learning objectives
·
different types of arrhythmia
· cellular mechanisms leading to arrhythmia formation
· how arrhythmia can be maintained by circular and re-entrant electrical paths
· common classes of anti arrhythmic agents
· mechanism of action for these drugs
· know some examples
action potential generated in nodal cells
↓
through gap junctions to
propagate myocytes
↓
activation and inactivation of sodium channels = upstroke
↓ effective refractory period
Balance of calcium and potassium channels =
plateau
↓
Repolarisation and sodium channels available normal 'smooth and coordinated
processes
cyclical excitation 68
Aberrant process disordered and chaotic
otherareasoing
as a pacemaker
maintains
/
the excitation
SAN is unstable since it has less I channels
causes
·
acute myocardial infarction ·
hypokalemia (especially in anorexia
nervosa)
· heart failure · autonomic dysfunction
therapeutic fever
· le .
g
.
digitals) and abase
drugs a
· Inherited mutations of cardiac ion channels
·
hyperthyroidism
, Arrhythmia types
bradycardia - slow HR
tachycardia >
-
fast HR
non-maintained skipped beat
blood clots a lot and can travel
atrial(a.k. a supra ventricular ( ↑
ventricular arrhythmia
cardiac arrhythmias are generated by abnormal impulse formation or impulse propagation
1 in the
changes repetitive SAN activity , depending on its pacemaker currents
AUN
2 creation of subsidiary pacemaker formation in specialised conducting or
purkinje fibres
s ectopic activity in
normally non-automatic atrial and ventricular cardiomyocytes when they are depolarized by some
pathological processes.
usually as a
consequence of defective ion channels , exchangers or ion
handling
Altered
causes automality
exaggeration of normal cellular capacity to fire
Y
funnyent
cations coming depolarisation
Increase in current faster SAN
funny =
in
may occur in a region outside of SAN
Altered automaticity block
first degree >
-
slowed conduction between AVN and ventricle
second degree- > intermittent failure of transmission from atria to ventricle
third degree or complete >
-
complete loss of transmission - uncoordinated atria and ventricle
·
different types of arrhythmia
· cellular mechanisms leading to arrhythmia formation
· how arrhythmia can be maintained by circular and re-entrant electrical paths
· common classes of anti arrhythmic agents
· mechanism of action for these drugs
· know some examples
action potential generated in nodal cells
↓
through gap junctions to
propagate myocytes
↓
activation and inactivation of sodium channels = upstroke
↓ effective refractory period
Balance of calcium and potassium channels =
plateau
↓
Repolarisation and sodium channels available normal 'smooth and coordinated
processes
cyclical excitation 68
Aberrant process disordered and chaotic
otherareasoing
as a pacemaker
maintains
/
the excitation
SAN is unstable since it has less I channels
causes
·
acute myocardial infarction ·
hypokalemia (especially in anorexia
nervosa)
· heart failure · autonomic dysfunction
therapeutic fever
· le .
g
.
digitals) and abase
drugs a
· Inherited mutations of cardiac ion channels
·
hyperthyroidism
, Arrhythmia types
bradycardia - slow HR
tachycardia >
-
fast HR
non-maintained skipped beat
blood clots a lot and can travel
atrial(a.k. a supra ventricular ( ↑
ventricular arrhythmia
cardiac arrhythmias are generated by abnormal impulse formation or impulse propagation
1 in the
changes repetitive SAN activity , depending on its pacemaker currents
AUN
2 creation of subsidiary pacemaker formation in specialised conducting or
purkinje fibres
s ectopic activity in
normally non-automatic atrial and ventricular cardiomyocytes when they are depolarized by some
pathological processes.
usually as a
consequence of defective ion channels , exchangers or ion
handling
Altered
causes automality
exaggeration of normal cellular capacity to fire
Y
funnyent
cations coming depolarisation
Increase in current faster SAN
funny =
in
may occur in a region outside of SAN
Altered automaticity block
first degree >
-
slowed conduction between AVN and ventricle
second degree- > intermittent failure of transmission from atria to ventricle
third degree or complete >
-
complete loss of transmission - uncoordinated atria and ventricle
