Coronary artery anomaly is known as one of the causes of angina pectoris and sudden death and is an important clinical entity that cannot be overlooked.The incidence of coronary artery anomalies is as low as 1%-2%of t...Coronary artery anomaly is known as one of the causes of angina pectoris and sudden death and is an important clinical entity that cannot be overlooked.The incidence of coronary artery anomalies is as low as 1%-2%of the general population,even when the various types are combined.Coronary anomalies are practically challenging when the left and right coronary ostium are not found around their normal positions during coronary angiography with a catheter.If there is atherosclerotic stenosis of the coronary artery with an anomaly and percutaneous coronary intervention(PCI)is required,the suitability of the guiding catheter at the entrance and the adequate back up force of the guiding catheter are issues.The level of PCI risk itself should also be considered on a caseby-case basis.In this case,emission computed tomography in the R-1 subtype single coronary artery proved that ischemia occurred in an area where the coronary artery was not visible to the naked eye.Meticulous follow-up would be crucial,because sudden death may occur in single coronary arteries.To prevent atherosclerosis with full efforts is also important,as the authors indicated admirably.展开更多
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
BACKGROUND Sudden death is unanticipated,non-violent death taking place within the first 24 h after the onset of symptoms.It is a major public health problem worldwide.Moreover,the effects of living at moderate altitu...BACKGROUND Sudden death is unanticipated,non-violent death taking place within the first 24 h after the onset of symptoms.It is a major public health problem worldwide.Moreover,the effects of living at moderate altitude on mortality are poorly understood.AIM To retrospectively report the frequency and the main causes of sudden deaths in relation to total deaths at Asir Central Hospital,2255 m above sea level,in the southern region of Saudi Arabia over a period of 4 years from 2013 to 2016.METHODS The medical records of 1821 deaths were examined and showed 353 cases(19.4%)of sudden death.RESULTS The highest incidence of sudden death was among the elderly(51%),whereas,the lowest was among children and adolescents(6.5%).With regard to gender,the incidence of sudden death was higher in males(54.4%)compared to 45.6% in females.In this study,we found that the most common direct causes of sudden death were cardiovascular diseases(29.2%),respiratory disease(22.7%),infectious disease(12.2%),cancer(9.4%)and hematological diseases(6.2%).With respect to seasonal variation,the highest incidence was during winter(31.32%)followed by summer(25.8%).CONCLUSION The results of this study will help emergency physicians and health care providers to exercise due care to reduce the incidence of sudden death and raise public awareness about the impact of sudden death.展开更多
Early repolarization syndrome(ERS), demonstrated as J-point elevation on an electrocardiograph, was formerly thought to be a benign entity, but the recent studies have demonstrated that it can be linked to a considera...Early repolarization syndrome(ERS), demonstrated as J-point elevation on an electrocardiograph, was formerly thought to be a benign entity, but the recent studies have demonstrated that it can be linked to a considerable risk of life- threatening arrhythmias and sudden cardiac death(SCD). Early repolarization characteristics associated with SCD include high-amplitude J-point elevation, horizontal and/or downslopping ST segments, and inferior and/or lateral leads location. The prevalence of ERS varies between 3% and 24%, depending on age, sex and J-point elevation(0.05 m V vs 0.1 m V) being the main determinants.ERS patients are sporadic and they are at a higher risk of having recurrent cardiac events. Implantable cardioverter-defibrillator implantation and isoproterenol are the suggested therapies in this set of patients. On the other hand, asymptomatic patients with ERS are common and have a better prognosis. The risk stratification in asymptomatic patients with ERS still remains a grey area. This review provides an outline of the up-to-date evidence associated with ERS and the risk of life- threatening arrhythmias. Further prospective studies are required to elucidate the mechanisms of ventricular arrhythmogenesis in patients with ERS.展开更多
We report an acute case of a native man from Bolivia suffered from cephalalgia which rapidly worsened and ended in his sudden and unexpected death.Magnetic resonance imaging(MRI) of the brain was obtained.Features dem...We report an acute case of a native man from Bolivia suffered from cephalalgia which rapidly worsened and ended in his sudden and unexpected death.Magnetic resonance imaging(MRI) of the brain was obtained.Features demonstrated on brain MRI scan were consistent with a diagnosis of neurocysticercosis(NCC).An autopsy showed the presence of intraventricular Taenia solium(T.solium) cysts which caused blockage of cerebrospinal fluid and secondary hydrocephalus.Due to the increasing travel movements of people neurocysticercosis must be considered as a cause of unexplained sudden death.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
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
Hypertrophic cardiomyopathy (HCM) is a common genetic cardiovascular disease that affects the left ventricle. HCM can appear at any age, with the majority of the patients remaining clinically stable. When patients com...Hypertrophic cardiomyopathy (HCM) is a common genetic cardiovascular disease that affects the left ventricle. HCM can appear at any age, with the majority of the patients remaining clinically stable. When patients complain of symptoms, these include: dyspnea, dizziness, syncope and angina. HCM can lead to sudden cardiac death (SCD), mainly due to ventricular tachyarrhythmia or ventricular tachycardia. High-risk patients benefit from implantable cardioverter-defibrillators. Left ventricular outflow tract obstruction is not a rare feature in HCM, especially in symptomatic patients, and procedures that abolish that obstruction provide positive and consistent results that can improve longterm survival. HCM is the most common cause of sudden death in young competitive athletes and preparticipation screening programs have to be implemented to avoid these tragic fatalities. The structure of these programs is a matter of large debate. Worldwide registries are necessary to identify the full extent of HCMrelated SCD.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
