The flashcards below were created by user LaurenFleming on FreezingBlue Flashcards.

  1. Cardiac Dysrhythmias
    Caused by changes in the ionic currents through ion channels of the myocardial cell membrane:
  2. What changes cause cardiac dystrhythmias
    –Sodium-influx into cell

    –Potassium-extruded from cell

    • –Calcium-influx into cell
    • Magnesium, Phosphorous
  3. Any drug used to treat an arrhythmia (dysrhythmia) can also cause
    an arrhythmia = proarrhythmia
  4. How many Classes of Dysrhythmic agents
  5. Class 1 dysrhythmic agents
    Sodium Channel Blockers

    Block cardiac sodium channels

    slow impulse conduction in the atria, ventricles , and His-Purkinjie System
  6. Class II Dysrhythmic agents
    Beta adrenergic blocking agents

    block adrenergic receptors, producing antisympathetic properties

    • SA node: Reduce automaticity, slow conduction
    • velocity, and reduce contractility
  7. Class III Dysrhythmic agents
    Potassium Channel Blockers

    • –lengthen the action potential duration and
    • effective refractory period
  8. Class IV Dysrhythmic agents
    Calcium Channel Blockers

    • –Same effects as beta blockers – reduction of
    • automaticity in the SA node, delay of conduction through AV node, and reduction
    • of myocardial contractility
  9. Other dysrhythmic drugs
    –Adenosine and Digoxin
  10. Class IA dysrhythmic agent
    Quinidine (Quinidex extendtabs)
  11. Quinidine (Quinidex extendtabs) Other drugs in class
    • Procainamide (Pronestyl, Procanbid),
    • dispyramide (Norpace),
    • tocainide (Tococard),
    • propafenone (Rythmol)
  12. Quinidine (Quinidex extendtabs) Therapeutic Uses
    Used to treat supraventricular and ventricular arrhythmias
  13. Quinidine (Quinidex extendtabs) Physiologic Actions
    Slows impulse conduction by blocking sodium channels

    Decreases myocardial excitability, conduction velocity, and contractility

    Prevents reentry phenomenon

    Strongly anticholinergic effects (atropine-like) increases ventricular rate
  14. Quinidine (Quinidex extendtabs) Side Effects
    Serious adverse effect: Cardiotoxicity, arterial embolism, hypotension with IV use
Card Set:
2011-08-16 16:45:00

Antidysrhythmic Drugs
Show Answers: