自主研发体外自动除颤器的实验研究

目的 评价自主设计和研制体外自动除颤器(AED)对室性心动过速(室速)/心室颤动(室颤)识别的敏感性、特异性以及除颤效果.方法 应用交流电刺激实验动物诱发室速/室颤,记录并分析AED对窜速/室颤的识别以及除颤放电的整个过程,评价其诊断识别和除颤性能.结果 诱颤96次,除颤145次,记录心电数据167段次,共计103 740 S.室速/室颤的识别准确性为99.5%,敏感性为98.2%,特异性为99.6%.除颤成功率和除颤能量呈正相关,成功除颤的能量阈值为(78.75±35.64)J,电量阈值为(0.11±0.04)C,电压阈值为(1216.67±260.87)V.结论 自主研制的AED具有较高的识别敏感性和特异性,其识别和除颤效果达到或优于国外同类产品.     

埋藏式自动复律/除颤器应用于70名病人中的临床经验、并发症和生存率

原始的埋藏式自动除颤器用一对穿透心脏的电极,既能感知心律失常,又能进行复律。它虽能感知心室颤动(室颤)和心室扑动,却不能可靠地探测全部引起低血压的室性心动过速(室速)。对原设计进行修改,增加另一对感知导线,即可用于持续性室速和室颤的复律和除颤。本文报道70例临床应用的经验、并发症和生存率。方法:1981年3月至1984年2月间连续70例病人应用埋藏式自动除颤器(AID)或双极心率感知型埋藏式自动除颤器(AID-BR)。1982年7月前植入的除颤器(AID),仅能感知室颤或正弦形室速。以后植入的属修正型(AIQ-BR),仅以平均心率检出需要中止的心律失常,既能复律又能除颤.治疗对象为由室速引起至少一次心脏停顿,或有反复发作的致命性持续性室速。大多数系经试验     

右美托咪定控制埋藏式心脏转复除颤器术后室性心律失常风暴一例

1例男性患者,埋藏式心脏转复除颤器(ICD)术后3个月,因"半天内ICD反复放电十余次"再次入院,程控ICD发现半天内放电34次,予提高室性心动过速(简称室速)/心室颤动(简称室颤)ICD低限识别频率,静脉补钾、泵入盐酸胺碘酮以及艾司洛尔等治疗无效,室速、室颤仍反复发作,部分需体外电除颤,遂静脉泵入右美托咪定,室速及室颤风暴获得明显控制,应用右美托咪定1h后再无室速/室颤发作。     

植入型心律转复除颤器治疗恶性室性心律失常的疗效评价

目的评价单中心40例植入型心律转复除颤器(ICD)治疗恶性室性心律失常的疗效及安全性。方法40例恶性室性心律失常包括室性心动过速(室速)或心室颤动(室颤)患者接受ICD治疗,男性35例,女性5例,平均年龄(49±15)岁,成功随访35例,应用体外程控仪获得ICD储存资料并结合临床随访资料进行分析。结果40例患者均成功植入ICD;35例患者平均随访25个月,其中26例患者共记录室速和室颤事件763阵,ICD成功除颤224阵(成功率99．1％),抗心动过速起搏1次成功终止室速375阵(成功率71．8％),低能量同步转复22阵(成功率100％);2例患者因窦性心动过速和心房颤动伴快速心室反应发生误放电4次。术后大多数患者联合应用抗心律失常药物。至随访期末,死亡4例,3例死于顽固性心力衰竭,1例死于肺栓塞。结论ICD联合应用抗心律失常药物能有效治疗恶性室性心律失常,预防心脏性猝死。     

预防心脏性猝死的一项无创性技术

心脏性猝死是上世纪和本世纪人类与医学面临的最大挑战之一。心律失常性猝死中，恶性室性心律失常引起者占83％，心室颤动（室颤）是这些人最终的致死原因，及时有效的电除颤是挽回患者生命最重要的抢救措施。资料表明，致命性室性心动过速（室速）或室颤发生后20～30S内迅速除颤，几乎100％能获成功而使病人得以幸存。除颤在1～2min内实施时，生存率80％～90％，而大于10min的电除颤治疗使患者最终的生存率低于10％。因此，致命性室速或室颤从患者倒地到有效的电除颤，每延迟1min，患者生存率将降低7％～10％，“时间就是生命”得到最直接的体现。     

