Implantable Cardioverter Defibrillators
Sudden cardiac death (SCD) is defined as death from a cardiac cause occurring unexpectedly within a short time of onset of symptoms (usually within 1 h). It accounts for 325,000 deaths per year in the USA – an incidence of 0.1–0.2% per year in the adult population. SCD represents the largest proportion of the deaths attributable to coronary artery disease. Several risk factors have been identified for SCD and include previous myocardial infarction and myocardial scars, active coronary lesions, for example, ulcerated atheromatous plaques with subtotal or total thrombotic occlusion, and compromised left ventricular systolic function. In addition, there are familial cardiac conditions that may increase the risk of SCD such as Long QT syndrome (Fig. 17.1) and Brugada Syndrome (Fig. 17.2).