心脏特异转录因子及其对心脏发育和心脏基因的调控

器官的形成需要器官特异细胞的定向分化及形态发育，这些都在特异基因的调控下完成。特异基因的表达由转录因子调控。心脏特异转录因子主要在心肌细胞表达，调节心脏特异基因表达，决定组织特异性，在心脏发育过程中起到了关键的作用。这些基因的突变会导致先天性心脏缺陷。我们感兴趣的是，这些转录因子以及它们所调控的心脏基因，在心脏发育中扮演了什么样的角色，这些基因的突变会有什么样的后果。本文主要综述了目前已经发现的一些转录因子在脊椎动物，尤其是小鼠和人类心脏发育的作用以及它们调控心脏基因表达的方式。     

置入双腔起搏心脏复律除颤器及经腋静脉送入心内电极的初步 …

目的 初步评价新型双腔起搏心脏复律颤除器抗室性心律过速／心室颤动（室速／室颤）及心动过缓起搏的临床效果，了解经腋静脉送入心房及心室电极的安全性及有效性，方法 ７例室速及（或）室颤同时伴有心动过缓患者接受了双腔起搏心脏和颤器治疗，其中冠心病５例，扩张性民肌病２例，心房及心室电极均在Ｘ线秀视，静脉注入造影剂指导下，直接穿刺腋静脉，从该静脉送入，结果 脉冲发生器埋在左上胸皮下５例，埋在胸大肌与胸小肌之间     

双腔起搏器传导功能的心电图

1．双腔起搏器的传导功能 双腔起搏器的心房电极导线植入的部位为右心耳．电极导线的头部被动固定在梳状肌中，心室电极导线植入部位为右室心尖部，电极导线的顶端被动固定在肌小梁中。由于双腔起搏器具有心房、心室的感知及顺序性心房、心室的起搏功能，因而能保持心房和心室先后顺序性收缩，使心房对心脏的辅助泵作用得到充分发挥。除感知与起搏功能外，双腔起搏器尚有房室间的传导功能，     

三腔起搏心电图(一)

<正>三腔起搏器分为两种,一种是双心房单心室三腔起搏器,另一种是单心房双心室三腔起搏器,其中后一种较常用,在此先于介绍。单心房双心室三腔起搏器(包括CRT-P及CRT-D),主要用于治疗扩张性心肌病伴室内传导阻滞的心衰患者,通过恢复房室、室间及室内同步性,改善心脏收缩功能。2013年中华医学会心电生理和起搏分会专家参考2012年ACC/AHA/HRS和ESC的指南结合我国的具体情     

起搏心电图中的融合波

当心脏内同时存在两个独立的节律点时，两者可同时或先后激动心脏的同一心腔（心房、心室），进而形成心电图中的心房或心室融合波。人工心脏起搏器植入人体后，使患者的心脏内一直共存两个节律点，即患者的自主心律和起搏器节律，因而使起搏心电图中融合波十分常见，尤其植入VVI和DDD起搏器患者的心电图中室性融合波更为常见。融合波是起搏心电图的重要内容，是阅读和分析起搏心电图的基本功。     

室性期前收缩揭示的室房传导现象

正心室异位搏动或起搏时,激动沿正常房室通道或旁道从心室传到心房时所表现的心电现象称为室房传导现象[1]。室房传导是房室结折返性心动过速、起搏介导性心动过速等心电现象的电生理基础,也是引发起搏器综合征的主要原因[1-2]。当心脏传导系及各腔室处于静息状态时,心房激动可通过房室交界区下传、并激动心室,同样,心室激动也可通过房室通道逆传心房。在有房室旁道解剖结构的基础上,心     

多腔室心脏起搏的临床应用

广义上的多腔室心脏起搏应包括双腔、三腔和四腔心脏起搏。但目前临床上的多腔室心脏起搏主要指三腔或四腔心脏起搏，尤指临床疗效较为确切的单房双室三腔心室再同步化心脏起搏。     

人工培养瓣膜可望用于治疗先天性瓣膜疾病

心脏由四个心腔组成,位于上面的两个心腔,称为心房,分为左右心房;下面的心腔称为心室,分左右心室。心房与心室之间、心室与大动脉之间都有一组瓣膜。左心房与左心室之间的瓣膜称为二尖瓣;右心房与右心室之间的瓣膜称为三尖瓣;左心室与主动脉之间的瓣膜称为主动脉瓣;右心室与肺动脉之间的瓣膜则称为肺动脉瓣。这些瓣膜就像房室之间、心室和动脉之间的门,都由两到三个瓣叶组成,瓣叶的一开一关起了控制血流进入和排出的作用。     