Pre-partecipation screening is the systematic practice of medically evaluating large populations of athletes before participation in sport activities for the purpose of identifying abnormalities that could cause disea...Pre-partecipation screening is the systematic practice of medically evaluating large populations of athletes before participation in sport activities for the purpose of identifying abnormalities that could cause disease progression or sudden death.In order to prevent sudden cardiac death(SCD),cardiovascular screening should include a strategy for excluding high-risk subjects from athletic and vigorous exercise.There are two major screening programmes in the world.In the United States competitive athletes are screened by means of family and personal history and physical examination.In Italy there is a mandatory screening for competitive athletes,which includes a resting electrocardiogram(ECG)for the detection of cardiac abnormalities.The most important issue to be addressed is whether a screened subject is really guaranteed that she/he is not suffering from any cardiac disease or at risk for SCD.Conceivably,the introduction of echocardiogram during the pre-participation screening,could be reasonable,despite the discrete sensitivity of ECG,in raising clinical suspicions of severe cardiac alterations predisposing to SCD.It is clear that the costbenefit ratio per saved lives of the ECG screening is abenchmark of the Public Health policy.On the contrary,the additional introduction of echocardiography in a large population screening programme seems to be too much expansive for the Public Health and for this reason not easily practicable,even if useful and not invasive.Even if we strongly believe that a saved life is more important than any cost-efficacy evaluation,the issue of the economical impact of this approach should be further assessed.展开更多
It is never an easy thing to diagnose heart vascular disease only depending on the unenhanced postmortem computed tomography(PMCT).This article reported a case of sudden natural death after the complaint of anterior c...It is never an easy thing to diagnose heart vascular disease only depending on the unenhanced postmortem computed tomography(PMCT).This article reported a case of sudden natural death after the complaint of anterior chest pain in which coronary artery calcification(CAC) was clearly displayed using PMCT scan.The entire coronary artery system was almost reconstructed via multiplanar reformation(MPR) and volume-rendering reconstruction(VR),and the total calcium score of the coronary arteries was obtained with CaScoring automatic analysis software.The results showed that CAC was conspicuous;the total calcium score was 640.3,considerably higher than 400.The pulmonary ground-glass opacity(GGO) and small amount of fluid both in the subglottic trachea and main bronchi were also found.The imaging results confirmed those of autopsy.In addition,the results concluded that PMCT might serve as an invaluable adjunct to the classic autopsy procedure.展开更多
文摘Coronary artery anomaly is known as one of the causes of angina pectoris and sudden death and is an important clinical entity that cannot be overlooked.The incidence of coronary artery anomalies is as low as 1%-2%of the general population,even when the various types are combined.Coronary anomalies are practically challenging when the left and right coronary ostium are not found around their normal positions during coronary angiography with a catheter.If there is atherosclerotic stenosis of the coronary artery with an anomaly and percutaneous coronary intervention(PCI)is required,the suitability of the guiding catheter at the entrance and the adequate back up force of the guiding catheter are issues.The level of PCI risk itself should also be considered on a caseby-case basis.In this case,emission computed tomography in the R-1 subtype single coronary artery proved that ischemia occurred in an area where the coronary artery was not visible to the naked eye.Meticulous follow-up would be crucial,because sudden death may occur in single coronary arteries.To prevent atherosclerosis with full efforts is also important,as the authors indicated admirably.
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.
文摘BACKGROUND Sudden death is unanticipated,non-violent death taking place within the first 24 h after the onset of symptoms.It is a major public health problem worldwide.Moreover,the effects of living at moderate altitude on mortality are poorly understood.AIM To retrospectively report the frequency and the main causes of sudden deaths in relation to total deaths at Asir Central Hospital,2255 m above sea level,in the southern region of Saudi Arabia over a period of 4 years from 2013 to 2016.METHODS The medical records of 1821 deaths were examined and showed 353 cases(19.4%)of sudden death.RESULTS The highest incidence of sudden death was among the elderly(51%),whereas,the lowest was among children and adolescents(6.5%).With regard to gender,the incidence of sudden death was higher in males(54.4%)compared to 45.6% in females.In this study,we found that the most common direct causes of sudden death were cardiovascular diseases(29.2%),respiratory disease(22.7%),infectious disease(12.2%),cancer(9.4%)and hematological diseases(6.2%).With respect to seasonal variation,the highest incidence was during winter(31.32%)followed by summer(25.8%).CONCLUSION The results of this study will help emergency physicians and health care providers to exercise due care to reduce the incidence of sudden death and raise public awareness about the impact of sudden death.
