Long-term outcome of patients with unexplained syncope treated with an electrophysiologic-guided approach in the implantable cardioverter-defibrillator era.

OBJECTIVES: We evaluated the long-term outcome of patients with coronary artery disease and unexplained syncope who were treated with an electrophysiologic (EP)-guided approach. BACKGROUND: Electrophysiologic studies are frequently performed to evaluate unexplained syncope in patients with coronary artery disease. Patients with this profile who have inducible ventricular tachycardia are considered at high risk for sudden death and increased overall mortality, and therefore are often treated with an implantable cardioverter-defibrillator (ICD). The impact of this EP-guided strategy is unknown because there are no data comparing the long-term outcome of ICD recipients with that of noninducible patients. METHODS: We evaluated 67 consecutive patients with coronary artery disease and unexplained syncope. All patients were treated with an EP-guided approach that included ICD implantation in patients with inducible ventricular tachycardia. RESULTS: Electrophysiologic testing suggested a plausible diagnosis in 32 (48%) of these patients. Inducible monomorphic ventricular tachycardia was the most common abnormality. Despite frequent appropriate therapy with ICDs, the total mortality for patients with inducible monomorphic ventricular tachycardia was significantly higher than for noninducible patients. The respective one- and two-year survival rates were 94% and 84% in noninducible patients and 77% and 45% in inducible patients (p = 0.02). CONCLUSIONS: Electrophysiologic testing suggests an etiology for unexplained syncope in approximately 50% of patients and risk stratifies these patients with regard to long-term outcome. Patients who receive an ICD for the management of inducible ventricular tachycardia have a high incidence of spontaneous ventricular arrhythmias requiring ICD therapy. However, despite ICD implantation and frequent appropriate delivery of ICD therapies, patients with inducible ventricular tachycardia have a significantly worse prognosis than do those who are noninducible.     

Voraussetzungen der ICD-Implantation

An electrophysiological study (EPS) and a programmed ventricular stimulation (PVS) are strongly recommended and clearly indicated before the implantation of a cardioverter defibrillator (ICD), if patients present with a cardiac arrest and no structural heart disease or a hypertrophic cardiomyopathy. In these patients the prevalence of a curable cause of the cardiac arrest, such as accessory pathways or an idiopathic ventricular tachycardia (VT), is high and the ICD implantation may be avoided. The same is true for patients who present with a cardiac arrest and a short PQ interval or a delta wave. If patients present with wide-complex tachycardias and the diagnosis of VT is unclear, an EPS and PVS are also clearly indicated. If patients have syncope or nonsustained VTs and a structural heart disease, PVS may be used for risk stratification. However, EPS and PVS may be of little use in patients with a structural heart disease and an impaired left ventricular function after a survived cardiac arrest or an unstable VT, which makes them candidates for ICD implantation anyway.     

Low recurrence of syncope in patients with inducible sustained ventricular tachyarrhythmias treated with an implantable cardioverter-defibrillator.

AIMS: To determine the effectiveness of the implantable cardioverter defibrillator (ICD) in preventing recurrence of syncope in patients with structural heart disease, previously unexplained syncope and inducible ventricular arrhythmias. METHODS: Thirty-eight patients with syncope, structural heart disease and inducible arrhythmias had an ICD implanted. All ICDs delivered antitachycardia pacing and shocks of adjusted energy. Detection and therapy were programmed according to uniform criteria. RESULTS: The mean age of the patients was 63+/-11 years and most of them were male (36/38). After a mean follow-up of 28+/-15 (4-61) months, six patients died and one underwent heart transplantation. Syncope recurred in three patients, but in none of them was it caused by an arrhythmic event. In 18 patients, 113 episodes of ventricular tachycardia/ventricular fibrillation were detected and appropriately treated by the ICD. The mean time from implant until first appropriate therapy was 18+/-14 months. The actuarial probability of receiving appropriate therapy was 20% and 42% at 12 and 24 months, respectively. CONCLUSIONS: In patients with unexplained syncope, structural heart disease and inducible arrhythmias, ICD prevents syncope associated with arrhythmic events. Frequent effective use of antitachycardia pacing and shocks of adjusted energy seem essential to this aim.     

