sinoatrial block

A sinoatrial block is a disorder in the normal rhythm of the heart, known as a heart block, that is initiated in the sinoatrial node. The initial action impulse in a heart is usually formed in the sinoatrial node (SA node) and carried through the atria, down the internodal atrial pathways to the atrioventricular node (AV) node.

In normal conduction, the impulse would travel across the bundle of His (AV bundle), down the bundle branches, and into the Purkinje fibers. This would depolarize the ventricles ...