why do we see Cannon a waves in PSVT(AV node reentry loops)?
AVNRT is just a small circuit around the AV node, impulse generate from the atria and ventricle simultaneously, therefore p wave is embedded within QRS, signals to atria and ventricle are sent from AV node at the same time, which makes Atria and ventricle to contract simultaneously, pressure in the hearts rises to peak, transferring to SVC (IJV connects through SVC) and thus there are tall a waves in JVP