Antiarrhytmics

Question 1

Mechanism of magnesium sulfate

Answer 1

Class IV anti arrhythmic
Decrease influx of calcium in myocytes, enhance sodium/potassium pump, stabilize membrane when refractory to other therapies

Question 2

Lidocaine antiarrhythmic class

Answer 2

Class 1B sodium channel blocker

Question 3

Lidocaine mechanism

Answer 3

Na channel blocker (class Ib anti arrhythmic)
Decreases action potential duration by shortening repolarization

Question 4

Mechanism of atropine

Answer 4

Slows the parasympathetic nervous system so the sympathetic system can take over by blocking acetylcholine released by the vagus nerve (musicarinic receptors)

Question 5

Mechanism of amiodarone

Answer 5

Class III antiarrhythmic potassium channel blocker.
Delays repolarization in phase 3 lengthening action potential and slowing conduction.

Question 6

Mechanism of calcium chloride

Answer 6

An electrolyte that increases myocardial contractility and ventricular automaticity.
Maintains membrane and capillary permeability.

Question 7

Mechanism of adenosine

Answer 7

Restores sinus rhythm by interrupting reentrant circuit slowing conduction through av node by stimulating a1 + a2 receptors on cardiac nodal tissue to open potassium channels and block calcium.