Abnormal QRS direction in V!-V2
Predominant R wave in V1 (R/S ratio >1)
- Normal variant (infant and young children, 1% in adult)
- RVH (Right ventricular hypertrophy)
- RBBB (Right bundle branch block)
- IVCD (Intraventricular conduction defect)
- True posterior MI
- WPW (Wolff-Parkinson-White syndrome)
- Massive pleural effusion or pneumothorax causing rightward displacement of the heart.
Anterior rotation
- Normal variant (R/S >1 in V2 in 8-10% in adult)
- RVH (Right ventricular hypertrophy) may cause both anterior or posterior rotation
- RBBB (Right bundle branch block)
- IVCD (Intraventricular conduction defect)
- True posterior MI
- WPW (Wolff-Parkinson-White syndrome)
- Massive pleural effusion or pneumothorax causing rightward displacement of the heart.
Poor R wave progression
- Normal variant
- Lead misplacement
- Anteroseptal and anterior MI
- LBBB
- LVH
- Dilated cardiomyopathy
- LAFB (Left Anterior Fasicular Block)
Posterior rotation
- Normal variation
- Lead misplacement
- RVH (Right Ventricular Hypertrophy) from COPD or emphysema
- Hyperinflate lung condition such as COPD or emphysema
- Anterior MI
- Dilated cardiomyopathy
- LAFB (Left Anterior Fasicular Block)