Hopefully your 2021 has started off on the right foot and you have put 2020 in the rearview. For the cardiovascular topic of 2021, I wanted to cover something that really gave me fits while I was in school and even in clinical practice……bundle branch blocks. We will review the electrical conduction system of the heart, the EKG criteria for diagnosing, and common conditions and pitfalls that are associated with these special types of dysrhythmias.