The Treadmilll Exercise Echocardiograph (ExEcho) is usually ordered for Patients who are experiencing symptoms of chest discomfort, shortness of breath or palpitations (irregular heart beat). Often these symptoms are related to physical activity.
The ExECHO is used as a test for the detection of coronary artery disease (a build up of plaque in the blood vessels to the heart causing a partial or complete obstruction). It is more accurate than a regular Treadmill Exercise Test (TET). It combines the usual TET with ultrasound imaging of the heart.
Prior to the ExECHO an Allied Health Care Professional will take a brief history including medication history and symptoms, ask you about your risk factors (High blood pressure, Cholesterol level, Smoking, Diabetes, etc…) and then explain the test to you. You will then be examined to make sure there is no reason to cancel the ExECHO. Once this is completed you will be asked to read and sign a consent form. The staff will answer any questions relating to the consent form.
The Allied Health Care Professional will then prepare the skin so the Electrocardiogram (ECG) can monitor your heart rhythm continuously throughout the ExECHO without interference. For Men this involves shaving the skin, rubbing it vigorously with alcohol and then gently roughening the skin with special abrasive paper. For Women the skin still has to be rubbed with alcohol and gently roughed. Ten electrodes are then applied to the chest. The electrodes are placed in a different position than the regular TET so that the Echocardiographer can obtain good Ultrasound images of the heart.
During your ExECHO there are always 2 experienced Physicians immediately available. One of these Physicians is experienced in the interpretation of Echocardiography. All the necessary resuscitation equipment and emergency medications are readily available. The staff takes yearly Basic Cardiac Life Support (BCLS) certification. There are 2 Allied Health Professionals present throughout the test. The Kingston Heart Clinic has performed over 12,000 ExECHO studies.
Before the ExECHO your blood pressure and ECG will be recorded in the sitting and standing position. The Echocardiographer will then take the resting ultrasound images of the heart. The Chest will be marked with marker pen to accurately localize where the best images were obtained. You will be instructed to remember the position you were laying when these images were obtained. This position will need to be duplicated as closely as possible after exercise. You will be instructed on how to breath after exercise and the importance of getting into position quickly after the completion of exercise.
We are now ready to begin walking. Initially the treadmill will be flat and moving very slowly, the technician will help you coordinate your walking. During the ExECHO you will be asked, how you are feeling and your blood pressure will be recorded every 3 minutes. Your heart rhythm is monitored continuously and an ECG is taken every 3 minutes as a permanent record for the Physician to review. If you are experiencing any difficulties this must be related to your attending staff memeber immediately. During the ExECHO the speed and incline of the treadmill will progressively increase.
The ExECHO is a heart rate limited and symptom limited test. The target heart rate is 85% of your maximum predicted heart rate (220-Age in years) plus an extra 10 beats per minute. The test will stop if you develop symptoms or if you achieve this target heart rate, whichever occurs first. You may ask to discontinue the test at any time. The test may also be stopped because of changes in the ECG or blood pressure.
At the end of exercise the treadmill will be stopped abruptly and you must resume your pre exercise position immediately so the Echocardiographer can re-record the ultrasound images as quickly as possible.
The Echocardiographer has only 90 seconds to record the ultrasound images so speed is essential. The sooner the images are obtained the better the information.
At the completion of the ExECHO your clinical condition, blood pressure, and ECG will be monitored until everything returns to baseline. Once this has occurred a final set of ultrasound images are obtained.
At the Kingston Heart Clinic all ExECHOs are interpreted by the supervising Physician and a formal written report will then be mailed and received by your Doctor within 10 days. Tests which are significantly abnormal are interpreted immediately and FAXed to the referring Physician. If necessary, the patient will be interviewed and advice and/or drug therapy initiated.
Frequently, echocontrast, DEFINITY is used to enhance the ultrasound images. There are complications associated with DEFINITY (serious~1%, total ~9% including backpain, headache, nausea and flushing).