initial states of the qubits (pure or mixed state), occurs even in the presence of decoherence. These results arising from the combination of the extended Werner-like initial state and dissipative environments suggest an approach to control and enhance the entanglement even after purity induced sudden birth, death and revival.
文摘Sudden unexpected death in epilepsy (SUDEP) is the most important direct epilepsy-related cause of death. Additionally, potential pathomechanisms for SUDEP is unknown, but it is very probable that cardiac arrhythmia during and between seizures, electrolyte disturbances, arrhythmogenic drugs or transmission of epileptic activity via the autonomic nervous system to the heart may play a potential role. Quite interestingly, clinical and experimental data have shown that physical activity can decrease seizure frequency, as well as lead to improved cardiovascular health in patients with epilepsy. Based on these facts, the purpose of this article is to review the body of literature of the possible contribution of physical exercise to the SUDEP prevention in a comprehensive manner.
基金Supported by the National Basic Research Program(973 Program)of China under Grant No.2012CB921900the National Natural Science Foundation of China under Grant No.10574166the Guangdong Natural Science Foundation under Grant No.8151027501000062
文摘Starting from famous Schrodinger equation within the framework of semi-c/assicai theory of light-matter interaction, we firstly obtain the anaiytical non-resonant solutions of the driven bipartite system's entanglement dynamics in independent and coherent double pathways. Numerical simulations show that under non-resonant condition, entanglement sudden death and revival between these transition patterns behave quite differently, indicating the utmost importance of transition pathways' interference. Furthermore, the laser pulse's area and detuning exert significant but quite distinct influences on the entanglement dynamics. Our analyses are helpful in manipulating entanglement in current experimental technology.
文摘Sudden Infant Death Syndrome (SIDS) is an unexpected death of infants under one year old. SIDS is the most common cause of death for infants after the first month of birth, commonly between two and four months. MEMS (Micro-Electro-Mechanical Systems) technology can be very useful to help us to avoid this horrible tragedy. In the present work, using a MEMS technology, an intelligent pacifier is designed to alarm any unusual changes in breathing during sleeping. A PZT (Piezoelectric) sensor is utilized to detect the force generated by breathing and convert it to a measurable voltage and alarm the risky breathing during infant's sleeping. This voltage can subsequently drive some simple alarm and make parents aware of hazard.
文摘Objective To find the pathogenesis of sudden infant death syndrome (SIDS) from changes of pulmonary surfactant. Methods By means of thin layer chromatography technique, surfactant in whole lung specimens of 10 infants with SIDS and 10 control infants without SIDS (dead of nonrespiratory diseases) were examined qualitatively and quantitatively. Results Eleven components in pulmonary surfactant were examined qualitatively, including lysophosphatidylcholine, sphingomyelin, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidic acid, cholesterol and neutral lipids. Quantitative examination showed that the amount of surfactant of whole lung specimens in sudden death group [(8.9±1.0) mg/g wet lung weight] was significantly less than that in control group [(12.6±1.4) mg/g wet lung weight, P<0.01]. Qualitative variance showed that the percentages of phosphatidylcholine (49.4%±2.0%) and phosphatidylglycerol (2.6%±0.7%) decreased markedly in sudden death group compared with those in control group (61.5%±3.0% and 4.3%±1.5%, P<0.01). Conclusion Before death there is serious defect on metabolism of pulmonary surfactant in sudden death infants, with the amount decreasing and the ratio of its components being disturbed, which is one of the important pathogenies of SIDS.
文摘Most heart failure (HF) related mortality is due to sudden cardiac death (SCD) and worsening HF, particularly in the case of reduced ejection fraction. Predicting and preventing SCD is an important goal but most works include no or few patients with advanced age, and the prevention of SCD in elderly patients with HF is still controversial. A recent reduction in the annual rate of SCD has been recently described but it is not clear if this is also true in advanced age patients. Age is associated with SCD, although physicians frequently have the perception that elderly patients with HF die mainly of pump failure, underestimating the importance of SCD. Other clinical variables that have been associated to SCD are symptoms, New York Heart Association functional class, ischemic cause, and comorbidities (chronic obstructive pulmonary disease, renal dysfunction and diabetes). Some test results that should also be considered are left ventricular ejection fraction and diameters, natriuretic peptides, non-sustained ventricular tachycardias and autonomic abnormalities. The combination of all these markers is probably the best option to predict SCD. Different risk scores have been described and, although there are no specific ones for elderly populations, most include age as a risk predictor and some were developed in populations with mean age 〉 65 years. Finally, it is important to stress that these scores should be able to predict any type of SCD as, although most are due to tachyarrhythmias, bradyarrhythmias also play a role, particularly in the case of the elderly.