文摘Early repolarization syndrome(ERS), demonstrated as J-point elevation on an electrocardiograph, was formerly thought to be a benign entity, but the recent studies have demonstrated that it can be linked to a considerable risk of life- threatening arrhythmias and sudden cardiac death(SCD). Early repolarization characteristics associated with SCD include high-amplitude J-point elevation, horizontal and/or downslopping ST segments, and inferior and/or lateral leads location. The prevalence of ERS varies between 3% and 24%, depending on age, sex and J-point elevation(0.05 m V vs 0.1 m V) being the main determinants.ERS patients are sporadic and they are at a higher risk of having recurrent cardiac events. Implantable cardioverter-defibrillator implantation and isoproterenol are the suggested therapies in this set of patients. On the other hand, asymptomatic patients with ERS are common and have a better prognosis. The risk stratification in asymptomatic patients with ERS still remains a grey area. This review provides an outline of the up-to-date evidence associated with ERS and the risk of life- threatening arrhythmias. Further prospective studies are required to elucidate the mechanisms of ventricular arrhythmogenesis in patients with ERS.
文摘We report an acute case of a native man from Bolivia suffered from cephalalgia which rapidly worsened and ended in his sudden and unexpected death.Magnetic resonance imaging(MRI) of the brain was obtained.Features demonstrated on brain MRI scan were consistent with a diagnosis of neurocysticercosis(NCC).An autopsy showed the presence of intraventricular Taenia solium(T.solium) cysts which caused blockage of cerebrospinal fluid and secondary hydrocephalus.Due to the increasing travel movements of people neurocysticercosis must be considered as a cause of unexplained sudden death.
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Hypertrophic cardiomyopathy (HCM) is a common genetic cardiovascular disease that affects the left ventricle. HCM can appear at any age, with the majority of the patients remaining clinically stable. When patients complain of symptoms, these include: dyspnea, dizziness, syncope and angina. HCM can lead to sudden cardiac death (SCD), mainly due to ventricular tachyarrhythmia or ventricular tachycardia. High-risk patients benefit from implantable cardioverter-defibrillators. Left ventricular outflow tract obstruction is not a rare feature in HCM, especially in symptomatic patients, and procedures that abolish that obstruction provide positive and consistent results that can improve longterm survival. HCM is the most common cause of sudden death in young competitive athletes and preparticipation screening programs have to be implemented to avoid these tragic fatalities. The structure of these programs is a matter of large debate. Worldwide registries are necessary to identify the full extent of HCMrelated SCD.
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Pre-partecipation screening is the systematic practice of medically evaluating large populations of athletes before participation in sport activities for the purpose of identifying abnormalities that could cause disease progression or sudden death.In order to prevent sudden cardiac death(SCD),cardiovascular screening should include a strategy for excluding high-risk subjects from athletic and vigorous exercise.There are two major screening programmes in the world.In the United States competitive athletes are screened by means of family and personal history and physical examination.In Italy there is a mandatory screening for competitive athletes,which includes a resting electrocardiogram(ECG)for the detection of cardiac abnormalities.The most important issue to be addressed is whether a screened subject is really guaranteed that she/he is not suffering from any cardiac disease or at risk for SCD.Conceivably,the introduction of echocardiogram during the pre-participation screening,could be reasonable,despite the discrete sensitivity of ECG,in raising clinical suspicions of severe cardiac alterations predisposing to SCD.It is clear that the costbenefit ratio per saved lives of the ECG screening is abenchmark of the Public Health policy.On the contrary,the additional introduction of echocardiography in a large population screening programme seems to be too much expansive for the Public Health and for this reason not easily practicable,even if useful and not invasive.Even if we strongly believe that a saved life is more important than any cost-efficacy evaluation,the issue of the economical impact of this approach should be further assessed.
基金This study was funded Natural Science Foundation would like to thank Prof. technical assistance, who Huadong Hospital, Shangh by the Council of National of China (GY2012-1). We ZHANG Guo-zhen for his works in the CT room of ai, China.
文摘It is never an easy thing to diagnose heart vascular disease only depending on the unenhanced postmortem computed tomography(PMCT).This article reported a case of sudden natural death after the complaint of anterior chest pain in which coronary artery calcification(CAC) was clearly displayed using PMCT scan.The entire coronary artery system was almost reconstructed via multiplanar reformation(MPR) and volume-rendering reconstruction(VR),and the total calcium score of the coronary arteries was obtained with CaScoring automatic analysis software.The results showed that CAC was conspicuous;the total calcium score was 640.3,considerably higher than 400.The pulmonary ground-glass opacity(GGO) and small amount of fluid both in the subglottic trachea and main bronchi were also found.The imaging results confirmed those of autopsy.In addition,the results concluded that PMCT might serve as an invaluable adjunct to the classic autopsy procedure.