Angina pectoris is a disease characterized primarily by subjective clinical phenomena. There is pain in the left side of the chest, occasionally with radiation of pain down the left arm. Objective clinical methods for the recognition of this disease are generally lacking, so that the patient's complaints must determine the diagnosis. Obviously, if other diseases exist that may give the same type of pain, careful differentiation must be attempted to avoid condemning those suffering with benign ailments to the rigid regimen of the anginal patient. The importance of this differentiation is exemplified by a patient seen in 1929 for a pain in the cervical spine. This man had been confined to bed for several weeks because of a supposedly bad heart. The internist had found no objective evidence of cardiac dysfunction, but. since the patient complained of severe pains in the precordium, at times stabbing in character and often associated