Patients of the Duke Executive Health Program can elect to undergo one or more of the tests offered by the non-invasive vascular laboratory. We use painless ultrasound technology, to look directly at the anatomy and stress response of your arteries to detect past and current cardiovascular disease progression.

The total package requires approximately two-and-a-half hours to complete.

Carotid Artery Intimal-Medial Thickness

Carotid artery intimal-medial thickness (C-IMT) is a stable measure of vessel disease accumulation over the life span and can also identify focal plaques. C-IMT levels have been shown to predict cardiovascular events (heart attack and stroke).

In conjunction with research generating normative data based on age, race, and sex, you will receive a prediction of your 10-year risk of cardiovascular events.

We assess three sections of your carotid vessels -- the common, bulb, and internal arteries -- from several angles, to locate diffuse or asymmetrical wall thickening.

The picture on the left shows measurements of the top and bottom walls in the common carotid artery. This picture represents a mild accumulation of plaque. Severe plaque accumulations protrude into the vessel and can obscure blood flow to the brain.

Time required for test: About one hour

Endothelial Function Test

Endothelial function testing is a dynamic measure of arterial responsiveness designed to help determine if the switch for cardiovascular disease progression is on or off.

The lining (endothelium) of arteries performs many functions in protecting the artery from disease. One of these controls the size of the vessel.

We use ultrasonography to measure the change in size of an artery in your arm following a physical stress (increased blood flow). Healthy arteries respond better than those with vascular disease. The response in the arm has been shown to be reflective of the coronary arteries and predictive for future cardiovascular events.

The advantage of this test is that endothelial function can be reassessed following lifestyle or medication changes to observe a treatment effect on risk. For example on the graph to the right the bars represent flow-mediated dilation (FMD), the index used to assess endothelial function.

The first measurement (red bar) was low and indicated an impaired endothelium, potentially reflecting current progression of cardiovascular disease. Cholesterol lowering medication was initiated, leading to an improvement in endothelial function (green bar).

Time required for test: About one hour

Ankle Brachial Blood Pressure Index

This test uses blood pressures at your ankles and your arms to assess the flow of blood to the lower extremities. Lack of normal perfusion to the feet may indicate a condition known as peripheral vascular disease (PVD). PVD is a form of cardiovascular disease and can lead to leg pain and difficulty walking if left untreated. The results of this test will allow your doctor to determine if PVD is a potential problem for you.

Time required for test: About 30 minutes

Arterial Stiffness

Arterial stiffness is a measure of the rigidity of your vessels. With ageing and with cardiovascular disease, vessels deposit calcium and collagen, making them more rigid. We use applanation tonometry on your carotid, radial, and femoral arteries to measure the conformation and velocity of blood pressure pulse waves throughout your vascular system. Analysis of these waveforms provides us with information about workload on the heart, coronary perfusion, and aortic and systemic stiffness.

Time required for test: About 20 minutes (if done with endothelial function, no additional time required)