cardiac murmur vs heart murmur

cardiac murmur and heart murmur both are nouns.

Word	Noun	Adjective	Verb	Adverb
cardiac murmur	Yes	No	No	No
heart murmur	Yes	No	No	No

As nouns, cardiac murmur and heart murmur are synonyms defined as:

cardiac murmur and heart murmur: an abnormal sound of the heart; sometimes a sign of abnormal function of the heart valves

Other synonyms of cardiac murmur include murmur.

cardiac murmur (noun)	heart murmur (noun)
an abnormal sound of the heart; sometimes a sign of abnormal function of the heart valves	an abnormal sound of the heart; sometimes a sign of abnormal function of the heart valves