right axis deviation

Introduction

ECG axis between +90 to +180

Using only ECG lead I & ECG lead II, between +90 to +120

Etiology

• right ventricular hypertrophy (most common)
  • cor pulmonale
    • pulmonary embolism
  • atrial septal defect
  • pulmonic valvular stenosis
• myocardial infarction (lateral or anterolateral wall)
• accessory pathway (WPW, left free wall location)
• left posterior fascicular block
• uncommon causes
  • tricyclic antidepressant (TCA) overdose
  • left pneumothorax
  • normal variant (young & tall, slender adults)