Torsades de pointes

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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.

1 Causes
2 Treatment
3 History and terminology
4 References

[edit] 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
- Familial long QT syndrome
R on T PVCs

[edit] Treatment

Acute treatment is with withdrawal of the offending agent (if related to medication - such as Class 1A anti-arrhythmic drugs), infusion of magnesium sulfate, defibrillation/cardioversion (however, it is frequently refractory to cardioversion) and antiarrhythmic drugs.

[edit] 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, when he observed this rhythm disorder in an 80-year-old female patient with complete intermittent atrioventricular block.