经静脉植入心律转复除颤器的临床应用

植入型心律转复除颤器（ｉｍｐｌａｎｔａｂｌｅ　ｃａｒｄｉｏｖｅｒｔｅｒ　ｄｅｆｉｒｉｌｌａ－ｔｏｒ，ＩＣＤ）的应用大大降低了由室性心动过速（室速）、心室颤动（室颤）引起的心脏性淬死的发生率。成为治疗室性快速心律失常最有效的方法。 资料和方法５例均为男性，年龄３９－７４岁。基础心脏病为冠心病３例（其中１例为前壁心肌梗死）、心肌病１例和扩张性心肌病１例。心肌梗死患者住院期间３次发生室颤，经电除颤转为窦性心律。其余４例均有院外晕厥发作。扩张性心肌病患者同时伴有左束支阻滞及一度房室阻滞。抗心律失常药物疗…     

植入型心律转复除颤器治疗Brugada综合征一例

Brugada综合征是一种与心脏性猝死相关的离子通道疾病,特发性多形室性心动过速（室速）、心室颤动（室颤）致猝死是Brugada综合征最严重的临床后果.目前,植入型心律转复除颤器（ICD）是惟一已证实对Brugada综合征治疗有效的方法。本院成功抢救以多次晕厥为首发表现的Brugada综合征伴室颤1例,并ICD治疗。随访14个月,患者自觉有2次发作并经程控证实为室颤发作,均ICD体内除颤成功。     

减少T波过感知有待于新一代植入型心律转复除颤器功能的研制和应用

误放电是植入型心律转复除颤器（ICD）术后的一个主要并发症,也是导致ICD患者再住院的重要原因.ICD误放电可诱发室性心动过速（室速）、心室颤动（室颤）,增加放电次数,加速ICD电池耗竭;反复电除颤损伤心肌并使心功能恶化;而且误放电明显影响患者的生活质量,可产生一系列心理问题.导致误放电的主要原因是由于室上性心律失常误识别以及感知过度,包括噪音感知和T波过感知.其中T波过感知是一个常见原因,临床处理较为棘手.     

植入心律转复除颤器患者的抗心律失常药物治疗

近20年的临床研究显示,与抗心律失常药物相比,植入型心律转复除颤器(ICD)可以显著减少心脏性猝死的发生率[1].但随访研究显示,致命性室性心律失常的2年复发率为30％ ～ 50％,植入ICD并不能预防室性心动过速(室速)/心室颤动(室颤)的复发,而且还可能有致心律失常作用.近年的临床研究显示,ICD反复多次电除颤,不但会导致患者躯体和精神的痛苦,降低患者的生活质量,还会使ICD植入患者的总体死亡率增加[2-5].因此,为减少室速/室颤的反复发作,     

埋藏式心脏复律除颤器与单极导线起搏器的合并应用一例报告

国内首次合并应用埋藏式心脏复律除颤器（ＩＣＤ）与单极起搏器１例。术中仔细观察起搏器对ＩＣＤ的影响，未发现ＩＣＤ对起搏心律的双感知，亦未发现对心室颤动（室颤）的感知不足，ＩＣＤ对３次诱发的室颤均迅速感知并一次除颤成功。术后１８９天储存资料显示患者共自发２１次室性心动过速，均被一次抗心动过速起搏有效终止，未发生误放电，亦未漏诊快速心律失常，初步观察效果满意。     

Sensitivity of an automatic external defibrillator for ventricular tachyarrhythmias in patients undergoing electrophysiologic studies

An automatic advisory external defibrillator (AED) was activated during all arrhythmias occurring at the time of 77 electrophysiologic studies in 45 patients. Sustained ventricular tachycardia (VT) occurred during 55 studies in 31 patients and nonsustained VT was induced during 10 studies in 9 patients. Ventricular fibrillation was induced 5 times in 5 patients and atrial arrhythmias with a rapid ventricular response occurred during 7 studies in 4 patients. The AED detection algorithm advised "shock" during 36 of 55 (65%) episodes of sustained VT and all 5 episodes of ventricular fibrillation. The device correctly advised "shock" for all 6 episodes of nonsustained VT that spontaneously terminated after analysis was complete. Thus, the sensitivity of the device for all ventricular arrhythmias analyzed was 47 of 66 (71%). The device recommended "shock" for all 31 episodes of rapid VT and 1 of 2 episodes of atrial fibrillation associated with systemic hypotension (32 of 33, 97%). The 19 episodes of VT for which "no shock" was advised were comparatively slow and were hemodynamically well tolerated. The device recommended "no shock" during all 21 episodes of normal sinus rhythm and all 20 episodes of rapid atrial pacing (cycle length 400 ms) analyzed. "No shock" was advised during 4 episodes of sustained narrow QRS complex supraventricular tachycardia and 4 brief episodes of nonsustained VT that terminated before analysis was complete. Thus, in this study the specificity of the AED for wide complex tachycardias was 100%.     

