TY - CHAP M1 - Book, Section TI - Chapter 10. Antiarrhythmic Drugs A1 - Panus, Peter C. A1 - Jobst, Erin E. A1 - Masters, Susan B. A1 - Katzung, Bertram A1 - Tinsley, Suzanne L. A1 - Trevor, Anthony J. Y1 - 2009 N1 - T2 - Pharmacology for the Physical Therapist AB - Cardiac arrhythmias reduce cardiac output and commonly occur in the presence of preexisting heart disease. They are the most common cause of death in patients who have had a myocardial infarction, and over 80% of patients with an acute myocardial infarction have arrhythmias. Cardiac arrhythmias also occur in up to 25% of patients treated with digitalis and in 50% of anesthetized patients. Patients with electrolyte imbalances also demonstrate arrhythmias, and diuretics are significant sources of such imbalances. Arrhythmias may require treatment because of rhythms that are too rapid, too slow, or asynchronous. Some arrhythmias may precipitate more serious or even lethal rhythm disturbances. For example, premature ventricular contractions (PVCs) can precipitate ventricular fibrillation, which is fatal unless corrected promptly. In such patients, antiarrhythmic drugs may be lifesaving. In contrast, pharmacologic treatment of asymptomatic or minimally symptomatic arrhythmias is avoided until clinically necessary because of the ability of many of these drugs themselves to induce lethal arrhythmias. In this chapter, we will review the conduction sequence and electrophysiology of normal cardiac rhythm, highlight the mechanisms of arrhythmias, and discuss the antiarrhythmic drugs used in their treatment. SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/04/24 UR - accessphysiotherapy.mhmedical.com/content.aspx?aid=6090034 ER -