ECG Findings Explained
Polymorphic Ventricular Tachycardia
Torsades de pointes is a Polymorphic Ventricular Tachycardia. Note that the QRS complexes vary in height, width, shape, and axis.
Twisting of the Pointes
A characteristic finding of torsades de pointes is a recurring reversal of waveform polarity. The gradual alteration in polarity gives the appearance of QRS complexes twisting around the baseline in a spindle-like fashion.
Associations
Torsades de pointes is associated with QTc prolongation. Other common etiologies include electrolyte disturbances (e.g., hypokalemia, hypocalcemia, hypomagnesemia) and medication side effects (e.g., quinidine, amiodarone).
Pitfalls
The rapid and gradual alteration of QRS complexes can be mistaken for ventricular fibrillation. Ventricular fibrillation, however, is completely chaotic without any discernible pattern or similarity between adjacent waveforms.
Summary
The main ECG findings that occur with torsade des pointes include:
Polymorphism of QRS complexes
Progressive changes in height, width, shape, and axis
Recurring reversal of waveform polarity
Video Lecture