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Tachycardia: Difference between revisions
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→Torsades de Pointes
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[[Image:Torsades_de_Pointes.png|thumb|400px|Torsade de Pointes, preceded by bigemini.]] | [[Image:Torsades_de_Pointes.png|thumb|400px|Torsade de Pointes, preceded by bigemini.]] | ||
Torsade de pointes (TdP) is a ventricular tachycardia associated with a prolonged QTc interval on the resting ECG. The ECG is characterized by twisting of the peaks of the QRS complexes around the isoelectric baseline during the arrhythmia (changing axis). Torsade de pointes is initiated by a short-long-short interval. A ventricle extrasystole (first beat: short) is followed by a compensatory pause. The following beat (second beat: long) has a longer QT interval. If the next beat follows shortly thereafter, there is a good chance that this third beat falls within the QT interval, resulting in the R on T phenomenon and subsequent Torsades de pointes. | |||
=== | ===Causes of Torsade de Pointes=== | ||
*Aquired long QT syndrome (complete list of drugs causing long QT syndrome: | *Aquired long QT syndrome (complete list of drugs causing long QT syndrome: http://www.torsades.org http://www.torsades.org]) | ||
*Congenital long QT syndrome | *Congenital long QT syndrome | ||
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===Treatment=== | ===Treatment=== | ||
Electrocardioversion is the first treatment for TdP. | Electrocardioversion is the first treatment for TdP. | ||
Additional treatments are: | Additional treatments are: | ||
*Withdrawal of any offending drugs and correction of electrolyte abnormalities (potassium repletion up to 4.5 to 5 mmol/liter). | *Withdrawal of any offending drugs and correction of electrolyte abnormalities (potassium repletion up to 4.5 to 5 mmol/liter). | ||