Implantable defibrillator event rates in patients with unexplained syncope and inducible sustained ventricular tachyarrhythmias: a comparison with patients known to have sustained ventricular tachycardia

OBJECTIVES

To assess the clinical significance of inducible ventricular tachyarrhythmias among patients with unexplained syncope.

BACKGROUND

Induction of sustained ventricular arrhythmias at electrophysiology study in patients with unexplained syncope and structural heart disease is usually assigned diagnostic significance. However, the true frequency of subsequent spontaneous ventricular tachyarrhythmias in the absence of antiarrhythmic medications is unknown.

METHODS

In a retrospective case-control study, the incidence of implantable cardiac defibrillator (ICD) therapies for sustained ventricular arrhythmias among patients with unexplained syncope or near syncope (syncope group, n = 22) was compared with that of a control group of patients (n = 32) with clinically documented sustained ventricular tachycardia (VT). Sustained ventricular arrhythmias were inducible in both groups and neither group received antiarrhythmic medications. All ICDs had stored electrograms or RR intervals. Clinical variables were similar between groups except that congestive cardiac failure was more common in the syncope group.

RESULTS

Kaplan-Meier analysis of the time to first appropriate ICD therapy for syncope and control groups produced overlapping curves (p = 0.9), with 57 ± 11% and 50 ± 9%, respectively, receiving ICD therapy by one year. In both groups, the induced arrhythmia was significantly faster than spontaneous arrhythmias, but the cycle lengths of induced and spontaneous arrhythmias were positively correlated (R = 0.6, p < 0.0001). During follow-up, three cardiac transplantations and seven deaths occurred in the syncope group, and two transplantations and five deaths occurred in the control group (36-month survival without transplant 52 ± 11% and 83 ± 7%, respectively, p = 0.03).

CONCLUSIONS

In patients with unexplained syncope, structural heart disease and inducible sustained ventricular arrhythmias, spontaneous sustained ventricular arrhythmias occur commonly and at a similar rate to patients with documented sustained VT. Thus, electrophysiologic testing in unexplained syncope can identify those at risk of potentially life-threatening tachyarrhythmias, and aggressive treatment of these patients is warranted.     

Significance of inducible ventricular fibrillation in patients with coronary artery disease and unexplained syncope

OBJECTIVES: This study was designed to determine the incidence and prognostic significance of inducible ventricular fibrillation (VF) in patients with coronary artery disease (CAD) and unexplained syncope. BACKGROUND: Current American College of Cardiology/American Heart Association practice guidelines recommend implantation of internal cardioverter-defibrillators (ICDs) in patients with unexplained syncope in whom either ventricular tachycardia (VT) or VF is inducible during electrophysiologic (EP) testing. Although the prognostic significance of inducible monomorphic VT is known, the significance of inducible VF remains undefined. METHODS: We evaluated 118 consecutive patients with CAD and unexplained syncope who underwent EP testing. Sustained monomorphic VT was inducible in 53 (45%) patients; in 20 (17%) patients, VF was the only inducible arrhythmia; and no sustained ventricular arrhythmia was inducible in the remaining 45 (38%) patients. The latter two groups of 65 (55%) patients make up the study population. RESULTS: There were 16 deaths among the study population during a follow-up period of 25.3 +/- 19.6 months. The overall one- and two-year survival in these patients was 89% and 81%, respectively. No significant difference in survival was observed between patients with and without inducible VF (80% power to detect a fourfold survival difference). CONCLUSIONS: In 17% of patients with CAD and unexplained syncope, VF is the only inducible ventricular arrhythmia. Within the limits of this pilot study, long-term follow-up of patients with and without inducible VF demonstrates no difference in survival between the two groups. Therefore, the practice of ICD implantation in patients with CAD, unexplained syncope and inducible VF, especially with triple ventricular extrastimuli, may merit reconsideration.     