右心房双心室起搏治疗充血性心力衰竭护理体会

充血性心力衰竭的主要病理改变是心脏扩大和心室收缩功能下降，心输出量不足，同时由于心室舒张末压及心房压的升高，引起肺循环和体循环淤血。自2002年以来，我们对2例晚期扩张型心肌病合并充血性心力衰竭患者实施右心房双心室三腔起搏治疗，效果满意，现将护理体会报告如下。     

置入双腔起搏心脏复律除颤器及经腋静脉送入心内电极的初步临床体会

目的初步评价新型双脏起搏心脏复律除颤器抗室性心动过速／心室颤动（室速／室颤）及心动过缓起搏的临床效果,了解经腋静脉送人心房及心室电极的安全性及有效性。方法７例室速及（或）室颤同时伴有心动过缓患者接受了双腔起搏心脏复律除颤器治疗,其中冠心病５例、扩张性心肌病２例。心房及心室电极均在Ｘ线透视、静脉注人造影剂指导下,直接穿刺腋静脉,从该静脉送人。结果脉冲发生器埋在左上胸皮下５例,埋在胸大肌与胸小肌之间２例。仪器对所有室速／室颤均能及时识别并成功治疗,同时提供有效的房室顺序起搏功能。所有心内电极均成功地经腋静脉送人,无并发症。结论双腔起搏心脏复律除颤器不但能有效地治疗严重室性心律失常,而且提供可靠的房室顺序性起搏功能。经腋静脉送入电极安全、可靠。     

Altered myocardial acetylcholine and norepinephrine concentrations in right ventricular hypertrophy and failure

Summary The progression of cardiac hypertrophy and failure is associated with marked changes in cardiac autonomic innervation, and there are sympathetic-parasympathetic interactions in the regulation of cardiac function. Although the indexes of sympathetic innervation have been found to be depressed with the development of heart failure, those of parasympathetic innervation have not yet been fully investigated. In order to better understand changes in markers of autonomic innervation associated with cardiac hypertrophy and failure, we measured the myocardial acetylcholine (ACh) store as a parasympathetic marker and the norepinephrine (NE) store as a sympathetic marker in pressure-overloaded right ventricular hypertrophy in rats. Two weeks after the injection of monocrotaline, significant right ventricular hypertrophy occurred. Three weeks after, severe right ventricular hypertrophy with no sign of heart failure occurred, and 4 weeks after, overt heart failure developed. In the right heart of monocrotaline rats, NE concentrations tended to increase at 1 week, returned to baseline at 2 weeks, decreased to one-half of the control values at 3 weeks, and then fell to 14% of the controls at 4 weeks. ACh concentrations in the right heart tended to increase at 1 week and exhibited a significant increase (136% and 129% of the controls in the right atrium and ventricle, respectively) at 2 weeks. As with NE, ACh concentrations in the right atrium and ventricle decreased to 76% and 54% of the controls at 3 weeks, and continued to decrease to 22% and 24% of the controls at 4 weeks after monocrotaline. Assessing the net changes, ACh contents (i.e., total mass contained in the whole atrium or ventricle) increased at 2 weeks, although NE contents remained unchanged at the early stages. The NE and ACh contents were maintained until 3 weeks after monocrotaline, whereas both contents were depleted at 4 weeks.Our results suggest that parasympathetic innervation shows a transient increase during progressive hypertrophy due to pressure overload, and that both NE and ACh are depleted with the progression of overt heart failure, although NE and ACh contents in the whole atrium or ventricle are maintained during the compensated state of heart failure.     

小儿心脏血流与四心腔径线及其比值的彩色多普勒研究

本文应用彩色多普勒对417例正常小儿（年龄1天－14岁）按体重分组法，进行心脏血流、四心脏径线及其比值的研究。所有参数均输入中国预防医学科学院编译的美国《STATA》统计软件进行统计学处理，结果显示：小儿心脏的二、三尖瓣口及主、肺动脉血流峰值；左室与右室及左房与右房的比值与体重无关。四心脏长、短轴径线与体重相关。各组的左房、室径线均大于右房、室。本研究旨在提供正常小儿心脏血流峰值及四心腔径线参数，这些参数以往鲜见报道；而其在小儿先天性及后天获得性心脏病的诊断上也颇具价值。     

Molecular and electrophysiological differences in the L-type Ca2+ channel of the atrium and ventricle of rat hearts.

