arrhythmias Flashcards
what are the 3 subtypes of arrhythmias
supraventricular, ventricular, atrio-ventricular
what are types of supra-ventricular arrhythmias
sinus bradycardia, sinus pause, atrial fibrillation, atrial flutter and ectopic atrial tachycardia, SVT and AV block
what are 4 types of ventricular arrhythmias
ventricular tachycardia, ventricular fibrillation, asystole, ventricular ectopic beats
where do bradyarrhythmias arise from
sinus node block or AV block
where do supraventricular arrhythmias arise from
between AV and SV node
where do ventricular arrhythmias arise from
below AV node
what are some abnormal anatomy causes of arrhythmias
LVH, accessory pathways, congenital disease
what are some autonomic NS causes of arrhythmias
sympathetic stimulation, increased vagal tone
what are some metabolic causes of arrhythmias
hypoxia, ischaemic myocardium, electrolyte imbalance
what is an ectopic beat?
beats that do not originate from SA node, can be a rhythm or individual beats
can ectopic beats be harmful?
yes, if originate from contractile area
what is re-entry
more than one conduction, an impulse does not die out but comes around again to excite AV node again
what can cause re-entry
accessory pathways, MI fibrosis, depressed conduction velocity, short refractory period
symptoms of arrhythmias
palpitations, SOB, dizzy, syncope, pre-syncope, angina
investigations
ECG, CXR, echocardiogram, electrophysical study
what is normal sinus arrhythmia
variation in HR due to decreased vagal tone during inspiration
what is sinus bradycardia, what causes it and how do you treat it?
less than 60bpm, drugs, ischaemia and athletic hearts can cause it. treat with atropine or pacemaker
what is sinus tachycardia, what causes it and how do you treat it?
100bpm, physiology or drugs, treat underlying cause, if severe Bblockers
what are the 2 types of supraventricular tachycardia
AV nodal re-entry tachycardia (AVNRT) and AV re-entry tachycardia (AVRT)
how do you treat acute supraventricular tachycardia
increase vagal tone - valsava, slow conduction of AVN: adenosine, verapamil
how do you treat chronic supraventricular tachycardia
radiofrequency ablastion (1st), bblockers, antiarrhythmic drugs
what is 1st degree AV block
conduction following p waves takes longer, no treatment needed
What is 2nd degree AV block and what are the 2 types
intermittent block at AVN,
mobitz I and mobitz II
what is mobitz I
progressively lengthening of PR interval eventually leading to dropped beat, usually vagal
what is mobitz II
pathological, some AP dont get through AB node, pacemaker indicated
what is 3rd degree AV block
no AP from SA gets to AV, treat with pacemaker
what causes ventricular ectopics and how do you treat them
LVH, heart failure, myocarditis, ischaemic HD and electrolytes, treat with Bblockers and ablation
what is ventricular fibrillation and how to you treat
irregular waveform and uncoordinated electrical activity, shock shock zap zap
what can cause ventricular tachycardia and what is it show on ECG
close together QRS, CAD, previous MI, myocardiopathy are rare.
how do you treat acute ventricular tachycardia
DCCV (electrical) and adenosine to confirm diagnosis
how do you treat chronic ventricular tachycardia
revascularisation, anti-arrhythmic drugs, VT catheter ablation
how would you describe Atrial fibrillation
chaotic and disorganised atrial activity, irregular and increases with age
what are the 3 types and characteristics of atrial fibrillation
paroxysmal: sudden and lasts less than 48 hrs, often recurrent , persistent: lasts more than 48hrs, unlikely to revers to NRS on it’s own, and permanent: inability of non or pharma to return to NSR
what are associated diseases with atrial fibrillation
high BP, heart disease, congenital, pericarditis, obesity
what is lone/ idiopathic AFib
absence of heart disease, no evidence of ventricular dysfunction. could be genetic
symptoms of AFib
palpitations, presyncope, syncope, chest pain, dyspnoea, sweatiness, fatigue
how would you see Afib on an ECG
atrial rate >300bpm, irregularly, irregular, p waves absent
what are the 3 things you can do you manage AFib
rhythm control, rate control, anticoagulation for thromboembolism
what would you do for restoration of NSR (rythm control) or if they are young?
DCCV is best if unstable, anti-arrhythmic eg amiodarone and lidocaine (class 1 and 3)
what would you do for maintenance of NS (rhythm control)
anti-A drugs amiodarone or lidocaine (1 . & 3) and catheter ablation
how would you control rate of AFib
digoxin, bblockers and ca antagonists 2 +3
how would you recognise an atrial flutter and how would you treat it
looks like a saw tooth with regular rhythm, ablation, DCCV, slow rate and maitain NSR with drugs, warfarin for TE
what are class 1 Antiarrhythmic drugs and example
reduce Na channel current, quindine and flecainide
what are class II Antiarrhythmic drugs and examples
Bblockers, eg propranolol
what are class III Antiarrhythmic drugs and examples
AP prolongation, eg amiodarone and dronedarone
what are class IV Antiarrhythmic drugs and examples
Ca channel blockers: verapamil
