Link between cor pulmonale and RBBB

RBBB

• • The right ventricle is not directly activated by impulses travelling through the right bundle branch

  • The left ventricle however, is still normally activated by the left bundle branch

  • These impulses are then able to travel through the myocardium of the left ventricle to the right ventricle and depolarise the right ventricle this way

  • As conduction through myocardium is slower than conduction through the Bundle of His-Purkinje fibres the QRS complex is seen to be widened

  • The QRS complex often shows an extra deflection which reflects the rapid depolarisation of the left ventricle followed by the slower depolarisation of the right ventricle

Link with cir pulmonale

• • The right bundle branch is vulnerable to stretch and trauma for two-thirds of its course when it is near the subendocardial surface

Conditons

• • Chronically increased right ventricular pressure, as in cor pulmonale

    • May also be associated with electrocardiographic findings of right ventricular hypertrophy

  • A sudden increase in right ventricular pressure with stretch, as in pulmonary embolism

  • Myocardial ischemia, infarction, or inflammation (as in myocarditis)

ECG

• • Diagnostic Criteria

    • Broad QRS > 120 ms

    • RSR’ pattern in V1-3 (‘M-shaped’ QRS complex)

    • Wide, slurred S wave in the lateral leads (I, aVL, V5-6)

  • Associated Features

    • ST depression and T wave inversion in the right precordial leads (V1-3)

  • Variations

    • Sometimes rather than an RSR’ pattern in V1, there may be a broad monophasic R wave or a qR complex

Pictures