Use of the fluid column in a cardiac catheter for emergency pacing

Given the not infrequent need for intracardiac pacemaking during intensive cardiac care, a new type of cardiac pacemaker has been designed and tested [1]. With this pacemaker the heart can be stimulated through the fluid column of any conventional catheter, provided it is filled with a 0.9% NaCl solution. This fluid column pacemaker (FCP) is of the “constant current” type. The FCP was tested in 37 animals, in 30 patients in sinus rhythm, and also in two critical patients. In addition to the pacemaker circuit, a special connector was designed, enabling a fast, effective, and safe contact between patient and pacemaker. The FCP is considered to be ideally suited for use in emergency cardiac pacing in intensive care units and other areas where sudden bradycardias may occur and where intrathoracic catheters are inserted for a variety of reasons.     

不同部位组合起搏对充血性心力衰竭患者急性血流动力学影响的研究

观察右房左室起搏对充血性心力衰竭 (CHF)患者急性血流动力学的影响。 8例心功能II～IV级CHF患者 ,分别置入右房、右室和左室电极 (经冠状静脉窦 ) ,行不同部位组合起搏的急性血流动力学研究 ,其中 6例获得成功。使用Bitronic公司生产的双腔起搏分析仪 (ERA30 0 )分别行单纯右室心尖部 (RVA)、右房右室 (RA +RV)、右房左室 (RA +LV)、右房双室 (RA +BiV)起搏 ,同时用二维超声心动图测定上述四种起搏状况下的血流动力学参数 ,并进行比较。结果 :右房左室起搏和右房双室起搏血流动力学参数两者间无显著差异 ,但比单纯右室心尖部起搏和右房右室起搏有所改善。结论 :右房左室起搏似可使更多的CHF患者在得益于起搏治疗的同时明显降低医疗费用。     

Implantable electrical devices in the management of tachyarrhythmias

Electrical therapy for tachyarrhythmias attempts to achieve one or more of three aims: a) prevention of tachycardia; (b) control of the hemodynamic effect of tachycardia; (c) termination of tachycardia. In practice, long term control of tachycardia in selected patients can be achieved with implantable devices which can automatically recognize and terminate tachycardias. Termination can be achieved with a number of pacing modalities. These pacing modalities are reviewed in this article and some guidelines to the choice of modality are given. Patients with supraventricular tachycardia are often more appropriately treated with drugs or surgery but some can be effectively treated with antitachycardia pacing. Some patients with ventricular tachycardia can be successfully treated with these devices but this group is at risk of tachycardia acceleration or degeneration in response to pacing. An implantable cardioverter-defibrillator should be used as a backup in these patients. Present generation devices now incorporate antitachycardia pacing, low energy cardioversion, and higher energy defibrillation in the same unit.     

Registro Español de Marcapasos. XVI Informe Oficial de la Sección de Estimulación Cardiaca de la Sociedad Española de Cardiología (2018)

Introduction and objectivesThis report describes the result of the analysis of the implanted pacemakers reported to the Spanish Pacemaker Registry in 2018.MethodsThe analysis is based on the information provided by the European Pacemaker Identification Card and supplier-reported data on the overall number of implanted pacemakers.ResultsInformation was received from 90 hospitals, with a total of 12 148 cards, representing 31% of the estimated activity. Use of conventional and resynchronization pacemakers was 825 and 77 units per million people, respectively. The mean age of the patients receiving an implant was 78.3 years, and 54% of the devices were implanted in people aged > 80 years. A total of 77.1% were first implants and 21.6% corresponded to generator exchanges. Bicameral sequential pacing was the most frequent pacing mode but was less frequently used in patients aged > 80 years and in women. Single chamber VVI/R pacing was used in 28% of patients with sick sinus syndrome and in 24.7% of those with atrioventricular block, despite being in sinus rhythm.ConclusionsThe total consumption of pacemaker generators in Spain increased by 1.2% compared with 2017, mainly due to an 8.7% increase in cardiac resynchronization therapy with pacemaker generators. Selection of pacing mode was directly influenced by age and sex.     

