002 Sinus Rhythm, atrial rate 90 Mobitz II - Blaufuss Multimedia

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146 Ventricular Tachycardia, rate 135
A-V Dissociation with Fusion (atrial rate 78)
Note: Wide complex tachycardias are often difficult to diagnose with certainty, but if A-V
dissociation and fusion beats are present, the diagnosis of ventricular tachycardia is assured,
as in this example. The fusion beats can be found in the V1 rhythm strip by looking for
narrower QRS complexes with shallower T waves: beats 4, 11, and 16. A-V dissociation can
be found by looking for P waves that are not obscured by QRS complexes (marked with
arrows below the rhythm strip). Hidden P waves can be found by setting the calipers for an
observed P-P interval, then swiveling forward and backward to look for distortion of the QRS or
T wave. Fusion beats will represent participation in the depolarization from ventricular and
supraventricular foci. In the Ladder, beats of ventricular origin are designated by asterisks (*)
and upward arrows, while fusion beats are shown by colliding arrows in the ventricular column.
146: P waves are marked with thin arrows at the bottom of the figure, and obscured P waves
can be plotted by setting the calipers for observed P-P intervals and dividing by 2.
The spectrum of A-V Dissociation is illustrated with Ventricular Tachycardia highlighted.