Antiarrythmics - Miscelaneous Flashcards Preview

CRRAB 1 - Block 3 > Antiarrythmics - Miscelaneous > Flashcards

Flashcards in Antiarrythmics - Miscelaneous Deck (8)
Loading flashcards...
1
Q

How does adenosine work?

A
  • activation of inward rectifier K+ channels (K+r) and inhibition of L-type Ca2+ channels.
  • Results in hyper-polarization and suppression of Ca2+ dependent AP (nodal tissue)
2
Q

How does digitalis work?

Try to get detailed!

A

activation of vagal efferent nerves to the heart:
-Reduces the conduction in the AV node, leading to partial block and ventricular rate falls.
-Inhibits Na+/K+/ATPase pumps: increases intracellular Na+ concentration -> reverses action on Na+/Ca2+ exchanger -> more Ca2+ into cell -> improves cardiac contractility (binds to troponin).
Increased SV -> increased CO -> decreased HR!

3
Q

Which of these two is the drug of choice for prompt conversion of paroxysmal SVT?

A

Adenosine!

4
Q

Which one of these two is short-acting so that you can halt side effects shortly after stopping the administration?

A

Adenosine!

5
Q

Which of these drugs has a side effect of extreme AV block?

And with overdose it can cause nausea, vomiting diarrhea, xanthopsia, halos, arrhythmias, tremors, seizure, and death?

A

Digitalis. Yikes.

6
Q

How is digitalis eliminated?

A

Kidneys! (so watch out for peeps with renal failure)

7
Q

What are the contraindications for use of these meds?

A

Both contraindicated in heart block

Digitalis also contraindicated in hypokalemia and Wolf-Park.-White

8
Q

What is the therapeutic use of digitalis?

A
  • Heart failure

- Reduces ventricular rate when it is being driven by high atrial rate (fibrillation or flutter)