A stress echocardiogram is a combined exercise treadmill test with an echocardiogram. It is generally used in the diagnosis of coronary artery disease, but gives the additional information of left ventricular function (systolic and diastolic) and valvular abnormalities. Stress echocardiogram has similar sensitivity and specificity to Thallium scanning. It requires a high end cardiac echo machine which VCS has available along with well trained personnel with credentials and experience in the technique. It has the advantages over Thallium of avoiding radiation and gives additional physiologic information such as left ventricular function, right heart pressures and valvular function. It is also considerably cheaper than a Thallium scan. It is best suited to those who can exercise adequately and are not excessively obese. It is certainly the test of choice in young females in whom the specificity of routine treadmill testing is reduced.
How do I organise to have a Stress Echo?
A Stress Echo is generally obtained when a doctor wishes to confirm or rule out the presence of coronary artery disease. A Stress Echo is also performed in patients who have disease involving the heart muscle or valve, or if a patient is having inappropriate shortness of breath and a cardiac cause is suspected. You must have a referral from your doctor or specialist before the test can be performed. Stress Echoes are available at the VCS Glen Waverley and Melbourne City rooms. For appointments at Glen Waverley or City - phone 03 8521 3114 Please ensure you bring your referral to your appointment.
How does Stress Echo work?
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 its 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), ECG 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.
How is a Stress Echo performed?
A Stress Echo is made up of three parts: A resting Echo study, Stress test, and a repeat Echo while the heart is still beating fast. The patient first has a "resting" study performed. This provides a baseline examination and demonstrates the size and function of various chambers of the heart. Particular attention is paid to the movement of all walls of the left ventricle (LV). Similar to a regular echocardiogram test, sticky patches or electrodes are attached to the chest and shoulders and connected to electrodes or wires to record the electrocardiogram (ECG). The ECG helps in the timing of various cardiac events (filling and emptying of chambers). A gel is then applied to the chest and the echo transducer is placed on top of it. The echo technologist then makes recordings from different parts of the chest to obtain several views of the heart. You may be asked to move from your back and to the left side. Instructions may also be given for you to breathe slowly or to hold your breath. This helps to obtain higher quality pictures. The images are constantly viewed on the monitor. 12 leads of the ECG are recorded on paper and the blood pressure is taken. Exercise is then started using a treadmill. Exercise is started at a slower warm-up speed. The speed of the treadmill and its slope or inclination is increased every 3 minutes. The treadmill is stopped when the patient exceeds 85% of the target rate (based upon the patient's age). Exercise may be stopped earlier if the patient develops symptoms such as chest discomfort, marked shortness of breath, weakness, dizziness, etc., or if there is dangerous elevation or drop in the blood pressure, significant ECG changes or a potentially dangerous irregular heart rhythm. Please remember that you have a Cardiologist in attendance. The above problems are uncommon and you are far safer if they occur in the presence of an experienced medical team rather than having them happen while you are exercising in a gym, jogging, or running up a flight of office stairs.
ECG recordings are made during and after exercise. Blood pressure is recorded during exercise. Immediately after stopping the treadmill, the patient moves directly to the examination table and lies on the left side. The Echo examination is immediately repeated. Images are stored and then played back by the screen. A video clip of multiple views of the resting and exercise study are compared side-by-side. They are analysed and then reported by the Cardiologist.
Preparing for the Stress Echo Test:
1. Please fast for at least one (1) hour prior to the test. This reduces the likelihood of nausea that may accompany strenuous exercise after a heavy meal. Diabetics, particularly those who use insulin, will need special instructions from their doctor.
2. Bring shoes suitable for walking and wear comfortable clothes such as tracksuit or similar.
3. Please refer to the medication list below for instructions about ceasing medication prior to your test
MEDICATIONS TO STOP AND WHEN TO STOP - Unless instructed otherwise by your referring doctor.
ALL BETA BLOCKERS (β-blockers):
|Atenolol||(Anselol, Atehexal, Noten, Tensig, Tenormin)||36 hours|
|Oxeprenolol||(Corbeton, Trasicor)||36 hours|
|Pindolol||(Barbloc, Visken)||36 hours|
|Propanolol||(Deralin, Inderal)||36 hours|
|Timolol Maleate||(Biocadren)||36 hours|
|Labetolol||(Presolol, Trandate)||36 hours|
|Carvedilol||(Kredex, Dilatrend)||36 hours|
|Metaprolol||(Betaloc, Lopresor, Metohexal, Metral)||36 hours|
|Sotalol||(Sotacor, Sotahexal, Cardol)||36 hours|
ALL CALCIUM ANTAGONISTS:
|Verapamil||(Anpec, Anpec SR, Verahexal, Cordilox SR, Isoptin SR, Veracaps SR)||36 hours|
|Diltiazem||(Auscard, Cardeal, Coras, Diltahexal Isoptin, Isoptin SR, Veracaps SR, Diltzem SBPA, Diltiazem, Cardizem CD)||36 hours|
|Felodipine||(Agon, Felodur, Plendil)||36 hours|
How long does the entire test take?
You should allow 45min 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. As noted earlier, 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. You should discuss with your doctor for alternative test if you are unable to walk on the treadmill or has an active back problem.
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 when the test is absolutely normal.
How long does the written report take?
Your doctor will generally receive the report within 3-4 working days after the test is performed, however in urgent cases a report can be given directly to your doctor over the phone or a written report can be available within 24hrs.
How much will it cost?
Please ask the secretary at the time of making the appointment. VCS does not bulk bill, however we do offer a discounted rate for pensioners and healthcare cardholders with valid cards.