BACKGROUND: Many pathological conditions induce electrical remodeling, possibly through intracellular Ca2+ overload, but the currently available L-type Ca2+ channel blockers may be detrimental because of their global negative inotropic effects. METHODS AND RESULTS: To determine whether the L-type Ca2+ channel is identical throughout the heart, the distribution of the mRNAs and proteins comprising the L-type Ca2+ channel and its electrophysiological properties were analyzed in rat atria and ventricles. The mRNA of alpha2delta-2 (Cacna2d2) was more abundantly expressed in the atrium (approximately 5-fold) than in the ventricle. In contrast, alpha1C (Cacna1c) (Cav1.2) mRNA was significantly less abundant in the atrium. The level of the alpha1C (Cacna1c) (Cav1.2) protein was decreased (approximately 0.5-fold) and that of alpha2 delta-1 (Cacna2d1) was increased (approximately 2-fold) in the atrium compared with the ventricle. Although the peak ICa,L density showed no significant differences, voltage dependence of inactivation and activation of the current showed a more depolarized shift in the atrium than in the ventricle. CONCLUSION: These results indicate that in the rat heart the L-type Ca2+ channel differs between the atrium and ventricle with regard to gene expression and electrophysiological properties.     

Assessment of severity of tricuspid regurgitation by analog computer analysis of dilution curves recorded by scintillation camera

To estimate the severity of tricuspid regurgitation, we developed a new mathematical model of the circulatory system, in which the right atrium and the right ventricle were represented by a single mixing chamber and tricuspid regurgitation was expressed as a reverse flow from the right ventricle to the right atrium with a time delay equivalent to one cardiac cycle. The actual dilution curves obtained from the right atrium and the right ventricle following rapid intravenous injection of Technetium-99m-macroaggregated human albumin were fitted to the theoretical curves based on the above-described model. The use of macroaggregated albumin avoided the contamination of the dilution curves by radio-activity from the left heart or by the recirculation of the tracer due to left to right shunt. Mean transit times and percentage of regurgitation, as given by the ratio of regurgitant flow to total outflow from the right ventricle, were determined by an analog computer. The correlations of these results with the findings of other examinations, including contrast echocardiography, demonstrated that the present method may be useful in detecting tricuspid regurgitation and in grading its severity.     

高血压左心结构改变与临床心功能分级的关系

本文分析１５０例高血压病人结果提示：高血压引起左心结构的改变有左室肥厚（向心性，偏心性，离心性）及左房扩大。在左室向心性及偏心性肥厚的病人，心功能多为Ⅱ级，以左室舒张功能受损为主，收缩功能正常。而离心性肥厚的病人，心功能为Ⅲ－Ⅳ级，以收缩功能受损为主；单纯左房扩大是高血压早期心脏受累的指标，亦为舒张功能受损，心功能Ⅰ－Ⅱ级。年龄及病程对心功能有一定影响。     

Infiltrative cardiac lymphoma with tricuspid valve involvement in a young man

Cardiac metastases are among the topics with limited systematic reviews.Theoretically,the heart can be infiltrated by any malignancy with the ability to spread to distant structures.Thus far,no specific tumors are known to have a predilection for the heart,but some do metastasize more often than others,for example,melanoma and primary mediastinal tumors.We report a case of cardiac metastasis from a diffuse large B cell lymphoma in a young man.The peculiarity of this case is that besides the involvement of right ventricle and atrium,the tricuspid valve was also infiltrated.Valvular metastasis is rarely reported in the medical literature.     

Natriuretic peptides as cardiac hormones in normotensive and spontaneously hypertensive rats. The ventricle is a major site of synthesis and secretion of brain natriuretic peptide.

To study synthesis, storage, and secretion of brain natriuretic peptide (BNP) in the heart, we have measured BNP mRNA and BNP concentrations in the hearts of Wistar-Kyoto rats and also have investigated its secretion from the isolated perfused heart. The atrium expressed the BNP gene at a high level, and a considerable amount of BNP mRNA also was present in the ventricle, which corresponded to approximately 40% of the atrial BNP mRNA concentration. When tissue weight was taken into account, the total content of BNP mRNA in the ventricle was approximately threefold larger than that in the atrium, although the atrial natriuretic peptide (ANP) mRNA content in the ventricle was only 7% of that in the atrium. By contrast, the BNP concentration in the ventricle was 4.07 +/- 0.97 pmol/g, which was less than 1% of that in the atrium (451 +/- 86 pmol/g). The basal secretory rate of BNP from the isolated perfused whole heart was 49.3 +/- 6.1 fmol/min, approximately 60% of which was maintained even after atrial removal, whereas the secretory rate of ANP was reduced to less than 5%. We also studied age-matched spontaneously hypertensive rats-stroke prone. The rank order of the BNP mRNA concentration in the hearts of these rats was left ventricle greater than right ventricle greater than right atrium = left atrium, and the total BNP mRNA content and BNP secretory rate in the ventricle were twice as large as in Wistar-Kyoto rats. These results demonstrate that BNP is a novel cardiac hormone in rats and is predominantly synthesized in and secreted from the ventricle. This is in striking contrast to ANP, which occurs mainly in the atrium. The results also suggest possible pathophysiological roles of BNP in certain cardiovascular disorders.