生理性双腔起搏时最佳AV间期选择与心功能关系的探讨

对 2 0例心肌病心力衰竭 (简称心衰 )患者 (心衰组 )及 10例心功能正常者 (对照组 )行双腔 (DDD)起搏治疗 ,探讨不同AV间期DDD起搏对心衰患者的急性血液动力学效应。经锁骨下静脉置入双腔起搏电极 ,并同时置入Swan Ganz导管 ,测量不同AV间期的急性血液动力学效应 ,二维超声多普勒测量超声形态学指标。结果 :急性起搏时心衰组AV间期在 10 0～ 140ms时 ,血液动力学较起搏前显著改善 ,而以AV为 111± 15ms为最佳。左室舒张末径、左室收缩末径、左房内径显著缩小 ,收缩期二尖瓣返流减轻 ,未发现舒张期二尖瓣返流。而对照组AV间期为16 0～ 180ms时 ,上述指标与起搏前相比显著改善。结论 :短AV间期的生理性起搏能即刻改善心衰患者的急性血液动力学效应和超声形态学指标。     

双腔起搏器置入患者最佳房室延迟不同设置方法的临床研究

对不同最佳房室延迟(OAVD)设置方法进行比较,探讨OAVD设置的简单、实用的方法。选择36例置入双腔起搏器的患者,设置不同的AVD,于超声心动图下记录左室射血分数(EF)、舒张期二尖瓣返流、A波结束至二尖瓣完全关闭的时间间期(Time1)、最早出现舒张期二尖瓣返流的AVD(临界AVD),并通过同步心电图测定QT间期(QTI)、QT离散度(QTD)及QRS波群时间(QRSI)。将各指标预测的OAVD与OAVD(EF最大时的AVD)进行比较。结果:①心功能正常者心房起搏或心房感知时在AVD为170ms或140~160ms时EF达到最大,且与OAVD时EF相比差异均无显著性;心功能不全者在AVD为130~140ms时EF达到最大,但与OAVD时EF相比差异有显著性。②三种心电图指标预测的OAVD与OAVD比较差异均无显著性,其预测的OAVD在心功能不全患者与OAVD显著相关。③预测OAVD、AVD=200或180ms时预测的OAVD与OAVD比较差异均无显著性。结论:在实际工作中,可通过下述简单方法设置OAVD:OAVD=200ms(或180ms)减去200ms(或180ms)时Time1,以提高随访效率。     

多普勒超声心动图在双腔心脏起搏最佳房室间期设置中的应用价值

目的 :探讨多普勒超声心动图在双腔心脏起搏最佳房室间期设置中的应用价值。方法 :19例患有完全性房室传导阻滞并植入永久性双腔心脏起搏器的患者 ,程控房室间期从 90ms逐渐递增至 2 5 0ms ,每次递增量 2 0ms ,脉冲多普勒测量不同房室间期时每搏量和二尖瓣血流频谱的变化。结果 :每搏量最大时的最佳房室间期为 (16 8.9± 15 .6 )ms ,二尖瓣血流频谱的A波终末与二尖瓣叶完全关闭信号同步时的房室间期为 (178.4±2 3.4 )ms ,两者之间存在良好的线性回归关系 (Y =86 .2± 0 .5X ,r =0 .70 ,SEE =11.5 ,P <0 .0 1)。结论 :多普勒超声可以对双腔心脏起搏时的最佳房室间期作出准确地选择 ,并且具有无创、可重复和简便易行的特点。     

