QT prolongation Flashcards
Name the acquired QT prolongation causes
from electrolyte derangements: hypocalcemia, hypokalemia, hypomagnesemia
Medication induced:
antihistamines: loratadine and diphenhydramine
antibiotics: macrolide fluoroquinolones,
psychotropics: antipsychotics (1st and 2nds), TCAs, SSRI’s, lithium toxicity
opioids: methadone oxycodone
antiemetics: ondansetron, granisetron, metoclopramide (zofran phenergan)
antiarrhythmics: quinidine, procainamide, flecainide, amiodarone, sotalol
antifungals- ketoconazole and fluconazole
anti-cancer: tamoxifiene
anti-malarials: chloroquine, hydroxychloroquine, quinine
MISC: tacrolimus
Inherited QT prolongation
Jervell Langue Nielsen syndrome (autosomal recessive condition) Romano Ward syndrome (autosomal dominant)
QTc>450 msec
QTC in males
QTC >470 msec in
considered prolonged in females
Congenital Long QT syndrome can have this presentation of
asymptomatic can have palpitations, pre syncope/syncope, seizures, cardiac arrest. can see torsades de pointes which may spontaneously or degenerate into V fib
management of prolonged QTc
avoid strenous exercise, electrolyte abnormalities like hypokalemia or hypomagnesemia or medications like anti psychotics and fluoroquinolones
how to treat congenital long QT syndrome?
treat with beta blockers (propranolol and nadolol) to decrease risk for symptomatic arrhythmias and sudden cardiac death
when to place a implantable cardioverter defibrillator in long QT syndrome
put ICD in pts who have syncope (if recurrent) or VT (torsades de pointes) on beta blocker therapy. ICD may be considered in pts who have strong family history of sudden cardiac death 1st line tx is still beta blocker as ICD has risk of infection or lead fracture) and ICD is meant for secondary prevention with an aborted cardiac arrest.
What medications can help treat symptomatic or asymptomatic pts who have congenital QT syndrome?
beta blockers (atenolol, metoprolol, and propranolol)
what meds cause QT prolongation?
Medication induced:
antihistamines: loratadine and diphenhydramine
antibiotics: macrolide fluoroquinolones,
psychotropics: antipsychotics (1st and 2nds), TCAs, SSRI’s, lithium toxicity
opioids: methadone oxycodone
antiemetics: ondansetron, granisetron, metoclopramide (zofran phenergan)
antiarrhythmics: quinidine, procainamide, flecainide, amiodarone, sotalol
antifungals- ketoconazole and fluconazole
anti-cancer: tamoxifiene, tyrosine kinase inhibitors (CML, GIST)
anti-malarials: chloroquine, hydroxychloroquine, quinine
MISC: tacrolimus
