Final answer:
Amiodarone is an antiarrhythmic drug that minimally affects normal myocardium and primarily targets ischemic tissue, functioning as a potassium channel blocker. It affects the repolarization phase of the cardiac action potential and is effective in treating various arrhythmias.
Step-by-step explanation:
The antiarrhythmic drug known for having minimal effect on normal myocardium while targeting ischemic myocardium is amiodarone. Amiodarone falls under the category of potassium channel blockers. These drugs affect the repolarization phase of the cardiac action potential, specifically during Phase 3. By doing so, they prolong the action potential duration and refractory period, which is particularly useful in areas of ischemic myocardium that are prone to arrhythmias. Amiodarone is also known for its broad spectrum of activity, making it effective for various types of arrhythmias without significantly impacting the healthy cardiac tissue.
As for other medications that impact heart function, beta blockers and calcium channel blockers are known as negative inotropic agents, reducing the strength of the heart's contractions and stroke volume. However, unlike amiodarone, these medications can also have an effect on the normal myocardium.