闭环式情绪体动双项感知频率适应性起搏器的临床应用

目的频率适应性起搏器临床应用的主要类型是感知体动,但存在局限性。本组使用感知情绪、体动变化的闭环式频率适应性起搏器,可同时感知情绪及体动变化,相应增加或减少起搏心率,满足机体需求。 方法患者10例,全部为窦房结功能障碍者,置入双腔闭环式频率适应性起搏器(BiotronikINOS     

闭环刺激频率适应性起搏器的临床应用体会

目的通过对13例Bitronik公司生产的Inos2／CLS和Protos DR／CLS闭环刺激双腔频率适应性起搏器的植入和随访,探讨该起搏器特点。方法植入后第5天开启闭环刺激频率适应功能,观察不同体力活动、情绪变化和思考活动时的频率变化。结果Bitronik公司的Inos2／CLS和Protos DR／CLS在体力和脑力活动时能较好地进行频率应答。不同的活动量产生不同的频率应答。结论Protos DR／CLS除能适应体力活动外,尚能适应自主神经变化的生理性频率应答,是目前最符合生理变化的频率应答起搏器。     

闭环刺激双腔频率适应性起搏器的临床应用

目的介绍感知体动和精神活动的闭环刺激双腔频率适应性起搏器的初步应用经验.方法植入第3d开启闭环刺激频率适应功能,患者进行坐卧位、散步、快走、上下楼、思考等活动,第7d动态心电图检查和起搏器程控.3个月后随访,重复上述活动和检查,对比分析结果.结果18例患者植入闭环刺激双腔频率适应性起搏器(Biotronik公司的Inos2CLSDDDR),心室起搏阈值0.3～0.7(0.4±0.3)V,R波振幅9.5～21.8(14.6±7.5)mV,阻抗520～870(610±78)Ω;心房起搏阈值0.3～0.8(0.5±0.3)V,A波振幅7.2～16.4(11.6±5.7)mV,阻抗510～872(697±92)mV.随访50～486(236±107)d,均为频率适应性双腔起搏,体力和脑力活动时起搏频率能按需增加.与植入时相比,频率适应功能增强且更加个体化.结论Inos2CLS除适应体动变化外,还能适应精神负荷变化,自动完成初始参数和昼夜频率调整,程控简单,随访方便.     

可对情绪变化起反应的闭环频率适应性起搏器的临床应用

目的　目前应用以感知运动的传感器为基础的频率适应性起搏器,在患者发生情绪变化时不能够提高起搏频率,本组报道新近开发的可感知情绪变化的闭环频率适应性起搏器的临床应用。方法　７ 例患者,男性５ 例,女性２ 例,因窦房结变时功能障碍,植入双腔频率适应性起搏器,其传感器为感知心室电极周围血液及心肌阻抗的变化的闭环传感器,不仅在运动时,而且可在情绪激动时增加起搏频率。术后对患者在平卧体位进行紧张试验,以观察在患者情绪变化时起搏器的频率适应功能。测试以患者倒数数的方法使患者保持情绪紧张。结果　患者试验前,平均起搏频率为６４ｐｐｍ ,情绪紧张时起搏频率上升至平均８６ｐｐｍ 。结论　感知心肌阻抗变化的闭环频率适应性起搏器在患者情绪紧张时可有效地使起搏频率增加,满足生理需求     

闭环刺激频率应答起搏器临床应用效果观察

双腔频率应答起搏器在临床上的使用 ,改善了心率的变时性 ,从而更符合人体生理的需求。传统的频率应答起搏器是开环正反馈式的 ,其感知信号仅与心排出量间接相关 ,不能自动调节起搏器频率 ,并需根据每个患者的情况分别设定很多参数 ,程控复杂 ,存在着明显的局限性。闭环刺激频率应答起搏器应用自身的交感神经系统控制 ,实现生理性闭环负反馈控制 ,理论上对患者的心排出量更有利。并且无特殊传感器 ,对电极无特殊要求 ,程控上只需设定基本频率和最大闭环频率。1　对象和方法　临床诊断为心动过缓患者 38(男 2 6 ,女 12 )例 ,年龄 47～ 6 7(平…     

两种不同类型起搏器传感器对情绪刺激频率适应性反应的比较

目的比较闭环式传感器与体动加速度传感器对情绪刺激引起的频率适应性反应。方法共91例患者植入Biotronic Protos起搏器,术后1个月,先后将起搏器程控为闭环式刺激方式(CLS)及体动加速度刺激方式(DDDR或VVIR),在相同情绪活动下,比较两种传感器引起的起搏频率改变。结果 91例患者中,28例起搏比例>75%,并有正常思维能力者纳入研究对象,在情绪试验2、4、6及8 min时间,CLS及体动加速度传感器引起的起搏器频率变化分别是(69.6±4.5)比(63.2±3.2)次/min,(77.6±6.1)比(65.9±5.1)次/min,(75.9±5.6)比(64.6±4.0)次/min及(69.1±5.4)比(66.2±5.0)次/min,各组配对比较差异均有统计学意义(P<0.001)。结论闭环式传感器对情绪刺激引起的起搏频率变化明显大于体动加速度传感器。     

