埋藏式心脏复律除颤器在治疗恶性室性心律失常中的作用

评价埋藏式心脏复律除颤器 (ICD)在恶性室性心律失常治疗中所起的作用。 4例因反复发作室性心动过速 心室颤动 (VT VF)住院患者 ,采用ICD和药物治疗 ,并随访 2 1～ 36个月。结果 :4例患者均有室性心律失常再发 ,复发率 10 0 %。在复发心律失常时全部经ICD治疗成功转复窦性心律 ,有效率 10 0 %。对 4例ICD患者随访发现 ,共有 34次持续性VT VF发作 ,相对集中在 8个不同时间段 ,而每个时段都与患者全身状态改变有关。 2例非心律失常源性死亡。结论 :恶性室性心律失常患者有较高的复发率 ,且多数于再次发作时危及生命。服用抗心律失常药能减少VT VF发作 ,但不能完全控制其发作 ,尤其当患者处于各种应激状下时易反复发作。ICD治疗效果肯定 ,对这类高危患者能起到良好的保护作用 ,能有效减少心律失常源性死亡     

Prevention of Recurrent Life-threatening Ventricular Arrhythmias by Temporary Cardiac Pacing

ABSTRACT Overdrive pacing has been applied in 26 patients to prevent frequent recurrent ventricular fibrillation (VF) and ventricular tachycardia (VT) occurring in the setting of ventricular extrasystole of 2–5 degrees graded by Lown. These patients had 3–47 recurrent attacks of VF and VT (11.4±2.4) which were not prevented with antiarrhythmic agents. Overdrive pacing was continued for 2–236 hours (21.3±3.7) and appeared to be effective in 23 (88.4%) of the 26 patients including those with prolonged QT intervals. Atrial pacing was more effective than ventricular overdriving and required stimulation at a slower rate. Antiarrhythmic therapy and overdrive pacing in combination were more effective than both used independently. Suppression of ventricular extrasystole and prevention of life-threatening arrhythmias were achieved by increasing the heart rate by 23.2±4.5 beats/min.     

Radiofrequency Catheter Ablation of Ventricular Tachycardia in Right Ventricular Cardiomyopathy:

RF Catheter Ablation of VT. Radiofrequency (RF) catheter ablation of ventricular tachycardia (VT) in patients with a right ventricular (RV) cardiomyopathy has only rarely been successful. This report demonstrates reentrant VT in the setting of RV cardiomyopathy in which the tricuspid valve annulus acted as one of the harriers of an isthmus of slow conduction, identified by the presence of entrainment with concealed fusion. The RF pulse was further targeted by analysis of the relationship between the postpacing interval with the tachycardia cycle length, and of the local activation time with the stimulation time. Long-term clinical follow-up has documented no recurrent VT.     

Catheter-based Ablation for Ventricular Arrhythmias

Catheter ablation for patients with recurrent ventricular arrhythmias has emerged as an important and effective treatment option. The approach to ablation, and the risks and likely efficacy are determined by the nature of the severity and type of underlying heart disease. Although implantable defibrillators remain the corner stone for prevention of sudden cardiac death, ablation successfully reduces tachycardia recurrences and storms of ventricular arrhythmias triggering defibrillator shocks in patients with structural heart disease. Our understanding of idiopathic ventricular tachycardia (VT) has grown substantially with several new sites of VT origin recognized in recent years. Ablation is often curative for idiopathic VT. This review discusses common mechanisms and clues to diagnosis of the various VTs, and current advances in ablation options. In particular, endocardial ablation techniques have been complemented by newer approaches such as percutaneous epicardial ablation. In rare cases, transcoronary alcohol ablation can be effective for life-threatening arrhythmia.     

Ventricular tachycardia. Diagnostic spectrum and therapeutic measures

The origin of ventricular tachycardia lies in the ventricular tissue and includes a variety of symptoms such as monomorphic and polymorphic ventricular tachyarrhythmia (VT), ventricular flutter and ventricular fibrillation. Due to transitions of one form of VT to another, any form of VT incurs in principal the risk of cardiac failure. Apart from different electrophysiologic mechanisms such as reentry or triggered activity, any occurrence of VT has to be considered in an individual context: VT can be caused by structural heart disease such as coronary artery disease or dilative cardiomyopathy, or primary electrical disease such as long or short QT syndromes or can even occur without any detectable cause (idiopathic VT). Correct identification of the underlying cause of the arrhythmia is essential for the prognosis, differential therapy and long-term treatment of patients.     

