https://en.wikipedia.org/wiki/Second-degree_atrioventricular_block#Type_2_(Mobitz_II/Hay) https://www.healio.com/cardiology/learn-the-heart/cardiology-review/topic-reviews/second-degree-type-ii-av-block Second-degree Atrioventricular block https://www.youtube.com/watch?v=8EwiZHOOoPQ
