Secondary Prevention Of Sudden Death Research Articles

12.8 ICD for primary and secondary prevention of sudden death in patients with dilated cardiomyopathy

Background and Aim: Although some patients (pts) with dilated cardiomyopathy (DC), also without history of sustained ventricular tachyarrhythmias, may be considered at high risk of sudden death (SD), the role of implantable defibrillator (ICD) for primary prevention remains uncertain. I P 481 HEALTH STATUS AND THE IMPACT OF ANXIETY ON

12.8 ICD for primary and secondary prevention of sudden death in patients with dilated cardiomyopathy

12.8 ICD for primary and secondary prevention of sudden death in patients with dilated cardiomyopathy

Efficacy of implantable cardioverter defibrillator therapy for primary and secondary prevention of sudden cardiac death in hypertrophic cardiomyopathy.

Risk stratification and effectiveness of implantable cardioverter-defibrillator (ICD) therapy are unresolved issues in hypertrophic cardiomyopathy (HCM), a cardiac disease that is associated with arrhythmias and sudden death. We assessed ICD therapy in 132 patients with HCM: age at implantation was 34 +/- 17 years, and 44 (33%) patients were aged </= 20 years. Indications were sustained ventricular tachycardia (VT) or cardiac arrest (secondary prevention) in 47 (36%) patients, and clinical features associated with increased risk for sudden death (primary prevention) in 85 (64%) patients. There were 6 deaths and 55 appropriate interventions in 27 (20%) patients during a mean follow-up period of 4.8 +/- 4.2 years: 5-year survival and event-free rates were 96%+/- 2%and 75%+/- 5%, respectively. ICD intervention-free rates were significantly less for secondary than for primary prevention:64%+/- 7%versus 84%+/- 6%at 5 years,P = 0.02. Notably, 59 of 67 events (cardiac arrest and therapeutic ICD interventions), or 88%, occurred during sedentary or noncompetitive activity. Incidence of therapeutic shocks was related to age but not to other reported risk factors, including severity of cardiac hypertrophy, nonsustained VT during Holter monitoring, and abnormal blood pressure response to exercise. ICD related complications occurred in 38 (29%) patients, including 60 inappropriate ICD interventions in 30 (23%) patients. However, 8 (27%) of the patients with inappropriate shocks also had therapeutic interventions. ICD is effective for secondary prevention of sudden death in HCM. However, selection of patients for primary prevention of sudden death, and prevention of device related complications require further refinement.

424 Differences in ventricular arrhythmias between heart failure patients implanted with biventricular ICD for primary or secondary prevention of sudden death: results of the InSync ICD Italian registry

424 Differences in ventricular arrhythmias between heart failure patients implanted with biventricular ICD for primary or secondary prevention of sudden death: results of the InSync ICD Italian registry

302 Implantable defibrillator for primary and secondary prevention of sudden death in dilated cardiomyopathy

302 Implantable defibrillator for primary and secondary prevention of sudden death in dilated cardiomyopathy

Implantable cardioverter defibrillator lead complications and laser extraction in children and young adults with congenital heart disease: implications for implantation and management.

Implantable cardioverter defibrillators (ICDs) are being implanted for primary and secondary prevention of sudden death in children and young adults with congenital heart disease. Over time, ICD leads adhere to venous endothelium and endocardium. Lead removal, when necessary, often requires disruption of this fibrous tissue. We retrospectively reviewed and analyzed our experience with ICD lead extraction in children and young adults with congenital heart disease. From April 1999 through January 2002, 14 patients underwent 15 lead extraction procedures to remove 21 leads (17 ICD leads and 4 pacing or sensing leads). Seven patients had surgically corrected structural heart disease (5 transposition of the great arteries with atrial switch repair and 2 corrected tetralogy of Fallot). Mean patient age at extraction was 17.9 +/- 5.7 years (range 9-32), and mean duration of lead implantation was 42.0 +/- 18.9 months (range 15-75). Fourteen of 15 procedures were performed for lead fracture or failure. A laser sheath was used for 20 of 21 lead extractions. Twenty of 21 leads (95%) were completely extracted. There were three instances of blood loss requiring transfusion. There were no major complications or deaths. Young congenital heart disease patients with an ICD are at risk for growth-related lead distortion. The use of a laser sheath is safe and effective for ICD lead extraction in congenital heart disease patients, despite coil adherence and altered anatomy. It may be advisable to avoid dual-coil leads in patients with the potential for future growth.