Brugada综合征的电生理检查和置入性心脏复律除颤器治疗

目的　探讨Brugada综合征的电生理检查和置入性心脏复律除颤器 (ICD)治疗临床研究。方法　心电图自发性或普罗帕酮药物试验表现为Brugada波的 10例患者行电生理检查 ,均为男性 ,平均年龄 (41± 10 )岁 ,经超声心动图和冠状动脉造影检查未发现器质性心脏病。电生理检查诱发心室颤动 (室颤 )并对有条件者置入ICD治疗。结果　 3例有家族性心脏猝死史 ,4例有反复晕厥史 ,其中 2例晕厥发作时心电图记录到室颤。电生理检查 ,AH和HV间期分别为 5 0～ 12 4 (86± 2 1)ms和 4 1～ 84 (5 8± 15 )ms ,4例晕厥者诱发室颤 ,1例心悸者诱发房室折返性心动过速 ,3例有自发性或诱发心房颤动。 4例诱发室颤者中 ,3例置入ICD ;另 1例因经济原因未置入ICD ,随访中发生猝死。1例诱发房室折返性心动过速者作左侧房室旁路射频导管消融治疗。结论　有晕厥症状的Brugada综合征患者 ,经电生理检查 ,室颤有很高的诱发率 ,是猝死的高危人群 ,为了防止猝死应置入ICD治疗。     

双心室起搏埋藏式心脏转复除颤器的安置

评价一次性置入双心室起搏埋藏式心律转复除颤器 (双腔ICD)的安全性和有效性。5例冠心病冠状动脉搭桥术后的患者 ,伴有严重的慢性充血性心力衰竭和恶性室性心律失常 ,置入双腔ICD。结果 :5例左室电极导管和双腔ICD均一次成功置入 ,左室电极放入冠状静脉的侧后枝 ,急性起搏阈值 0 .8± 0 .6V ,电阻 72 2± 12 8Ω ,R波振幅18.6± 5 .3mV ,电流 1.6± 0 .5mA ,而双心室起搏时其起搏电极参数均优于左室电极 ,除颤阈值≤ 14J。结论 :对伴严重慢性充血性心力衰竭和恶性室性心律失常的患者 ,置入双腔ICD是安全、易行的。     

Follow-up of patients with unexplained syncope and inducible ventricular tachyarrhythmias: analysis of the AVID registry and an AVID substudy. Antiarrhythmics Versus Implantable Defibrillators

INTRODUCTION: A prospective registry and substudy were conducted in the Antiarrhythmics Versus Implantable Defibrillators (AVID) Study to clarify the prognosis and recurrent event rate, risk factors, and impact of implantable cardioverter defibrillator (ICD) therapy in patients with unexplained syncope, structural heart disease, and inducible ventricular tachyarrhythmias. METHODS AND RESULTS: Included in the AVID registry were patients from all participating sites who had "out of hospital syncope with structural heart disease and EP-inducible VT/VF with symptoms." In addition, 13 collaborating sites provided more in-depth clinical and electrophysiologic data as part of a formal prospective substudy. Patients in the substudy were followed by local investigators for recurrent arrhythmic events and mortality. Registry patients were tracked for fatal outcomes by the National Death Index. A total of 429 patients with syncope were entered in the AVID registry, of whom 80 participated in the substudy. Of the substudy patients, 21 patients (26%) had inducible polymorphic ventricular tachycardia/ventricular fibrillation (VT/VF), 11 patients (14%) had sustained monomorphic VT <200 beats/min, and 48 patients (60%) had sustained monomorphic VT > or = 200 beats/min. The ICD was used as sole therapy in 75% of the syncope substudy patients (and with antiarrhythmic drug in an additional 9%) and in 59% of the syncope registry patients. Survival rates at 1 and 3 years were 93% and 74% for the substudy patients and 90% and 74% for the registry patients, respectively. Survival of the syncope substudy patients (predominantly treated by ICD) was similar to the VT patients treated by ICD and superior to the VT patients treated by an antiarrhythmic drug (P = 0.05) in the randomized main trial. Mortality events in the substudy were marginally predicted by ejection fraction (P = 0.06) but not by electrophysiologic study-induced arrhythmia. The significant predictor of increased mortality in the registry was age (P = 0.003) and of reduced mortality was treatment with ICD (P = 0.006). CONCLUSION: The results of these analyses support the role of the ICD as primary antiarrhythmic therapy in patients with unexplained syncope, structural heart disease, and inducible VT/VF at electrophysiologic study.     

