QRS Patterns - ECG
The description of waves in QRS complexes is actually quite easy. There are just some rules that should be followed.
- Bigger amplitudes are marked with big letters and vice versa
- If the QRS complex starts with a negative wave, we mark it as Q (q). There can be only one Q (q) in the complex
- Positive waves are always marked as R (r)
- Negative wave following a positive wave is always marked as S (s)
- If there are more positive waves, then the first is marked as R (r), the second R' (r'), the third R''(r''), etc.
Some clinical significance can have the following patterns:
- rSr' occurs in V1 lead in incomplete RBBB
- rSR' occurs in V1 lead in complete RBBB
- QS located in more leads can be related to a post-infarction scar
- QS or rS in V1 combined with RsR' in V6 is typical for LBBB