Arrhythmias – Ventricular Tachycardia (VT) Flashcards
Define ventricular tachycardia arrhythmia
An abnormality of the heart’s rate or rhythm, originating in the ventricles
What are examples of Ventricular Tachyarrhythmias?
Ventricular Ectopic beats, Prolonged QT syndrome, Torsade de Pointes
What is Long QT syndrome?
an abnormal prolongation of the QT interval
Describe the pathophysiology of long QT syndrome (LQTS)
- This prolonged QT interval causes the repolarisation of the ventricles to be delayed, leading to abnormal heart rhythms
- LQTS is primarily genetic, with the genes affecting ion channels that are responsible for regulating the flow of ions into and out of the heart muscle cells
What can trigger LQTS?
can be triggered by things such as exercise, emotional stress, loud noises, swimming, and medications that prolong the QT interval
What can LQTS lead to?
Torsades de Pointes
What investigation can be done for LQTS?
ECG - long QT interval
What is the treatment for LQTS?
Drug of choice – Longer-acting Beta Blockers
For high-risk patients - Implantable cardioverter defibrillator (ICD)
- Be careful of QT prolonging drugs
What is Torsades de Pointes (TdP)?
an arrhythmia associated with a prolonged QT interval and is life-threatening due to its potential to degenerate into ventricular fibrillation
What is TdP caused by?
Long QT syndrome
QT-prolonging medications
Electrolyte imbalances
Bradycardia
Structural heart disease
What investigation is done for TdP?
ECG
What is seen on ECG for TdP?
- Characterised by a twisting/oscillating pattern of the QRS
- This results from the changing axis of the QRS, which rotates around the baseline
What is the acute treatment for TdP?
- Defibrillation (if necessary)
- Cessation of any QT-prolonging drugs
- IV magnesium
- Isoprenaline to accelerate HR
What is the long-term treatment for TdP?
- Treat the underlying cause
What are the symptoms for LQTS and TdP?
- Palpitations
- Tachycardia
- Chest discomfort
- Dizziness
- Syncope
- Other symptoms of heart failure
