Torsades De Pointes Flashcards
What is Torsades de Pointes?
It is a polymorhphic ventricular tachycardia associated with a long QT interval
What does a prolonged QT interval represent? What is the cause?
A prolonged repolarisation of the heart muscles cells, which is the period of recovery before the heart muscles are ready to depolarise again
Inhibition of K+ channels
What happens as a result of prolonged repolarisation?
Afterdepolarisations
These are random spontaneous depolarisations, which spread throughout the ventricles, leading to a ventricular contraction prior to proper repolarisation occurring
What can Torsades de pointes lead to?
Ventricular Fibrillation
What are the seven risk factors associated with Torsades de Pointes?
Jervell-Lange-Nielsen Syndrome
Romano-Ward Syndrome
Myocarditis
Subarachnoid Haemorrhage
Electrolyte Disturbances
Drug Administration
Hypothermia
What three electrolyte disturbances are associated with Torsades de Pointes?
Hypocalcaemia
Hypokalaemia
Hypomagnesaemia
What eight drugs are associated with Torsades de Pointes?
Amiodarone
Sotalol
Class 1a Antiarrythmics
Macrolide Antibiotics
Tricyclic Antidepressants
Citalopram
Chloroquine
Terfenadine
What do macrolide antibiotics end in?
-‘mycin’
What investigation is used to diagnose Torsades de Pointes?
ECG Scan
What three features indicate Torsades de pointes on ECG scans?
QRS Complex Twists Around Baseline
QRS Complex Height Progressively Gets Smaller, Then Larger, Then Smaller, etc
Prolonged QT Interval
What are the three acute management options of Torsades de Pointes?
Correct Underlying Cause
IV Magnesium Sulphate
Defibrillation
What is the first line acute management option of Torsades de Pointes?
IV Magnesium Sulphate
What are the two chronic management options of Torsades de Pointes?
Beta-blockers
Pacemaker
