心脏生物起搏的研究进展

心脏生物起搏主要包括基因生物起搏和细胞生物起搏。生物起搏尚处于动物实验研究阶段,应用于临床还面临许多问题,但是随着基因工程技术和分子生物学的不断发展,生物起搏将成为治疗缓慢性心律失常的新技术。     

心脏生物起搏的研究进展

心脏生物起搏主要包括基因生物起搏和细胞生物起搏。生物起搏尚处于动物实验研究阶段,应用于临床还面临许多问题,但是随着基因工程技术和分子生物学的不断发展,生物起搏将成为治疗缓慢性心律失常的新技术。     

心脏生物起搏及其相关研究

近来,生物起搏逐渐成为心脏起搏治疗研究的新热点。目前国内外研究已取得一定进展:包括利用基因工程增加细胞舒张期内向电流、降低细胞复极电流、增加4期除极速度以提高心肌细胞自律性;利用不同起搏细胞移植技术进行修复或替代心脏起搏或传导细胞;以及基因和细胞技术的联合来达到生物起搏的目的。但各种研究手段尚存在的不足,如:稳定性差、持续时间短、调控困难、安全性低等问题尚待解决。     

干细胞移植治疗病态窦房结综合征

病态窦房结综合征是指窦房结及其周围组织病变和功能减退而引起一系列心律失常的综合征。传统的治疗方法是植入电子起搏器,随着分子生物学技术的发展,生物起搏为病态窦房结综合征的治疗开辟了一个全新的领域。生物起搏是指利用细胞分子生物学及其相关技术对受损的自律性节律点或特殊传导系统的细胞进行修复或替代,使心脏的起搏和传导功能得以恢复。生物起搏包括基因生物起搏,细胞生物起搏和基因工程干细胞生物起搏。现就干细胞移植用于治疗病态窦房结综合征的研究取得的进展与存在问题做一综述。     

超极化激活的环核苷酸门控的离子通道与生物心脏起搏器构建

超极化激活的环核苷酸门控的离子通道（HCN）是心脏的起搏基因，负责心脏起搏节律的产生和调控，该基因的遗传缺陷可以导致某些先天性的窦房结功能紊乱。近年来构建生物心脏起搏器治疗窦房结功能紊乱的研究十分活跃，涉及到基因和细胞治疗的各个方面。其中利用HCN来构建起搏器是该领域研究的热点，包括直接发送HCN治疗、间充质干细胞运送HCN治疗、工程化HCN构建生物心脏起搏器协同电子起搏器治疗三个方面的研究。     

细胞治疗在生物起搏中的研究进展

随着分子生物学、细胞生物学和基因工程改造细胞技术的飞速发展，以及对起搏电流的进一步阐明，生物起搏成为心律失常治疗中的探索“热点”。心脏生物起搏指利用细胞分子生物学及其相关技术对受损的自律性节律点或特殊传导系统的组织进行修复和替代，使心脏的起搏和传导功能得以恢复。目前生物起搏的研究策略大多在基因领域和细胞领域，本文就其中细胞生物起搏领域里近年来的研究成果及存在问题作一综述。     

生物起搏细胞调控方法的研究进展

自从电子起搏器进入临床以来,无数房室传导阻滞和病态窦房结综合征患者的生活质量得到了极大改善,但它仍存在感染、缺乏生理反应性和电池寿命有限等问题.生物起搏就此应运而生,生物起搏核心的问题是获得和正常窦房结细胞具有相同功能的起搏细胞,目前调控生物起搏细胞生成的方法多种多样,例如可通过单基因、多基因联合以及信号通路调控等方法...     

超极化激活的环核苷酸门控的离子通道与生物心脏起搏器构建

超极化激活的环核苷酸门控的离子通道(HCN)是心脏的起搏基因,负责心脏起搏节律的产生和调控,该基因的遗传缺陷可以导致某些先天性的窦房结功能紊乱。近年来构建生物心脏起搏器治疗窦房结功能紊乱的研究十分活跃,涉及到基因和细胞治疗的各个方面。其中利用HCN来构建起搏器是该领域研究的热点,包括直接发送HCN治疗、间充质干细胞运送HCN治疗、工程化HCN构建生物心脏起搏器协同电子起搏器治疗三个方面的研究。     

三尖瓣生物瓣置换术后右室心内膜起搏一例

1例男性患者,76岁,因三尖瓣重度关闭不全,置换生物瓣。术后出现Ⅲ度房室传导阻滞,经三尖瓣生物瓣口植入右室主动固定起搏电极导线,行心内膜VVI起搏。术后随访4年,患者症状改善,起搏系统功能良好,三尖瓣无明显返流。     

生物起搏:电信号的产生与传导

利用细胞移植结合基因技术构建生物起搏器已取得初步成果,其关键问题在于起搏电信号的产生及其传导。本文将分别从这两个角度总结分析现有的生物起搏器研究,并提出目前存在的问题。     

无导线起搏器——你知道多少？

传统心脏起搏器的导线（及囊袋）与术后并发症密切相关，促使无导线起搏器的研制与发展。目前已有三种无导线起搏器研制成功，包括超声能量介导的无导线起搏器、磁传导介导的无导线起搏器和微型无导线起搏器。特别是由于其简易、微创与无需囊袋，微型无导线起搏器近年来发展迅猛并已成功商业化。可以预计无导线技术前景广阔，并将在未来起搏器行业中占主导地位。     

核磁共振成像与心脏起搏器的研究进展

核磁共振成像（MRI）环境可严重影响起搏器功能,从而植入心脏起搏器患者接受MRI检查成为禁忌.为了解决MRI对心脏起搏器产生的危害,MRI兼容性起搏器应运而生 现对MRI与心脏起搏器相互作用、心脏起搏器的改进及MRI兼容性起搏器的类型等方面作一阐述.     

生物起搏器的研究进展和展望

心脏生物起搏器是近年来心脏起搏的研究热点,目前主要集中在三大治疗策略;(1)细胞治疗;(2)基因治疗;(3)激素治疗.心脏生物起搏器处于研究初步阶段,应用于临床面临许多问题,但是随着分子生物学和基因-工程技术的发展,心脏生物起搏器必将造福于人类.     

Importance of maintained atrio-ventricular synchrony in patients with pacemarkers

The effect of atrial contraction on cardiac function is reviewedin patients with dual chamber and rate-responsive ventricularpacemakers. The question posed was is there any haemodynamic,clinical or prognostic advantage of AV synchrony in dual chamberpacemakers in comparison to rate-responsive ventricular pacemakers?Optimal A V delay in dual chamber pacing favours cardiac performanceat rest, while during exercise the increase in heart rate ratherthan A V synchrony influences cardiac performance and workingcapacity. However, there is little information on the benefitof maintained A V synchrony in patients' daily activities. Patientswith pacemakers which maintain AV synchrony seem to have lessmorbidity and mortality than patients with ventricular stimulationalone, and there are comparable rates of complication in carriersof single and dual chamber pacemakers, the former showing problemswith the pacemaker syndrome and the latter with atrial sensingand pacemaker-induced tachycardias. The disadvantage of dualchamber pacemakers are higher costs and time-consuming controls.     

心脏起搏器术后并发症的分析及处理

目的 分析永久性心脏起搏器置入术后并发症的原因及处理方法.方法 回顾性分析325例心脏起搏器置入术后出现并发症患者的临床资料.结果 发生起搏相关的并发症包括囊袋血肿8例,电极穿孔2例,电极导线脱位4例,起搏器综合征3例,深静脉血栓3例,BackupVVI起搏1例,导线断裂1例.结论 充分认识起搏相关的各种并发症,重视术...     

妊娠及分娩中的心脏起搏治疗(附七例报告)

报道安置心脏起搏器的严重缓慢心律失常孕妇７例，其中病窦综合征２例、高度房室阻滞５例。２例在临时起搏保护下终止妊娠；另５例安置永久起搏器（ＶＶＩ２台、ＶＶＩＲ３台）。起搏并配以适当的药物治疗，使５例患者均顺利渡过妊娠期并安全分娩。对于严重缓慢心律失常的孕前或孕期妇女，安置心脏起搏器后，酌情调整起搏频率，或者应用频率自适应起搏器，方能适应妊娠、分娩的需要。对心功能较差或（和）伴有快速心律失常的孕妇，在起搏治疗的保持下，更便于应用强心、利尿、抗心律失常药物，使妊娠、分娩更安全     

