Cardiovascular autonomic neuropathy(CAN)is a debilitating condition that mainly occurs in long-standing type 2 diabetes patients but can manifest earlier,even before diabetes is diagnosed.CAN is a microvascular compli...Cardiovascular autonomic neuropathy(CAN)is a debilitating condition that mainly occurs in long-standing type 2 diabetes patients but can manifest earlier,even before diabetes is diagnosed.CAN is a microvascular complication that results from lesions of the sympathetic and parasympathetic nerve fibers,which innervate the heart and blood vessels and promote alterations in cardiovascular autonomic control.The entire mechanism is still not elucidated,but several aspects of the pathophysiology of CAN have already been described,such as the production of advanced glycation end products,reactive oxygen species,nuclear factor kappa B,and pro-inflammatory cytokines.This microvascular complication is an important risk factor for silent myocardial ischemia,chronic kidney disease,myocardial dysfunction,major cardiovascular events,cardiac arrhythmias,and sudden death.It has also been suggested that,compared to other traditional cardiovascular risk factors,CAN progression may have a greater impact on cardiovascular disease development.However,CAN might be subclinical for several years,and a late diagnosis increases the mortality risk.The duration of the transition period from the subclinical to clinical stage remains unknown,but the progression of CAN is associated with a poor prognosis.Several tests can be used for CAN diagnosis,such as heart rate variability(HRV),cardiovascular autonomic reflex tests,and myocardial scintigraphy.Currently,it has already been described that CAN could be detected even during the subclinical stage through a reduction in HRV,which is a non-invasive test with a lower operating cost.Therefore,considering that diabetes mellitus is a global epidemic and that diabetic neuropathy is the most common chronic complication of diabetes,the early identification and treatment of CAN could be a key point to mitigate the morbidity and mortality associated with this long-lasting condition.展开更多
Heart failure(HF)is a complex clinical syndrome characterized by the activation of at least several neurohumoral pathways that have a common role in maintaining cardiac output and adequate perfusion pressure of target...Heart failure(HF)is a complex clinical syndrome characterized by the activation of at least several neurohumoral pathways that have a common role in maintaining cardiac output and adequate perfusion pressure of target organs and tissues.The sympathetic nervous system(SNS)is upregulated in HF as evident in dysfunctional baroreceptor and chemoreceptor reflexes,circulating and neuronal catecholamine spillover,attenuated parasympathetic response,and augmented sympathetic outflow to the heart,kidneys and skeletal muscles.When these sympathoexcitatory effects on the cardiovascular system are sustained chronically they initiate the vicious circle of HF progression and become associated with cardiomyocyte apoptosis,maladaptive ventricular and vascular remodeling,arrhythmogenesis,and poor prognosis in patients with HF.These detrimental effects of SNS activity on outcomes in HF warrant adequate diagnostic and treatment modalities.Therefore,this review summarizes basic physiological concepts about the interaction of SNS with the cardiovascular system and highlights key pathophysiological mechanisms of SNS derangement in HF.Finally,special emphasis in this review is placed on the integrative and up-to-date overview of diagnostic modalities such as SNS imaging methods and novel laboratory biomarkers that could aid in the assessment of the degree of SNS activation and provide reliable prognostic information among patients with HF.展开更多
AIMTo assess the prevalence of depressed heart rate variability (HRV) after an acute myocardial infarction (MI), and to evaluate its prognostic significance in the present era of immediate reperfusion.METHODSTime-doma...AIMTo assess the prevalence of depressed heart rate variability (HRV) after an acute myocardial infarction (MI), and to evaluate its prognostic significance in the present era of immediate reperfusion.METHODSTime-domain HRV (obtained from 24-h Holter recordings) was assessed in 326 patients (63.5 ± 12.1 years old; 80% males), two weeks after a complicated MI treated by early reperfusion: 208 ST-elevation myocardial infarction (STEMI) patients (in which reperfusion was successfully obtained within 6 h of symptoms in 94% of cases) and 118 non-ST-elevation myocardial infarction (NSTEMI) patients (percutaneous coronary intervention was performed within 24 h and successful in 73% of cases). Follow-up of the patients was performed via telephone interviews a median of 25 mo after the index event (95%CI of the mean 23.3-28.0). Primary end-point was occurrence of