So these are the manoeuvres discussed in the comment thread to the previous post: http://epfellow.posterous.com/update-to-narrow-complex-tachycardia
What manoeuvres in sinus rhythm can be used to suggest a cause of narrow complex tachycardia?
Incremental atrial pacing – to expose 'latent' preexcitation, and suggest dual AV nodal physiology
Atrial extrastimuli – to expose dual AV nodal physiology, AV nodal echoes
ParaHisian pacing – reveal the presence of a concealed septal pathway
Incremental ventricular pacing – pattern of retrograde activation (e.g. left lateral pathway 1st in distal CS, right free wall first in HRA catheter); minimal decrement in VA intervals before VA block suggesting a concealed bypass tract
Ventricular extrastimuli – assess whether VA conduction is decremental with similar implications to above
Differential ventricular pacing – VA interval at the RV base is usually < VA interval at the RV apex in the presence of a septal pathway
With that in mind....
Figure 1: Incremental ventricular pacing
Figure 2: Single Atrial extrastimulus
Figure 3: Double Atrial extrastimuli
Figure 4: Theory for the manoeuvre in Figure 5
Figure 5: RV pacing from the base and the apex
What would you do now since tachycardia was not able to be induced?
(Thanks again to Eraldo Moraes for the hard work he put into this case).