文摘BACKGROUND There is a high risk for sudden cardiac death(SCD) in certain patient groups that would not meet criteria for implantable cardioverter defibrillator(ICD) therapy.In conditions such as hypertrophic cardiomyopathy(HCM) there are clear risk scores that help define patients who are high risk for SCD and would benefit from ICD therapy. There are however many areas of uncertainty such as certain patients post myocardial infarction(MI). These patients are high risk for SCD but there is no clear tool for risk stratifying such patients.AIM To assess risk factors for sudden cardiac death in major cardiac disorders and to help select patients who might benefit from Wearable cardiac defibrillators(WCD).METHODS A literature search was performed looking for risk factors for SCD in patients post-MI, patients with left ventricular systolic dysfunction(LVSD), HCM, long QT syndrome(LQTS). There were 41 studies included and risk factors and the relative risks for SCD were compiled in table form.RESULTS We extracted data on relative risk for SCD of specific variables such as age,gender, ejection fraction. The greatest risk factors for SCD in post MI patients was the presence of diabetes [Hazard ratio(HR) 1.90-3.80], in patient with LVSD was ventricular tachycardia(Relative risk 3.50), in LQTS was a prolonged QTc(HR36.53) and in patients with HCM was LVH greater than 20 mm(HR 3.10). A proportion of patients currently not suitable for ICD might benefit from a WCDCONCLUSION There is a very high risk of SCD post MI, in patients with LVSD, HCM and LQTS even in those who do not meet criteria for ICD implantation. These patients may be candidates for a WCD. The development of more sensitive risk calculators to predict SCD is necessary in these patients to help guide treatment.
基金Project supported by National Natural Science Foundation of China (Grant No 10604053).
文摘In this paper the so-called sudden death effect of entanglement is investigated in a quantum model. The results show that one can expect the resurrection of the original entanglement to occur in a periodic way following each sudden death event. The length of the time interval for the zero entanglement depends not only on the degree of entanglement of the initial state but also on the initial state.
文摘Sudden cardiac death threats ischaemic and dilated cardiomyopathy patients. Anti- arrhythmic protection may be provided to these patients with implanted cardiac defibrillators(ICD), after an efficient risk stratification approach. The proposed risk stratifier of an impaired left ventricular ejection fraction has limited sensitivity meaning that a significant number of victims will remain undetectable by this risk stratification approach because they have a preserved left ventricular systolic function. Current risk stratification strategies focus on combinations of non invasive methods like T wave alternans, late potentials, heart rate turbulence, deceleration capacity and others, with invasive methods like the electrophysiologic study. In the presence of an electrically impaired substrate with formed post myocardial infarction fibrotic zones, programmed ventricular stimulation provides important prognostic information for the selection of the patients expected to benefit from an ICD implantation, while due to its high negative predictive value, patients at low risk level may also be detected. Clustering evidence from different research groups and electrophysiologic labs support an electrophysiologic testing guided risk stratification approach for sudden cardiac death.
文摘An increased cardiovascular morbidity and mortality, including the risk of sudden cardiac death(SCD), has been shown in patients with rheumatoid arthritis(RA). Abnormalities in autonomic markers such as heart rate variability and ventricular repolarization parameters, such as QTc interval and QT dispersion, have been associated with sudden death in patients with RA. The interplay between these parameters and inflammation that is known to exist with RA is of growing interest. In this article, we review the prevalence and predictors of SCD in patients with RA and describe the potential underlying mechanisms, which may contribute to this. We also review the impact of biologic agents on arrhythmic risk as well as cardiovascular morbidity and mortality.
文摘Early detection of sudden cardiac death may be used for surviving the life of cardiac patients. In this paper we have investigated an algorithm to detect and predict sudden cardiac death, by processing of heart rate variability signal through the classical and time-frequency methods. At first, one minute of ECG signals, just before the cardiac death event are extracted and used to compute heart rate variability (HRV) signal. Five features in time domain and four features in frequency domain are extracted from the HRV signal and used as classical linear features. Then the Wigner Ville transform is applied to the HRV signal, and 11 extra features in the time-frequency (TF) domain are obtained. In order to improve the performance of classification, the principal component analysis (PCA) is applied to the obtained features vector. Finally a neural network classifier is applied to the reduced features. The obtained results show that the TF method can classify normal and SCD subjects, more efficiently than the classical methods. A MIT-BIH ECG database was used to evaluate the proposed method. The proposed method was implemented using MLP classifier and had 74.36% and 99.16% correct detection rate (accuracy) for classical features and TF method, respectively. Also, the accuracy of the KNN classifier were 73.87% and 96.04%.
