Common Diagnostic Criteria for Left and Right Atrial Abnormalities

Left Atrial Abnormality

  • Prolonged P wave duration of >120 msec in lead II
  • Prominent notching of the P wave, usually most obvious in lead II, with an interval between the notches of >40 msec (p mitrale)
  • Ratio between the duration of the P wave in lead II and the duration of the PR segment of >1.6
  • Increased duration and depth of the terminal negative portion of the P wave in lead V1 (the P terminal force) so that the area subtended by it exceeds 0.04 mm-sec (Morris index)
  • Leftward shift of the mean P wave axis to between -30 and +45 degrees

Right Atrial Abnormality

  • Peaked P waves with amplitudes over 250 muV in lead II (p pulmonale)
  • Rightward shift of the mean P wave axis to above 75 degrees
  • Increased area under the initial positive portion of the P wave in lead V1 to >0.06 mm-sec

 

 

References:

  1. Edhouse J, Thakur RK, Khalil JM. ABC of clinical electrocardiography. Conditions affecting the left side of the heart. BMJ. 2002 May 25;324(7348):1264-7. [Medline]
  2. Harrigan RA, Jones K. ABC of clinical electrocardiography. Conditions affecting the right side of the heart. BMJ. 2002 May 18;324(7347):1201-4. [Medline]

Created: January 04, 2006