Carolinas Core Concepts Core Concepts in EM; a repository for Carolinas lecture summaries.


Littmann’s EKG Course: P waves

  • P-wave inversions in lead I are never normal.  Consider 3 common etiologies:
    1. Ectopic atrial rhythm - V1-V6 also reveal inverted P's from an abnormal depolarization site.
    2. Dextrocardia - V1-V6 show r-wave regression.
    3. Limb lead reversal - lead II shows a "flat line", repeat the EKG with a better tech.
  • Parkinsonian tremor and oscillators both can cause a 5hz artifact (300bpm) and are mistaken for aflutter.  Look for sinus rhythm in other leads.

    Parkinsonian tremor masquerading as artifact

    NSR seen in lead III with "flutter waves" in other leads. This patient has Parkinsons.

  • Always look for atrial flutter if the computerized interpretation on an EKG is any of these red flags; the computer routinely misinterprets flutter.
    1. "Sinus tachycardia with 1° AV block"
    2. "Sinus tachycardia with short PR"
    3. * cannot find p-wave axis
      Missed atrial flutter
      Look for the red flags!