P1540 Implantable cardioverter-defibrillator therapy for primary and secondary prevention of sudden death in patients with arrhythmogenic right-ventricular cardiomyopathy/dysplasia

P1540 Implantable cardioverter-defibrillator therapy for primary and secondary prevention of sudden death in patients with arrhythmogenic right-ventricular cardiomyopathy/dysplasia

Use of antiarrhythmics and implantable cardioverter-defibrillators in congestive heart failure

As much as half of the mortality in patients with congestive heart failure (CHF) resulting from left ventricular systolic dysfunction is attributable to sudden cardiac death. Thus, the identification of risk and prevention of sudden death are important components of treating this population of patients. Antiarrhythmic drugs have been shown to be either neutral or harmful when studied in patients with prior myocardial infarction and impaired left ventricular function. Amiodarone, when studied in patients with CHF, may be of benefit. This benefit may be more pronounced in patients with nonischemic cardiomyopathy. Implantable cardioverter defibrillators (ICDs) are of clear benefit when used in the primary and secondary prevention of sudden death in selected populations. Studies soon to be completed should clarify the role of the cardioverter-defibrillator in patients with CHF. Antiarrhythmic medications are often used in conjunction with ICDs for a variety of reasons. However, these drugs have the potential to adversely affect defibrillator function, and knowledge of these effects is important when using this strategy.

Management of hypertrophic cardiomyopathy in children.

Hypertrophic cardiomyopathy (HCM) is an inherited cardiac disease characterized by unexplained left ventricular hypertrophy, typically involving the interventricular septum. Hypertrophy may be present in infants, but commonly develops during childhood and adolescence. Management of children with HCM aims to provide symptomatic relief and prevention of sudden death, which is the primary cause of death. Unfortunately, no randomized comparative trials to date have assessed different treatment options in HCM. Medical treatment with negative inotropic agents (beta-adrenoceptor antagonists [beta-blockers], verapamil) is the first therapeutic choice in all symptomatic patients. Beta-blockers also appear to have prognostic merit in children. Surgical myectomy is effective in reducing symptoms in children with left ventricular (LV) obstruction who are unresponsive to medical treatment, although a repeat operation may be needed in a substantial proportion of patients due to relapse of LV obstruction. The recently introduced percutaneous septal ablation can also be regarded as a feasible alternative in this cohort. Technical limitations of both invasive therapeutic options should be carefully considered, preferably in experienced centers. Results of recent randomized trials indicate that dual chamber pacing, once considered a therapeutic option for patients with HCM, should only be used as treatment for conduction abnormalities. Regular clinical risk stratification for sudden death is of vital importance for the prevention of sudden death in young patients. Familial history of sudden death at a young age, LV hypertrophy >3 cm, unexplained syncope, nonsustained ventricular tachycardia in Holter monitoring, and abnormal blood pressure response during exercise are currently considered clinical risk factors for sudden death. Each factor has a low positive predictive accuracy, but patients having two or more of these risk factors are deemed as high risk. Secondary prevention of sudden death in patients successfully resuscitated from cardiac arrest and/or sustained ventricular tachycardia warrants treatment with an implantable cardioverter defibrillator (ICD). Primary prevention of sudden death in patients considered to be at high risk should aim at the management of obvious arrhythmogenic mechanisms (paroxysmal atrial fibrillation, sustained monomorphic ventricular tachycardia, conduction system disease, accessory pathway, myocardial ischemia), and the prevention and/or management of ventricular tachyarrhythmias with amiodarone and/or ICD implantation, respectively. The choice of treatment in children is greatly influenced by technical aspects, such as adverse effects of amiodarone, and ICD implantation difficulties or complications. Amiodarone could also be used as a bridge in children at high risk, until they reach adulthood, possibly achieving a lower risk status, or until their physical growth permits ICD implantation as long-term therapy.

Pacemakers, recent directions and developments

Pacemaker and implantable cardiovertor defibrillator utilization is evolving rapidly. Expanding indications are reviewed. Current pacemakers are smaller, more dependable, longer lasting and have rate-adaptive features. Implantable cardiovertor defibrillators use transvenous leads and have advanced pacing abilities. Primary pacing indications remain sinus node dysfunction or atrioventricular conduction abnormalities. Dual-chamber pacemakers compared with single chamber ventricular pacemakers, have small quality of life advantages and result in less atrial fibrillation, but decrease stroke rates and mortality. In congestive heart failure patients with delayed ventricular conduction, cardiac resynchronization therapy (atrially timed biventricular pre-excitation) improves physiological parameters, performance indices and quality of life. Atrial arrhythmias may be prevented or treated with appropriate pacing strategies. Pacing-related improvements for symptomatic neurally mediated syncope and symptomatic hypertrophic obstructive cardiomyopathy have been demonstrated. For patients with coronary artery disease and low ejection fractions, implantable cardiovertor defibrillators are well established in the secondary prevention of sudden death, and may be helpful for primary prevention if there are inducible ventricular arrhythmias. Combining cardiac resynchronization and implantable cardiovertor defibrillators in similar patients is under investigation. The role of atrial defibrillators is being defined. Electromagnetic interference remains possible with these devices, particularly in electromagnetically hostile environments. More pacemakers and implantable cardiovertor defibrillators will be encountered. Despite increasing sophistication, most often only basic anti-bradycardia modes are essential in the perioperative setting. Understanding the indications for implantation will help the anesthesiologist better support the physiological needs of the patient. Existing perioperative pacemaker-related guidelines for the anesthesiologist still apply.

