Second Degree AV Block (Mobitz type II)



P wave

Normal with constant P-P intervals


Usually widened because this is usually associated with a bundle branch block.


P-R interval may be normal or prolonged, but it is constant until one P wave is not conducted to the ventricles.


Usually regular when AV conduction ratios are constant

This block usually occurs below the Bundle of His and may progress into a higher degree block.

It can occur after an acute anterior MI due to damage in the bifurcation or the bundle branches.

It is more serious than the type I block.

Treatment is usually artificial pacing.