一种新型的频率应答起搏器:利用心内阻抗变化作为感知器原理的闭环刺激系统(附一例报告)

探讨一种闭环频率应答起搏器的临床应用。患者男性 ,76岁 ,Ⅲ度房室阻滞 ,因心室按需起搏器电池耗竭入院更换成BIOTRONIK公司的INOS2 + CLS闭环频率应答起搏器。结果发现 :INOS2 + CLS在不同的体力负荷、情绪变化和思维活动时均能较好地进行频率应答 ,血压也有正常的波动。患者术后心功能由Ⅱ～Ⅲ级改善为Ⅰ级 (NYHA分级 ) ,左、右房较术前明显缩小或恢复正常 ,轻度肺动脉高压消失。提示 :INOS2 + CLS起搏器能够实现由自主神经系统控制的生理性频率应答     

闭环刺激双腔起搏器防治血管迷走神经性晕厥的疗效观察

目的:观察植入闭环刺激双腔起搏器防治血管迷走神经性晕厥（VVS）的效果。方法: 将40例经直立倾斜试验确诊为VVS且近期多次发作的患者,分为起搏器组（18例）和药物治疗组（22例）,所有患者均给予口服美托洛尔缓释片（475 mg,1次/d）,起搏器组植入具有闭环刺激功能（CLS）的双腔起搏器,药物治疗组不做其他治疗,两组患者治疗3个月后复查直立倾斜试验并随访观察。结果: 起搏器组直立倾斜试验转阴率94%,药物治疗组直立倾斜试验转阴率29%,两组比较差异有统计学意义（P<001）。两组患者随访观察6～21(13±5)个月,起搏器组所有患者均未再发晕厥,2例有晕厥先兆,但症状较前明显减轻;药物治疗组9例再发晕厥,但发作次数较前减少。两组患者间晕厥复发率差异有统计学意义（P<001）。结论: 具有闭环刺激功能双腔起搏器能有效的防治血管迷走神经性晕厥。     

植入体动式频率适应性起搏器适应证的商榷

我院自1991年开展生理性心脏起搏以来已植入17例频率适应性起搏器(rate—responsiv epacemaker)，其中体动式频率适应性起搏器16例，呼吸感知型频率适应性起搏器1例。频率适应性起搏器适合于各种需要植入水久心脏起搏器的患者，但往往忽视体动式频率适应性起搏器术后患者体力活动能力的估计。相组结合我院病例对体动式频率适应性起搏器的适应证加以探讨：     

Closed loop stimulation and accelerometer-based rate adaptation: results of the PROVIDE study

Aims: We compared pacing rate adaptation based on closed loop stimulation(CLS) or accelerometer sensor (AS) during acute mental and physicalstress in the same patient. Methods and results: One month after Protos (Biotronik, Germany) pacemaker implantation,131 chronotropically incompetent patients were randomized toAS or CLS for 3 months with crossover. Arithmetic and 6 minwalk tests were performed in the non-rate-adaptive mode andAS and CLS rate-adaptive modes, respectively. At the end, patientshad to select the individually preferred pacemaker sensor. Heartrate during mental stress was higher (3.0 ± 9.2 bpm)in the CLS than in the AS mode (P = 0.004). Benefit in the walkingdistance compared with non-rate-adaptive pacing was similarfor the two modes: added 27 ± 96 m (AS, P = 0.013) and30 ± 116 m (CLS, P = 0.025). At the end of the walk,heart rate was higher by 4.8 ± 21.4 bpm in AS than inCLS (P = 0.049). Twice as many patients preferred CLS over AS(P < 0.01). Conclusion: The arithmetic test was associated with a significantly higherheart rate for CLS than for AS, showing a greater sensitivityof CLS-based rate adaptation to mental stress. Performance duringphysical stress was comparable. Patients preferred CLS.     

The DDDR closed loop stimulation for the prevention of vasovagal syncope: results from the INVASY prospective feasibility registry.

