Class 2 Anti-arrhythmics Flashcards
Class 2 anti-arrhythmics are also known as?
Beta blockers
T/F: Class 2 anti-arrhythmics are the treatment of choice for any arrhythmias in cats.
TRUE (Propranolol/Atenolol usually first)
Name 5 Beta-blockers.
- Propranolol
- Timolol
- Metoprolol
- Atenolol
- Esmolol
Why are cats with hyperthyroidism more predisposed to tachycardias and arrhythmias?
Up regulation of beta 1 receptors. Elevation of thyroid hormone in the blood increases the density of beta 1 receptors in the heart and they suffer tachycardia and tachyarrhythmias. Drug of choice is a beta-blocker!
Beta-blockers cause ____________ by inhibiting renin release.
Vasodilation
Propranolol is a ___________ beta blocker
Non-selective
Atenolol is a ___________ beta blocker.
Selective
For a dog that is showing signs of VPCs, Lidocaine is typically your first line of treatment but beta blockers can also be useful. Describe what you’d use.
Esmolol IV then Sotalol/Propranolol. Beta blockers will slow sympathetic activity.
A dog presents with supraventricular premature depolarizations or supraventricular tachycardia, to slow the heart rate you’d use….
Esmolol IV (act at the AV node to block sympathetic effect) + Diltiazam (Ca2+ channel blocker), you may also want to thump on the chest (cardioversions, vagal maneuver).
A dog that either has supraventricular premature depolarizations or supraventricular tachycardia, what would you use for maintenance drugs?
Sotalol + Diltiazam
When treating a dog with a-fib where the heart function is normal but the heart rate is up (>150 bpm) to slow the ventricular response rate you’d use…
Beta blocker + Diltiazam
When treating a dog with a-fib where the heart function is decreased and the rate is up (>150 bpm), to slow the ventricular response rate you’d use…
Beta blocker + Diltiazam AND Digoxin (parasympathomimetic- slows the heart down)
Cats usually have a-fib due to what?
HCM
What are the drugs you’d use to treat a-fib in cats.
Propranolol or Diltiazam NOT Digoxin