Ventricular Tachycardia

Congenitally Corrected Transposition and VT. Ventricular tachycardia (VT) is an uncommon finding in patients with congenitally corrected transposition of the great arteries (CCTGA). Cardiac death in patients with CCTGA has been attributed to complete heart block, systemic ventricular dysfunction, or severe AV valve regurgitation with heart failure. We descrihe the case of a patient who presented with palpitations and near-syncope that was associated with clinical episodes of VT. Programmed ventricular stimulation revealed easily inducible sustained VT that immediately degenerated to ventricular fibrillation and subsequently required therapy with an implantable cardioverter defibrillator.     

Health Care Utilization After Ventricular Tachycardia Ablation: A Propensity Score-Matched Cohort Study

Background

Catheter ablation of ventricular tachycardia (VT) can reduce the burden of ventricular arrhythmia (VA) but its effect on health care utilization and costs after such therapy is poorly known. We sought to compare the rates of cardiovascular (CV)-related hospitalizations, survival, and health care costs in patients with recurrent VT treated either with VT ablation or with medical therapy.

Ventricular tachycardia in the era of ventricular assist devices

Sustained ventricular tachycardia (VT) in patients with advanced cardiomyopathy is a potentially life-threatening arrhythmia. Newer treatment strategies have evolved that combine the use of catheter ablation to target the substrate for VT and ventricular assist devices (VADs) to hemodynamically support the failing ventricle. This editorial is targeted to the practicing clinician caring for these difficult patients. The current article reviews the use of percutaneous VADs to support catheter ablation of VT, the use of durable VADs to support the failing heart in patients with recurrent VT, ventricular arrhythmias in patients with durable VADs, and the use of catheter ablation to treat VT in patients with durable VADs.     

Long-Term Results of Visually Guided Left Ventricular Reconstruction as Single Therapy to Treat Ventricular Tachycardia Associated with Postinfarction Anteroseptal Aneurysm

Visually Guided Left Ventricular Reconstruction for Recurrent VT. Introduction: Postinfarction ventricular tachycardia (VT), anteroseptal aneurysm. and ventricular dysfunction are commonly associated and predict a poor long-term prognosis. Surgical left ventricular reconstruction, which includes double plication of the anterior and septal wall, can improve ventricular function. This article analyzes the long-term efficacy of such a procedure to control recurrence of VT in a group of 50 consecutive patients.
Methods and Results: The study group consisted of 50 consecutive patients operated on between December 1986 and December 1994. The group comprised 44 men and 6 women. The mean age was 56 ± 11 years. All patients had spontaneous VT following an anterior myocardial infarction. Twenty-five patients had two or more episodes of VT (eight presented as cardiac arrest, nine as syncope). Coronary artery disease was limited to the left anterior descending artery in 27 patients. An anteroseptal aneurysm was present in 49 patients. All patients had VT induced by programmed ventricular stimulation before surgery, and left ventricular reconstruction was performed without intraoperative mapping in all cases. Total mortality, VT recurrence, and sudden death rate were the endpoints of the study. In-hospital mortality was 8%. Postoperative left ventricular ejection fraction improved from 0.38 to 0.50 ( P < 0.05). Only two patients had postoperative inducible VT. Overall survival, VT recurrence rate, and sudden death rate were 73%, 12%, and 10%, respectively, after a median follow-up period of 6.25 years (0 to 8 years).
Conclusion: Visually guided left ventricular reconstruction with septal and anterior wall plicature can he utilized effectively to treat recurrent VT associated with postinfarction anteroseptal aneurysm.     

