Detection of Coronary Stenosis With Intravenous Microbubbles

Inclusion Criteria: * subjects scheduled for routine echocardiogram to look for evidence of Coronary artery disease or a stress echocardiogram * women of child-bearing potential must be taking a medically approved form of birth control with a negative urine pregnancy test * be conscious and coherent, and be able to communicate effectively with study personnel * last eight patients will be diabetics who smoke * provide informed consent after receiving a verbal and written explanation of the purpose and nature of the study Exclusion Criteria: * severe valvular heart disease by Doppler Echocardiography * females of child-bearing potential who are not taking a medically approved method of birth control will be excluded. If the patient is pregnant she will be excluded. * patients who are allergic to blood or blood products will be excluded * have contraindication to Optison, Definity, or PESDA (pulmonary HTN, cardiac shunt) * non diabetics, non smokers