RT Book, Section A1 Katzung, Bertram G. A1 Kruidering-Hall, Marieke A1 Tuan, Rupa Lalchandani A1 Vanderah, Todd W. A1 Trevor, Anthony J. SR Print(0) ID 1180555736 T1 Antiarrhythmic Drugs T2 Katzung & Trevor's Pharmacology: Examination & Board Review, 13e YR 2021 FD 2021 PB McGraw-Hill Education PP New York, NY SN 9781260117127 LK accesspharmacy.mhmedical.com/content.aspx?aid=1180555736 RD 2024/03/28 AB Cardiac arrhythmias are the most common cause of death in patients with a myocardial infarction or terminal heart failure. They increase in prevalence in the elderly and atrial fibrillation is particularly common in this group. Arrhythmias are also the most serious manifestation of digitalis toxicity and are often associated with anesthetic procedures, hyperthyroidism, and electrolyte disorders. The drugs used for arrhythmias fall into five major groups or classes, but most have very low therapeutic indices and when feasible, nondrug therapies (cardioversion, pacemakers, ablation, implanted defibrillators) are used. In addition, conditions associated with certain arrhythmias, especially increased risk of thromboembolism in atrial fibrillation, must be treated with appropriate drugs from other groups (eg, anticoagulants).