Mechanism:

• Hypertrophy of the right ventricular musculature as a consequence of systolic or diastolic overload

ECG characteristics:

• Often right axis
  
• P pulmonale (P wave in II, III > 0.3 mV)
  
• Positive Sokolow–Lyon index (RV1 + SV5 >1.05 mV)
  
• Right ventricular repolarization changes
  
• Right bundle branch block (possible)