An Overview of Arrhythmias and Antarrhythmic Approaches

Although treatment of cardiac arrhythmias has been revolutionized in the past decade, patients with atrial fibrillation (AF) still represent a major challenge. With the graying of the population, AF is increasing in prevalence and is responsible for significant morbidity, mortality, and health care expenditures. Drug therapy will be required for the majority of patients with this disorder. Patients with ventricular tachyarrhythmias represent the other major challenge to the cardiac electrophysiologist. The use of implantable cardioverter-defibrillators (ICDs) has reduced the sudden death mortality to 1% or less per year in patients at risk of dying from a ventricular tachyarrhythmia. Unfortunately, high-risk patients who receive an ICD are only a small proportion of the patients who die suddenly each year. Considering the number of at-risk patients, it is likely that drug therapy will remain the mainstay of treatment of patients with ventricular tachyarrhythmias. Therefore, the major challenge is to recognize patients at risk and treat them with antiarrhythmic drugs to prevent sudden cardiac death. Consequently, it has become clear that we have come to a crossroad with regard to antiarrhythmic drugs. Our knowledge of the molecular biology of cardiac ion channels, electrophysiology, and emerging antiarrhythmic drugs provides us an opportunity to create new pharmacologic stratagems.