Arrhythmia's Flashcards
2 shockable rhythms
ventricular tachycardia
ventricular fibrillation
2 non-shockable rhythms
pulseless electrical activity
asystole
treating supraventricular tachycardias
continuous ECG carotid sinus massage valsava manouevres adenosine DC cardioversion
treating ventricular tachycardia
amiodarone
atrial flutter
re-entrant rhythm in either atrium
electrical signal re-circulates in self-perpetuating loop
300bpm
atrial flutter on ECG
sawtooth appearance
p wave after p wave
atrial flutter associated conditions
hypertension
IHD
cardiomyopathy
thyrotoxicosis
treating atrial flutter
beta blockers/cardioversion
treat underlying cause
radiofrequency ablation
anticoagulation
what causes SVT?
electrical signal re-enter atria from ventricles
narrow complex tachycardia
3 main types of SVT
AV node re-entrant
Atrioventricular re-entrant (Wolff-parkinson-white) accessory pathway
atrial tachycardia - atria other that SAN
Adenosine
slows cardiac conduction through AVN/accessory pathway
brief asystole/bradycardia
WPW
extra connection apart from AVN between atria and ventricles
bundle of kent
definitive treatment wpw
radiofrequency ablation
ECG changes wpw
short PR interval
wide QRS
delta wave - slurred upstroke on QRS
What conditions is radiofrequency ablation curative for?
AF
Atrial flutter
SVT
WPW syndrome
Radiofrequency ablation
catheter ablation
femoral veins under xray guidance
heat applied to accessory pathways and scar tissue no longer conducts
causes of prolonged QT
long QT syndrome
medications eg antipsychotics, amiodarone, macrolide antibiotics
electrolyte disturbance eg hypocalcaemia/kalaemia
managing long QT
beta blockers
pacemaker
(magnesium infusion)
ventricular ectopics
premature ventricular beats
symptoms ventricular ectopics
random, brief palpitations
managing ventricular ectopics
bloods - anaemia, elctrolytes, thyroid
ventricular ectopics - ECG
individual, abnormal broad QRS complexes on a normal ECG
1st degree heart block
delay AVN conduction
every p wave results in QRS
PR interval >0.2
2nd degree heart block
some p waves do not lead to QRS
2nd degree heart block - Mobitz 1
atrial impulse gradually weaker until it does not pass through AVN
fails to stimulate ventricular contraction goes back to being strong
cycle repeats
increasing PR interval until no conduction then normal
Mobitz type 2
missing QRS
3 p waves to 1 QRS
risk of asystole
2:1 heart block
2 p waves for each QRS
3rd degree heart block
complete
no relationship between p and QRS
significant risk of asystole
Treating heart block
atropine 500mcg IV
other inotropes
transcutaneous cardiac pacing
permanent implantable pacemaker
atropine
antimuscarinic
inhibits parasympathetic nervous system
pupil dilatation, urinary retention, dry eyes and constipation
