Sunday, October 22, 2017

Pacemaker failure: Failure to Sense

The pacemaker is not sensing the intrinsic rhythm and firing after the QRS complex.


  1. Rather than not sensing the intrinsic rhythm, this looks like it is sensing the wrong rhythm. The ventricular pacer fires a fixed time after both sinus QRS complexes and PVCs, so I think the pacer is sensing the QRS as a P-wave and ignoring the sinus P-waves. True, it's not inhibited by the QRS, but I think the bigger problem is the complex misidentification (?lead migration).

    1. Thanks for your insight Vince. The pacemaker was interrogated that day and was found to working properly. So, it may be that it was recognizing the complexes as you suggest.