sem 2: antiarrhythmic drugs Flashcards
what is a arrhythmia
abnormalities in heart rhythm which leads to incorrect filling and ejection of blood
what is some symptoms of an arrhythmia
palpitations, dizziness, fainting, blood coagulation
causes of arrhythmia
cardiac ischaemia
excess sympa stimulation
hypertension, heart failure, heart block
two types of origin for arrhythmia
supra-ventricular (sa node, atria, AV node)
ventricular
what is atrial fibrillation
no discrete p waves
clot producing
irregular ventricular contraction
what is supra ventricular tachycardia (SVT)
p wave buried in t wave
fast ventricular contractions due to inc HR
what is heart block
failure of conduction system (SAN,AVN or bundle of His)
uncoordinated atria/ventricular contractions
what is ventricular tachycardia
fast and regular
ventricular fibrillation
fast and irregular
no proper ejection
two types of mechanisms of arrhythmias
abnormal impulse generation - ectopic pacemaker activity
abnormal conductions - reentry, heart block
two types of abnormal impulse generation
ectopic triggered rhythms (EAD,DAD)
what is EAD (abnormal impulse generation)
abnormal levels of Ca during plateau phase due to heart failure
stimulate Na/Ca exchanger
early depolarisation
what is reentry (abnormal conductions)
damage to myocardium
refractory felt at different place causing reentry pathway
what is heart block due to
fibrosis/ ischaemic damage
how many degrees of heart block
3