植入型心律转复除颤器35例次随访

目的报告35例植入型心律转复除颤器（ICD）的随访结果.方法对我院1998年5月至2004年4月植入的31例,另有4例更换ICD患者进行电话询问和门诊随访（3～70个月,平均36.5个月）,通过常规心电图、动态心电图及ICD存储的资料,对患者病情和ICD工作情况进行分析.结果 4例患者死亡.31例患者共发作持续性室性心动过速/心室颤动（VT/VF）725次（VT534次,占73.7%,VF191次,占26.3%）,其中719次（96.8%）治疗成功,6次（3.2%）失败.534次VT中,454次（85.5%）经抗心动过速起搏（ATP）终止,80次（14.5%）经低能量复律（CV）终止.191次VF中,185次（96.9%）经高能量除颤（DF）终止,1例患者无效放电6次.3例患者发生误放电7次.结论 ICD疗效肯定,须密切随访,及时调整工作参数;应高度重视ICD患者的心理治疗.     

Out-of-hospital defibrillation with automated external defibrillators: postshock analysis should be delayed

STUDY OBJECTIVE: The American Heart Association protocols for use of automated external defibrillators (AEDs) recommend that a rhythm analysis be done immediately after each defibrillation attempt. However, shock is often followed by electrical silence or marginally organized electrical activity before ventricular fibrillation (VF) or ventricular tachycardia (VT) recurs. The optimal timing of postshock analysis for identification of recurrent VF/VT is unknown. This study examines the time to recurrence of VF/VT after a defibrillation attempt with AED. METHODS: Over an 18-month period, all tapes from patients with out-of-hospital cardiac arrest who received shocks at least once with an AED were screened for recurrent VF/VT. All cases come from a single emergency medical services system providing basic life support, defibrillation with AED, and intubation with an esophageal-tracheal twin-lumen airway device (Combitube) for a population of 633,511 individuals. Pediatric and traumatic cases were excluded. When VF/VT recurred within 3 minutes of the defibrillation attempt, rhythm strips were printed and included in the study. Two cardiology fellows, blinded to the study objectives, measured the time from defibrillation to recurrent VF/VT for each strip. RESULTS: Over the study period, 222 tapes from 96 patients met the inclusion criteria. Only 44 (20%) occurrences of VF/VT had recurred within 6 seconds of defibrillation, 162 (73%) at 60 seconds, and 200 (90%) at 90 seconds. CONCLUSION: Eighty percent of VF/VT recurred more than 6 seconds after defibrillation and were missed when using current American Heart Association AED protocols. Subsequent analysis should be postponed until at least 30 seconds after defibrillation. Performing 30 seconds of chest compressions after defibrillation before subsequent AED rhythm analysis would increase AED identification of VF/VT to 52%.     

Radiofrequency Ablation of Ventricular Fibrillation and Multiple Right and Left Atrial Tachycardia in a Patient with Brugada Syndrome

Brugada syndrome is a well-known form of idiopathic ventricular fibrillation (VF). Few data suggest that this arrhythmia may be triggered by ventricular premature beats (VPBs), and an association with other arrhythmia such as monomorphic ventricular tachycardia (VT) or supraventricular tachycardia (SVT) has been reported. In a highly symptomatic 18-year-old-male patient with this syndrome, frequent episodes of VF, fast polymorphic VT, and fast monomorphic sustained regular tachycardia were observed. The tachycardia episodes were classified as VT or VF and as a consequence received appropriate therapies with the implanted cardioverter defibrillator (ICD). Precipitating VPBs that were stored in the ICD memory and on the electrocardiogram (ECG) exhibited the same morphology as frequent isolated VPBs. During the electrophysiological study, right and left atrial tachycardia (AT) with one-to-one atrioventricular conduction were also induced and successfully ablated. VF was ablated using the same noncontact mapping (NCM) system triggering VPBs from right ventricular outflow tract (RVOT).     

