Antiarrhythmic drugs

Question 1

membrane at phase 4 is

Answer 1

polarised

Question 2

stage 0 is

Answer 2

depolarisation

Question 3

stage 1 is

Answer 3

early repolarisation

Question 4

stage 2 Is

Answer 4

plateau

Question 5

stage 3 is

Answer 5

final repolarisation

Question 6

spino atrial nodes

Answer 6

designed to reach the threshold quicker

pacemaker cells

Question 7

Effective refractory period

Answer 7

refrain from further stimulation

Question 8

reentry tachyarrhythmia

Answer 8

occur where there is damage to the tissue
at a junction one branch is damage
continues down the working branch
causes the impulse to circulate and ‘reenter’ because the refractory period has passed

Question 9

class 1

Answer 9

Na channel blockers
lignocaine
flecainide
slows the course of the impulse so that it arrives too late and a new rhythm has come so it can’t cause a reentry rhythm

Question 10

adverse effects of class 1

Answer 10

slows conduction in latent circuses, causing timing to fall into critical range
specialist only drug

Question 11

class 2

Answer 11

beta 1 adrenoceptor blockers

don’t trigger non-existent arythmias

Question 12

class 2 examples

Answer 12

metoprolol, atenolol, bisoprolol

Question 13

class 3

Answer 13

prolonged action potential duration and ERP

Question 14

class 4

Answer 14

calcium channel blockers

Question 15

adenosine

Answer 15

receptors on atrial and AV conducting tissue
lowers resting membrane potential
ectopic impulses are not enough to reach -40mV threshold