Cardiovascular Medicine Book




P Wave

Aka: P Wave
  1. Findings: Normal
    1. Upright: I, II, avF, V4, V5, V6
    2. Inverted: aVR
    3. Variable: III, avL, V1, V2, V3
  2. Causes: P Wave Inversion (other than aVR)
    1. Ectopic atrial focus
    2. AV nodal rhythm
  3. Causes: High Amplitude - Atrial hypertrophy or atrial dilatation
    1. Mitral valve or tricuspid valve disease
    2. Hypertension
    3. Cor Pulmonale
    4. Congenital Heart Disease
  4. Causes: Low Amplitude (short P Wave)
    1. Hyperkalemia (associated with a tall T Wave)
  5. Causes: Wide P Wave (over .11 sec)
    1. Left atrial enlargement
  6. Causes: Biphasic P Wave (second half negative in III or V1)
    1. Left Atrial Enlargement
  7. Causes: M shaped or notched P Wave
    1. M-Mitral: Left atrial enlargement
    2. Findings
      1. Over 0.04 seconds between peaks
      2. Taller in I than in III
  8. Causes: Peaked P Wave
    1. P-Pulmonale: Right atrial enlargement
    2. Findings
      1. Tall and pointed
      2. Taller in Lead III than in I
  9. Causes: P Waves absent
    1. Precaution
      1. Look closely for regularly spaced "artifact" on the ekg (e.g. low voltage P Waves)
    2. Atrial Fibrillation or Atrial Flutter
    3. Sinoatrial node block
    4. AV Nodal rhythm

P wave feature (C0429084)

Definition (NCI) An electrocardiographic finding of the current of atrial contraction when they are depolarized. The initial portion of the P wave is largely a reflection of right atrial depolarization and the terminal portion reflects depolarization of the left atrium.
Concepts Organism Attribute (T032)
SnomedCT 142070006, 33405001
LNC MTHU024602
English p wave, p waves, P Wave, P wave (observable entity), P wave, P wave feature (observable entity), P wave feature
Spanish onda P (entidad observable), onda P
Derived from the NIH UMLS (Unified Medical Language System)

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