Histone deacetylases and cardiovascular cell lineage commitment

Cardiovascular diseases(CVDs), which include alldiseases of the heart and circulation system, are the leading cause of deaths on the globally. During the development of CVDs, choric inflammatory, lipid metabolism disorder and endothelial dysfunction are widely recognized risk factors. Recently, the new treatment for CVDs that designed to regenerate the damaged myocardium and injured vascular endothelium and improve recovery by the use of stem cells, attracts more and more public attention. Histone deacetylases(HDACs) are a family of enzymes that remove acetyl groups from lysine residues of histone proteins allowing the histones to wrap the DNA more tightly and commonly known as epigenetic regulators of gene transcription. HDACs play indispensable roles in nearly all biological processes, such as transcriptional regulation, cell cycle progression and developmental events, and have originally shown to be involved in cancer and neurological diseases. HDACs are also found to play crucial roles in cardiovascular diseases by modulating vascular cell homeostasis(e.g., proliferation, migration, and apoptosis of both ECs and SMCs). This review focuses on the roles of different members of HDACs and HDAC inhibitor on stem cell/ progenitor cell differentiation toward vascular cell lineages(endothelial cells, smooth muscle cells and Cardiomyocytes) and its potential therapeutics.

Exercise-mediated regulation of autophagy in the cardiovascular system

Cardiovascular disease is the leading cause of human death worldwide. Autophagy is an evolutionarily conserved degradation pathway,which is a highly conserved cellular degradation process in which lysosomes decompose their own organelles and recycle the resulting macromolecules.Autophagy is critical in maintaining cardiovascular homeostasis and function, and excessive or insufficient autophagy or autophagic flux can lead to cardiovascular disease. Enormous evidence indicates that exercise training plays a beneficial role in the prevention and treatment of cardiovascular diseases. The regulation of autophagy during exercise is a bidirectional process. For cardiovascular disease caused by either insufficient or excessive autophagy, exercise training restores normal autophagy function and delays the progression of cardiovascular disease.An in-depth exploration and discussion of exercise-mediated regulation of autophagy in the cardiovascular system can broaden our view about the prevention of various autophagy-related diseases through exercise training. In this article, we review autophagy and its related signaling pathways,as well as autophagy-dependent beneficial effects of exercise in cardiovascular system.

Secondary cardiovascular prevention in older adults： an evidence based review

1 BackgroundIn the United States, life expectancy is rising, particularly among the older population （〉 65 years）, with projected estimates approaching 20% by year 2050. Despite improved survival estimates, cardiovascular diseases remain the leading cause of morbidity and mortality resulting in substantial increase in health care cost. For younger adults, the evidence for secondary cardiovascular prevention is well established and corroborated by robust data. However, the application of risk reduction strategies in older populations remains an area of active debate. Many assume that vulnerability to chronic cardiovascular diseases is an inexorable part of aging such that the risks attributable to prevention outweigh potential benefits.

Foundations of medical decision-making for older adults with cardiovascular disease

In order to help older adults with cardiovascular disease navigate complex decisions, clinicians must know tenets of medical ethics and have good communication skills. The elements of decision making capacity and informed consent are reviewed, using relevant clinical ex- amples to illustrate the basic concepts. The shared decision making model, by which clinician and patient work together to determine the plan of care, is described. Useful communication techniques to implement shared decision making are suggested.

Emerging Techniques for Cardiovascular PET

Positron emission tomography(PET)has been successfully applied to an increasing number of cardiovascular conditions.This review will highlight the status of cardiovascular PET,including the present state of the art and the expanding pool of clinical evidence guiding its use.Additionally,we highlight upcoming developments in the fi eld,including the development of new tracers and applications of PET to novel indications within cardiovascular medicine.

Cardiovascular Risk Factors and Evidence-Based Health Education

The number of deaths associated with cardiovascular events remains constant in many countries due to new therapeutic approaches for prevention and treatment of atherosclerosis. This condition is widely attributable to unhealthy outcomes in its association with risk factors such as smoking and sedentary behavior. Risk factors play a significant role in the progression of coronary artery disease. We conducted a review of the literature with the purpose of identifying primary risk factors for coronary disease, lifestyle change interventions, and expectations for a reduction in cardiovascular events on the basis of evidence-based health education strategies. In addition, we sought to contextualize this review so that nurses are trained to use these findings in their practice at different levels of care.

