Arrhythmias Flashcards
Treatment for tachycardia causing a patient to be unstable
DC Cardioversion
QRS complex width determined by
His-Purkinje
Ventricles contracting
Narrow complex tachycardia
Ventricles activated via normal conduction system (His-Purkinje)
In terms of mechanism, is supra ventricular tachycardia
Supra ventricular tachycardias categories
Atrial flutter/tachycardia
Atrio-Ventricular Nodal Reentrant Tachycardia
Atrio-Ventricular Re-entrant Tachycardia
Atrial flutter/tachycardia
Regular narrow complex
Originates from atria- focal or re-entrant circuit
Atrial flutter
P wave- saw tooth like, most prominent in inferior (negative in inferior)
Counter-clockwise circuit in RA
Atrial Fibrillation
Common
Prevalence increases with age
Fibrillatory waves
R-R waves irregular
AF treatment
Acute rate + rhythm management- try to achieve haemodynamic stability
Manage Precipitating factors
Assess stroke risk
In long run, consider if continue with rate management or try to get them out of AF
AF Stroke risk
Increased
CHADS VASc score
Oral anticoagulation
AF rate + rhythm management
Catheter ablation
Atrio-ventricular nodal re-entrant tachycardia
Small circuit that occurs around AV Nodal tissue
Reentry within AV node
Fast regular
Regular narrow complex tachy
Atrio-ventricular re-entrant tachycardia
Typically occurs in patients with pre-excitation (initial slurring of QRS complex with short PR interval)
Wolff-Parkinson-White syndrome
Arises from atrio-ventricular re-entrant tachycardia
Pre-excited ECG AND documented tachycardia/palpitation symptoms
Orthodromic AVRT
Ventricle activated down His Purkinje system, activation going back up atrium via accessory pathway
Narrow QRS
Antidromic AVRT
Ventricles activated by accessory pathway
Right ventricle activated before left- goes back up to atrium via AV node
Broad complex tachycardia
Pre-excited AF
Fast broad irregular rhythm
AF in top chambers, AF goes down to ventricle via both AV node and accessory pathway
Accessory pathway conducts very fast so can have very fast rhythm- can lead to VF
Medical emergency
DC Cardioversion
Inpatient Ablation for accessory pathway
Nodal dependent tachycardia
Termination with vagal manouver/adenosine
Adenosine in atrial arrhythmias
Increase AV block
Doesn’t terminate tachy
Narrow QRS- irregular
Possible AF
Treat AF
Narrow QRS- Regular
Supra-ventricular tachy
Vagal manoeuvre to determine if nodal dependent
Adenosine- 6mg rapid bolus, if no effect further 12mg, if no effect further 12mg after –> if terminates, probably nodal dependent SVT
If sinus rhythm not achieved, probably atrial flutter- beta blockers etc.
Broad complex tachy
Ventricular activation not via normal specialised conduction system
VT
Ventricle activated not via His but from somewhere else in ventricle
Broad QRS, Regular
SVT with abberancy
Broad complex QRS
Supraventricular tachy, with bundle branch block (cause of broadness)
Activated by His purkinje system that’s not working as it should
Paced rhythm
Broad complex QRS
Pre-excited rhythm
Broad complex QRS
VT- clues ECG
Regular broad complex VA dissociation (fusion beats, capture beats, independent p wave activity) Ventricular concordance Bizarre frontal axis Very broad QRS
Broad QRS irregular
AF with BBB
Pre-excited AF
Complete HB
Complete dissociation between p waves and QRS
Device therapy
Bradycardia- pacemaker
Susceptibility to VT/VF- ICD (implantable cardioverting defibrillator)
Cardiac resynchronisation- BiV/CRT device- works at all times, to make right and left ventricle work in conjunction
Situations where risk of arrhythmias
Cardiomyopathy patients
History of syncope/FH SCD (brugada syndrome, ARVC, long QT syndrome)
Other medical conditions (infiltrative conditions, myotonic dystrophy)