Comparison of event rates and survival in patients with unexplained syncope without documented ventricular tachyarrhythmias versus patients with documented sustained ventricular tachyarrhythmias both treated with implantable cardioverter-defibrillators

Patients with unexplained syncope and inducible ventricular tachyarrhythmias during electrophysiologic testing have an increased cardiac mortality rate. We compared event rates and survival of 178 patients with unexplained syncope and no documented ventricular arrhythmias (syncope group) versus 568 patients with documented sustained ventricular tachycardia (VT or fibrillation (VF) (VT/VF group) treated, as part of a lead (Ventritex TVL) investigation, with similar implantable cardioverter-defibrillators (ICDs) capable of extensive data storage. The 2 groups shared similar clinical characteristics. The mean follow-up was 11 months for the syncope group and 14 months for the VT/VF group. The mean time from device implantation to first appropriate therapy was similar in the 2 groups (109 +/- 140 vs 93 +/- 131 days, p = 0.40). Actuarial probability of appropriate ICD therapy was 49% and 55% at 1 and 2 years, respectively, in syncope group and 49% and 58% in VT/VF group (p = 0.57). Recurrent syncope was associated with ventricular tachyarrhythmias in 85% and 92% of the syncope group and VT/VF group, respectively (p = 0.54). At 2 years, actuarial survival was 91% in the syncope group and 93% in VT/VF group (p = 0.85). We conclude that patients treated with ICD with unexplained syncope and induced VT/VF have an equally high incidence of appropriate ICD therapy and low mortality compared with similar patients with documented VT/VF. These findings, plus the high association between recurrent syncope and ventricular arrhythmias, indicate that VT/VF are likely etiologies in selected patients with unexplained syncope and support ICD therapy in such cases.     

Differences in mechanisms and outcomes of syncope in patients with coronary disease or idiopathic left ventricular dysfunction as assessed by electrophysiologic testing

OBJECTIVES: This study evaluated the causes of syncope and the significance and differences in left ventricular (LV) dysfunction, coronary disease, and idiopathic dilated cardiomyopathy (DCM). BACKGROUND: Risk stratification of and indications for an automated defibrillator could differ according to the cause of LV dysfunction. METHODS: Electrophysiologic study, including atrial and ventricular programmed stimulation, was performed in 119 patients with coronary disease (group I) and 61 patients with DCM (group II) with an left ventricular ejection fraction (LVEF) <40% and syncope. Patients were followed from one to six years (mean 4 +/- 2 years). RESULTS: Sustained monomorphic ventricular tachycardia (VT) was induced in 44 group I patients (37%) and 13 group II patients (21%); ventricular flutter (>270 beats/min) or ventricular fibrillation (VF) was induced in 24 group I patients (19%) and 9 group II patients (15%); and various other arrhythmias were identified. Syncope remained unexplained in 34 group I patients (30%) and 16 group II patients (27%). Prognosis depended on the heart disease: VT or VF induction was a predictive factor of mortality in coronary disease and identified a group with high cardiac mortality (46%), compared with patients with a negative study, who had a lower mortality (6%; p < 0.001) than in other studies. Cardiac mortality was only correlated with LVEF in DCM. CONCLUSIONS: Various causes could explain syncope in 70% of patients with coronary disease and DCM, but differences were noted: VT was frequent in coronary disease with a bad prognosis, and ischemia could explain syncope; in DCM, different causes such as atrial tachycardia could be responsible for syncope, but the prognosis only depended on LVEF.     

