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 implantable cardioverter 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). There were 5288 cardiac arrests from a range of small communities to large provincial cardiac arrest registries in 2002. They were men (62.6% to 70.1%) in their sixties and seventies, witnessed (35.2% to 55.0%), rarely receiving bystander cardiopulmonary resuscitation (CPR) (14.7% to 46.0%), often in asystole (35.7% to 51.3%), arresting at home (56.1%) and rarely surviving to hospital discharge (4.3% to 9.0%).
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.