The Conduction Pathways of Broad Complex Tachycardias

The vast majority of broad complex tachycardias will have a ventricular origin. The spread of electrical activity through that ventricular myocardia obviously produces the QRS complex. But what's going on with the widened QRS of an atrial beat? Well, if the conduction through one of those bundle branches is interrupted or blocked, then that will either delay the transmission through those normal electrical pathways. Or it will force the wave of depolarization to pass through the myocardium outside of the normal conduction pathway. And both of those situations are going to lengthen the conduction time through the ventricles, again, resulting in a broader QRS Complex. This all