According to Nerve
A nerve is an enclosed, cable-like bundle of nerve fibres called axons
Being an Axon
An axon (from Greek ἄξων áxōn, axis), or nerve fiber, is a long, slender projection of a nerve cell, or neuron, in vertebrates, that typically conducts electrical impulses known as action potentials
In the other hand,
The electrical conduction system of the heart transmits signals generated usually by the sinoatrial node to cause contraction of the heart muscle.
The conduction system consists of specialised heart muscle cells
Is this conduction system consisted of cells (which I assume also transmits electrical signals through axons) different in nature to nerves?