68 year old male with syncope.
Question 1: Why do some of the T waves look different than others?
Question 2: Where in the conduction system does the second PAC fail to conduct?
Question 3: Why does one of the PACs conduct while the other PACs do not?
-Premature atrial contractions (intermittently blocked)
-Atrial premature complexes
-Low voltage, limb leads
Question 1: The PACs occur during the T wave and distort the normal appearance of the T waves.
Question 2: AV node.
Question 3: The conducted PAC falls outside of the refractory period of the AV node. The blocked PACs fall within the refractory period of the AV node.