Dysrhythmias after direct-current cardioversion

The success rate of direct-current (DC) countershocks and postshock arrhythmias are of concern for the design of automatic devices. Results of 112 DC shocks for induced ventricular tachycardia/fibrillation (VT/VF) (n = 99) or atrial fibrillation (AF) were analyzed. Clinical and arrhythmia characteristics were related to the success rate of DC shocks as well as postshock arrhythmias. Sixty-one patients were men and 14 were women; mean age was 52 +/- 15 years. Coronary artery disease was present in 56 patients and cardiomyopathy in 4. The other patients had no apparent structural heart disease. The success rate of transchest DC shocks for VT and VF were identical. The first DC shock interrupted 80% of VT and VF episodes. All episodes were terminated by 4 or fewer DC shocks. A single DC shock changed morphologic pattern or rate of 4 episodes of VT. Asystole after VT/VF (1,900 +/- 960 ms) was longer than after atrial fibrillation (1,150 +/- 470 ms, p less than 0.01). VT/VF recurred (within 3 minutes) after 26 of 99 initially successful DC shocks, requiring repeat shocks in 2 cases. Sinus bradycardia (n = 18) or high degree atrioventricular block (n = 11) necessitated rate support pacing in 10 patients. Antiarrhythmic drugs did not prevent postshock tachycardias, but facilitated the development of bradycardias. In conclusion, reliable and continuous analysis of cardiac rhythm after discharge is mandatory to enable automatic devices to correct unsuccessful discharges or recurring VT/VF. In addition, demand pacing capability is desirable to prevent severe bradycardia after DC shocks in patients receiving antiarrhythmic drugs.     

Ventricular arrhythmia storms in postinfarction patients with implantable defibrillators for primary prevention indications: a MADIT-II substudy.

BACKGROUND: Much of prognostic implications of ventricular arrhythmia storms remain unclear. OBJECTIVE: We evaluated the risk associated with electrical storm in patients with defibrillators in the Multicenter Automatic Defibrillator Implantation Trial II (MADIT-II) study. METHODS: Electrical storm was defined as > or =3 episodes of ventricular tachycardia (VT) or ventricular fibrillation (VF) in 24 hours. RESULTS: Of the 719 patients who received internal cardiac defibrillator (ICD) implants and had follow-up in the MADIT-II, 27 patients (4%) had electrical storm, 142 (20%) had isolated episodes of VT/VF, and the remaining 550 patients had no ICD-recorded VT events. Baseline clinical characteristics among the groups were similar. Patients who experienced electrical storm had a significantly higher risk of death. After adjustments for relevant clinical covariates, the hazard ratio (HR) for death in the first 3 months after the storm event was 17.8 (95% confidence interval [CI] 8.0 to 39.5, P <.01) in comparison with those with no VT/VF. This risk continued even after 3 months for those with electrical storm (HR of 3.5, 95% CI 1.2 to 9.8, P = .02). Study patients with isolated VT/VF episodes also were at an increased risk of dying (HR = 2.5, 95% CI 1.5 to 4.0, P <.01) when compared with patients without VT/VF episodes. Statistically significant predictors of electrical storm were interim postenrollment coronary events (myocardial infarction or angina) HR 3.1 (95% CI 1.2 to 8.1, P = .02) and isolated VT or VF HR 9.2 (95% CI 4.0 to 20.9, P <.01). CONCLUSION: Postinfarction patients with severe left ventricular dysfunction in whom electrical storm developed have significantly higher mortality than patients with only isolated VT/VF as well as those without any episodes of VT/VF. Patients who experienced postenrollment ventricular arrhythmias and/or interim coronary events during follow-up were at higher risk for VT/VF storms.     

