Cannon A Waves on Neck Examination Cannon a waves! Notice that it occurs randomly, not predictably w/ the cardiac cycle or respiration. Cannon a waves indicate AV dissociation: 3rd deg AV block, or, as this case, VVI (asynchronous) pacing. The patient had a dual-chamber PPM set for DDI and an atrial tachycardia much faster than the PPM’s max tracking rate. Vivek Kulkarni MD @VivekKulkarniMD #CannonA #AWaves #Neck #PhysicalExam #JVP #Clinical #Video #Cardiology
