Author Question: The nurse educator is providing patient education about the Cardiac Arrhythmia Suppression Trial ... (Read 47 times)

Kthamas · **on:** Jul 23, 2018

The nurse educator is providing patient education about the Cardiac Arrhythmia Suppression Trial (CAST). The nurse correctly explains that the trial demonstrated that pharmacologic suppression of dysrhythmias

a. reduced mortality by 50 but increased morbidity.
b. significantly reduced the risk of a second myocardial infarction.
c. doubled the risk of a second myocardial infarction.
d. should be used in all patients who have had an MI regardless of rhythm.

Question 2

The class I antidysrhythmic drugs block sodium channels. However, the nurse needs to realize that class I drugs have different actions. Which category of class I antidysrhythmic drugs accelerates repolarization?

a. Class IA
b. Class IB
c. Class IC
d. Class IA and IB

Brenm · **Reply #1 on:** Jul 23, 2018

Answer to Question 1

ANS: C
In the CAST, class IC dysrhythmic drugs were used to prevent dysrhythmias after MI. These drugs were found to actually double the rate of mortality.
The antidysrhythmic drugs did not reduce mortality or the risk of a second MI. They should not be used for any MI patients with associated dysrhythmias unless the dysrhythmias are life-threatening.

Answer to Question 2

ANS: B
Only class IB drugs increase repolarization.
Class IA drugs delay repolarization.
Class IC drugs prolong prodysrhythmic actions.
Class IA drugs delay repolarization; class IB drugs increase repolarization.