The pacemaker syndrome: old and new causes

The pacemaker syndrome refers to symptoms and signs in the pacemaker patient caused by inadequate timing of atrial and ventricular contractions. The lack of normal atrioventricular synchrony may result in decreased cardiac output and venous "cannon A waves." A sudden increase in atrial pressure at the onset of asynchrony may elicit a systemic hypotensive reflex response. A wide range of symptoms can be observed. The pacemaker syndrome is encountered in a significant number of patients with ventricular (VVI) pacemakers, mostly when 1:1 retrograde ventriculoatrial conduction is present. The risk of occurrence of the pacemaker syndrome is minimized if pacemaker systems are used which restore or maintain the normal atrioventricular contraction sequence. Hence, in sinus node disease, atrial stimulation with or without ventricular stimulation should be employed, while in high-grade atrioventricular block dual-chamber pacing is recommended. The pacemaker syndrome is not restricted to the VVI stimulation mode. It can be seen, though rarely, in atrial and dual-chamber pacing, and an awareness of these new causes is necessary. An established pacemaker syndrome can often be counteracted by adjusting the pulse generator function.     

Prediction of Significant Conduction Disease through Noninvasive Assessment of Cardiac Calcification

Aims: Cardiac calcification is associated with coronary artery disease, arrhythmias, conduction disease, and adverse cardiac events. Recently, we have described an echocardiographic‐based global cardiac calcification scoring system. The objective of this study was to evaluate the severity of cardiac calcification in patients with permanent pacemakers as based on this scoring system. Methods and Results: Patients with a pacemaker implanted within the 2‐year study period with a previous echocardiogram were identified and underwent blinded global cardiac calcium scoring. These patients were compared to matched control patients without a pacemaker who also underwent calcium scoring. The study group consisted of 49 patients with pacemaker implantation who were compared to 100 matched control patients. The mean calcium score in the pacemaker group was 3.3 ± 2.9 versus 1.8 ± 2.0 (P = 0.006) in the control group. Univariate and multivariate analysis revealed glomerular filtration rate and calcium scoring to be significant predictors of the presence of a pacemaker. Conclusion: Echocardiographic‐based calcium scoring correlates with the presence of severe conduction disease requiring a pacemaker.     

Runaway pacemaker: a still existing complication and therapeutic guidelines

Runaway pacemaker is a rare, but still existing potential lethal complication in permanent pacemakers. Within 4 1/2 years, we saw two cases of runaway pacemaker in patients with multiprogrammable, VVI pacemakers (Siemens-Elema, Model 668). In both cases a pacemaker-induced ventricular tachycardia (rate 240-260 beats/min) was documented. One patient died. Runaway pacemakers must be exchanged as soon as possible. Until this can be accomplished, different emergency maneuvers should be tried. As documented in the cases presented, placing a magnet over the pacemaker may result in a lower, more physiological pacing rate. Reprogramming the pulse generator to a lower output or the use of external chest wall overdrive stimulation may also be successful, but these procedures require the presence of an adequate escape rhythm. If this is not the case or the former maneuvers have failed, an external pacemaker may be connected to the permanent pacing lead. Thereafter, the lead can be safely cut. As an alternative, a temporary transvenous pacing lead may be established prior to disconnecting the permanent pacing lead.     

Permanent pacemaker implantation in the cardiac catheterization laboratory: The subclavian vein approach

During a 36-month period, 171 permanent pacemaker procedures were performed in the cardiac catheterization laboratory by invasive cardiologists. This included 111 initial pacemaker system implants, via the percutaneous subclavian vein approach, 45 pulse generator changes, and 15 miscellaneous procedures. In no case did subclavian vein puncture result in pneumothorax, hemothorax, or brachial plexus injury. In patients undergoing initial lead placement, the dislodgment rate was 0.8% over a 16-month follow-up period. The reoperation rate for causes other than premature battery depletion was 5.4% during the first 12 months. The implantation of permanent pacemakers can be safely and effectively accomplished by experienced invasive cardiologists in the cardiac catheterization laboratory. In our series not only was continuity of patient care improved, but also medical costs were reduced.