Arrhythmias Flashcards
Two non-dihydropiridine CCB
Verapamil & Diltiazem
MOA CCB
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”)
What to monitor for while on CCB
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
MOA BB
block beta-adrenergic receptors in heart
results in decreased conduction through A-V, increased refractory period at AV node
Name 3 non-selective BB
Propranolol, Nadolol, & Timolol
Name 2 main cardioselective BB (B1, which also affects kidneys and adipose tissue)
Atenolol and Metoprolol
What to monitor/AE of BB, and CI
bradycardia, hypotension, exacerbation of CHF
relative contraindicated in asthma due to bronchoconstriction
CNS adverse effects include fatigue, lethargy, depression, sexual dysfunction.
4 main classes to treat Atrial Fibrillation
CCB, BB, Digoxin, & Amiodarone
MOA for Digoxin
increases vagal tone to slow conduction at AV node
Name 2 situations that digoxin has advantages in treating A-fib.
Hypotension-no affect on BP
CHF exacerbation-dig improves heart contractility
Adverse effects of Digoxin & ae of chronic use
AE short: monitor for hypo -kalemia & -magnesia, new arrhythmia or A-fib
AE chronic: hallucinations, nausea/vomiting, AV block, sinus pauses, arrhythmias, vision changes
Amiodarone MOA/class and what it may do
BB and CCB that may convert A-fib to NSR
When to anticoagulate before converting A-fib?
> 48 hours
Need 3 weeks of Warfarin (INR 2-3) & 4 weeks post conversion
What main drug is used to treat Paroxysmal Supraventricular Tachycardia?
Adenosine. Verap/Diltiaz and BB also effective
Amiodarone MOA
Briefly interrupts conduction at AV node to break re-entry
What to monitor in Amiodarone, when to use with caution, and when CI?
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
Main treatment of Ventricular arrhythmia
Defibrillators
Unstable vs. Stable V-tach
Stable: adequate BP, mental status intact, & no CP
Unstable: SBP
Treatment of acute V-tach non-emergent for both stable & unstable
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
First three things to do during cardiac arrest?
CPR, defibrillator, & maintain airway
What drugs can be given to improve perfusion during CPR & what to do after giving them?
Epinephrine or Vasopressin
Flush with saline 20 ml
What drugs are used to “fix” rhythm in v-fib/v-tach
- Amiodarone
- Lidocaine
- Procainamide
Indications for Mag Sulfate
Torsades, suspected hypo magnesia, refractory ventricular arrhythmia, and dig tox
What drug to give in asystole or pulseless electrical activity?
Atropine-it’s anti-cholinergic effects can reverse vagal stimulation on the heart to increase SA firing and AV conduction
Do you shock asystole?
NO
The potential causes of asystole (5 H’s & 5 T’s)
Hypovolemia Tablets (OD)
Hypoxia Tamponade
Hydrogen ion (acidosis) Tension Pneumothorax
Hyper-hypokalemia Thrombosis, coronary (MI)
Hypothermia Thrombosis, pulmonary (PE)
