Anti-Arrhythmics Flashcards
What is an odd AE of all anti-arrhythmics that make them difficult to use?
All anti-arrhythmics can cause arrhythmias
T/F: Anti-arrhythmics are generally safe for CHF patients.
False –> most anti-arrhythmics are negative inotropes
What cells in the heart act as the pacemaker and why?
SA node because they depolarize the fastest
What are the two most common causes of a cardiac arrhythmia?
- Slowed conduction in the pacemaker system leading to re-entry circuits
- Altered rate of spontaneous discharge (ectopic pacemakers)
Describe the mechanism of action of Class 1 anti-arrhythmics.
Sodium channel blockers that slow depolarization and stabilize the cell membrane
Other than in the myocardium, what physiologic effects result from membrane stabilizing medications?
Weak numbing effects –> local anesthetics
Differentiate among class 1A, 1B, and 1C anti-arrhythmics.
1A: Intermediate Na channel blockers –> quinidine, disopyramide, procainamide
1B: Fast Na channel blockers –> lidocaine, mexiletine, tocainide, phenytoin
1C: Slow Na channel blockers –> flecainide, propafenone
What is the AE of class 1A anti-arrhythmics?
Highly anti-cholinergic
In what patients is use of procainamide specifically contraindicated?
Patients with SLE
What is the primary use of class 1B anti-arrhythmics?
Ventricular arrhythmias
Which anti-arrhythmic is commonly used as a local anesthetic?
Lidocaine
T/F: Class 1C anti-arrhythmics are the most commonly used anti-arrhythmic agents.
False: not hot because they have recently been shown to increase cardiovascular morbidity and mortality
What is the mechanism of action of class 2 anti-arrhythmics?
Beta-blockers
What is the mechanism of action of class 3 anti-arrhythmics?
Potassium channel blockers
What is unique about class 3 anti-arrhythmics and what pateints benefit?
They are least likely to cause negative inotropy –> beneficial to CHF patients
