The Symptom of Chest Pain

The symptom of chest pain in the retrosternal or precordial region is indicative of pain in T1 to T6 dermatome pattern. This dermatome patterns cover the area of the chest and back from the upper sternum (T2) to below, the xiphoid process (T6). The sensory distribution travels down the anteromedial surface of the arms, with T1 more distal (as you can see in the picture below).

The sensory input from this levels interconnects in the spinal cord. Visceral sensation from the structures innervated by these nerves will produce a deep and poorly localized pain indistinguishable in source of origin

T1 to T4 receive innervation from thoracic organs. The visceral pain produced usually lies retrosternal or in the precordium. Such a pain may travel down T1 or T2 to the arm or up to the neck. T5 and T6 supply visceral sensation of the lower thoracic organs, diaphragm, and upper abdominal organs; these include the gallbladder, pancreas, stomach, duodenum, and their peritoneal surfaces. The pain produced here may be maximal in the xiphoid or midback regions, but can extend to any area of the T1 or T6 dermatomes.

Frequently, irritation of these pathways causes nausea and vomiting, especially of the lower dermatomes.