Poor R wave progression refers to the absence of the normal increase in size of the R wave in the precordial leads when advancing from lead V1 to V6.
In lead V1, the R wave should be small. The R wave becomes larger throughout the precordial leads, to the point where the R wave is larger than the S wave in lead V4. The S wave then becomes quite small in lead V6.
Note that an old anterior myocardial infarction can cause poor R wave progression. In this setting, there is no R wave in the anterior precordial leads and instead Q waves are present; see Anterior Myocardial Infarction Topic Review.
The causes of PRWP are as follows:
Old anterior myocardial infarction
- Lead misplacement (frequently in obese women)
- Left bundle branch block or left anterior fascicular block
- Left ventricular hypertrophy
- Wolff-Parkinson-White syndrome
- Tension pneumothorax with mediastinal shift
- Congenital heart disease
1. Chou’s Electrocardiography in Clinical Practice: Adult and Pediatric, 6e
2. Surawicz B, et al. AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram. Circulation. 2009; doi:10.1161/CIRCULATIONAHA.108.191095.