QT prolongation
what is this QT interval actually?
- represents time for ventricular depolarisation and repolarisation
- inversely proportional to heart rate (i.e. shortens with higher HR)
- prolonged QT → risk of Torsades
electrolytes
genetic causes
- LQT1/LQT2 (K channel mutation); LQT3 (Na channel mutation)
- Jervell and Lange-Nielsen syndrome (associated with deafness)
other causes
- myocardial ischaemia
- post-ROSC
drugs: so many
Antiarrhythmics, ironically
flecainide
procainamide
Amiodarone
Atenolol
Antimicrobials
Erythromycin
Clarithromycin
Ciproflaxacin
Moxifloxacin
Fluconazole
Ketoconazole
Antipsychotics (all have some risk)
Risperidone
Haloperidol
Chlorpromazine
Quetiapine
Clozapine
Antidepressants
Citalopram
Fluoxetine
Amitriptyline, Clomipramine, Imipramine, Lofepramine - Tricyclic antidepressants
Dosulepin
Doxepin
Antiemetics
Domperidone
Droperidol
Ondansetron
Granisetron
Others
- Chloroquine
- Hydroxychloroquine
- Quinine
- Macrolides: Erythromycin; Clarithromycin
- Adrenaline
generic management
- treat underlying cause
- beta blockade
- avoid sympathetic surge
- pacing
- ICD