不同房室间期对双腔起搏左室收缩功能的影响

为探讨双腔起搏不同房室间期对左室收缩功能的影响及最佳房室间期 ,选择 18例置入DDD起搏器的病窦综合征患者 ,在DOO起搏方式下随机将房室 (AV)间期程控为 10 0 ,130 ,15 0 ,170 ,2 0 0ms,在超声心动图下观察左室收缩功能指标 ,每次测量间隔 5min以上。结果 :AV间期为 15 0ms时左室收缩功能最好 ,与AV间期为 10 0ms时相比 ,左室收缩功能明显改善。以心输出量 (CO)为标准 ,18例中有 9例AV间期在 15 0ms时CO最佳 ,5例在 2 0 0ms时CO最佳 ,3例在 170ms时CO最佳 ,1例在 130ms时CO最佳 ;以CO为标准 ,DOO起搏方式最佳AV间期为 16 6±2 4ms。结论 :双腔起搏的AV间期对左室收缩功能有重要的影响 ,以CO为标准 ,个体化地选择双腔起搏的最佳AV间期对改善患者的心脏功能有重要的意义。     

房室顺序起搏的A-V间期

病态窦房结综合征双结病变型等是植入DDD起搏器的最佳适应证。人体植入DDD起搏器后，就如植入一个窦房结和房室结，心房的电活动可经DDD起搏器设置的A-V间期下传至心室。由于心房激动经体内自身房室结下传更有利于保护心脏的功能，故一般情况下，DDD起搏器将起搏A-V问期程控得比自身P-R间期长，以保证激动尽量经自身房室结下传。研究发现，当P-R间期在120-180ms时心功能较好，故选择合适的AV延迟以及与自主神经（心率）相适应的A-V间期对双腔起搏至关重要。而且，与频率相适应的房室顺序传导，可以产生较好的血流动力学影响。     

较长I度房室阻滞置人心脏永久起搏器一例

患者女，78岁，因高血压病史10多年，胸闷、呼吸困难2个月，ECG示较长PR间期（0．46s）入院，彩色多普勒超声：心脏各腔室不大，左室舒张径35mm，经二尖瓣多普勒血流示：E峰和A峰融合，舒张期二尖瓣返流明显，冠状动脉造影检查正常。给患者安装DDD型心脏永久起搏器，调整适当AV间期后，临床心力衰竭症状明显改善。结论：对较长PR间期I度房室阻滞、且伴心力衰竭的患者，安装DDD型心脏永久起搏器，似可给患者带来明显的血流动力学益处。     

DDD起搏器不同房室延迟对血流动力学的影响

笔者对 15例Ⅲ度房室阻滞置入DDD起搏器的患者 ,观察不同的AV间期时超声心动图左室射血分数 (EF)与心输出量 (CO)、血浆心钠素水平及平板运动试验参数的变化 ,以评价不同AV间期对血流动力学的影响。结果显示不同的AV间期将产生不同的左室EF与CO及血浆心钠素水平 ,当AV间期最佳时 (15 3 .67± 18.75ms)将产生最佳左室EF与CO ,血浆心钠素水平最低。结论 :对置入DDD起搏器的病人应加强随访 ,调整AV间期可使起搏器发挥最大效能。     

病窦综合征患者起搏器术后房室传导方式对血浆BNP水平的影响

目的评估固定的长AV间期下的DDD起搏模式对SSS患者在减少心室起搏方面的效果;比较应用固定的长AV间期保留自身房室传导与最适AV间期下房室顺序起搏两种模式的优劣性,为临床选择具有最佳血流动力学效应的起搏参数设置提供依据。方法选取因SSS而安置双腔心脏永久起搏器进行治疗的45例患者,分3次随访进行,每次随访时间间隔为2个月,将起搏器程控与血液生化指标测量相结合,进行两种不同AV间期下房室顺序起搏模式的血流动力学效应评估与对比。结果与临床经验性AV间期相比,固定的长AV间期(350 ms)下的房室顺序起搏使心室起搏百分比由31.8%降低至1.18%(P=0.000);由最适AV间期下转为固定的长AV间期下的房室顺序起搏模式后,血浆BNP浓度明显降低(P=0.02)。结论固定的长AV间期(350 ms)下的房室顺序起搏能够有效减少心室起搏,且在血流动力学方面优于最适AV间期下的房室顺序起搏。     

