pacemaker vs cardiac pacemaker

pacemaker and cardiac pacemaker both are nouns.

Word	Noun	Adjective	Verb	Adverb
pacemaker	Yes	No	No	No
cardiac pacemaker	Yes	No	No	No

As nouns, pacemaker and cardiac pacemaker are synonyms defined as:

pacemaker and cardiac pacemaker: a specialized bit of heart tissue that controls the heartbeat

Other synonyms of pacemaker include SA node, sinoatrial node.

pacemaker (noun)	cardiac pacemaker (noun)
a horse used to set the pace in racing	a specialized bit of heart tissue that controls the heartbeat
an implanted electronic device that takes over the function of the natural cardiac pacemaker
a specialized bit of heart tissue that controls the heartbeat
a leading instance in its field