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