Suspected ischemic heart disease (IHD) or coronary artery disease (CAD) is commonly diagnosed by stress testing where patients undergo exercise tests in order to make their hearts work hard and beat fast to require more blood and oxygen. Pharmacological-induced stress is employed in the case where the patient is unable to exercise. Since plaque-narrowed arteries cannot supply enough oxygen-rich blood to meet the heart's needs, the stress test can show signs and symptoms of IHD. Some of the symptoms include abnormal changes in the heart rate or blood pressure, shortness of breath, chest pain, or abnormal changes in the heart's rhythm and electrical activity.