Torsade de Pointes: Difference between revisions

Torsade de pointes is a ventricular tachycardia associated with a [[Conduction#The_QT_time|long QT interval]] on the resting ECG. Torsade de pointes is typically 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, ther 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. During Torsades de pointes the ventricles depolarize in a circular fashion resulting in QRS complexes with a continuously turning heart axis around the baseline (hence the name ''Torsade de Pointes''). Read the chapter on the [[Long_QT_syndrome|Long QT Syndrome]] for an list of causes. Also, a more rare form of [[short coupled Torsades de Pointes]] has been observed.<cite>Leenhardt</cite>