Exercise sustains the hallmarks of health

Exercise has long been known for its active role in improving physical fitness and sustaining health.Regular moderate-intensity exercise improves all aspects of human health and is widely accepted as a preventative and therapeutic strategy for various diseases.It is well-documented that exercise maintains and restores homeostasis at the organismal,tissue,cellular,and molecular levels to stimulate positive physiological adaptations that consequently protect against various pathological conditions.Here we mainly summarize how moderate-intensity exercise affects the major hallmarks of health,including the integrity of barriers,containment of local perturbations,recycling and turnover,integration of circuitries,rhythmic oscillations,homeostatic resilience,hormetic regulation,as well as repair and regeneration.Furthermore,we summarize the current understanding of the mechanisms responsible for beneficial adaptations in response to exercise.This review aimed at providing a comprehensive summary of the vital biological mechanisms through which moderate-intensity exercise maintains health and opens a window for its application in other health interventions.We hope that continuing investigation in this field will further increase our understanding of the processes involved in the positive role of moderate-intensity exercise and thus get us closer to the identification of new therapeutics that improve quality of life.

Anatomic Correlates of Mitral Systolic Anterior Motion in Transposition of the Great Arteries Following Atrial Switch Operation

Introduction:We sought to investigate whether the development of sub-pulmonic systolic anterior motion(SAM)may be inherent to the anatomy of the the mitral valve(MV)or affected by external factors,such as a dilated right ventricle or chest abnormalities in d-looped transposition of the great arteries post atrial switch operation(d-TGA/AtS).Methods:Analysis was performed of clinical and cardiac imaging studies acquired on 19 adult patients with d-TGA/AtS(age 42±6 years old,56%male)between 2015–2019.Echocardiography data included mitral apparatus anatomy,and CT/MRI data included biventricular dimensions,function,and Haller index(HI)for pectus deformity.Results:Patients with leaflet SAM(n=6)compared to patients without SAM(n=13)had higher MV protrusion height(2.3±0.5 vs.1.5±0.4 cm,p≤0.01)and longer anterior MV leaflet length(3.1±0.4 cm vs.2.6±0.3 cm p≤0.05),when compared to those without.CT/MRI showed higher sub-pulmonic left ventricular ejection fraction(LVEF)in the SAM group(71%±8%vs.54%±7%,respectively).RV size and function,significant chest deformity(HI>3.5),presence of a ventricular lead pacemaker,and septal thickness did not play a role in development of SAM.Conclusions:An elongated mitral apparatus is associated with the development of SAM,and the development of left ventricular outflow tract obstruction(LVOTO),in d-TGA/AtS.LV hyperkinesia is associated with SAM.Systemic RV dimensions,septal thickness,and degree of chest deformity did not differ significantly between subjects with SAM and those without.

Model construction and clinical therapeutic potential of engineered cardiac organoids for cardiovascular diseases

Cardiovascular diseases cause significant morbidity and mortality worldwide.Engineered cardiac organoids are being developed and used to replicate cardiac tissues supporting cardiac morphogenesis and development.These organoids have applications in drug screening,cardiac disease models and regenerative medicine.Therefore,a thorough understanding of cardiac organoids and a comprehensive overview of their development are essential for cardiac tissue engineering.This review summarises different types of cardiac organoids used to explore cardiac function,including those based on co-culture,aggregation,scaffolds,and geometries.The self-assembly of monolayers,multilayers and aggravated cardiomyocytes forms biofunctional cell aggregates in cardiac organoids,elucidating the formation mechanism of scaffold-free cardiac organoids.In contrast,scaffolds such as decellularised extracellular matrices,three-dimensional hydrogels and bioprinting techniques provide a supportive framework for cardiac organoids,playing a crucial role in cardiac development.Different geometries are engineered to create cardiac organoids,facilitating the investigation of intrinsic communication between cardiac organoids and biomechanical pathways.Additionally,this review emphasises the relationship between cardiac organoids and the cardiac system,and evaluates their clinical applications.This review aims to provide valuable insights into the study of three-dimensional cardiac organoids and their clinical potential.

室性早搏的新认识

窜性早搏（ventricular premature complexes，VPCs）是最常见的心律失常之一，可以表现为单个或成对的VPCs，也可连续出现，表现为短阵的室性心动过速（非持续性室性心动过速，

