Heart Disease - Symptoms/Screening for Coronary Artery Disease (CAD)
- Blood cholesterol: Blood tests to monitor cholesterol levels are typically performed once every five years for adults between the ages of 20 and 35 if the levels are normal. After age 35, cholesterol tests are typically monitored every two years or every year depending on age, family history, test results, etc.
|Total cholesterol (mg/dL)||LDL cholesterol (mg/dL)||HDL cholesterol (mg/dL)|
|Ideal: Less than 200
Borderline high risk: 200-239
High risk: 240 and over
|Ideal: less than 130
Borderline high risk: 130-159
High risk: 160 or higher
|Ideal: 60 or higher
High risk: lower than 40
- Blood pressure: Blood pressure is usually taken during each office visit or other regular interval.
|(mm Hg)||Ideal||Normal||High Normal||Hypertension|
|Systolic (top number)||Less than 120||Less than 130||130-139||140 or higher|
|Less than 80||Less than 85||85-89||90 or higher|
*source: American Heart Association
- Chest x-ray: A chest x-ray images the heart and surrounding thoracic anatomy, shows heart size and shape, and reveals whether the heart is misshaped or enlarged due to disease. Abnormal calcification (hardened blockage due to cholesterol build up) in the main blood vessels and fluid in the lungs (possible indication of congestive heart failure) can also be seen. Chest x-rays can also be used to image pacemakers and artificial heart valves to check for correct positioning.
- Electrocardiogram (ECG or EKG): An electrocardiogram is a graphical record of the electrical activity of the heart. A normal ECG, in most cases, rules out the presence of other cardiac diseases. An abnormal ECG indicates the presence of a cardiac disease and further investigations are performed. An ECG can be beneficial in detecting the disease and sometimes even the extent of the disease.
- Stress test: A stress test involves taking an EKG before, during and after a treadmill workout to detect possible cardiac disease and/or damage, including the extent of CAD. However, false positive results are possible with stress tests. A stress test is typically performed on adults 40 years of age or older who are at high risk for CAD.
|This multi-slice CT image shows narrowing of the arteries (stonosis). Image courtesy of http://www.heartinformation.com|
- Fast/multi-slice CT scan: Fast/multi-slice spiral CT scan with ECG gating is a new non-invasive method of imaging the heart and coronary arteries. In some cases, ECG gated fast/multi-slice CT eliminates the need for conventional cardiac angiography which requires invasive catheterization. Fast/multi-slice CT is particularly useful in that it can show calcium deposits in the coronaries that form with plaque-build up and may eventually lead to myocardial infarction (heart attack). Early imaging of stenoses (narrowing of arteries) and calcium deposits in the coronary arteries can allow aggressive preventive measures or treatment to be implemented, thus lowering the risk of myocardial infarction.
|3D reconstructed heart showing coronary arteries in red, acquired with EBCT|
- EBCT has established itself as a very
fast, non-invasive means to image the heart and coronary arteries. EBCT eliminates the
need for catheterization and contrast injection which is required in conventional cardiac
angiography. EBCT is particularly useful in that it can show calcium deposits in the
coronaries. The calcium deposits form along with the plaque-build up and eventually lead
to heart failure. Early imaging of calcium deposits in the coronary arteries can allow
aggressive preventive measures to be implemented, thus lowering the risk of heart attack.
EBCT is a special type of computed tomography (CT) that uses a sweeping electron beam to create the rotating x-ray effect needed to make a computed tomography image. This makes EBCT different from conventional CT which has an x-ray tube mounted on a rotating frame. By using a sweeping electron beam, EBCT images can be acquired in as fast as 50 or 100 milliseconds, or some 10 times faster than the fastest slip-ring CT systems that can acquire an image in about 500 milliseconds. In order to image the beating heart and eliminate all image degradation caused by heart motion, image acquisition time must be in the 100 millisecond or faster range. In other words, a conventional slip-ring CT scanner can acquire one to two image per second while an EBCT system can acquire at a much faster rate of 10 to 20 images per second.
- Ambulatory monitoring: If no abnormality, disease or damage is detected and the patient still feels uneasy when performing stressful activities (such as climbing stairs) but feels okay under normal activity, then an ambulatory monitor may be used. An ambulatory monitor is a portable EKG system (often worn around the waist) that continuously monitors the hearts electrical activity.
Updated: February 29, 2008