Please review the following animated video tutorial of Idioventricular Rhythm.  There is an optional audio file which may be utilized at the same time. Optional

It occasionally occurs that the SA node ceases to function, as well as the AV node and junction, all tissues of the atria become electrically silent.

Please see the animated video below with optional audio covering Idioventricular Rhythm.  The audio may be played simultaneously with the video.  Video is best viewed