Implantable cardioverter-defibrillator therapy improves long-term survival in patients with unexplained syncope, cardiomyopathy, and a negative electrophysiologic study

OBJECTIVES: The purpose of this study was to evaluate the long-term outcomes of patients with unexplained syncope, ischemic or nonischemic cardiomyopathy, and a negative electrophysiologic study (EPS). BACKGROUND: EPS is frequently performed to evaluate syncope in patients with left ventricular dysfunction. Limited long-term data evaluating all-cause mortality in patients with no inducible arrhythmia or examining the potential benefits from implantable cardioverter-defibrillator (ICD) therapy are available. METHODS: We evaluated 102 consecutive patients with unexplained syncope, cardiomyopathy, and a negative EPS from September 1996 to December 2000. A blinded matched case-control analysis utilized 51 of these patients (19 treated with an ICD and 32 matched controls treated with conventional therapy). We compared primary endpoint of death and documented cardiac arrest of patients treated with ICD therapy to matched controls. RESULTS: Baseline characteristics were similar between groups. There were 14 primary events among the study population during a follow-up period of 44.3 +/- 20 months: 2 in the ICD group and 12 in the conventional therapy group. The hazard ratio for the risk of event in the ICD group compared with the conventional therapy group was 0.18 (95% confidence interval, 0.04-0.85; P = .04). Other comorbid conditions, including age, sex, ischemic etiology of heart failure, ejection fraction, and antiarrhythmic use, did not predict outcome. Appropriate ICD shocks occurred in 26% of patients at 2 years. CONCLUSIONS: This study suggests that empiric ICD therapy improves long-term outcomes in patients with unexplained syncope, ischemic or nonischemic cardiomyopathy, and negative EPS.     

Implantable cardioverter defibrillator discharge rates in patients with unexplained syncope, structural heart disease, and inducible ventricular tachycardia at electrophysiologic study

BACKGROUND AND HYPOTHESIS: The implantable cardioverter defibrillator (ICD) is the best available strategy to protect patients from life-threatening ventricular arrhythmia. Although unproven, it is commonly utilized to treat subjects with syncope, a negative clinical workup, structural heart disease, and inducible sustained monomorphic ventricular tachycardia (VT) on programmed electrophysiologic stimulation (EPS). The purpose of this paper was to validate this approach. METHODS: We retrospectively identified 36 subjects who received primary ICD therapy for syncope in the setting of structural heart disease with inducible sustained monomorphic VT on EPS. The cohort was predominantly male (32/36) with underlying coronary artery disease (29/36). The mean left ventricular ejection fraction was 31 +/- 12%, and a third of the patients (12/36) had undergone bypass surgery. RESULTS: The study group was followed for a mean of 23 +/- 15 months (range 3-81 months) and experienced an ICD event rate of 22% at 3 months, which increased to 55% at 36 months. This event rate was comparable with the 66% event rate seen in a group of patients with primary ICD therapy for spontaneous life-threatening VT treated during the same time period. No future predictors of ICD events in the study group could be identified. CONCLUSION: Syncope patients with negative workup, structural heart disease, and sustained monomorphic VT at EPS are at high risk for future tachyarrhythmic events. Based on present evidence, primary ICD therapy in this group appears warranted and justified.     

Primary prevention of sudden cardiac death: indications for cardioverter-defibrillator implantation.

Sudden cardiac death accounts for 400,000 to 450,000 deaths annually in Europe and in the United States. In patients with previous life-threatening arrhythmia, several perspective, randomized, controlled studies have demonstrated that implantable cardioverter-defibrillator (ICD) therapy is superior to the best antiarrhythmic therapy in prolonging survival. Furthermore, in a stratified-risk population with coronary artery disease, left ventricular ejection fraction < or = 35%, non-sustained ventricular arrhythmias, and inducible ventricular tachycardia, the ICD supports the class I level of recommendation by the guidelines published in 1998. The American College of Cardiology, American Heart Association, and North American Society of Pacing and Electrophysiology have updated the 1998 guidelines on the implantation of arrhythmia devices including in a class IIa level of recommendation also patients with a previous Q wave myocardial infarction and left ventricular ejection fraction < or = 30%, independently of their arrhythmic risk profile. In the recent years several randomized studies assessed the role of ICD treatment for primary prevention of sudden cardiac death and total mortality reduction in high-risk groups of patients with ischemic and non-ischemic dilated cardiomyopathy, with special reference to those with heart failure and ventricular dysfunction. This article reviews those trials that have resulted in defining indications for ICD, and that will expand its use in the future.     