Thallium-201 perfusion imaging with atrial pacing or dipyridamole stress testing for evaluation of cardiac risk prior to nonvascular surgery

Preoperative assessment of cardiac risk using thallium-201 scintigraphy and atrial pacing (n=42) or dipyridamole stress testing (n=35) was performed in 77 patients (mean age 65±7 years), who subsequently underwent elective nonvascular surgery. All patients were at low cardiac risk by clinical criteria; none could perform exercise stress testing due to physical limitations. ST depression consistent with ischemia occurred in 11 patients during atrial pacing and in 1 patient during dipyridamole stress testing (p<0.01). Nine patients had reversible perfusion defects with atrial pacing, and 10 patients with dipyridamole stress testing; fixed defects were present in 15 and 8 patients, respectively. Only one patient (fixed perfusion defect with atrial pacing, left main disease on coronary angiography) underwent preoperative coronary revascularization. Two patients subsequently had postoperative cardiac events. One patient (reversible perfusion defect with dipyridamole stress testing) experienced sudden death after a nonvascular procedure, while a second patient (normal thallium images with dipyridamole testing) had a nonfatal myocardial infarction. In patients having atrial pacing or dipyridamole stress testing, thallium-201 scans that are normal or show only a fixed perfusion defect confirm a low risk of cardiac complications following nonvascular surgery. The presence of a reversible perfusion defect does not preclude a postoperative course free of cardiac complications in patients at low cardiac risk by clinical criteria.     

Application and perspectives of transesophageal stress echocardiography using monoplane and biplane instruments

Transesophageal stress echocardiography has been reported to have a high sensitivity and specificity for noninvasive identification and assessment of coronary artery disease. Its advantage is the virtually never obstructed acoustic window on the heart yielding superior image quality in almost all patients. Pharmacological stress as well as simultaneous atrial pacing--attaching electrodes to the echoscope--have been applied as stress modalities. Both transesophageal stress echocardiography modalities have been shown to be well tolerated, safe, and feasible in most patients. These promising initial experiences led to clinical application of this method for preoperative risk evaluation, for detection of restenosis after PTCA, and for evaluation of hibernating myocardium. This technique was also successful for evaluation of stress induced changes of transmitral and pulmonary venous flow in patients with left ventricular hypertrophy and coronary artery disease. Although all studies published so far were performed with monoplane technique, the sensitivity for detection of one-vessel and, even more so, multivessel disease was high. However, apical and basal wall-motion abnormalities may go undetected using monoplane equipment. The advent of biplane transesophageal imaging enables the visualization of more ventricular segments. Future studies will show to which degree biplane transesophageal stress echocardiography improves the diagnostic accuracy.     

Progressive implantable cardioverter-defibrillator therapies for ventricular tachycardia: The efficacy and safety of multiple bursts,ramps, and low-energy shocks

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右室选择性部位起搏

右室心尖部起搏产生异常心室电活动,导致心室不同步收缩、腔内分流和二尖瓣反流,患者生活质量下降,心房颤动、心力衰竭发生率及死亡率增加.目前一些研究提示右室选择性部位起搏有较右室心尖更好的电生理稳定性和心室同步性,同时有较好的临床可行性.但最终结果还有待更大规模的临床研究.     

低位房间隔起搏的初步临床应用

目的探索主动固定电极导线在低位右心房间隔部起搏的可行性、安全性；比较低位房间隔起搏与高位右心房游离壁起搏对，心房激动时间和起搏参数的影响。方法共入选了50例，患者平均年龄（64．8±11．2）岁，随机分配到低位房间隔起搏组（n=25）和高位右心房游离壁起搏组（n=25），通过比较植入术时间、X线曝光时间、导线固定成功率、起搏参数、植入术并发症等评价低位右心房间隔起搏的可行性；测定不同部位起搏时P波宽度，以评价起搏部位对心房激动时间的影响。结果与高位右心房游离壁起搏组结果比较，低位房间隔起搏组的植入时间、X线曝光时间略有延长；低位房间隔起搏组的导线固定成功率低于右心房游离壁起搏组（84％ VS 100％），两组间的起搏参数、植入术并发症相比差异无统计学意义。低位房间隔起搏时心房激动时问明显短于高位右心房游离壁起搏[（140．5±23．0）ms VS（89．0±14．0）ms]，差异具有统计学意义。结论采用主动固定电极导线在低位房间隔起搏是安全、可行的，它明显缩短左、有心房激动时间，使心房的除极趋于同步化。但低位房间隔起搏的主动固定电极导线植入技术具有一定的难度，需要熟练掌握主动固定导线植入技术的人员方可实施。