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Conduction Disorders
Conduction Disorders

Right Bundle Branch Block



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

    • 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
  • May be associated with ST depression / T wave inversion in V1 and V2
    • Causes of Right Bundle Branch Block

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