超声指导下心脏再同步治疗后参数优化的研究

目的探讨如何进行参数优化以提高心脏再同步化治疗(CRT)疗效。方法对8例慢性心力衰竭CRT患者,术后在超声心动图指导下优化AV间期,在组织多普勒显像下优化VV间期,达到CRT最佳治疗目的。结果8例CRT后心功能都得到改善,心功能NYHA分级,从Ⅲ～Ⅳ级改善为Ⅱ～Ⅲ级,起搏时的AV间期与窦性心律时的AV间期之比优化至130～180/100～150ms,使得左室充盈时间从354±147ms升至420±112ms,二尖瓣返流由8.41±4.55cm2减少至5.36±4.71cm2;VV间期优化至4～40ms,使得左室内各室壁收缩期达峰时间标准差从48.4±17.9ms减少至30.2±18.6ms,左室流出道速度时间积分由20.6±9.0cm/s上升至26.1±3.1cm/s。结论术后个体化的参数优化可以提高CRT疗效。     

不同起搏方式房室延迟优化的对比研究

目的观察双腔起搏(DDD)患者不同起搏方式时最佳房室延迟(AVD)的差异。方法对20例置入DDD起搏器的患者经左侧锁骨下静脉插入Swan-Ganz导管,分别测量DDD方式及心房感知心室起搏(VDD)方式下的不同AVD起搏的急性血流动力学效应。结果DDD右心耳起搏优化AVD(149±15ms)比VDD起搏AVD(114±12ms)延长了38±12ms,差异有非常显著性意义(P<0.01)。结论双腔起搏时DDD右心耳起搏可使AVD达到最优。     

Three layer functional model and energy exchange concept of aging process

Relying on a certain degree of abstraction, we can propose that no particular distinction exists between animate or living matter and inanimate matter. While focusing attention on some specifics, the dividing line between the two can be drawn. The most apparent distinction is in the level of structural and functional organization with the dissimilar streams of ‘energy flow’ between the observed entity and the surrounding environment. In essence, living matter is created from inanimate matter which is organized to contain internal intense energy processes and maintain lower intensity energy exchange processes with the environment. Taking internal and external energy processes into account, we contend in this paper that living matter can be referred to as matter of dissipative structure, with this structure assumed to be a common quality of all living creatures and living matter in general. Interruption of internal energy conversion processes and terminating the controlled energy exchange with the environment leads to degeneration of dissipative structure and reduction of the same to inanimate matter, (gas, liquid and/or solid inanimate substances), and ultimately what can be called ‘death.’ This concept of what we call dissipative nature can be extended from living organisms to social groups of animals, to mankind. An analogy based on the organization of matter provides a basis for a functional model of living entities. The models relies on the parallels among the three central structures of any cell (nucleus, cytoplasm and outer membrane) and the human body (central organs, body fluids along with the connective tissues, and external skin integument). This three-part structural organization may be observed almost universally in nature. It can be observed from the atomic structure to the planetary and intergalactic organizations. This similarity is corroborated by the membrane theory applied to living organisms. According to the energy nature of living matter and the proposed functional model, the decreased integrity of a human body's external envelope membrane is a first cause of the structural degradation and aging of the entire organism. The aging process than progresses externally to internally, as in single cell organisms, suggesting that much of the efforts towards the restoration and maintenance of the mechanisms responsible for structural development should be focused accordingly, on the membrane, i.e., the skin. Numerous reports indicate that all parts of the human body, like: bones, blood with blood vessels, muscles, skin, and so on, have some ability for restoration. Therefore, actual revival of not only aging tissue of the human body's membrane, but the entire human body enclosed within, with all internal organs, might be expected. We assess several aging theories within the context of our model and provide suggestions on how to activate the body's own anti-aging mechanisms and increase longevity. This paper presents some analogies and some distinctions that exist between the living dissipative structure matter and inanimate matter, discusses the aging process and proposes certain aging reversal solutions.     