CHA2DS2-VASc评分对非瓣膜病心房颤动患者射频消融前左房血栓的风险评估

目的探讨未经正规华法林抗凝的非瓣膜病心房颤动患者，射频消融术前经食道心脏超声检查左房血栓的发生率，CHA2DS2-VASc不同评分对左房血栓的预测能力。方法分析了212例未经正规华法林抗凝的非瓣膜病心房颤动（atrial fibrillation, AF）患者，经食道心脏超声（transesophageal echocardiography，TEE）检查左房血栓的发生率，左房血栓与左室射血分数、性别、年龄、高血压、糖尿病等危险因素的相关性；分析CHA2DS2-VASc不同评分与左房血栓相关性。结果左房血栓患者33例，其发生率为15.6%。CHA2DS2-VASc 评分低危患者57例，左房血栓0例；中危患者61例，左房血栓2例（ 3.28%）；高危患者94例，左房血栓31例（ 32.98%）。左房血栓发生率随CHA2DS2-VASc 评分增高而增加，低危、中危和高危3组间有明显差异 （P〈0.01）。单变量分析发现年龄≥65岁、左房内径＞40 mm、高血压、糖尿病、冠心病、卒中、CHA2DS2-VASc评分均与左房血栓相关；但多变量logistic回归分析显示，仅CHA2DS2-VASc ≥2 是预测左房血栓较好的指标（OR=7.637, 95%CI：1.144～50.986, P〈0.05）。结论未经正规华法林抗凝的非瓣膜病AF患者左房血栓发生率相对较高，CHA2DS2-VASc评分危险分层与左房血栓密切相关，提示其对AF患者射频消融前TEE检查有筛选价值，高危患者应加强抗凝治疗后仍需TEE检查。

硝酸甘油对局部心肌氧代谢和心肌收缩功能的影响

目的评价硝酸甘油对局部心肌氧代谢和心肌收缩功能的影响。方法实验应用8只具有静息状态血流限制的左前降支或左回旋支近端狭窄的开胸犬。以二维超声心动图评价室壁增厚率(%WT),放射性微球定量心肌血流量(MBF),用磷猝熄法在体直接测定心肌组织氧压(tPO_2)。分别在静息和左冠脉主干内输注硝酸甘油(0.3～0.6mg·kg-1)状态下,进行二维超声检查、核素微球注射,以及tPO_2和心肌氧耗量(MVO_2,ml·min-1·100g-1)测定,MVO_2等于冠状动脉与冠状静脉氧浓度差乘以MBF,心肌氧输送能力等于冠状动脉氧浓度差乘以MBF。结果与静息状态相比,经左冠脉主干内输注硝酸甘油时,无论是正常灌注区抑或是缺血灌注区的MBF明显增加(P<0.05),同时伴有%WT明显增加(P<0.05)。正常和缺血灌注区的心肌氧输送能力明显增加(P<0.05),尽管缺血灌注区的MVO2有明显增加(P<0.05),但是缺血灌注区的tPO_2仍明显增高(P<0.05)。缺血区心肌tPO_2增加的程度明显大于MBF增加的程度。结论硝酸甘油可明显提高正常和缺血灌注区心肌氧浓度,提高缺血灌注区血氧的解离和释放,可能具有正性肌力效应。除了其直接血管效应之外,硝酸甘油还通过对心肌氧代谢和收缩功能的影响在心血管中发挥重要的调节作用。

硝酸甘油对心肌血流灌注直接影响的对比超声评价

目的应用心肌对比成像（MCE）评价硝酸甘油对心肌血流灌注的直接影响。方法实验应用12只具有静息状态血流限制的左前降支近端狭窄的开胸犬（其中6只结扎远处的冠脉以消除侧支循环的影响）,根据远处的冠脉是否结扎分组（非结扎犬为组1、结扎犬为组2）。分别在静息和左冠脉主干内直接输注硝酸甘油（0.3-0.6μg·kg^-1）状态下,测定全血黏滞性（WBη）和心肌血管阻力（MVR）,同步应用放射性标记微球测定心肌血流量（MBF）,MCE评估心肌血流容积（A）和心肌血流速度（β）。结果与静息状态相比,经冠脉内输注硝酸甘油时,组1和组2实验犬正常区、整个缺血区和缺血中心区的MBF均明显增加（P〈0.05）,同时伴有MVR和WBη明显减低（P〈0.05）。MCE显示正常灌注区和整个缺血区β增加的程度明显大于标准化A增加的程度（P〈0.05）;标准化A和β增加（%）与A与β的乘积（A×β）增加（%）之间均有良好的相关性。然而,无论正常灌注区和整个缺血区标准化A增加（%）与A×β增加（%）之间相关方程的斜率明显小于β增加（%）与A×β增加（%）之间的斜率（P〈0.05）。结论硝酸甘油可降低血液黏滞性和心肌血流阻力,进而增加心肌的血液供应,后者主要是源于红细胞在心肌微循环中流动的速度增快所致。MCE是全面定量评价心肌血流灌注的良好方法。

