Cardiovascular- Arrhythmias

Question 1

What do potassium channels contribute to?

Answer 1

action potential duration

Question 2

What do T-type calcium channels do?

Answer 2

initiate action potential

Question 3

What do L-type calcium channels do?

Answer 3

sustain action potential

Question 4

What are the stages of the action potential

Answer 4

Resting =4
Depolarization =0
Early repolarization= 1
Plateau= 2
Final repolarization =3

Question 5

What are Class I antiarrhythmics?

Answer 5

Fast sodium channel blockers
Slows phase 0 depolarization
-lidocaine
-quinidine

Question 6

What are Class II

Answer 6

Beta blockers
Suppresses phase 4 depolarization
-metoprolol

Question 7

What are Class III

Answer 7

Repolarization prolongation
Prolongs phase 3 repolarization
-amiodarone

Question 8

What are Class IV

Answer 8

Calcium Channel Blockers
Shortens action potential
-verapamil
-diltiazem

Question 9

What are Class V

Answer 9

Calcium accumulation in cardiac cells
vagal effect
-digoxin

Question 10

What is Vaughn-Williams- IA

Answer 10

Quinidine

Question 11

What is Quinidine used for?

Answer 11

Atrial tachyarrhythmias

AV-junctional & ventricular arrhythmias

Question 12

What are ADRs of Quinidine?

Answer 12

Diarrhea
hemolytic anemia
aggravates HF
Liver failure
Digoxin interaction

Question 13

What is Vaughn-Williams- IB?

Answer 13

Lidocaine

Question 14

What is Lidocaine used for?

Answer 14

Ventricular arrhythmias

Question 15

What are some ADRs of Lidocaine?

Answer 15

Worsens certain arrhythmias
seizures
CNS effects
Contraindicated in 2nd or complete heart block

Question 16

What is Vaughn-Williams- IC?

Answer 16

Propafenone (Rhythmol)

Question 17

What is Propafenone indicated for?

Answer 17

life-threatening ventricular tachycardia or ventricular fibrillation
or refractory supraventricular tachycardia

Question 18

What are ADRs of Propafenone?

Answer 18

Potential to worsen HF
Prone to drug-drug interactions that can raise warfarin and digoxin levels
CYP2D6

Question 19

When must Propafenone be dose adjusted?

Answer 19

Patients with liver impairment

Concern over drugs that inhibit CYP2D6

Question 20

Dose a Vaughn-Williams-1C

Answer 20

Propafenone 225 mg

One tablet q8 hrs

Question 21

What are Vaughn-Williams II?

Answer 21

Beta Blockers

Question 22

What metabolizes beta blockers?

Answer 22

CYP2D6, extensive first pass effect

Question 23

Dose Metoprolol for a home dose

Answer 23

Metoprolol 50mg

One tablet twice a day

Question 24

Give examples of Vaugn Williams III

Answer 24

Amiodarone
Dofetilide
Sotalol

Question 25

What is amiodarone indicated for?

Answer 25

Supraventricular arrhythmias Afib/flutter Vtach or v-fib

Question 26

What are some ADRs of Amiodarone?

Answer 26

Pulmonary toxicity Photosensitivity Possible bradycardia Thyroid toxicity

Question 27

What are some ADRs of Dofetildide?

Answer 27

QTc prolongation

Question 28

What does Dofetilide do?

Answer 28

Prolongs action potentials in atria and ventricles

Question 29

Dose Amiodarone

Answer 29

Amiodarone 200mg | 1 tablet daily

Question 30

What drugs are included in Vaughn-Williams IV

Answer 30

Verapamil | Diltiazem

Question 31

What is Verapamil indicated for?

Answer 31

slows ventricular responses to afib/flutter | terminates PSVT

Question 32

What are ADRs of verapamil?

Answer 32

Bradycardia | Hypotension

Question 33

When is verapamil contraindicated?

Answer 33

WPW and a-fib

Question 34

What is Diltiazem used for?

Answer 34

PSVT afib/flutter

Question 35

Dose Diltiazem

Answer 35

20mg IV bolus now | infuse 10mg/hr

Question 36

What is adenosine indicated for

Answer 36

PSVT associated with WPW

Question 37

What are ADRs of adenosine?

Answer 37

Chest pain, flushing, tightness in throat

Question 38

Dose adeonsine

Answer 38

6mg IV bolus | repeat at 12 mg if first dose ineffective