sem 2: antiarrhythmic drugs

Question 1

what is a arrhythmia

Answer 1

abnormalities in heart rhythm which leads to incorrect filling and ejection of blood

Question 2

what is some symptoms of an arrhythmia

Answer 2

palpitations, dizziness, fainting, blood coagulation

Question 3

causes of arrhythmia

Answer 3

cardiac ischaemia
excess sympa stimulation
hypertension, heart failure, heart block

Question 4

two types of origin for arrhythmia

Answer 4

supra-ventricular (sa node, atria, AV node)

ventricular

Question 5

what is atrial fibrillation

Answer 5

no discrete p waves
clot producing
irregular ventricular contraction

Question 6

what is supra ventricular tachycardia (SVT)

Answer 6

p wave buried in t wave

fast ventricular contractions due to inc HR

Question 7

what is heart block

Answer 7

failure of conduction system (SAN,AVN or bundle of His)

uncoordinated atria/ventricular contractions

Question 8

what is ventricular tachycardia

Answer 8

fast and regular

Question 9

ventricular fibrillation

Answer 9

fast and irregular

no proper ejection

Question 10

two types of mechanisms of arrhythmias

Answer 10

abnormal impulse generation - ectopic pacemaker activity

abnormal conductions - reentry, heart block

Question 11

two types of abnormal impulse generation

Answer 11

ectopic 
triggered rhythms (EAD,DAD)

Question 12

what is EAD (abnormal impulse generation)

Answer 12

abnormal levels of Ca during plateau phase due to heart failure
stimulate Na/Ca exchanger
early depolarisation

Question 13

what is reentry (abnormal conductions)

Answer 13

damage to myocardium

refractory felt at different place causing reentry pathway

Question 14

what is heart block due to

Answer 14

fibrosis/ ischaemic damage

Question 15

how many degrees of heart block

Answer 15

3

Question 16

how does first degree heart block present

Answer 16

longer PR interval

Question 17

what is second degree heart block

Answer 17

time taken for p wave to reach ventricles too long so doesnt initiate

Question 18

what is third degree heart block

Answer 18

complete block, atria and ventricles beat independently

from eachother

Question 19

what are class 1 drugs and example

Answer 19

Na channel blockers - dont allow depolarisation
lidocaine
non nodal tissue

Question 20

what are Na channel blockers used for

Answer 20

VT and VF in non-nodal tissue

Question 21

what are class 2 drugs

Answer 21

b blockers

atenolol

Question 22

what do b blockers do

Answer 22

reduce VT after MI by slowing down conduction

also used in SVT

Question 23

what are class 3 drugs

Answer 23

k channel blockers

Question 24

is k channel blockers nodal or non

Answer 24

non nodal tissue

Question 25

what does a k channel blocker do

Answer 25

increases length of action potential and increases refractory period used in SVT and VT

Question 26

what are class 4 drugs

Answer 26

Ca channel antagonists

Question 27

Ca channel antagonists nodal or non

Answer 27

both

Question 28

what doe Ca channel antagonists do

Answer 28

prevent atria from contracting used in SVT relaxation of VSMCs