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Right Bundle Branch Block



Right bundle branch block occurs due to failure of conduction down the right bundle, resulting in slowed right ventricular depolarisation.


  • Causes of Right Bundle Branch Block

  • Right ventricular hypertrophy
  • Pulmonary embolism
  • Rheumatic heart disease
  • Ischaemia


  • ECG Findings

  • Wide QRS >120ms (complete BBB) or 110-120ms (incomplete BBB)
  • Added R wave in right precordial leads (R') - RSR' pattern in leads V1 or V2
  • Slurred S wave in lateral leads - S wave duration > R wave duration (or >50ms) in leads I, V5 and V6
  • Diagnosis
May be associated with ST depression / T wave inversion in V1 and V2
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