Third Degree AV Block or Complete AV Block
Complete block of the atrial impulses occurs at the A-V junction, common bundle or bilateral bundle branches.
Another pacemaker distal to the block takes over in order to activate the ventricles or ventricular standstill will occur.
May be caused by:
- digitalis toxicity
- acute infection
- MI and
- degeneration of the conductive tissue.
Treatment modalities include:
- external pacing and atropine for acute, symptomatic episodes and
- permanent pacing for chronic complete heart block.
In a third degree heart block, the P waves are "married" to the QRS complexes.