The study is designed to evaluate the predictive diagnostic accuracy of SonoMedica's CardioSond digital electronic stethoscope in the detection of coronary artery disease (CAD) in patients without known disease who are referred to cardiac computed tomography angiography (CT scans).

The CardioSond is a completely noninvasive medical device which detects heart sounds and murmurs using ultrasensitive acoustic technology. The CardioSond produces a flow micro bruit score which is used to determine the likelihood of coronary artery disease.

The CardioSond exam will be given to patients who agree to participate in the study upon signing of an informed consent form and prior to the administration of beta blocker agents and / or vasodilators as part of the normal cardiac CT angiography protocol.

CardioSond data will be sent to an independent acoustic core lab which will determine data quality and produce a flow micro bruit score. CT angiography data will be analyzed by staff at North Shore University Hospital.

A data review panel lead my the principal investigator will examine the results of both the CardioSond and CT angiography data to determine the accuracy of the CardioSond in detecting CAD in the study population at large and in specific patient subgroups.

Inclusion Criteria:

• Subjects who are undergoing routine screening coronary CT angiography
• Willingness to sign informed consent form

Exclusion Criteria:

• Inability to provide informed consent form
• Age less than 21 years
• Any contraindications to coronary CT angiography
• Known atherosclerotic heart disease, including a history of prior myocardial infarction, percutaneous coronary intervention, coronary artery bypass graft surgery or an established diagnosis of CAD by prior X-ray or CT angiography
• Supraventricular or ventricular arrhythmias that would be expected to affect CT-angiography image quality (e.g., atrial fibrillation, atrial flutter, ventricular tachycardia, bigeminy, and trigeminy). Patients with isolated premature atrial contractions and premature ventricular contractions may enroll.
• Use of intravenous vasodilators
• Any pulmonary conditions that would create abnormal physical findings that would interfere with the fidelity of the cardiac sound recording (e.g., obstructive pulmonary disease, such as asthma or COPD, with audible wheezing).
• Presence of audible aortic or pulmonic diastolic murmurs, tricuspid or mitral flow diastolic murmurs, or continuous murmurs

Study population will be sourced from patients presenting themselves for cardiac CT angiography who meet appropriate inclusion / exclusoin criteria.