Bundle Branch Block

• Abnormal ventricular excitation as the result of blockage to the right bundle branch, the left bundle branch, or left anterior fascicular block.

Right Bundle Branch Block

Characterised by the failure or delay of conduction through the right bundle branch. Left ventricle is unaffected.

Causes

Pulmonary embolism, heart worm, electrolyte disturbances, congenital diseases etc.

ECG Appearance: Wide QRS complex, Wide S wave

Treatment

Treat the underlying cause

Left Bundle Branch Block

Characterised by the failure of conduction through the left bundle branch. Right ventricle is unaffected.

Causes

Congenital abnormalities, myocardial diseases etc.

Treatment

Treat the underlying cause

Left Anterior Fascicular Block=characterised by the failure of conduction through the anterior fascicle of the left bundle branch.

Causes: Electrolyte abnormalities, hypertrophic cardiomyopathy (cat), etc.

ECG Appearance: Normal QRS, tall R waves, deep S waves

Treatment: Treat the underlying cause