Antiarrhythmics: 4.1: Class 1

Question 1

Class I antiarrhythmics block _____ channels.

Answer 1

opened or inactivated Na+

Question 2

What drug causes cinchonsm?

Answer 2

quinidine

Question 3

Name some ADRs of disopyramide.

Answer 3

• drug induced lupus
• induces/worsen HF

Question 4

What class of antiarrythmics can be used to treat A-fib?

Answer 4

class IC (propafenone and flecainide)

Question 5

What happens in phase 0 of the cardiac AP?

Answer 5

upstroke via Na+

Question 6

What happens in phase 3 of the cardiac AP?

Answer 6

repolarization via K+

Question 7

Name some ADRs of quinidine.

Answer 7

• cinchonsm (tinnitus, HA, dizziness)
• thrombocytopenia

Question 8

This is a supraventricular tachycardia caused by signals passing thru an accessory pathway outside the AV node .

Answer 8

Wolff-Parkinson-White (WPW) syndrome

Question 9

Class IA antiarrhythmics (quinidine, procainamide, disopyramide) are used for _____ arrhythmias.

Answer 9

supraventricular and ventricular

Question 10

Class IB antiarrhythmics (lidocaine, mexiletine, phenytoin) _____ the refractory period and AP.

Answer 10

shorten

Question 11

What happens in phase 2 of the cardiac AP?

Answer 11

plateau via Ca++

Question 12

What class of antiarrythmics can be used for rhythm control?

Answer 12

class IC (propafenone and flecainide)

Question 13

What are the ADRs for class IB antiarrhythmics (lidocaine, mexiletine, phenytoin)?

Answer 13

• neuro SEs (paresthesias, tremor, slurred speech, convulsions)

Question 14

_____ are used for ischemia-induced ventricular arrhythmias.

Answer 14

Class IB antiarrhythmics (lidocaine, mexiletine, phenytoin)

Question 15

Class I antiarrhythmics ____ the QRS complex.

Answer 15

widen

Question 16

What is Wolff-Parkinson-White (WPW) syndrome?

Answer 16

a supraventricular tachycardia caused by signals passing thru an accessory pathway outside the AV node

Question 17

Class IB antiarrhythmics (lidocaine, mexiletine, phenytoin)are more specific for the _____ arrhythmias.

Answer 17

ventricular

Question 18

Name a specific syndrome that Class IA antiarrhythmics are used.

Answer 18

Wolff-Parkinson-White (WPW) syndrome

Question 19

What do the class IA antiarrhythmics (quinidine, procainamide, disopyramide) block? What is the result?

Answer 19

• block Na+ AND K+ channels
• prolonged refractory period (prolonged AP)

Question 20

Name 3 class IA antiarrhythmics.

Answer 20

1. quinidine
2. procainamide
3. disopyramide

Question 21

What is quinidine?

Answer 21

a Class IA antiarrhythmic drug

Question 22

Name 3 class IB antiarrhythmics.

Answer 22

1. lidocaine
2. mexiletine
3. phenytoin

Question 23

Class I antiarrhythmics block Na+ channels, which cause a _____ slope in phase 0 of the cardiac upstroke.

Answer 23

decreased

Question 24

Class IC antiarrhythmics (propafenone and flecainide) _____ the QRS and _____ the AP duration.

Answer 24

• QRS = prolonged
• AP = unchanged

Question 25

In whom are Class IC antiarrhythmics (propafenone and flecainide) contraindicated?

Answer 25

pts with structural or ischemic heart disease, esp. post-MI

Question 26

Class IC antiarrhythmics (propafenone and flecainide) treat ______ arrhythmias.

Answer 26

supraventricular and ventricular

Question 27

Name 2 class IC antiarrhythmics.

Answer 27

1. propafenone
2. flecainide