Diagnosaurus
Long QT syndrome
Etiology
Electrolyte abnormalities
- Hypokalemia
- Hypomagnesemia
- Hypocalcemia
- Class Ia antiarrhythmics (quinidine, procainamide)
- Class Ic antiarrhythmics (propafenone)
- Class III antiarrhythmics (amiodarone, bretylium, sotalol)
- Tricyclic antidepressants
- Astemizole, terfenadine
- Antibiotics: erythromycin, trimethoprim-sulfamethoxazole, levofloxacin, ketoconazole, itraconazole
- Phenothiazines, haldol
- Prednisone
- Congenital long QT syndrome
- Third-degree A-V block
- Second-degree A-V block
- Left ventricular hypertrophy (LVH)
- Myocardial ischemia
- Significant bradycardia
- Stroke or subarachnoid hemorrhage
- Hypothermia
There's more to see -- the rest of this topic is available only to subscribers.
Last updated: December 1, 2014
Citation
Zeiger, Roni F.. "Long QT Syndrome." Diagnosaurus, 4th ed., McGraw-Hill Education, 2014. Emergency Central, emergency.unboundmedicine.com/emergency/view/Diagnosaurus/114580/all/Long_QT_syndrome.
Zeiger RFR. Long QT syndrome. Diagnosaurus. McGraw-Hill Education; 2014. https://emergency.unboundmedicine.com/emergency/view/Diagnosaurus/114580/all/Long_QT_syndrome. Accessed October 31, 2025.
Zeiger, R. F. (2014). Long QT syndrome. In Diagnosaurus (4th ed.). McGraw-Hill Education. https://emergency.unboundmedicine.com/emergency/view/Diagnosaurus/114580/all/Long_QT_syndrome
Zeiger RFR. Long QT Syndrome [Internet]. In: Diagnosaurus. McGraw-Hill Education; 2014. [cited 2025 October 31]. Available from: https://emergency.unboundmedicine.com/emergency/view/Diagnosaurus/114580/all/Long_QT_syndrome.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC
T1 - Long QT syndrome
ID - 114580
A1 - Zeiger,Roni F,
Y1 - 2014/12/01/
BT - Diagnosaurus
UR - https://emergency.unboundmedicine.com/emergency/view/Diagnosaurus/114580/all/Long_QT_syndrome
PB - McGraw-Hill Education
ET - 4
DB - Emergency Central
DP - Unbound Medicine
ER -
