Patients with coronary artery blockages may have minimal or no symptoms during rest. However, symptoms and signs of heart disease may be unmasked by exposing the heart to the stress of exercise. During exercise, healthy coronary arteries dilate (develop a more open channel) than an artery with a blockage. This unequal dilation causes more blood to be delivered to heart muscle supplied by the normal artery. In contrast, narrowed arteries end up supplying reduced flow to it's area of distribution. This reduced flow causes the involved muscle to "starve" during exercise. The "starvation" may produce symptoms (like chest discomfort or inappropriate shortness of breath), EKG abnormalities and reduced movement of the heart muscle. The latter can be recognized by examining the movement of the walls of the left ventricle (the major pumping chamber of the heart) by Echocardiography.
Sticky patches or electrodes are attached to the chest and shoulders and connected to electrodes or wires to record the electrocardiogram (EKG or ECG). The EKG helps in the timing of various cardiac events (filling and emptying of chambers). EKG is recorded and the blood pressure is taken as the patient Exercises using a treadmill.
Immediately after stopping the treadmill, the patient moves directly to the examination table and lays on the left side. The Echo examination is immediately repeated. Images are stored and then played back by the computer. A video clip of multiple views of the resting and exercise study are compared side-by-side. They are analyzed by the physician. Normally, one expects an increased EF or ejection fraction (a measure of how well the heart is pumping). Also, the LV walls do not show any exercise-induced abnormal movement. In contrast, a drop in EF and/or a new wall motion abnormality is an indicator of disease.
You can have a light meal with a drink the day of the test but no caffeine (no tea, coffee, chocolate, soda pop).
You should bring comfortable exercise clothing and shoes (preferably running shoes) appropriate for exercising on a treadmill.
Bring a list of all active medications.
Your physician may decide to temporarily stop certain heart medications prior to the test. These are discontinued because they may affect the accuracy of the test. Your physician MUST inform you whether to discontinue these heart medications 48 hours prior to the test. DO NOT STOP any medication on your own without checking with your physician. You may resume taking your medications following the exercise test. Get directions from your physician.
An explanation of the test is provided and the patient is asked to sign a consent form.
A written report will be sent to your physician upon completion of analysis of the test. Your physician will then explain the test results to you.
How long does the entire test take? A patient should allow 1 1/2 to 2 hours for the entire test, including the preparation, echo imaging and stress test.
How safe is a Stress Echo test? There are no known adverse effects from the ultrasound used during Echo imaging. The risk of the stress portion of the test is rare and similar to what you would expect from any strenuous form of exercise (jogging in your neighborhood, running up a flight of stairs, etc.). Experienced medical staff is in attendance to manage the rare complications like sustained abnormal heart rhythm, unrelieved chest pain or even a heart attack. These problems could potentially have occurred if the same patient performed an equivalent level of exercise at home or on a jogging track.
What is the reliability of Stress Echo? If a patient is able to achieve the target heart rate and if the ECHO images are of good technical quality, a Stress Echo is capable of diagnosing important disease in more than 85% of patients with coronary artery disease. Also, it can exclude important disease in more than 90% of cases when the test is absolutely normal.
Apr 22, 2017 Healthy Heart Day
Cambridge Cardiac Care is located in the heart of Waterloo Region in downtown Cambridge.
Cambridge Cardiac Care serves patients throughout southwestern Ontario, including Cambridge, Kitchener, Waterloo, Guelph, Brantford, Paris, Fergus, Elora, Elmira, Owen Sound, Kincardine, and Stratford.