植入型心律转复除颤器抗心动过速起搏治疗室性心动过速疗效评价

目的恶性室性心律失常（室性心动过速,心室颤动）是心脏性猝死的主要直接原因.而大部分患者先发生室性心动过速（室速）,继而蜕变为心室颤动（室颤）.研究表明,抗心动过速起搏（ATP）可有效终止室速.本文观察了172例植人植入型心律转复除颤器（ICD）的患者应用ATP终止室速的效果.方法172例植入ICD的患者,男性137例,女性35例,平均年龄52.8岁.103例患者术前有阿-斯综合征发作史,其中75例有电击除颤史.137例术前记录到室速或室颤心电图.植入ICD患者定期随访,随访时应用体外程控仪调出ICD储存记录,分析ICD治疗中ATP治疗室速的效果.结果在平均随访37个月中,ICD共记录室速l 789阵.其中,316阵为短阵室速,在ICD治疗前自行终止;1 473阵室速接受了ICD有效治疗.其中ATP治疗成功981阵（成功率66.6%）,余492阵室速由低能量转复终止.在981阵ATP治疗成功的事件中,ICD第一次发放ATP成功终止室速513阵（成功率52.3%）.结论ICD抗室速起搏功能可有效终止大多数室速,对于植入ICD前有明确室速史的患者,ICD治疗应尽量先采用ATP治疗,以减少ICD放电,延长ICD使用寿命及避免电击时的痛苦,即所谓的＂无痛性ICD治疗＂.     

埋藏式心脏复律除颤器治疗恶性室性心律失常的随访观察

对２２例埋置了埋藏式心脏复律除颤器（ＩＣＤ）的有晕厥史的恶性室性心律失常患者进行了随访，观察ＩＣＤ的治疗效果。２２例中扩张型心肌病８例、肥厚型心肌病２例、冠心病７例、ＱＴ延长综合症１例，４例未发现器质性心脏病。所有患者均经临床证实有室性心动过速或（和）心室颤动（ＶＴ／ＶＦ）发作。ＩＣＤ具有多项治疗及信息储存记忆功能（即第三代）。随访时通过体外程控仪调出ＩＣＤ储存的资料进行分析。平均随访７．１（１～２３）个月，１１例患者（５０．０％）ＶＴ／ＶＦ发作１１８次，其中５４次为非持续性ＶＴ，均自行终止；接受ＩＣＤ治疗的６４次为ＶＴ／ＶＦ发作，４５次为ＶＴ，２２次由ＩＣＤ的抗心动过速起搏（ＡＴＰ）终止、１６次由低能量（２～１５Ｊ）转复终止、２次发作为窦性心动过速（误判为ＶＴ），其余５次ＶＴ在ＡＴＰ治疗过程中加速转为ＶＦ，由高能量除颤终止。ＩＣＤ诊断的ＶＦ发作共有１９次，发生于４例患者，有１例患者接受除颤１６次，４次系为频率超过ＶＦ感知频率的ＶＴ。１９次发作均被ＩＣＤ有效除颤终止。２例扩张型心肌病患者，１例术后３个月死于心功能衰竭，另１例术后２个月反复发作ＶＦ，多次接受ＩＣＤ除颤治疗，最后死于心功能衰竭。结果表明常规进行?     

Clinical and electrophysiologic predictors of ventricular tachyarrhythmia recurrence in patients with implantable cardioverter defibrillators

INTRODUCTION: Not all patients experience recurrent sustained ventricular tachyarrhythmias after placement of an implantable cardioverter defibrillator (ICD). We evaluated the clinical and electrophysiologic predictors of ventricular tachycardia (VT) and ventricular fibrillation (VF) recurrence following ICD implantation. METHODS AND RESULTS: Consecutive patients (n = 133) underwent 4 +/- 3 serial electrophysiologic studies (EPS) over 50 +/- 26 months following ICD implantation. Sustained VT/VF could always be induced during follow-up EPS in 49 patients; sustained VT/VF was sometimes induced during follow-up EPS in 47 patients; and sustained VT/VF could never be induced during follow-up EPS in 37 patients. Spontaneous VT/VF requiring ICD therapy occurred in 107 patients during follow-up. Patients with sustained VT/VF that was always inducible or sometimes inducible during follow-up experienced more frequent episodes of VT/VF following ICD implant (20.5, 95% CI 12.7-33.0; and 17.8, 95% CI 11.3-28.1 episodes/patient respectively; vs 3.0, 95% CI 2.0-4.6 episodes/patient for patients with VT/VF never induced, P < 0.001). Inducibility of sustained VT/VF post-ICD implant (P < 0.001) and sustained VT as the presenting arrhythmia (P = 0.02) were independent predictors of spontaneous VT/VF recurrence. CONCLUSION: Reproducibly inducible VT/VF following ICD implantation predicts a high probability of VT/VF recurrence and identifies a cohort of patients who experience frequent episodes of VT/VF over time. Persistent noninducibility of sustained VT/VF identifies a group of patients who experience no or very few episodes of VT/VF recurrence.