Ventricular arrhythmias in congestive heart failure: clinical significance and management

The benefit of defibrillator therapy has been well established for patients with LV dysfunction (ejection fraction less than 35%), coronary artery disease, NSVT, and inducible and nonsuppressible ventricular tachycardia. Implantable cardioverter-defibrillator therapy is also indicated for all CHF patients in NYHA functional classes I, II, and III who present with aborted sudden cardiac death, or ventricular fibrillation, or hemodynamically unstable ventricular tachycardia--and also in patients with syncope with no documented ventricular tachycardia but with inducible ventricular tachycardia at electrophysiology study. The ongoing MADIT II trial was designed to evaluate the benefit of prophylactic ICD implantation in these patients (ejection fraction less than 30%, coronary artery disease, and NSVT) without prior risk stratification by PES. The CABG Patch trial concluded that prophylactic placement of an ICD during coronary artery bypass grafting in patients with low ejection fraction and abnormal SAECG is not justifiable. Except for the indications described above, ICD implantation has not been proved to be beneficial as primary or secondary therapy. Until more data are available, patients should be encouraged to enroll in the ongoing clinical trials.     

埋藏式心脏转复除颤器安置的临床经验

总结非开胸经锁骨下静脉穿刺安置埋藏式心脏转复除颤器 (ICD)的手术方法、除颤阈值 (DFT)测定及ICD工作参数设置等临床经验。 10例患者 ,6例有反复晕厥病史。 2例晕厥时心电图证实为心室颤动 (简称室颤 ) ,体外电除颤成功 ,另 8例心内电生理均诱发出持续性室性心动过速或室颤。其中冠心病 8例 (1例合并Brugada综合征 ) ,扩张性心肌病 1例 ,原发性室颤 1例。 5例术前口服胺碘酮治疗。结果 :全部经锁骨下静脉置入ICD ,术中所有患者成功诱发室颤 ,并一次电击成功。手术时间 92± 2 7min。DFT≤ 2 0J,电击阻抗 4 1.2± 15 .3Ω ,R波高度 16 .3± 6 .6mV ,无手术并发症。结论 :经锁骨下静脉置入ICD方法简单 ,安全可靠 ;术前口服适量胺碘酮对术中诱发室颤无影响。     

Implantable defibrillator event rates in patients with idiopathic dilated cardiomyopathy, nonsustained ventricular tachycardia on Holter and a left ventricular ejection fraction below 30%

OBJECTIVES: This study investigated the incidence of appropriate implantable cardioverter defibrillator (ICD) interventions for ventricular tachycardia (VT) or ventricular fibrillation (VF) in patients with idiopathic dilated cardiomyopathy (IDC) and nonsustained VT in the presence of a left ventricular ejection fraction below 30%, versus in patients with syncope and patients with a history of VT or VF. BACKGROUND: To date, only limited information is available about the prophylactic use of ICDs in patients with IDC. METHODS: From January 1993 to July 2000, 101 patients with IDC underwent implantation of ICDs with electrogram storage capability at our institution. Patients were placed into one of three groups according to their clinical presentation: asymptomatic or mildly symptomatic nonsustained VT in the presence of a left ventricular ejection fraction < or = 30% (49 patients, prophylactic group), unexplained syncope or near syncope (26 patients, syncope group) and a history of sustained VT or VF (26 patients, VT/VF group). RESULTS: During 36 +/- 22 months follow-up, 18 of 49 patients (37%) in the prophylactic group received appropriate shocks for VT or VF, compared with 8 of 26 patients (31%) in the syncope group and with 9 of 26 patients (35%) of the VT/VF group. Multivariate Cox analysis of baseline clinical variables identified left ventricular ejection fraction, atrial fibrillation and a history of sustained VT or VF as predictors for appropriate ICD interventions during follow-up. CONCLUSIONS: Patients with IDC and prophylactic ICD implantation for nonsustained VT in the presence of a left ventricular ejection fraction < or = 30% had an incidence of appropriate ICD interventions similar to that of patients with a history of syncope or sustained VT or VF. These findings indicate that ICDs may have a role in not only secondary but also primary prevention of sudden death in IDC.     

