Abnormal Q waves

Morphology
1. QR Wave
2. Qr Wave
3. QS Wave
  1. Also due to LBBB, LVH, cor pulmonale or cardiomyopathy
    1. V1 to V3
4. qR Wave
Normal Q waves
1. rapid depolarisation of thin septal wall between two ventricles
2. Maybe found in most leads
3. very short and low amplitude
4. Lead III, aVR, V1
Location
1. Lead V2 & V3
2. Leads I, II, aVL, aVF, or V4 to V6
  1. > or = 0.03 sec
  2. 2 contiguous leads
3. Lead V4
  1. > 1mm deep or at least 0.02 sec or > Q wave in V5
4. Lead aVL
  1. > 0.04 sec or > 50% amplitude of QRS complex with upright P wave
5. Lead III
  1. > or = 0.04 sec
Q Wave Equivalents
1. tall R waves in leads V1 & V2
  1. Posterior infarction
2. Poor R wave progression
  Annotations:
  - localised R wave diminution
  1. localised R wave diminution
3. reverse R wave progression
  1. R waves decrease in amplitude from V1 to V4
dead or necrotic tissue act as an "electrical window" transmitting depolarising forces (R wave) from opposite position of heart
1. Completely developed in 8-12 hours of occulsion
2. 10% patients don't develop until 3-11 days after MI

Resource summary

	Created by drmjmurphy over 11 years ago