Digoxin Flashcards
What is the digoxin effect?
Downsloping ST depression “reverse tick” +/- biphasic T waves, QT shortening +/- U wave
Is the digoxin effect a sign of toxicity?
No - just that they’re on digoxin
What causes the digoxin effect?
Shortening of the atrial and ventricular refractory periods!
How does digoxin work?
Na/K ATPase inhibitor leading to increased IC calcium and more forceful contraction and slowing of HR increasing EF
Positive inotrope
Negative chronotrope
What vaughan williams class if digoxin?
V (also Magnesium)
When is digoxin contrainidcated?
- Ventricular fibrillation in patients with an accessory atrioventricular (AV) pathway (worsens)
- Pre-existing sinus node disease and AV block
What does this ECG show?
Digoxin effect
What are the symptoms of digoxin toxicity?
Blurred/yellow vision
N/V/D
Abdominal pain
Confusion/lethargy
What electrolyte abnormality increases digoxin toxicity?
Hyperkalaemia
What is the treatment of digoxin toxicity?
Atropine 400mcg IV Q2-5 minutely PRN
Adrenaline 10mcg push PRN (may aggravate cardiac irritability)
MgSO4
Digibind
Rx hyperkalaemia
It may be resistant to standard ALS therapies
What arrythmias can dig toxicity cause?
Tachy or bradyarrythmias
What are the indications for digibind?
- Paediatric ingestion >4mg
- Adult ingestion >10mg
- Cardiac arrest
- Life threatening dysrhythmia
- K > 5
- Consider >2ng/ml
What toxic dig sign does this ECG show?
What toxic dig sign does this ECG show?
What toxic dig sign does this ECG show?
What toxic dig sign does this ECG show?
What toxic dig sign does this ECG show?
How does digoxin affect QT interval?
Shortens QT interval
