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Torsades de pointes is a medical condition, the name of which means in French "twisting of the points". The name is derived from a manoeuvre in ballet, similarly named. It is a potentially deadly form of ventricular tachycardia. On the electrocardiogram (ECG/EKG), it will present like ventricular tachycardia, but the QRS complexes will swing up and down around the baseline in a chaotic fashion, which prompted the name. The etiology of TdP (Torsades de pointes) is prolongation of the QT interval.
Causes
The primary cause for torsades de pointes is hypomagnesemia (low blood levels of magnesium). It is commonly seen in malnourished individuals like alcoholics, as chronic abuse of alcohol will lead to low levels of magnesium, calcium, thiamine, and other nutrients.
Factors that are associated with an increased tendency toward torsades de pointes include:
- Agents that increase the QT interval
- Hypokalemia
- Hypomagnesemia
- Hypoxia / acidosis
- Left ventricular dysfunction
- Heart failure
- Left ventricular hypertrophy
- Slow heart rate
- Female gender
- Long baseline QT interval
- R on T PVCs
Treatment
Acute treatment is with withdrawal of the offending agent (if related to medication - such as Class 1A drugs), infusion of magnesium sulfate, defibrillation/cardioversion and antiarrhythmic drugs.
History and terminology
The French term is largely due to the fact that the phenomenon was originally described in a French medical journal by Dessertenne in 1966.
References
- Dessertenne F. Ventricular tachycardia with two variable opposing foci. Arch Mal Coeur Vaiss 1966;59:263-72. PMID 4956181.
"Torsades de pointes"