Pwave from .16 to .42?

  1. Anyone ever see this before? We were kinda stooped at work yesterday on this one. Pt had normal sinus rhythm with a pwave interval of .16. Then, went to a pwave interval of .42. Mind you, we realized this was a first degree block. But, the pt kept going in and out of this rhythm a few times. Eventually, pt converted back to normal sinus rhythm with the pwave at .16. We asked cardiologist about it. Couldn't really figure out what he said. Was this just a fluke thing? This was only showing up in one lead. Checked all leads, they were good. The Pwave was not inverted. Otherwise I would have gone with something like a junctional rhythm. Anyone familiar with this? I'm just curious because I have never seen this type thing happen before.
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    About mamason

    Joined: Sep '06; Posts: 574; Likes: 220
    Specialty: 5 year(s) of experience in cardiac


  3. by   hypocaffeinemia
    It happens all the time. Could be a transient second degree (type I), could be medication-induced heart block, could be a wandering pacer.

    As with any FLB (funky lookin' beats), it's best to clinically correlate your findings with the patient.
  4. by   richard1980
    If it's just showing up in 1 lead it's probably nothing.
  5. by   Cathlabnurse46
    was it consistant at .42 for several beats? how long did it last?

    Was it just a retrograde P (as you stated a junctional). Was it a WB? The SA has a recovery time (in EP called SNRT) in which the SA none in older hearts or deseased hearts can only recieve a signal so fast then it refuses to let out a P wave.... this is what is called a Weinke-Back. The SA node recovery acts as a gate for signal transmission and only "pulses" so fast until it "resets". What you might have seen was simply a Sinus arrest.

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