Sudden cardiac arrest (SCA) and sudden cardiac death (SCD) refer to the sudden cessation of cardiac activity with hemodynamic collapse, typically due to sustained ventricular tachycardia or ventricular fibrillation. These events mostly occur in patients with structural heart disease (that may not have been previously diagnosed), particularly coronary heart disease. (See "Pathophysiology and etiology of sudden cardiac arrest".)
The event is referred to as SCA (or aborted SCD) if an intervention (eg, defibrillation) or spontaneous reversion restores circulation. The event is called SCD if the patient dies. However, the use of SCD to describe both fatal and nonfatal cardiac arrest often persists by convention. (See "Overview of sudden cardiac arrest and sudden cardiac death", section on 'Definitions'.)
The treatment of SCA consists of acute resuscitation followed, in survivors, by therapy to prevent recurrence. Patients with ventricular tachycardia/ventricular fibrillation not due to a reversible cause generally receive an implantable cardioverter-defibrillator (ICD). Antiarrhythmic drugs are used in select patients as adjunctive therapy, or as primary therapy when an ICD is not indicated or refused by the patient.
This topic will review the role of pharmacologic therapy in survivors of SCA, with an emphasis on the role of antiarrhythmic drugs. Issues related to the acute management of SCA, the evaluation of survivors, and the utility of an ICD, arrhythmic surgery or radiofrequency ablation are discussed separately. (See "Supportive data for advanced cardiac life support in adults with sudden cardiac arrest" and "Evaluation of the survivor of sudden cardiac arrest" and "Secondary prevention of sudden cardiac death in heart failure and cardiomyopathy".)
Pharmacologic therapy, in the form of beta blockers and antiarrhythmic medications, can be helpful in controlling arrhythmias in survivors of sudden cardiac arrest (SCA). However, due to the efficacy of the implantable cardioverter-defibrillator (ICD) in treating sustained ventricular tachyarrhythmias and improving mortality, antiarrhythmic drugs are generally reserved for use in select patients as adjunctive therapy, or as primary therapy when an ICD is not indicated or refused by the patient. (See 'ICD therapy' below.)