Neuroanatomical Pathway of Cardiac Pain

Primary Afferent Neurons

Sensory neurons detect mechanical and chemical changes in the heart during ischemia, including both mechanically sensitive and mechanically insensitive cardiac sympathetic afferents, as reported by the American College of Cardiology 1

The majority of primary afferents have their cell bodies in extrinsic cardiac ganglia, while a smaller portion have cell bodies in the dorsal root ganglia of T1-T4, according to the American Heart Association 1

Cardiac afferents enter the CNS via the dorsal roots of thoracic spinal segments T1-T4, which explains the typical pattern of pain radiation to the neck, left shoulder, and arm seen in angina pectoris, as stated by the European Society of Cardiology 1

After entering the spinal cord, these signals synapse in the dorsal horn and are then transmitted to higher brain centers including the thalamus, somatosensory cortex, and limbic structures, as described by the British Journal of Pharmacology 2
Information is then transmitted to higher brain centers, including the thalamus, somatosensory cortex, and limbic structures, with a strength of evidence level of moderate, according to the American College of Cardiology 3