Efficacy of implantable cardioverter-defibrillators for the prevention of sudden death in patients with hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy is a genetic disease associated with a risk of ventricular tachyarrhythmias and sudden death, especially in young patients. We conducted a retrospective multicenter study of the efficacy of implantable cardioverter-defibrillators in preventing sudden death in 128 patients with hypertrophic cardiomyopathy who were judged to be at high risk for sudden death. At the time of the implantation of the defibrillator, the patients were 8 to 82 years old (mean [+/-SD], 40+/-16), and 69 patients (54 percent) were less than 41 years old. The average follow-up period was 3.1 years. Defibrillators were activated appropriately in 29 patients (23 percent), by providing defibrillation shocks or antitachycardia pacing, with the restoration of sinus rhythm; the average age at the time of the intervention was 41 years. The rate of appropriate defibrillator discharge was 7 percent per year. A total of 32 patients (25 percent) had episodes of inappropriate discharges. In the group of 43 patients who received defibrillators for secondary prevention (after cardiac arrest or sustained ventricular tachycardia), the devices were activated appropriately in 19 patients (11 percent per year). Of 85 patients who had prophylactic implants because of risk factors (i.e., for primary prevention), 10 had appropriate interventions (5 percent per year). The interval between implantation and the first appropriate discharge was highly variable but was substantially prolonged (four to nine years) in six patients. In all 21 patients with stored electrographic data and appropriate interventions, the interventions were triggered by ventricular tachycardia or fibrillation. Ventricular tachycardia or fibrillation appears to be the principal mechanism of sudden death in patients with hypertrophic cardiomyopathy. In high-risk patients with hypertrophic cardiomyopathy, implantable defibrillators are highly effective in terminating such arrhythmias, indicating that these devices have a role in the primary and secondary prevention of sudden death.

Secondary prevention of sudden death.

Secondary prevention of sudden death.

Secondary prevention of sudden death: the Dutch study, the antiarrhythmics versus implantable defibrillator trial, the cardiac arrest study Hamburg, and the Canadian implantable defibrillator study

Although indisputably effective in the prevention of sudden death, use of implantable cardioverter defibrillator (ICD) therapy may not necessarily affect all-cause mortality, as most patients at risk also present with severely depressed left ventricular dysfunction. Correction of the sudden death risk in these patients creates a new clinical condition in need of a careful assessment. Should all-cause mortality be affected by the expected reduction in sudden death rate associated with ICD therapy, issues of critical importance, such as the time extent of life prolongation and the associated quality of life, still remain to established. To investigate the potential benefit of ICD therapy compared with antiarrhythmic drug treatment, 4 prospective studies—the Dutch trial, the Antiarrhythmics Versus Implantable Defibrillators (AVID) study, the Cardiac Arrest Study Hamburg (CASH), and the Canadian Implantable Defibrillator Study (CIDS)—have been conducted in which patients with documented sustained ventricular arrhythmia were randomized to 1 of these 2 treatment strategies. The enrollment criteria differed in these 4 studies: (1) in the Dutch trial, they included cardiac arrest secondary to a ventricular arrhythmia, old (>4 weeks) myocardial infarction, and inducible ventricular arrhythmia; (2) in AVID and CIDS, ventricular fibrillation or poorly tolerated ventricular tachycardia; and (3) in CASH, cardiac arrest secondary to a ventricular arrhythmia regardless of the underlying disease. With regard to the antiarrhythmic drugs, the Dutch trial tested class I and III agents, whereas AVID and CIDS compared ICD therapy with class III agents (mostly amiodarone). In CASH, 3 drug subgroups were investigated: propafenone, amiodarone, and metoprolol. All trials used all-cause mortality as the primary endpoint. Data from these trials provide support for ICD as a therapy superior to antiarrhythmic drugs in prolonging survival in patients meeting the entry criteria. This review briefly summarizes the methods, results, limitations, and clinical implications of these 4 studies.