Arrhythmias

Question 1

Two non-dihydropiridine CCB

Answer 1

Verapamil & Diltiazem

Question 2

MOA CCB

Answer 2

work via effects on intracellular calcium ion influx at the AV node to decreases conduction velocity and increases refractory period

this produces a direct effect to the AV node and therefore actions persist during exercise or high stress to SLOW DOWN the ventricular rate (“ventricular response”)

Question 3

What to monitor for while on CCB

Answer 3

blood pressure - diltiazem and verapamil are vasodilators

signs of congestive heart failure in susceptible patients due to negative inotropic effect
do not use in patient with decompensated heart failure

Question 4

MOA BB

Answer 4

block beta-adrenergic receptors in heart

results in decreased conduction through A-V, increased refractory period at AV node

Question 5

Name 3 non-selective BB

Answer 5

Propranolol, Nadolol, & Timolol

Question 6

Name 2 main cardioselective BB (B1, which also affects kidneys and adipose tissue)

Answer 6

Atenolol and Metoprolol

Question 7

What to monitor/AE of BB, and CI

Answer 7

bradycardia, hypotension, exacerbation of CHF

relative contraindicated in asthma due to bronchoconstriction

CNS adverse effects include fatigue, lethargy, depression, sexual dysfunction.

Question 8

4 main classes to treat Atrial Fibrillation

Answer 8

CCB, BB, Digoxin, & Amiodarone

Question 9

MOA for Digoxin

Answer 9

increases vagal tone to slow conduction at AV node

Question 10

Name 2 situations that digoxin has advantages in treating A-fib.

Answer 10

Hypotension-no affect on BP

CHF exacerbation-dig improves heart contractility

Question 11

Adverse effects of Digoxin & ae of chronic use

Answer 11

AE short: monitor for hypo -kalemia & -magnesia, new arrhythmia or A-fib

AE chronic: hallucinations, nausea/vomiting, AV block, sinus pauses, arrhythmias, vision changes

Question 12

Amiodarone MOA/class and what it may do

Answer 12

BB and CCB that may convert A-fib to NSR

Question 13

When to anticoagulate before converting A-fib?

Answer 13

> 48 hours

Need 3 weeks of Warfarin (INR 2-3) & 4 weeks post conversion

Question 14

What main drug is used to treat Paroxysmal Supraventricular Tachycardia?

Answer 14

Adenosine. Verap/Diltiaz and BB also effective

Question 15

Amiodarone MOA

Answer 15

Briefly interrupts conduction at AV node to break re-entry

Question 16

What to monitor in Amiodarone, when to use with caution, and when CI?

Answer 16

peripheral vasodilation - hypotension, flushing, SOB, chest tightness, apprehension (all of short duration)

use with caution in patients with severe obstructive lung disease

contraindicated in heart transplant patients

Question 17

Main treatment of Ventricular arrhythmia

Answer 17

Defibrillators

Question 18

Unstable vs. Stable V-tach

Answer 18

Stable: adequate BP, mental status intact, & no CP
Unstable: SBP

Question 19

Treatment of acute V-tach non-emergent for both stable & unstable

Answer 19

Stable
1. Amiodarone:
150mg IV over 10 minutes,
then 1mg/min x 6 hours,
then continuous infusion 0.5 mg/min
2. Lidocaine, 1-1.5 mg/kg IV,
then 0.5-0.75 mg/kg every 5-10 minutes up to 3mg/kg,
then continuous infusion 1-4 mg/min
3. Procainamide (only if preserved heart function – EF > 40%),
17mg/kg IV no greater than 20-30mg/min.
a. Stop infusion if QRS widens > 50% or hypotension
4. Torsades de pointes with prolonged baseline QT interval
Correct electrolytes, Give Magnesium 1-2 gm IV, may repeat

Unstable
-Urgent Synchronized cardioversion

Question 20

First three things to do during cardiac arrest?

Answer 20

CPR, defibrillator, & maintain airway

Question 21

What drugs can be given to improve perfusion during CPR & what to do after giving them?

Answer 21

Epinephrine or Vasopressin

Flush with saline 20 ml

Question 22

What drugs are used to “fix” rhythm in v-fib/v-tach

Answer 22

1. Amiodarone
2. Lidocaine
3. Procainamide

Question 23

Indications for Mag Sulfate

Answer 23

Torsades, suspected hypo magnesia, refractory ventricular arrhythmia, and dig tox

Question 24

What drug to give in asystole or pulseless electrical activity?

Answer 24

Atropine-it’s anti-cholinergic effects can reverse vagal stimulation on the heart to increase SA firing and AV conduction

Question 25

Do you shock asystole?

Answer 25

NO

Question 26

The potential causes of asystole (5 H’s & 5 T’s)

Answer 26

Hypovolemia Tablets (OD)
Hypoxia Tamponade
Hydrogen ion (acidosis) Tension Pneumothorax
Hyper-hypokalemia Thrombosis, coronary (MI)
Hypothermia Thrombosis, pulmonary (PE)