If a patient develops back heart pain, it is usually a precursor of the following diseases: 1. The patient may be a precursor of cardiogenic diseases, such as when the patient develops coronary atherosclerotic heart disease, unstable angina, myocarditis, pericarditis, infective endocarditis, heart valve disease, hypertrophic obstructive cardiomyopathy, congenital heart disease, all of which will have pain at the undershirt as a precursor. 2. If the patient develops heart If a patient has a neurological disorder, such as a disorder of the vegetative nerves, pain in the undershirt may occur. 3. If a patient has a respiratory disease, such as a large pneumothorax, lung infection, or pleurisy, pain in the back and front of the undershirt may occur. 4. The symptoms of pain in the above mentioned areas may also be a precursor.