Class IC Antidysrhythmic Agents

Encainide and flecainide are prototypical class IC agents. They have no effect on the duration of the action potential or the refractory period. They cause marked depression of automaticity (phase 4) of pacemaker cells and slow conduction velocity (phase 0). These agents are not used in the Ed setting because of associated prodysrhythmic effects. They were earlier thought helpful for the treatment of atrial fibrillation and refractory VT. However, the Cardiac Arrhythmia Suppression Trial (CAST) demonstrated an increased mortality associated with class IC agents when used to suppress ventricular ectopy in patients with a history of a recent MI and LV dysfunction.2 In fact, encainide was voluntarily taken off the market because of its prodysrhythmic tendencies. It is available only on a limited basis.

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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