all-cause or cardiac death; secondary end-point was occurrence of major clinical events (MCE, defined as mortality or readmission for new MI, new revascularization, episodes of heart failure or stroke). Possible correlations between HRV parameters (mainly the standard deviation of all normal RR intervals, SDNN), clinical features (age, sex, type of MI, history of diabetes, left ventricle ejection fraction), angiographic characteristics (number of coronary arteries with critical stenoses, success and completeness of revascularization) and long-term outcomes were analysed.RESULTSMarkedly depressed HRV parameters were present in a relatively small percentage of patients: SDNN < 70 ms was found in 16% and SDNN < 50 ms in 4% of cases. No significant differences were present between STEMI and NSTEMI cases as regards to their distribution among quartiles of SDNN (χ<sup>2</sup> =1.536, P = 0.674). Female sex and history of diabetes maintained a significant correlation with lower values of SDNN at multivariate Cox regression analysis (respectively: P = 0.008 and P = 0.008), while no correlation was found between depressed SDNN and history of previous MI (P = 0.999) or n展开更多
Hypertension is a complex disease that constitutes an important public health problem and demands many studies in order to understand the molecular mechanisms involving his pathophysiology. Therefore, an increasing nu...Hypertension is a complex disease that constitutes an important public health problem and demands many studies in order to understand the molecular mechanisms involving his pathophysiology. Therefore, an increasing number of studies have been conducted and new therapies are continually being discovered. In this context, exercise training has emerged as an important non-pharmacological therapy to treat hypertensive patients, minimizing the side effects of pharmacological therapies and frequently contributing to allow pharmacotherapy to be suspended. Several mechanisms have been associated with the pathogenesis of hypertension, such as hyperactivity of the sympathetic nervous system and renin-angiotensin aldosterone system,impaired endothelial nitric oxide production, increased oxygen-reactive species, vascular thickening and stiffening, cardiac hypertrophy, impaired angiogenesis, and sometimes genetic predisposition. With the advent of microRNAs(miRNAs), new insights have been added to the perspectives for the treatment of this disease, and exercise training has been shown to be able to modulate the miRNAs associated with it. Elucidation of the relationship between exercise training and miRNAs in the pathogenesis of hypertension is fundamental in order to understand how exercise modulates the cardiovascular system at genetic level. This can be promising even for the development of new drugs. This article is a review of how exercise training acts on hypertension by means of specific miRNAs in the heart, vascular system, and skeletal muscle.展开更多
文摘Cardiovascular autonomic neuropathy(CAN)is a debilitating condition that mainly occurs in long-standing type 2 diabetes patients but can manifest earlier,even before diabetes is diagnosed.CAN is a microvascular complication that results from lesions of the sympathetic and parasympathetic nerve fibers,which innervate the heart and blood vessels and promote alterations in cardiovascular autonomic control.The entire mechanism is still not elucidated,but several aspects of the pathophysiology of CAN have already been described,such as the production of advanced glycation end products,reactive oxygen species,nuclear factor kappa B,and pro-inflammatory cytokines.This microvascular complication is an important risk factor for silent myocardial ischemia,chronic kidney disease,myocardial dysfunction,major cardiovascular events,cardiac arrhythmias,and sudden death.It has also been suggested that,compared to other traditional cardiovascular risk factors,CAN progression may have a greater impact on cardiovascular disease development.However,CAN might be subclinical for several years,and a late diagnosis increases the mortality risk.The duration of the transition period from the subclinical to clinical stage remains unknown,but the progression of CAN is associated with a poor prognosis.Several tests can be used for CAN diagnosis,such as heart rate variability(HRV),cardiovascular autonomic reflex tests,and myocardial scintigraphy.Currently,it has already been described that CAN could be detected even during the subclinical stage through a reduction in HRV,which is a non-invasive test with a lower operating cost.Therefore,considering that diabetes mellitus is a global epidemic and that diabetic neuropathy is the most common chronic complication of diabetes,the early identification and treatment of CAN could be a key point to mitigate the morbidity and mortality associated with this long-lasting condition.
