arrhythmias Flashcards
what is the issue in AV block
impaired conduction between atria and ventricles
what is 1st degree heart block
PR interval >0.2 seconds
how is 1st degree HB managed
does not need treatment
what is 2nd degree HB (Mobitz I)
PR interval lengthens until a dropped beat occurs
what is 2nd degree HB (Mobitz II)
PR interval is constant but there are occasional dropped QRS’s (3:1 or 2:1)
what is 3rd degree heart block
no association between P waves + QRS
symptoms of heart block
syncope // HF // wide pulse pressure // regular bradycardia //JVP cannon waves // variable S1
in unstable heart block what mx is recommended
IV atropine x2 –> IV adrenaline –> trancut pacing eg defib
how is AV block mobitz type II or complete heart block managed
temporary cardiac pacing –> permanent pacemaker
how is complete heart block following a posterior MI managed differently
if haenodynamically stable can observe
what conditions does supraventricular tachycardia cover (4)
any tachycardia not from ventricles: normal tachycardia // AV nodeal re-entry tachy (AVNRT) // AV re-entry tachycardias (AVRT) // junctional tachycardias
how do SVTs present + what type of QRS
sudden onset and termination // narrow complex QRS
what 1st line non medical management can be done in SVTs
vagal manouvres eg vasalva // carotid sinus massage
what 2nd and 3rd line mx for SVTs
IV adenosine (6mg–>12–>18) –> direct current cardioversion
what can be given instead of adenosine in SVTs and what type of patients mayrequire it
verapamil - asthmatics
what can be done for longterm prevention of SVT episodes
BB // radio frequency ablation
where is the reentry point in AVNRT
AV node
where is the rentry point in AVRT
accessory pathways eg purkinje fibres
what are vaslava manouvres used for
terminate SVT + normalise middle ear pressure
what commonly causes monoporphic v tach
MI
what commonly causes polymorphic v tach
long QT –> torsades de pointes
in an unstable patient how should V tach be treated
ALS guidelines (pulseless v tach or V fib)
drug management V tach
amiodarone // lidocaine // procainamide
if drug therapy fails what mx for ventricular tachycardia
EPS or ICD (implantable cardio-defib)
what drug should be avoided in v tach
verapamil
what can v tach progress too
v fib
what is torsades de pointes
polymorphic V tach with long QT
what congenital conditions can cause long QT
Jervell-lange + romano ward
what meds can cause torsades de points
antiarrhythmics eg amiodarone // TCAs + SSRIs // antipsychotics eg haloperidol // anti-histamine eg terfenadine // sotalol
what abx can cause torsades de poinrs
erythrmoycin + chloroquine
what cocnditions can cause torsades de pointes (4)
hypoK/Ca/Mg // myocarditis // hypothermia // SAH
mx torsades de ponts
IV mag sulphate
what is long QT syndrome + what is the common variant
inherited condition which delays depolarisation of ventricles // slow K channel
what is long QT1 assoc with
exercise syncope esp swimming
what is long QT2 assoc with
syncope with emotional, excercise or auditory
what is long QT3 assoc with
sudden events at night or rest
what drug management for long QT
BB EXCEPT SOTALOL
if drugs fail what mx for long QT
impantable cardio defib (ICD)
what type of arrhythmia is WPW
SVT –> AVRT from accessory conducting pathway
ECG features WPW
short PR // wide QRS + delta wave // left (right accessory) or right axis (left accessory) deviation
how can you differentiate between left and rights sided WPW on ECG
left pathway (type A) = dominant R wave in V1 // right pathway (type B) = no dominant R wave V1
what is WPW assoc with (5)
HCOM // mitral prolapse // thryoid problem // ASD // ebsteins
mx WPW
radiofrequency ablation
mx WPW
antiarrhymics eg BB blockers, amiodarone, flecainide
what 1st line invx should all patients with palpitations receive
ECG // TFT // U+E // FBC
DVLA after explained + treated syncope episode
4 weeks