Ventricular Fibrillation in a Patient with Prominent J (Osborn) Waves and ST Segment Elevation in the Inferior Electrocardiographic Leads:

Recurrent ventricular fibrillation was observed in a 29-year-old Vietnamese man who did not exhibit structural heart disease. The patient's ECG showed prominent J (Osborn) waves and ST segment elevation in the inferior leads that were not associated with hypothermia, serum electrolyte disturbance, or myocardial ischemia. Rate-dependent change in the amplitude of J waves and ST segment elevation also were observed. An implantable cardioverter defibrillator (ICD) was implanted. Adjunctive treatment with amiodarone reduced J wave amplitude, preventing ventricular fibrillation and ICD shocks. Prominent J waves and ST segment elevation in the inferior leads may serve as an important diagnostic sign to detect high-risk individuals with a history of unexplained syncope. ICD implantation plus amiodarone is the treatment of choice.     

60例晕厥患者的电生理检查及治疗分析

目的探讨心内电生理检查对晕厥诊断及治疗的作用。方法回顾分析晕厥原因不明患者的电生理检查结果。分析有无器质性心脏病及心电图异常,晕厥病程及发作频率对电生理检查阳性率的影响。电生理检查后的治疗及随访。结果入选晕厥患者60例,电生理检查阳性患者14例。25例有器质性心脏病或心电图异常的患者中有9例阳性(36%);35例无器质性心脏病或心电图异常的患者中有5例阳性(14%)。3例无器质性心脏病或心电图异常的患者诱发出心室颤动后植入埋藏式心脏转复除颤器,平均随访2年均无放电。结论有器质性心脏病或心电图异常的晕厥患者电生理检查的阳性率较高,没有器质性心脏病或心电图异常的晕厥患者诱发心室颤动的临床意义需谨慎对待。     

Unexplained syncope in patients with structural heart disease and no documented ventricular arrhythmias: value of electrophysiologically guided implantable cardioverter defibrillator therapy.

AIMS: To evaluate electrophysiologically guided implantable cardioverter defibrillator (ICD) therapy in patients with syncope, structural heart disease and no documented sustained ventricular tachycardia (sVT). METHODS AND RESULTS: Programmed ventricular stimulation (PVS) was performed in 52 patients (age 62+/-10 years): 40 patients had ischaemic and 12 patients had idiopathic dilated cardiomyopathy. On PVS sVT and ventricular fibrillation were induced in seven and four patients, respectively, and two patients spontaneously experienced symptomatic sVT. These patients received an ICD (ICD group, n=13). Non-inducible patients were left on conventional therapy (non-ICD group, n=39). During 5+/-2.8 years five ICD patients received therapies, all appropriate. There were seven non-sudden deaths and overall survival analysis revealed no significant difference. Recurrent syncope occurred in five ICD and four non-ICD patients and did not correlate well with sVT. The positive and negative predictive values of PVS for tachyarrhythmias or sudden death were 36 and 98%, respectively. CONCLUSION: Syncope per se does not necessarily herald a bad prognosis. PVS identifies high-risk patients. Induction of ventricular fibrillation with double or triple extrastimuli is of limited value. Patients with poor left ventricular function and bad clinical condition benefit most from an ICD. Syncope and sVT are not necessarily correlated during follow-up, which may merit consideration.     

Kardiale Resynchronisationstherapie—immer mit ICD?

Sudden cardiac death is responsible for about 50% of all deaths in heart failure. In studies on primary and secondary prevention of sudden cardiac death, the implantable cardioverter defibrillator (ICD) has proven superior to antiarrhythmic drug therapy mainly in patients with coronary artery disease and reduced left ventricular function. Thus, in recent years the question arose whether prophylactic ICD treatment can reduce mortality as well in an unselected patient group with heart failure of any etiology. This is even more important for patients that are candidates for cardiac resynchronization therapy because, first, presence of an intraventricular conduction delay indicates an increased risk of sudden death and, second, the additional operative morbidity of ICD implantation is minimal compared to implant of a biventricular pacemaker. Recent studies have proven the benefit of conventional ICD treatment in patients with heart failure as well as the benefit of biventricular pacing in heart failure patients with ventricular conduction delay. In the present article, these studies and their influence on the system choice in cardiac resynchronization therapy are discussed.