R Wave Progression
Normal QRS progression in chest leads
- QRS predominantly downgoing in V1
- QRS predominantly upgoing in V5 or V6
- There is a gradual increase in the R/S ratio from V1 -> V4
QRS predominantly upgoing in V1 (R/S ratio > 1) – differential diagnosis:
- QRS wide>0.12
- RBBB: V1 rSR'
- VT: fast, V1 not consistent with RBBB, typically no P-QRS relationship
- WPW: short PR, delta wave, V1 not consistent with RBBB
- BiV paced: pacer spikes in front of QRS complexes
- QRS narrow <.11
- RVH: T negative in V1, RAD, deep S waves in V5-V6, clinical picture (emphysema)
- Posterior MI: T upright in V1, inverted Ts in lateral and inferior leads, clinical picture (chest pain)
- Subtle preexcitation: short to short-normal PR, subtle delta wave
- V1-V3 lead reversal: R wave regression from V1 to V3, may be read as anterior MI, biphasic P wave in V3
- Normal Variant: no other signs of WPW, RVH, MI
QRS predominantly downgoing in V5 and V6
- QRS wide>0.12
- paced rhythm
- WPW
- VT
- paced rhythm
- QRS narrow <.11
- emphysema
- RVH
- LAFB
- lateral MI
- emphysema
Regression of R/S ratio in chest leads
- Possible anterior MI
- Severe emphysema, RVH
- Morbid obesity
- RBBB
- Dextrocardia
- Incorrect electrode placement