Arrthymias Flashcards
Is a VT QRS complex broad or narrow?
broad (>120ms)
Give examples of narrow complex tachycardias
AF, atrial flutter, sinus and SVT
Describe the ecg for atrial flutter
Regular
sawtooth: 2 atrial contractions to 1 QRS complex
What is the mx of atrial flutter?
Rate/rhythm control with beta blockers or cardioversion
Treat the reversible underlying condition (e.g. hypertension or thyrotoxicosis)
Radiofrequency ablation of the re-entrant rhythm
Anticoagulation based on CHA2DS2VASc score
What are the shockable rhythms?
Ventricular tachycardia
Ventricular fibrillation
What are the different types of SVT?
Atrioventricular nodal reentrant tachycardia → Goes back up via AVN
Atrioventricular reentrant tachycardia → MOST COMMON, goes back through accessory pathway (wolff-parkinson-white)
Atrial tachycardia → abnormal electrical activity originating in atria
Describe the appearance of wolf-parkinson-white on an ecg?
slurred stroke to the QRS complex (delta wave) and short PR interval (<120ms)
mx of stable SVT?
valsalva manoevre
carotid sinus massage
adenosine (alt = verapamil) to try “reset”
mx of stable SVT?
valsalva manoevre
carotid sinus massage
adenosine (alt = verapamil) to try “reset”
mx of unstable SVT?
synchronised cardioversion via a defibrillator, shocked at the R wave
DO NOT shock during a T wave as sends into cardiac arrest
mx of unstable SVT?
synchronised cardioversion via a defibrillator, shocked at the R wave
DO NOT shock during a T wave as sends into VF
mx of reccurent episode of any narrow complex SVT?
BB
CCB
amiodarone
ablation
Define VT on an ecg
very broad QRS (>160 bpm)
AV dissociation
Fusion beats — occur when a sinus and ventricular beat coincide to produce a hybrid complex of intermediate morphology.
Brugada’s sign – The distance from the onset of the QRS complex to the nadir of the S-wave is > 100ms.
Positive or negative concordance throughout the chest leads, i.e. leads V1-6 show entirely positive (R) or entirely negative (QS) complexes, with no RS complexes seen.
RSR’ complexes with a taller “left rabbit ear”. This is the most specific finding in favour of VT. This is in contrast to RBBB, where the right rabbit ear is taller.
What can prolonged QT lead to?
VT, specficially Torsades de pointes
As waiting a longer time for repolarisation (long QT) can result in random spontaneous depolarisation in some areas of heart myocytes. These abnormal spontaneous depolarisations prior to repolarisation are known as “afterdepolarisations”. These depolarisations spread throughout the ventricle, leading to a ventricular contraction prior to proper repolarisation occurring.
