Torsade de pointes
Torsade de pointes | |
DiseasesDB | 29252 |
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MeSH | D016171 |
Torsades de pointes Microchapters |
Diagnosis |
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Treatment |
Case Studies |
Torsade de pointes On the Web |
American Roentgen Ray Society Images of Torsade de pointes |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]
Clinical Correlation
- Drugs: quinidine, PCA, norpace, amiodarone, phenothiazines, Tricyclic antidepressants, pentamidine.
- with quinidine majority of the cases occur within one week of initiation, and with therapeutic levels
- Electrolyte imbalances: Hypokalemia, hypomagnesemia, hypocalcemia
- CAD
- MVP
- Variant angina
- Myocarditis
- Subarachnoid hemorrhage
- Congenital QT prolongation
- Liquid protein diets
- Hypothyroidism
- because of bradycardia and a prolonged QT syndrome
- Organophosphate poisoning [1] [2]
Video: Torsade de pointes
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Torsade de pointes is characterized by constantly changing rhythm amplitude. 'Torsade de pointes' in French means "Twisting of the Points". The changing rhythm amplitudes comes from the ventricular depolarizing waves constantly shifting its axis. It is usually caused by hypomagnesemia, hypokalemia, and malnourished alcoholics. Although Torsades de Pointes (TdP) is a rare ventricular arrhythmia, it can degenerate into ventricular fibrillation, leading to death without rapid medical intervention. TdP is associated with long QT syndrome, a condition whereby prolonged QT intervals are visible on the ECG.
Other lab studies
- Electrolytes levels to rule out hypokalemia, hypomagnesemia, and hypocalcemia.
- Cardiac enzymes
- Echocardiography to rule out structural heart disease
Treatment
Acute Treatment
If the episode of does not terminate on its own and degenerates into ventricular fibrillation, cardioversion is required.
Once the patient is back in normal sinus rhythm, a vigorous search for and correction of conditions that predispose to torsades de pointes which include hypokalemia, hypomagnesemia, and bradycardia should be made. Magnesium sulfate (1-2 g IV over 30-60 seconds) reduces the influx of calcium thereby lowering the amplitude of early after depolarizations and should also be infused even if the magnesium is normal. [3][4] Administration of lidocaine is generally not effective, but mexiletene may be helpful in suppressing the recurrence of torsade de pointes.
Additional Information
Examples
EKG's shown below are courtesy of C. Michael Gibson MS MD, and copylefted
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12 lead EKG at admission
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Examples from different resources
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Arrhythmias in a patient with short coupled torsade de pointes[5]
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Arrhythmias in a patient with short coupled torsades de pointes degenerating in ventricular fibrillation[5]
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A 12 lead ECG recording example of TdP[6]
References
- ↑ Chou's Electrocardiography in Clinical Practice Third Edition, pp. 398-409.
- ↑ Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:194 ISBN 1591032016
- ↑ Hoshino K, Ogawa K, Hishitani T, Isobe T, Eto Y (2004). "Optimal administration dosage of magnesium sulfate for torsades de pointes in children with long QT syndrome". J Am Coll Nutr. 23 (5): 497S–500S. PMID 15466950. Unknown parameter
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ignored (help) - ↑ Hoshino K, Ogawa K, Hishitani T, Isobe T, Etoh Y (2006). "Successful uses of magnesium sulfate for torsades de pointes in children with long QT syndrome". Pediatr Int. 48 (2): 112–7. doi:10.1111/j.1442-200X.2006.02177.x. PMID 16635167. Unknown parameter
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ignored (help) - ↑ 5.0 5.1 5.2 5.3 Leenhardt A, Glaser E, Burguera M, Nuernberg M, Maison-Blanche P, and Coumel P. Short-coupled variant of torsade de pointes. A new electrocardiographic entity in the spectrum of idiopathic ventricular tachyarrhythmias. Circulation 1994 Jan; 89(1) 206-15. PMID 8281648
- ↑ Khan IA. Twelve-lead electrocardiogram of torsade de pointes Tex Heart Inst J. 2001; 28 (1): 69. PMID 11330748