p.78 抽出テキスト
Circulation. 2018;138:e272–e391. DOI: 10.1161/CIR.0000000000000549 September 25, 2018 e349 CLINICAL STATEMENTS AND GUIDELINES the wearable cardioverter-defibrillator may allow the patient to be discharged from the hospital with protection from VT/SCA until the clinical situation allows reimplantation of an ICD. 2. The patients listed in this recommendation are represented in clinical series and registries that demonstrate the safety and effectiveness of the wearable cardioverter-defibrillator. Patients with recent MI, newly diagnosed NICM, recent revascularization, myocarditis, and secondary cardiomyopathy are at increased risk of VT/SCA. However, the wearable cardioverter-defibrillator is of unproven benefit in these settings, in part because the clinical situation may improve with therapy and time. In patients awaiting transplant, even with anticipated survival <1 year without transplant, and depending on clinical factors such as use of intravenous inotropes and ambient VA, a wearable cardioverter-defibrillator may be an alternative to an ICD. 11.3 Automated External Defibrillator External defibrillation can save lives when used within minutes of the onset of VF. The AED is an efficient method of delivering defibrillation to persons experiencing out-of-hospital cardiac arrest, and its use by first responders is safe and effective.S11.3-1–S11.3-3 Federal efforts have been effective in placing AEDs in airports/ airplanes and federal buildings, while varying efforts at the state and community levels have been effective in placing AEDs in many. but not all, schools, sporting events, high-density residential sites, and airports as well as in police and fire department vehicles.S11.3-4–S11.3-7 Resuscitation protocols with or without AED placement are required in most states for fitness clubs, although alternate indoor exercise facilities may have higher rates of arrest and provide for increased survival over other indoor public sites.S11.3-8 In a study population of 21 million, survival to hospital discharge was nearly twice as high when an AED was applied for out-of-hospital cardiac arrest.S11.3-9 Expanded and coordinated placement of AEDs in the community, including in high-risk geographic locations such as schools and organized sports arenas, can substantially increase the proportion of patients with cardiac out-of-hospital cardiac arrest who receive AED therapy.S11.3-10 The US Food and Drug Administration has approved over-the-counter sales of AEDs. Approximately 70% of SCAs occur in the home, and the rate of survival to hospital discharge after AED placement by emergency medical services is significantly lower for arrest at home (12%) versus public settings (34%).S11.3-11 However, in an RCT of AEDS, home AED placement did not improve the survival of patients recovering from an anterior MI.S11.3-12 Appropriate device location to reduce time delay after onset of SCA is criti- cal. In addition to prevention, critical components of survival from SCA include immediate recognition and activation of the emergency response system, early high-quality CPR, and rapid defibrillation for shockable rhythms.S11.3-13 12 SPECIAL CONSIDERATIONS FOR CATHETER ABLATION Recommendations for Catheter Ablation References that support the recommendations are summarized in Online Data Supplement 57. COR LOE Recommendations I C-LD 1. In patients with bundle-branch reentrant VT, catheter ablation is useful for reducing the risk of recurrent VT and ICD shocks.S12-1–S12-3 IIa B-NR 2. In patients with structural heart disease who have failed endocardial catheter ablation, epicardial catheter ablation can be useful for reducing the risk of recurrent monomorphic VT.S12-4–S12-6 Synopsis Bundle-branch reentrant VT is due to reentry involving the bundle branches. Catheter ablation is the preferred therapy for this VT, which is encountered in <10% of patients with recurrent sustained monomorphic VT and structural heart disease (see Section 7.2.3). Recommendation-Specific Supportive Text 1. Bundle-branch reentrant VT can occur in any form of heart disease associated with slow infra- Hisian conduction. The most common mechanism involves antegrade conduction over the right bundle branch and retrograde conduction over the left bundle branch, thereby producing left bundle-branch block QRS morphology during VT, which is often rapid and poorly tolerated. Catheter ablation of the right or left bundle branch interrupts the circuit and is usually curative.S12-1–S12-3 After ablation, severely impaired atrioventricular conduction can be present, requiring permanent pacing, which can have hemodynamic consequences.S12-4,S12-6 Many patients have other inducible scar related VTs or meet eligibility for an ICD due to severity of associated heart disease. 2. Endocardial catheter ablation failure can be due to location of the arrhythmia substrate in the midmyocardium or epicardium, and this is more likely in patients with nonischemic rather than ischemic cardiomyopathy, and in arrhythmogenic right ventricular cardiomyopathy.S12-7–S12-9 In the Downloaded from http://ahajournals.org by on October 7, 2026