Unusual responses of nocturnal pineal melatonin synthesis and secretion to swimming: Attempts to define mechanisms

Abstract: The effect of swimming at night on rat pineal melatonin synthesis was compared with that of light exposure at night. Rats were forced to swim at 0030 hr (lights out at 2000 hr) and sacrificed by decapitation 15 and 30 min later, immediately after swimming. Other groups of animals were exposed to white light (650μW/cm²) for 15 and 30 min at same time. Swimming caused a rapid and highly significant drop in the melatonin content in the pineal gland; however, the activity of N-acetyltransferase (NAT), the supposed rate limiting enzyme in the melatonin production, was not changed. Despite the drop in pineal melatonin levels, serum concentrations of the indole remained elevated in the rats that swam. In contrast, melatonin levels in the pineal and serum of light exposed rats fell precipitously, accompanied by a significant suppression of NAT activity. Since we anticipated that the strenuous exercise associated with swimming may induce release of artrial natriuretic peptide (ANP) from the heart, which in turn could cause the release of pineal melatonin, in a second study we injected physiological saline intravenously to stretch the cardiac muscle and release ANP. Three milliliters of normal saline was injected during the day into the jugular vein of anesthetized rats that were pretreated with isoproterenol to stimulate pineal melatonin production. Animals were killed 15 min after the saline injection, and pineal NAT activity and pineal melatonin levels were measured. The saline injections caused no alteration in the elevated levels of either NAT or melatonin. These data suggest that the disparity in pineal NAT activity (which was high) and pineal melatonin (which was low), in animals swum at night, may not be caused by ANP which is released during strenuous exercise such as swimming.     

Melatonin and photoperiodic time measurement: Seasonal breeding in the sheep

Abstract: Well-established circadian physiology supports the view that photoperiodic time measurement utilizes the coincidence between the presence of light and a photosensitive phase of a 'biological clock' to alter reproductive status—the so-called external coincidence model of seasonal breeding. In this review, we examine the mechanism whereby photoperiod interacts with presumed suprachiasmatic nuclei activity to allow endogenous melatonin to normally synchronize reproductive activity to the optimal time of year. The Romney Marsh sheep is particularly explored as an experimental model. It is suggested that the on/off activity of seasonal reproduction may be a robust mechanism able to be predictably manipulated by the judicious use of the light/dark cycle and exogenous melatonin, but firmly based on circadian principles.     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Serological survey of HIV and syphilis in pregnant women in Madagascar

Objectives Peripartal transmission of human immunodeficiency virus (HIV) and Treponema pallidum, the causative agent of syphilis, leads to severe consequences for newborns. Preventive measures require awareness of the maternal infection. Although HIV and syphilis testing in Madagascar could be theoretically carried out within the framework of the national pregnancy follow‐up scheme, the required test kits are rarely available at peripheral health centres. In this study, we screened blood samples of pregnant Madagascan women for HIV and syphilis seroprevalence to estimate the demand for systemic screening in pregnancy. Methods Retrospective anonymous serological analysis for HIV and syphilis was performed in plasma samples from 1232 pregnant women that were taken between May and July 2010 in Ambositra, Ifanadiana, Manakara, Mananjary, Moramanga and Tsiroanomandidy (Madagascar) during pregnancy follow‐up. Screening was based on Treponema pallidum haemagglutination tests for syphilis and rapid tests for HIV, with confirmation of positive screening results on line assays. Results Out of 1232 pregnant women, none were seropositive for HIV and 37 (3%) were seropositive for Treponema pallidum. Conclusions Our findings are in line with previous studies that describe considerable syphilis prevalence in the rural Madagascan population. The results suggest a need for screening to prevent peripartal Treponema pallidum transmission, while HIV is still rare. If they are known, Treponema pallidum infections can be easily, safely and inexpensively treated even in pregnancy to reduce the risk of transmission.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.