Ablation of Ventricular Arrhythmias in Arrhythmogenic Right Ventricular Dysplasia

VT Ablation in Right Ventricular Dysplasia. Arrhythmogenic right ventricular dysplasia (ARVD) is a genetically determined myocardial disease characterized by fibrofatty replacement of the right ventricular wall. Ventricular tachyarrhythmias can be seen in the early stages of the disease, which is one of the most important causes of sudden death in young healthy individuals. Radiofrequency (RF) catheter ablation is an option for the treatment of medically refractory ventricular arrhythmias and it has shown to successfully abolish recurrent ventricular tachycardias (VT) as well as reduce the frequency in defibrillator therapies. However, variable acute and long‐term success rates have been reported. The current mapping and ablation techniques include activation and entrainment mapping during tolerated VT and substrate ablation using 3‐dimensional electroanatomic mapping systems. This article aims at providing a comprehensive review of RF catheter ablation of ventricular arrhythmias in the context of ARVD. (J Cardiovasc Electrophysiol, Vol. 21, pp. 473‐14, April 2010)     

REVIEW: Management of Ventricular Tachycardia in Patients with Structural Heart Disease

Patients with structural heart disease and ventricular tachycardia (VT) can be difficult to manage clinically. Many treatment options are available, but no single approach can be applied to every patient. This review aims to discuss the current options available for the management of this population. VT can be associated with cardiomyopathy of any etiology, both ischemic and nonischemic. Antiarhythmic drugs have not been shown to decrease mortality in this patient population, but they can help reduce episodes. While the advent of the implantable cardioverter‐defibrillator has revolutionized the treatment of VT, patients with recurrent shocks for VT have high morbidity and mortality. The development of catheter ablation over the past few decades has greatly aided the ability to control VT in these patients. The approach to patients with VT and structural heart disease is multifaceted. Often, a combination of therapeutic techniques is required to obtain the best result.     

Ventricular tachycardia induced by atrial stimulation in patients without symptomatic cardiac disease

Ten patients with an unusual form of ventricular tachycardia (VT) are described. All were young (mean age 21 years) at the onset of VT, symptoms were of long duration (mean 7 years), none had symptomatic organic heart disease, VT was induced by atrial and ventricular stimulation, VT had a characteristic QRS morphologic picture resembling right bundle branch block with left-axis deviation and 9 had early retrograde His deflections during VT. Supraventricular tachycardia (SVT) was excluded in every patient by electrophysiologic study, although QRS morphologic characteristics and clinical stability of these patients during tachycardia frequently led to the diagnosis of SVT before referral. Four patients received verapamil during electrophysiologic testing. Verapamil slowed and terminated VT in all. Three patients are being treated chronically with oral verapamil, 3 patients with conventional antiarrhythmic agents and 1 with a radiofrequency ventricular pacemaker.     

Management of Ventricular Fibrillation with Transvenous Defibrillators Without Baseline Electrophysiologic Testing or Antiarrhythmic Drugs

Tranvenous Defibrillators Without EP Testing. Introduction : Baseline electrophysiologic study (EPS) is routinely performed in patients resuscitated from ventricular fibrillation (VF) to risk stratify and select patients for chronic antiarrhythmic drug therapy. The role of EP testing prior to insertion of a multiprogrammable implantable cardioverter defibrillator (ICD), however, is unclear.
Methods and Results: This study was a retrospective review of outcome in 66 survivors of an initial episode of out-of-hospital VF not associated with a Q wave myocardial infarction or reversible causes, treated with transvenous ICDs as first-line therapy. Patients were excluded from the study if they had a previous history of monomorphic ventricular tachycardia (VT), a clinical history suggestive of supraventricular tachycardia, or had undergone preoperative EP testing. Fifty-two of the patients (79%) were male with an average age of 58 ± 11 years. Coronary artery disease was present in 43 patients (66%), cardiomyopathy in 15 patients (23%), and valvular heart disease in 1 patient (1.5%). Seven patients (11%) had no detectable structural heart disease. The mean left ventricular ejection fraction was 0.40 ± 0.16. With an average follow-up of 25 ± 12 months, survival free of death from any cause was 100%. Twenty-three patients (35%) experienced 48 episodes of recurrent rapid VT or VF (average cycle length: 236 ± 47 msec) treated by their device. The mean time to first therapy was 223 ± 200 days. Only one of these patients also received antitachycardia pacing for two episodes of VT. One patient (1. 5%) temporarily received amiodarone after removal of an infected device that was subsequently replaced. No other patient received antiarrhythmic drug therapy.
Conclusion : After a cardiac arrest due to primary VF, select patients treated with multiprogrammable ICDs can be managed successfully without baseline EPS or antiarrhythmic drug therapy.     

