This post is on some common and important Ventricular Tachyarrhythmias (e.g. Ventricular Fibrillation). See Cardiac Arrhythmias for a complete overview. A Quick Guide to ECG will also give you tips on how to approach an ECG.
Typically Board Complex (QRS>0.12)
General Approach to the acute management of Ventricular Tachyarrhythmias is ACLS or Advanced Life Support (ALS). VF & pVT are both shockable rhythms.
VF (V-fib)
Most serious. Cardiac Output = 0.
VF is a medical emergency that requires prompt BLS interventions.
Key ECG Features
- Irregular rhythm
- No measurable rate
- Loss of P Waves
- No discernible QRS complex
VF via ECGPedia
VT
Most common cause is myocardial ischaemia or scarring following an AMI. Pulseless VT is a major threat to life.
Key ECG Features
- QRS Regular (occasionally slightly irregular) and wide (>0.12s)
- Ventricular rate = 150 - 250 bpm
- P Waves do link up with QRS Complexes
- Hard to seperate QRS Complex and T Waved
VT via ECGPedia
Ventricular tachycardia: treatment LAMB:
L idocaine
A miodarone
M exiltene/ Magnesium
B eta-blocker
Consider DC Cardioversion (repeat up to 3 times).
Pulseless VT: Commence ALS. Early defibrillation is the priority.
Torsades
Torsades de pointes, or simply torsades, is a French term that literally means "twisting of the points." Wikipedia
Can progress to VF.
Key ECG Features
- Regular (mostly)
- Rotation of the heart's electrical axis by at least 180°
- Ventricular rate = 150-300 bpm
Torsades adapted from Wikipedia
RFs: FLASH
F Familial Long QT syndrome
L eft Ventricular Hypertrophy
A cidoisis / Antiarrhythmics (Class III)
S low heart rate / SAH
H ypos (e.g. Hypokalemia, Hypocalaemia, Hypomagnesaemia, Hypothermia)
Tx: Withdrawal of the offending agent, infusion of Mg2+ sulfate, antiarrhythmic drugs, and electrical therapy as needed.
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