The most common electrophysiologic mechanisms leading to SCD are tachyarrhythmias such as ventricular fibrillation (VF) or ventricular tachycardia (VT). Interruption of tachyarrhythmias, using either an automatic external defibrillator (AED) or an implantablecardioverter defibrillator (ICD), has been shown to be an effective treatment for VF and VT. The implantable defibrillator has become the central therapeutic factor in the prevention and treatment of sudden cardiac death.
Patients with tachyarrhythmias, especially VT, carry the best overall prognosis among patients with sudden cardiac arrest (SCA).During the study period, 55 sudden cardiovascular deaths occurred in screened athletes (1.9 deaths/100,000 person-years) and 265 sudden deaths in unscreened nonathletes (0.79 deaths/100,000 person-years). The annual incidence of sudden cardiovascular death in athletes decreased by 89% (from 3.6/100,000 person-years in 1979-1980 to 0.4/100,000 person-years in 2003-2004; P for trend < .001), whereas the incidence of sudden death among the unscreened nonathletic population did not change significantly. The mortality decline started after mandatory screening was implemented and persisted to the late screening period.
Compared with the prescreening period (1979-1981), the relative risk ofsudden cardiovascular death in athletes was 0.56 in the early screening period (95% CI, 0.29-1.15; P = .04) and 0.21 in the late screening period (95% CI, 0.09-0.48; P = .001).CPR: Immediate cardiopulmonary resuscitation (CPR) is critical to treating sudden cardiac arrest. By maintaining a flow of oxygen-rich blood to the body's vital organs, CPR can provide a vital link until more advanced emergency care is available. Ongoing Research is being done at cardiac centres.