Mobitz type 1, Non-Weinkebach?

  1. Has anyone heard of a second degree heart block that is considered type 1 but not a weinkebach? I was taught in an EKG course that there is also a Mobitz type 1 called 2 to 1 conduction, where you have 2 p waves for every QRS. I know that in type 2 mobitz you can have multiple p waves and dropped beats, but the p waves that have an associated qrs will have a constant p-r interval and in weikebach the p-r gets longer and then drops. i just can't seem to find other nurses that have heard of this other mobitz type 1 that is called 2-1 conduction. Did my instructor make this one up?

    Last edit by LeLeeFNP on Feb 23, '10 : Reason: typo
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    About LeLeeFNP

    Joined: Sep '09; Posts: 231; Likes: 56
    Nurse Practitioner; from US
    Specialty: 6 year(s) of experience in ICU, CVICU, Surgical, LTAC


  3. by   VAJenny
    I am with you and the other nurses.. i dont think I have heard of anything different like that what is her rationale as to type 1 vs wenkeback
  4. by   EricJRN
    Wenckebach block is a synonym for a second-degree Mobitz I block. They are the same thing. I think she was confused or she might have been trying to say something a little different.

    If you have a consistent 2:1 ratio of P's to QRS's, you can't make the distinction between Mobitz I (Wenckebach) and Mobitz II.

    If you only have two P waves in every 'cycle' and only one of those P waves is followed by a QRS, it's impossible to say whether you have a consistent PR interval or a lengthening PR interval... which would be the difference between Mobitz I (Wenckebach) and Mobitz II.

    In other words, with 2:1 you can say that you have a second-degree block, but you can't specify which type of second-degree block (until you run into a cycle that is at least 3:2).
  5. by   chare
  6. by   KungFuFtr