Prospective evaluation of a discriminant function for prediction of recurrent symptomatic ventricular tachycardia or ventricular fibrillation in coronary artery disease patients receiving amiodarone and having inducible ventricular tachycardia at electrophysiologic study

Induction of ventricular tachycardia (VT) at electrophysiologic study in patients taking amiodarone poorly predicts recurrence of VT. Consequently, a discriminant function was developed (using parameters based on retrospective data) that appeared to identify high-risk patients. These parameters included ventricular effective refractory period, corrected QT interval, initiation of a repetitive ventricular response and the mode of VT induction. In the present study these parameters were prospectively evaluated in 60 patients with coronary artery disease and sustained VT or ventricular fibrillation (VF), in whom VT was still induced at electrophysiologic study during amiodarone therapy. Thirteen patients had recurrent events (sudden death in 8 and sustained VT in 5) and 47 patients had no symptomatic arrhythmia recurrence (follow-up for 16 +/- 2 months, mean +/- standard error of the mean). The ventricular effective refractory period, corrected QT interval and presence of a repetitive ventricular response did not discriminate between patients with and without symptomatic arrhythmia recurrence. However, an easier mode of VT induction during amiodarone therapy versus control was highly predictive of arrhythmia recurrence: 9 of 13 (69%) recurrences were in this group. In contrast, only 4 of 44 (9%) patients who had either the same or harder mode of VT induction had a recurrent event. Overall, 9 of 16 (56%) patients with an easier mode of VT induction had a recurrence, including 6 of the 8 patients with subsequent sudden cardiac death. It is concluded that electrophysiologic testing during amiodarone therapy is useful to identify high-risk patients.     

Efficacy of verapamil in chronic, recurrent ventricular tachycardia

Verapamil, 0.25 mg/kg, was given to 24 patients with chronic, recurrent ventricular tachycardia (VT) whose clinical tachyarrhythmias were reproduced at electrophysiologic study. Seven patients (29%) responded acutely to verapamil: VT was not inducible in 5 and spontaneously terminated within 5 seconds of induction in 2 patients in whom it was previously sustained. Four of the 7 responders had no identifiable structural heart disease, and 3 had coronary artery disease. Responders were younger and had better left ventricular function than did nonresponders. Long-term therapy with verapamil, attempted in 5 of the 7 responders, was effective in 3, ineffective in 1, and of uncertain efficacy in 1. Verapamil therapy was discontinued because of worsened congestive heart failure in 2 patients.

The short-term efficacy of verapamil in these patients compares favorably with the efficacy of other antiarrhythmic agents against VT induction in patients with long-term, recurrent, drug-refractory VT. The short-term efficacy of verapamil correlated with its long-term efficacy. These observations provide preliminary evidence that verapamil may be useful in the treatment of some patients with recurrent VT. When standard drugs are not effective, verapamil should be given a trial, especially in young patients with good left ventricular function.     

Robotic Catheter Ablation of Ventricular Tachycardia in a Patient with Congenital Heart Disease and Rastelli Repair

Robotically assisted catheter ablation has been proven feasible in patients with a variety of atrial arrhythmias. The potential to provide improved catheter tip maneuvering and stability potentially makes it ideal for complex ablation procedures. We present the case of a patient with complex congenital heart disease with previous Rastelli repair and recurrent ventricular tachycardia (VT) who underwent robotically assisted mapping and ablation for right ventricular VT, utilizing substrate mapping techniques.     

Clinical Experience with the Combination of an Antitachycardia Pacemaker (Orthocor II) and the Implantable Cardioverter-Defibrillator in Drug-Refractory Ventricular Tachycardia

Four men with remote myocardial infarction, left ventricular dysfunction, aborted episodes of sudden death, and recurrent ventricular tachycardia (VT) slowed but not controlled by drugs (mean five trials) were treated with an automatic antitachycardia pacemaker (ATP) (Orthocor II) and an implantable cardioverter-defibrillator (ICD). Cardiac electrophysiological evaluation had disclosed that the VT could be reliably terminated with decremental extrastimuli. Two defibrillation patches and two epimyocardial sensing electrodes were used. The ATP was implanted separately using a bipolar endocardial electrode. During follow-up three patients died. One from hepatitis B at two months, and two from sudden cardiac death at 10 and 13 months. One of these deaths was related to ICD battery depletion, the other to a high defibrillation threshold. One patient is alive after 41 months. During the first year postimplant, 359 episodes of VT occurred and there were 105 ICD discharges. The rate and duration of VT episodes terminated by the ICD were 208 ± 7 bpm and 22 ± 9 seconds; and of VT episodes terminated by the ATP were 158 ± 15 bpm and 6 ± 1.8 seconds, respectively. Deleterious device-to-device interactions could be avoided. All patients required full antiarrhythmic drug therapy. Conclusions: (1) In highly selected patients, drug-resistant VT can be terminated by antitachycardia pacing unperceived by the patient; (2) An ICD must provide reliable back-up defibrillation capability for rapid or accelerated VT or ventricular fibrillation; (3) this initial experience demonstrates the feasibility of utilizing the Orthocor II ATP in combination with an ICD as therapy for refractory clinically recurrent VT.     