BACKGROUND: The contraction dynamics of the ventricular myocardium are affected before and during vasovagal fainting suggesting that the Closed Loop Stimulation (CLS) pacemaker could be useful for the treatment of these patients. CLS is a new concept of heart rate modulation in cardiac pacing. The pacemaker INOS(2) CLS (Biotronik, Germany) derives its information for heart rate optimization from myocardial contraction dynamics, by measuring right ventricular intracardiac impedance. The pacemaker becomes an integral part of the circulatory regulation and, therefore, reacts appropriately to different cardiovascular demands. METHODS: In a prospective registry, 34 patients with a history of recurrent vasovagal syncopal events were implanted with INOS(2) DDDR CLS pacemakers. The aim of the study was to evaluate both long term clinical outcome, including the first recurrence of syncope, with DDDR-CLS pacing and acute precipitation of vasovagal fainting with DDDR-CLS mode compared with DDD during head up tilt testing. RESULTS: During a follow up period of 12-50 months, 30 patients experienced no further syncopal events in daily life; 1 patient had no syncope but night palpitations, which were eliminated by pacemaker reprogramming; 2 patients had presyncopal episodes but not syncopes; 3 syncopal recurrences occurred in one patient in chronic atrial fibrillation, possibly not an ideal candidate for implantation. CONCLUSIONS: Further studies for detailed understanding of the preventive mechanism of DDDR-CLS pacing in vasovagal syncope are warranted. A randomized multicentre prospective new study (INotropy controlled pacing in VAsovagal SYncope: INVASY) is now in progress to confirm the beneficial effect of DDDR-CLS pacing in a larger group of patients with recurrent vasovagal syncope.     

闭袢性小肠梗阻的超声诊断

目的 探讨闭袢性小肠梗阻的声像图特征及其超声诊断价值。方法 应用超声诊断仪对2．0例闭袢性小肠梗阻的超声表现进行观察和研究。结果 闭袢性小肠梗阻表现有局ISR性扩张的积液肠袢、肠壁增厚及腹腔积液三大声像特征，根据肠壁增厚的不同特点将其分为：①单纯增厚型；②增厚分层分离型。结论 了解闭袢性小肠梗阻的声像图特征对诊断具有重要的价值，并能估测有肠管无坏死。     

Prospective randomized study comparing permanent pacing with rate drop response and closed loop stimulation in patients with vasovagal syncope where permanent pacing is indicated and selected as the appropriate treatment option

Background

Pacing for vasovagal syncope is established. Two pacing algorithms are available. The rate-drop-response (RDR-Medtronic) is triggered by falling heart rate acting with modified rate-hysteresis. The closed loop stimulation or system (CLS-Biotronik) is triggered by impedance changes in the right ventricle reflecting falling volume and rising contractility. These are very different physiologically. Both algorithms carry favorable reports in clinical use.

Methods

A randomized-controlled superiority trial is proposed to compare the two algorithms for the control of vasovagal syncope in patients for whom pacing is indicated by current guidelines in North America and Europe. Available recent evidence may be seen as supporting superiority of CLS. No comparison between the two algorithms has been made. In this trial, patients will be centrally randomized to one or other algorithm on a 1:1 basis. Two-hundred-seventy-six patients in each group will be recruited. Sample size is determined using a confidence interval of 95%, a power of 90%, and a drop-out rate of 10% to detect an 11% difference between CLS and RDR. Recurrent symptom comparison will be made by an independent committee. The Co-primary endpoints will be recurrent syncope burden compared with that in 24-months preimplant, and occurrence of syncope in 24-months follow-up. Each outcome will be compared between the two algorithms. Secondary endpoints will be program and drug therapy changes over 24-months follow-up and quality of life by questionnaire at baseline,1 and 2 years.

Results and Conclusions

These are anticipated to clarify the device algorithm choice and, therefore, to improve patient care.     

Visceral response to acute retrograde gastric electrical stimulation in healthy human

AIM: To investigate the visceral response to acute retrograde gastric electrical stimulation (RGES) in healthy humans and to derive optimal parameters for treatment of patients with obesity. METHODS: RGES with a series of effective parameters were performed via a bipolar mucosal electrode implanted along the great curvature 5 cm above pylorus of stomach in 12 healthy human subjects. Symptoms associated with dyspepsia and other discomfort were observed and graded during RGES at different settings, including long pulse and pulse train. Gastric myoelectrical activity at baseline and during different settings of stimulation was recorded by a multi-channel electrogastrography. RESULTS: The gastric slow wave was entrained in all the subjects at the pacing parameter of 9 cpm in frequency, 500 ms in pulse width, and 5 mA in amplitude. The frequently appeared symptoms during stimulation were satiety, bloating, discomfort, pain, sting, and nausea. The total symptom score for each subject significantly increased as the amplitude or pulse width was adjusted to a higher scale in both long pulse and pulse train. There was a wide diversity of visceral responses to RGES among individuals. CONCLUSION: Acute RGES can result in a series of symptoms associated with dyspepsia, which is beneficial to the treatment of obesity. Optimal parameter should be determined according to the individual sensitivity to electrical stimulation.     

