Patients with coronary artery disease may experience anterior chest and back pain, which is called coronary atherosclerotic heart disease, and usually the anterior chest and back pain will be dominated by angina pectoris attacks. The pain is felt especially after physical exercise or after excessive emotional anxiety or stress. Patients may experience a distinct burning sensation behind the sternum or even throughout the precordial region, lasting for a few minutes or less, which can be relieved with nitroglycerin. If the patient’s symptoms do not improve significantly in 15 minutes, or if the pain lasts even longer, up to half an hour or even an hour, unstable angina is suspected, and the patient must immediately go to the hospital for consultation.