基金Project supported by the National Natural Science Foundation of China (Grant No. 11074072)
文摘The dynamics of distillability entanglement between qutrit-qutrit systems interacting with a thermal reservoir is investigated in this paper. We discovered an interesting phenomenon that under a thermal reservoir certain initially prepared free=entangled states become bound-entangled states in a finite time, which is called distillability sudden death (DSD). We use a realignment criterion to measure the nine-dimensional density matrix of the entanglement. Moreover, we analyze some other parameters to investigate the effects to the systems. Explanations are then given.
基金Project supported by the National Natural Science Foundation of China (Grant No.11004050)the Scientific Research Fund of Hunan Provincial Education Department of China (Grant Nos.+3 种基金 09A013 and 10B013)the Science and Technology Research Foundation of Hunan Province of China (Grant No.2010FJ4120)the Excellent Talents Program of Hengyang Normal University of China (Grant No.2010YCJH01)the Science Foundation of Hengyang Normal University of China (Grant Nos.10A46 and 10B69)
文摘Tis paper demonstrates that multipartite Bell-inequality violations can be fully destroyed in a finite time in three- qubit states coupled to a general XY spin-chain with a three-site interaction environment. The Mermin Ardehali- Belinksii-Klyshko inequality is used to detect the degree of nonlocality, as measured by the extent of their violations. The effects of system-environment couplings, the size of degrees of freedom of the environment and the strength of the three-site interaction on the Bell-inequality violations are given. The results indicate that the Bell-inequality violations of the tripartite states will be completely destroyed by decoherence under certain conditions for the GHZ state. The decoherence-free subspaces of our model are identified and the entanglement of quantum states is also discussed.
文摘Background: The potential benefits of implantable cardioverter-defibrillator (ICD) therapy in patients with sudden cardiac death (SCD) treated with therapeutic hypothermia (TH) have not been well studied. Methods: Incidence of recurrent non-sustained ventricular arrhythmia, ICD therapy, and death were ascertained in 64 consecutive survivors of SCD due to ventricular fibrillation or tachycardia, who were treated with TH. Follow-up was 31.5 +/- 3.3 months in 41 ICD recipients and 36.3 +/- 3.9 months in 23 patients who did not receive an ICD due to the presence of a reversible cause of cardiac arrest, an acute myocardial infarction in 87%. Results: Combined incidence of ventricular arrhythmia, ICD therapy, or death in patients who underwent ICD placement (21.9%) were similar to overall mortality in the patients who did not receive an ICD (21.7%, p = 0.752). ICD placement was associated with a significant mortality benefit;95.1% survival in ICD recipients vs. 78.3% in the no-ICD group (p = 0.038). Electrocardiographic findings of ST segment elevation on admission were associated with increased event rate in ICD recipients (p = 0.039) and increased mortality in SCD patients who did not receive an ICD (p Conclusions: SCD survivors treated with TH are at increased risk for recurrent arrhythmic events and derive significant mortality benefit from ICD implantation. Increased mortality in revascularized SCD patients with acute coronary syndrome, thought to have a reversible cause of cardiac arrest, calls for prospective trials investigating utility of ICD in this vulnerable patient population.
文摘BACKGROUND:There have been numerous reports of sudden cardiac death attributable to the condition of commotio cordis. Primarily, these are reports from the USA. Although three Australian cases have been mentioned in the published literature, the present case appears to be the first described Australian case. METHODS:A man was brought to the Emergency Department after sudden collapse while playing cricket. His medical history was suggestive of hitting by a cricket ball while batting. RESULTS:The epidemiology and mechanism of arrhythmia induction in commofio cordis are discussed. The emergency management of commotio cordis is outlined. CONCLUSIONS: Commofio cordis is rare in sports (and Emergency Medicine). However it has a high mortality rate, and rapid recognition of the condition allows early defibrillation, generally with a good outcome. The improvement of participant care is recommended at community and other sport events.
文摘Brugada syndrome (BrS) is primary electrical disorder characterized by ST segment elevation with right bundle branch block morphology in patients with apparent structurally normal hearts, It predisposes affected individuals to ventricular tachycardia/fibrillation (VT/VF) and sudden cardiac death (SCD).A number of studies have identified risk factors that are associated with a more malignant course of disease. These include male gender, syncope, a spontaneous type 1 ECG pattern, family history of SCD, family history of Brugada syndrome,