People with high blood pressure are more likely to develop coronary artery disease because high blood pressure puts added force against the artery walls. Over time, this extra pressure can damage the arteries making them more vulnerable to the narrowing and plaque build up associated with atherosclerosis. The narrowed artery limits or blocks the flow of blood to the heart muscle depriving the heart of oxygen. The hardened surface of the artery can also encourage the formation of small blood clots.

What Are the Symptoms of Atherosclerosis?

Atherosclerosis usually has no symptoms until the narrowed coronary arteries severely restrict blood flow to the heart. At this point, you may feel chest pain because not enough blood is reaching the heart. These pains may come with exertion or can occur when the person is at rest.

What Is a Heart Attack?

A heart attack is permanent damage to the heart muscle caused by loss of blood flow to the heart. A heart attack occurs when a clot or spasm blocks an already narrowed coronary artery. Left without oxygen, the portion of the heart muscle served by the blocked artery is injured.

How Is Atherosclerosis Diagnosed?

Atherosclerosis isn't usually diagnosed until a person complains of chest pain. At this point, the doctor may conduct tests to evaluate your risk for heart disease, including:

Electrocardiogram (EKG or ECG): This test measures the electrical activity, rate, and rhythm of your heartbeat via electrodes attached to your arms, legs, and chest. This test may show if you've had a heart attack in the past or if you are currently having a heart attack, strain, or thickening of the heart muscle. It can also convey information about the size of your heart as well. It cannot predict your future risk.
Exercise stress test: During this test you exercise on a stationary bicycle or treadmill to increase your heart rate while EKG readings are taken. This test is often performed with imaging of the heart, such as an echocardiogram or nuclear scans, to provide better detection of heart disease.
Cardiac catheterization: During this procedure, a catheter -- a small flexible tube -- is inserted into an artery and guided to the coronary arteries, allowing the doctor an opportunity to locate any blockages in the coronary arteries and observe pressure and blood flow in the heart. During a cardiac cath, a cardiologist may be able to open up clogged arteries directly from the inside with a procedure called an angioplasty. This may also involve placing a small metal mesh tube in the vessel called a stent.
Echocardiogram: This test sends ultrasound waves that provide pictures of the heart's valves and chambers, giving information about chamber size and wall thickness and how blood is flowing within the chambers.
Carotid ultrasound: This test sends ultrasound waves that provide pictures of blood flow in the arteries of the neck.
Computed tomography (CT) scan: An X-ray and a computer are used to construct a cross-sectional image of the heart.
Magnetic resonance arteriography (MRA): This test provides images of blood vessels to show where they may be blocked.