Chest pain is not a symptom you should ever ignore, for obvious reasons. Chest pain, as almost anyone knows, may indicate a cardiac problem. For this reason alone, if you have chest pain you should be evaluated by a doctor.
Definition of cardiac muscle. : the principal involuntary-muscle tissue of the vertebrate heart made up of striated fibers joined at usually branched ends and functioning in synchronized rhythmic contraction.
Cardiac muscle is found only in the heart. The word cardiac is an adjective specific to the heart, for example cardiac arrest is a heart attack. Cardiac muscle is special because it has large cells with a single nucleus unlike skeletal muscle and cardiac muscle cells are branched with intercalated discs connecting them.