Heart transplantation in therapy-resistant, recurrent ventricular tachycardias and ventricular fibrillation

In life-threatening, drug resistant ventricular tachycardia (VT) or ventricular fibrillation (VF), orthotopic heart transplantation should be considered as an alternative to a directed surgical approach or to the implantation of an automatic defibrillator. We report on nine patients with primary VT or VF who underwent transplantation. These comprised eight men and one woman with a mean age of 35 years (range, 19-51 years); dilative cardiomyopathy was present in seven and coronary artery disease in two. Left ventricular ejection fraction was 19% (11-26%), arrhythmia was recurrent VF in five cases, recurrent VT in two, and recurrent VT/VF in two. Two patients died, one due to acute rejection, and the other 8 months postoperatively due to chronic rejection. The seven other patients are all asymptomatic and leading normal lives without arrhythmias or antiarrhythmic drug therapy. Based on our preliminary experience, some advantages and disadvantages of heart transplantation are discussed in comparison with other treatment modalities. Despite limited indications for orthotopic heart transplantation we feel that it should become the therapy of first choice in young patients with progressive, surgically incorrectable cardiac disease complicated by drug resistant VT or VF.     

The role of percutaneous left ventricular assist devices during ventricular tachycardia ablation

Ventricular tachycardia (VT) is a common but serious arrhythmia that significantly adds to the morbidity and mortality of patients with structural heart disease. Percutaneous catheter ablation has evolved to be standard therapy to prevent recurrent implantable cardioverter defibrillator shocks from VT in patients on antiarrhythmia medications. Procedural outcomes in patients with structural heart disease are often limited by haemodynamically unstable VT. Although substrate- and pace-mapping techniques have become increasingly popular for VT ablation, these approaches can often times may not address inducible clinical and non-clinical VTs. Activation and entrainment mapping can help the operator target VT exit sites in a precise fashion minimizing the amount of radiofrequency ablation needed for a successful ablation. An evolving alternative strategy that allows induction and mapping of VT in the setting of severe cardiomyopathy and haemodynamic instability is through maintaining perfusion with a percutaneous ventricular assist device (pVAD). This review will discuss these pVAD technologies, distinguish technical applications of use, highlight the published clinical experience, provide a clinical approach for support device selection, and discuss use of these technologies with current mapping and navigational systems.     

Low doses of intravenous epinephrine for refractory sustained monomorphic ventricular tachycardia

We report three cases of sustained monomorphic ventricular tachycardia(VT) in the setting of coronary artery disease,resistant to beta-blockers in two patients and to amiodarone in all,successfully terminated by low doses of intravenous(IV) epinephrine.VT was the first manifestation of coronary artery disease in one patient,whereas the other two patients had a previous history of myocardial infarction and were recipients of an implantable cardioverter-defibrillator(ICD).One of these two patients experienced an arrhythmic storm.All had hemodynamic instability at the time of epinephrine administration.A single slow administration of IV epinephrine(0.5 to 1 mg administered over 30 to 60 s) restored sinus rhythm after 30-90 s with only minor side effects.In the ICD patient with recurrent VT and several cardioversions due to transformation of VT to ventricular fibrillation,epinephrine injection led to the avoidance of further shocks.Although potentially harmful,low doses of IV epinephrine used alone or in combination with beta-blocker treatment and electrical cardioversion may be an alternative effective therapy for sustained monomorphic VT refractory to amiodarone.The role of epinephrine in the termination of VT should be studied further,especially in patients pre-treated with amiodarone in combination with beta-blockers.