Author Question: Which of the following are differences between cardioversion and defibrillation? 1. In ... (Read 164 times)

theo · **on:** Jul 16, 2018

Which of the following are differences between cardioversion and defibrillation?

1. In cardioversion, the countershock is synchronized with the R wave.
2. In defibrillation, more energy is applied.
3. In cardioversion, the countershock is synchronized with the R wave.
4. In defibrillation, more energy is applied.
a. 1 only
b. 1 and 2 only
c. 2 only
d. 3 and 4 only

Question 2

Causes of ventricular fibrillation include which of the following? 1. Damage to the sinoatrial node 2. Digitalis overdose 3. Severe hypoxia 4. Myocardial infarction (MI)

a. 2 and 4 only
b. 1, 2, and 3 only
c. 2, 3, and 4 only
d. 1, 3, and 4 only

jennafosdick · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

ANS: B
Cardioversion is similar to defibrillation, with two major exceptions. First, the countershock is synchronized with the heart's electrical activity (the R wave). Synchronization is necessary be-cause electrical stimulation during the refractory phase (part of the T wave) can cause ventricular fibrillation or tachycardia. Second, the energy used during cardioversion usually is less than that applied during defibrillation.

Answer to Question 2

ANS: C
The most common causes include electrical shock, anesthesia, mechanical irritation of the heart, severe hypoxia, MI, and large doses of digitalis or epinephrine.