Difference between revisions of "QT prolongation"

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*>500 = real concern (may result in torsades)
 
*>500 = real concern (may result in torsades)
  
==DDX==
+
==Differential Diagnosis==
 
#Pause Dependent (Aquired)
 
#Pause Dependent (Aquired)
 
##Drug induced
 
##Drug induced
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##Unstable/sustained torsades--> unsynch countershock
 
##Unstable/sustained torsades--> unsynch countershock
 
##Stable
 
##Stable
###slow HR (B-blockers)
+
###Slow HR (B-blockers)
 
###May consider magnesium
 
###May consider magnesium
  
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*Rosen
 
*Rosen
 
*Tintinalli
 
*Tintinalli
 +
 +
==External Links==
 +
[http://youtu.be/jrp_XT07fd4 Amal Mattu's Case of the Week (10/13/2014)]
  
 
[[Category:Cards]]
 
[[Category:Cards]]
 
[[Category:Tox]]
 
[[Category:Tox]]

Revision as of 22:46, 26 October 2014

Diagnosis

  • QTc >440 (male), >460 (female)
  • >500 = real concern (may result in torsades)

Differential Diagnosis

  1. Pause Dependent (Aquired)
    1. Drug induced
      1. Antidyrhythmics
      2. Phenothiazines
      3. TCAs
      4. Organophosphates
      5. Antihistamines
    2. Electrolyte Abnormalities (hypoKalemia, hypoMag, hypoCa)
    3. Diet related (starvation, low protein)
    4. Severe Bradycardia/AV Block
    5. Hypothyroid
    6. Contrast injection
    7. CVA (intraparenchymal)
    8. MI
  2. Adrenergic Dependent
    1. Congenital
      1. Jarvel/Lange-Nielsen
        1. (+deafness; AR)
      2. Romano-Ward synd
        1. (nl hearing; AD)
      3. Sporatic
      4. Mitral valve prolapse
    2. Acquired
      1. CVA (subarachnoid)
      2. Autonomic surg (catechol excess: neck dissection, carotid endarterect, truncal vagotomy)

Treatment

  1. Pause Dependent (precipitated by bradycard)
    1. Unstable/sustained torsades--> unsynch countershock
    2. Stable
      1. Treat underlying prob
      2. Increase HR (isoproterenol or overdrive pacing
      3. Magnesium sulfate IV
      4. Consider amiodarone
  2. Adrenergic Dependent (precipited by tachycardia)
    1. Unstable/sustained torsades--> unsynch countershock
    2. Stable
      1. Slow HR (B-blockers)
      2. May consider magnesium

Drug List

  1. Antiarrhythmics
    1. Amiodarone, disopyramide, dofetilide, flecainide, ibutilide, mexiletine, procainamide, quinidine, sotalol
  2. Antibiotics
    1. Macrolide
      1. Azithromycin, erythromycin, clarithromycin
    2. Fluoroquinolone
      1. Ciprofloxacin, gatifloxacin, gemifloxacin, levofloxacin, moxifloxacin, ofloxacin
    3. Other
      1. Pentamidine, telithromycin, trimethoprim-sulfamethoxazole
  3. Antidepressants
    1. Amitriptyline, citalopram, doxepin, fluoxetine, nortriptyline, paroxetine, sertraline, venlafaxine
  4. Antiemetics
    1. Dolasetron, droperidol, granisetron, ondansetron
  5. Antifungals
    1. Fluconazole, itraconazole, ketoconazole, voriconazole
  6. Antihypertensives
    1. Nicardipine
  7. Antineoplastics
    1. Lapatinib, nilotinib, sunitinib, tamoxifen
  8. Antimalarials
    1. Chloroquine, halofantrine
  9. Antipsychotics
    1. Chlorpromazine, clozapine, galantamine, haloperidol, lithium, paliperidone, pimozide, quetiapine, risperidone, thioridazine, ziprasidone
  10. Antivirals
    1. Amantadine, atazanavir, foscarnet
  11. Diuretics
    1. Indapamide
  12. Immune suppressants
    1. Tacrolimus
  13. Opiates
    1. Methadone
  14. Phosphodiesterase inhibitors
    1. Sildenafil, vardenafil
  15. Skeletal muscle relaxants
    1. Tizanidine
  16. Urinary antispasmodics
    1. Solifenacin

See Also

Source

  • Rosen
  • Tintinalli

External Links

Amal Mattu's Case of the Week (10/13/2014)