文摘Heart failure(HF)is a complex clinical syndrome characterized by the activation of at least several neurohumoral pathways that have a common role in maintaining cardiac output and adequate perfusion pressure of target organs and tissues.The sympathetic nervous system(SNS)is upregulated in HF as evident in dysfunctional baroreceptor and chemoreceptor reflexes,circulating and neuronal catecholamine spillover,attenuated parasympathetic response,and augmented sympathetic outflow to the heart,kidneys and skeletal muscles.When these sympathoexcitatory effects on the cardiovascular system are sustained chronically they initiate the vicious circle of HF progression and become associated with cardiomyocyte apoptosis,maladaptive ventricular and vascular remodeling,arrhythmogenesis,and poor prognosis in patients with HF.These detrimental effects of SNS activity on outcomes in HF warrant adequate diagnostic and treatment modalities.Therefore,this review summarizes basic physiological concepts about the interaction of SNS with the cardiovascular system and highlights key pathophysiological mechanisms of SNS derangement in HF.Finally,special emphasis in this review is placed on the integrative and up-to-date overview of diagnostic modalities such as SNS imaging methods and novel laboratory biomarkers that could aid in the assessment of the degree of SNS activation and provide reliable prognostic information among patients with HF.
文摘AIMTo assess the prevalence of depressed heart rate variability (HRV) after an acute myocardial infarction (MI), and to evaluate its prognostic significance in the present era of immediate reperfusion.METHODSTime-domain HRV (obtained from 24-h Holter recordings) was assessed in 326 patients (63.5 ± 12.1 years old; 80% males), two weeks after a complicated MI treated by early reperfusion: 208 ST-elevation myocardial infarction (STEMI) patients (in which reperfusion was successfully obtained within 6 h of symptoms in 94% of cases) and 118 non-ST-elevation myocardial infarction (NSTEMI) patients (percutaneous coronary intervention was performed within 24 h and successful in 73% of cases). Follow-up of the patients was performed via telephone interviews a median of 25 mo after the index event (95%CI of the mean 23.3-28.0). Primary end-point was occurrence of all-cause or cardiac death; secondary end-point was occurrence of major clinical events (MCE, defined as mortality or readmission for new MI, new revascularization, episodes of heart failure or stroke). Possible correlations between HRV parameters (mainly the standard deviation of all normal RR intervals, SDNN), clinical features (age, sex, type of MI, history of diabetes, left ventricle ejection fraction), angiographic characteristics (number of coronary arteries with critical stenoses, success and completeness of revascularization) and long-term outcomes were analysed.RESULTSMarkedly depressed HRV parameters were present in a relatively small percentage of patients: SDNN < 70 ms was found in 16% and SDNN < 50 ms in 4% of cases. No significant differences were present between STEMI and NSTEMI cases as regards to their distribution among quartiles of SDNN (χ<sup>2</sup> =1.536, P = 0.674). Female sex and history of diabetes maintained a significant correlation with lower values of SDNN at multivariate Cox regression analysis (respectively: P = 0.008 and P = 0.008), while no correlation was found between depressed SDNN and history of previous MI (P = 0.999) or n
基金Supported by Grants from Funda■o de AmparoàPesquisa do Estado de Sao Paulo-FAPESP,No.2009/18370-3 and 2010/50048-1by Conselho Nacional de Desenvolvimento Científico e Tecnológico-CNPq,No.476515/2012-2,USP/PRP-NAPmiR+1 种基金by the grant from FAPESP,No.2012/04104-2,No.2013/10472-7 and No.2010/09438-0by the grant from CNPq,No.159827/2011-6,No.159827/2011-6 and No.308267/2013-3
文摘Hypertension is a complex disease that constitutes an important public health problem and demands many studies in order to understand the molecular mechanisms involving his pathophysiology. Therefore, an increasing number of studies have been conducted and new therapies are continually being discovered. In this context, exercise training has emerged as an important non-pharmacological therapy to treat hypertensive patients, minimizing the side effects of pharmacological therapies and frequently contributing to allow pharmacotherapy to be suspended. Several mechanisms have been associated with the pathogenesis of hypertension, such as hyperactivity of the sympathetic nervous system and renin-angiotensin aldosterone system,impaired endothelial nitric oxide production, increased oxygen-reactive species, vascular thickening and stiffening, cardiac hypertrophy, impaired angiogenesis, and sometimes genetic predisposition. With the advent of microRNAs(miRNAs), new insights have been added to the perspectives for the treatment of this disease, and exercise training has been shown to be able to modulate the miRNAs associated with it. Elucidation of the relationship between exercise training and miRNAs in the pathogenesis of hypertension is fundamental in order to understand how exercise modulates the cardiovascular system at genetic level. This can be promising even for the development of new drugs. This article is a review of how exercise training acts on hypertension by means of specific miRNAs in the heart, vascular system, and skeletal muscle.
