Heart block refers to a group of disorders characterized by variable conduction from the atria to the ventricles.
Heart block can be classified as
- 1st degree heart block – prolonged conduction across the atrio-ventricular node
- 2nd degree heart block – failure of SA impulse to activate the ventricular myocardium
- 3rd degree heart block – no conduction through AV node, and ventricular activation is due to an automatic subsidiary pacemaker focus (escape focus)