lecture 12 pharmacology unfinished Flashcards
two types of cell in the heart
myocytes
pacemakers
SAN where
junction between the superior vena cava and the right atrium
where is the AVN
base of the atrial septum
bundle of his where
interventricular septum
what does the bundle of his separate into
right and left purkinje fibers
fastest conduction and why
bundle and purkinje
so the ventricle contracts as one
what is complete heart block
electrical impulses cant cross annulus fibrosus
APR
absolute refractory period
RPR
relative refractory period
what is the resting membrane potential
neg
why is resting potential neg
potassium freely moves out
negative impermeable ions in the cell
what causes depolarisation
calcium influx
P wave
spread of excitation through atria
P-R
atria contract
AVN blocks
1st
2nd (mobitz 1 and 2)
complete
tachycardias
SVT
VT
mobitz type 2
QRS dosent follow P
why are we worried about mobitz type 2
has the potential to develop into CHB
what sign would there be with CBH
either no radial or very slow
cause of CHB
ischemia
what would you give someone with CBH
beta 1 agonist: adrenaline/isoprnaline
what does BBB show as
widened QRS
difference between AF and atrial flutter
flutter dosent resolve the steady line
Torsades de pointes
this is VT
causes of Torsades de pointes
heart block
hypokalemia/hypomagnesemia
drugs (tricyclic antidepressant overdose)
congenital long QT syndrome
management of arrhythmias non pharma
vagotonic manouvres
other management of arhhythmias
DC cradioversion
pacemaker
surgery/ablation
drugs
what is atropine
anticholinergic agent
what would you use to treat bradycardia
atropine
what would you use to treat bradycardia with spinal injury
theophylline
phase 0
depolarisation of the mebrane
influx of sodium
which drugs affect phase 0
class 1 - prolong depolarisation
phase 1
short period of repolarisation
outflow of potassium
phase 2
inward movement of calcium
what drugs affect phase 2
class 4
phase 3
second repolarisation
potassium moves out of cells
what class affects phase 3
class 3
example of a class 3 drug
amiodarone
what is phase 4
resting
class 1 name
sodium channel blocker
class 1 example
disopyramide
class 1 is used for
SVT and VT
class 2 name
beta blockers
class 2 example
atenolol
what does class 2 do
blocks SAN conduction
class to is used in
SVT
class 3 name
potassium channel blocker
class 3 example
amioderone
what does classs 3 do
lengthen the action potential
class 3 used for
SVT and VT
class 4 name
calcium channel blocker
class 4 example
veramapril
class 4 do?
blocks SAN and AVN conduction
class 4 used 4
SVT
class 1a drugs block
sodium channel
what does 1a reduce
rate of depolarisation
what does 1a prolong
duration of the action potential
class 1b block
sodium channel
class 1b reduces
rate of depolarisation
class 1b shortens
duration of the action potantial
class 1c blocks
sodium channel
class 1 c and depolarisation
reduces the rate
class 1c action potential
no affect
class 2 reduces
sytmpathetic effect
class 3 blocks
potassium channel
class 4
calcium channel blockers
amioderone class
mainly 3
some 1 and 2
sotalol class
beta blocker also some class 3
adenosine MOA
potassium channel activator
effects of adenosine
slow the pacemaker
slow AVN conduction
what is adenosine used for
SVT
digoxin MO
blocks the sodium potassium ATPase channel, linked to the sodium calcium exchanger channel
increase in intracellular sodium so there is reduced calcium exchanged with the sodium.
digoxin effect
slow AVN conduction
positive inotropic effect
digoxin is used for
AF and AF in congestive heart failure
magnesium MOA
calcium channel blocker
atropine class
antimuscarinic
atropine increases
firing of SAN and AVN conduction
atropine is used for
bradycardia
how is digoxin removed
entrirely renally excreted unchanged
bad point about digoxin
low therapeutic window
gynocamastia
digoxin interacts with
diuretics
amioderone
veramapril
lidocaine is for
VT when you cant use amioderone
lidocaine class
class 3 blocks sodium channels
beta blockers are used for
hypertension, IHD, arrhythmias and heart failure
Contraindications of beta blockers
asthma, cardiogenic shock, hypotension and AV block
calcium channel blcokers are used for
hypertension, angina and arrhythmia
