Class 2, Phase 4

Question 1

What do most of the class 2 beta blockers end in?

Answer 1

“-olol”
Acebutolol
Esmolol
Propranolol

Question 2

What are the other drugs of antiarrhythmics drugs and what do they do differently than the other beta blockers?

Answer 2

• act on the autonomic nervous system.
  Digoxin: increases intracellular calcium - enhances contractility, increase fatal tone slowing heart rate. - Slows release of calcium leaving the cell- prolongs action potential between the AV+SA nose- very effective for atrial issues. Can cause increase in coronary artery blood flow.
  Adenosine: Inhibits calcium, reducing conduction speed through AV node, decreasing potassium in cells. Hyperpolarizing cells. Less likely to fire action potentials. Specifically used for SVT when other measures are not effective. Short duration of action- can go in a-systole for a moment before normal rhythm.

Question 3

What happens in phase 4 of the action potential of the cardiac muscle cells?

Answer 3

Back at rest and ready to start all over again.
These drugs block this phase by completely blocking beta receptor sites in the heart and kidneys, decreasing hr, cardiac excitability, and cardiac output - slows conduction through AV node.

Question 4

What happens in phase 4 of the action potential of the cardiac muscle cells?

Answer 4

Back at rest and ready to start all over again.
These drugs block this phase by completely blocking beta receptor sites in the heart and kidneys, decreasing hr, cardiac excitability, and cardiac output - slows conduction through AV node.

Question 5

What class of drugs are in class 2, phase 4?

Answer 5

Beta Adrenergic blockers

Question 6

What are the class 2 classifications of antiarrhythmics and what do they do?

Answer 6

Act in the autonomic receptors.
Class II - Beta-Adrenergic Blockers: These act on autonomic receptors to decrease heart rate, cardiac excitability, and cardiac output. Examples include acebutolol, esmolol, and propranolol.