Describe the third-degree AV block (complete heart block).
Description
Third-degree AV block is a complete block with no conduction between the atria and ventricles.
P waves and QRS complexes have their own regular rhythm but bear no relationship to each other (AV dissociation).
Risk of progression to cardiogenic shock or cardiac arrest: High; Sudden onset 3° AV block can result in ventricular asystole, which lasts until an escape rhythm takes over.
Escape rhythms: can be generated by sites that are usually located near the AV node or near the bundle of His.
Ventricular escape rhythm [11]
A rhythm generated at the level of the bundle of His
Heart rate 20–40/minute
Wide QRS complexes
Junctional escape rhythm [11]
A rhythm generated at the level of the AV node
Heart rate 40–60/minute
Narrow QRS complexes
Idiopathic paroxysmal AV block [12]
A subtype of third-degree AV block that can affect patients with otherwise normal AV conduction.
Recurrent episodes may lead to Stokes-Adams attacks.
DDs in general?
Left bundle branch block
Right bundle branch block
Left anterior fascicular block
Left posterior fascicular block
Sinus node dysfunction
Last changed2 years ago