Heart rate reactivity during minor mental stress in men in their 50s and 70s

Modifications with aging in heart rate reactivity was investigated during minor mental stress. 27 normal male volunteers, aged 51-55 years (n = 10) and 71-74 years (n = 17), were studied in control conditions and while passing a series of 5 psychometric test measuring memory or intellectual speed. Men in their 70s had both lower heart rate baseline levels and lower reactivity during cognitive tasks.     

Closed loop stimulation in prevention of vasovagal syncope. Inotropy Controlled Pacing in Vasovagal Syncope (INVASY): a multicentre randomized, single blind, controlled study.

OBJECTIVES: To determine whether dual-chamber rate-adaptive Closed Loop Stimulation (CLS) could prevent recurrence of Vasovagal Syncope (VVS). BACKGROUND: During VVS, an increase in myocardial contractility associated with a reduction of ventricular filling produces an increase in baroreceptor afferent flow and a consequent decrease in the heart rate. The CLS algorithm is a form of rate-adaptive pacing, which responds to myocardial contraction dynamics, by measuring variations in right ventricular intracardiac impedance: during an incipient VVS it could increase paced heart rate and avoid bradycardia, arterial hypotension and syncope. METHODS: Fifty patients (27 males, mean age 59+/-18 year) with severe and recurrent vasovagal syncope and positive Head Up Tilt Test (HUTT) with cardioinhibition, received a CLS pacemaker (INOS2, Biotronik GmbH Co., Germany). The primary end point was recurrence of two VVSs during a minimum of 1 year of follow-up. Randomization between DDD-CLS and DDI mode (40 bpm) pacing was performed only during the first stage of the study (first year): 9/26 randomized to DDI mode (control group) and 17/26 in DDD-CLS mode. All the 24 patients recruited in the second stage of the study (second year) were programmed in DDD-CLS mode. RESULTS: Of the nine patients randomized to the DDI mode, seven had recurrences of syncope during the first year. At the end of the first year the nine patients were reprogrammed to the CLS mode and no syncope occurred after reprogramming. The 41 patients programmed to CLS had a mean follow-up of 19+/-4 months: none reported VVS, only four (10%) reported occasional presyncope and their quality of life greatly improved. Positive HUTT at the end of the first year failed to predict the clinical response to CLS pacing. CONCLUSIONS: The study demonstrates the effectiveness of CLS pacing in preventing cardioinhibitory VVS. A possible placebo effect of pacemaker implantation occurred in 22% of patients.     

Long-term outcomes of patients with ventricular arrhythmias and negative programmed ventricular stimulation followed with implantable loop recorders: Impact of delayed-enhancement cardiac magnetic resonance imaging

Background

Programed ventricular stimulation (PVS) is a risk stratification tool in patients at risk for adverse arrhythmia outcomes. Patients with negative PVS may yet be at risk for adverse arrhythmia-related events, particularly in the presence of symptomatic ventricular arrhythmias (VA).

Objective

To investigate the long-term outcomes of real-world patients with symptomatic VA without indication for device therapy and negative PVS, and to examine the role of cardiac scaring on arrhythmia recurrence.

Methods

Patients with symptomatic VA, and late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMR), and negative PVS testing were included. All patients underwent placement of implantable cardiac monitors (ICM). Survival analysis was performed to investigate the impact of LGE-CMR findings on survival free from adverse arrhythmic events.

Results

Seventy-eight patients were included (age 60 ± 14 years, women n = 36 (46%), ejection fraction 57 ± 9%, cardiomyopathy n = 26 (33%), mitral valve prolapse [MVP] n = 9 (12%), positive LGE-CMR scar n = 49 (62%), history of syncope n = 23 (29%)) including patients with primarily premature ventricular contractions (n = 21) or nonsustained VA (n = 57). Patients were followed for 1.6 ± 1.5 years during which 14 patients (18%) experienced VA requiring treatment (n = 14) or syncope due to bradycardia (n = 2). Four/9 patients (44%) with MVP experienced VA (n = 3) or syncope (n = 1). Baseline characteristics between those with and without adverse events were similar (p > 0.05); however, the presence of cardiac scar on LGE-CMR was independently associated with an increased risk of adverse events (hazard ratio: 5.6 95% confidence interval: [1.2–27], p = 0.03, log-rank p = 0.03).

Conclusions

In a real-world cohort with long-term follow-up, adverse arrhythmic outcomes occurred in 18% of patients with symptomatic VA despite negative PVS, and this risk was significantly greater in patients with positive DE-CMR scar. Long term-monitoring, including the use of ICM, may be appropriate in these patients.