心肌对比超声评价多巴酚丁胺对冠状动脉微循环的直接效应：与腺苷对比

目的评价多巴酚丁胺对正常和狭窄冠状动脉微循环的直接效应,并与腺苷对比。方法实验应用9条健康杂种犬,制备左前降支静息无血流限制性狭窄。在静息状态和左冠状动脉主干内连续输注多巴酚丁胺(2mg·kg^-1·min^-1)和腺苷(5mg·kg^-1·min^-1)时,进行间断谐波心肌对比成像评估心肌血流容积(A)和心肌血流速度(b),并同步应用放射性标记微球测定心肌血流量(MBF),计算心率血压乘积和心肌血管阻力(MVR)。结果两种药物引起正常和狭窄冠状动脉供血区MBF明显增加和MVR明显降低(P<0.05)。在正常冠状动脉供血区,腺苷对A无明显影响,MVR的降低完全是阻力血管的扩张所致(99%),MBF增加主要是由于b的加快(△β/△A=13.6);多巴酚丁胺可引起部分A增加(28%),使总MVR降低中的32%来自这种毛细血管征募,但MBF增加主要还是由于b的加快(△β/△A=5.9)。在狭窄冠状动脉供血区,两种药物引起MBF增加的程度相同,MBF增加均完全是由于b的加快;多巴酚丁胺和腺苷引起毛细血管的关闭分别导致14%和15%心肌毛细血管阻力的增加。结论经冠状动脉内直接给药物时,多巴酚丁胺对冠状动脉微循环的直接效应与腺苷对冠状动脉微循环的直接效应非常相近,MBF增加主要由于心肌血流速度的增快所致。

晕厥的评估和处理策略

晕厥是一种短暂的意识丧失综合征（通常不超过1～2min），是低血压导致脑供血不足最常见的结果…。意识丧失引起姿势张力丧失，导致患者坠地。偶尔患者在意识丧失后会有阵挛性抽动；由于这些肌肉运动，晕厥易被无经验的目击者误认为是癫痫。

Takotsubo cardiomyopathy: Pathophysiology,diagnosis and treatment

In 1990,takotsubo cardiomyopathy(TCM)was first discovered and reported by a Japanese cardiovascular specialist.Since then,this heart disease has gained worldwide acceptance as an independent disease entity.TCM is an important entity that differs from acute myocardial infarction.It occurs more often in postmenopausal elderly women,is characterized by a transient hypokinesis of the left ventricular(LV)apex,and is associated with emotional or physical stress.Wall motion abnormality of the LV apex is generally transient and resolves within a few days to several weeks.Its prognosis is generally good.However,there are some reports of serious TCM complications,including hypotension,heart failure,ventricular rupture,thrombosis involving the LV apex,and torsade de pointes.It has been suggested that coronary spasm,coronary microvascular dysfunction,catecholamine toxicity and myocarditis might contribute to the pathogenesis of TCM.However,its pathophysiology is not clearly understood.

Management of ventricular tachycardia storm in patients with structural heart disease

Electrical storm(ES) is a medical emergency characterized by repetitive episodes of sustained ventriculararrhythmias(VAs) in a limited amount of time(at least 3 within a 24-h period) leading to repeated appropriate implantable cardioverter defibrillator therapies. The occurrence of ES represents a major turning point in the natural history of patients with structural heart disease being associated with poor short-and longterm survival particularly in those with compromised left ventricular ejection fraction(LVEF) that can develop hemodynamic decompensation and multi-organ failure. Management of ES is challenging with limited available evidence coming from small retrospective series and a substantial lack of randomized-controlled trials. In general, a multidisciplinary approach including medical therapies such as anti-arrhythmic drugs, sedation, as well as interventional approaches like catheter ablation, may be required. Accurate patient risk stratification at admission for ES is pivotal and should take into account hemodynamic tolerability of VAs as well as comorbidities like low LVEF, advanced NYHA class and chronic pulmonary disease. In high risk patients, prophylactic mechanical circulatory support with left ventricular assistance devices or extracorporeal membrane oxygenation should be considered as bridge to ablation and recovery. In the present manuscript we review the available strategies for management of ES and the evidence supporting them.

64层CT血管成像与选择性血管造影对肾动脉支架评价的前瞻性对照研究

目的以选择性肾动脉（RA）血管造影为参考标准，前瞻性评价64层CTRA血管成像评估RA支架内再狭窄（ISR）的诊断准确性。材料与方法本研究由医学委员会批准，获取了知情同意书。86例病人[46例男性，40例女性：平均年龄为（71±9）岁1共95个RA支架，在高年资心脏科医师行选择性RA血管造影前一天，由高年资放射科医师进行RA64层CT血管成像。