Cardiac implantable electronic devices: an overview for primary care

[摘要] BACKGROUND TO CARDIAC IMPLANTABLE ELECTRONIC DEVICES Cardiac rhythm management (CRM) is the treatment of arrhythmias. Arrhythmias can cause a range of symptoms including palpitations, dizzy spells, blackouts, and sudden cardiac arrest. Contemporary management of arrhythmia may involve cardiac implantable electronic devices (CIEDs) and catheter ablation.1CIEDs are used to manage slow and fast heart rates, and in the treatment of selected patients with heart failure. Types of CIED include permanent pacemakers (PPMs), implantable cardioverter defibrillators (ICDs), and cardiac resynchronisation therapy (CRT) devices. CIEDs are usually implanted under the skin, with one to three leads threaded down a vein to connect to the heart.1PPMs: types and what they doPPMs monitor the heart rate and, when necessary, give tiny electrical impulses to trigger the heartbeat. The leads may be implanted in the right atrium, the right ventricle (single-chamber device), or both (dual-chamber device; see Figure 1).ICDs can deliver life-saving therapy in the form of anti-tachycardia pacing (ATP) or shocks within seconds of detecting the abnormal rhythm to restore normal rhythm. They may be placed prophylactically in patients at increased risk of arrhythmias (primary prevention) or in those who have had a life-threatening arrhythmia (secondary prevention). Most ICDs have pacing functionality in addition to ATP and shocks.CRT devices are used in patients with heart failure due to weak and/or poorly coordinated ventricles. This usually manifests as a bundle branch block on a 12-lead electrocardiogram. CRT devices pace the left ventricle (via the coronary sinus) in addition to the right ventricle, to improve the coordination of the heartbeat and thus ‘synchronising’ the heart. CRT can be a feature of both pacemakers (CRT-P) and defibrillators (CRT-D).

[学科分类] 卫生学