Dobutamine Stress Echocardiogram
What is it?
It is a non-invasive stress investigation that involves the use of echocardiogram for individuals who are unable to exercise adequately on the treadmill. Instead of exercising on the treadmill, dobutamine will be given to you intravenously to make your heart pump as hard as if you were exercising.
An echocardiogram is a non-invasive imaging technique that enables your cardiologist to visualize how your heart pumps. It makes use of sound waves to produce moving images of your heart while it pumps blood around your body.
How it works
Before the test, the cardiac sonographer will spread gel and applies sticky patches (electrodes) on your chest wall. The sonographer will then apply a device (known as a transducer) on the gel, aiming an ultrasound beam against your heart at different angles in order to obtain a collective set of moving images of your heart produced by the computer. The moving images will be displayed on the monitor which you can see “live”.
Why do I need one?
After weighing the risks and benefits of this procedure, your Cardiologist would have determined on the basis of your condition that it is more beneficial for you to undergo this procedure.
This test is necessary to evaluate the function of your heart and valves while it undergoes “stress”. Your Cardiologist will be able to assess how your heart pumps and how your heart valves function while your heart exercises under the influence of dobutamine infusion.
Your Cardiologist can also assess the possibility you having any significant coronary artery disease (narrowed or blocked arteries).
What are the risks involved?It is generally a very safe procedure. However, there are a few risks involved: Bleeding and bruising around the puncture site (<5%). Allergic reaction to contrast (minimal risk). Major bleeding and bruising (<1%). Injuries to blood vessels at the puncture site, eg. pseudo-aneurysm, dissection etc (<1%). Major bleeding into the abdominal cavity (very rare). Heart attack or need for emergency bypass surgery (very rare). Stroke or mini-stroke (very rare).
How do I prepare for the procedure?You are required to fast (nothing to eat or drink) for at least 6 hours prior to the procedure. For diabetics: Please do not take your diabetic medications in the morning of your procedure. Please do not take metformin for 48 hours after the procedure.
What can I expect when I am transferred to the cardiac catheterization laboratory (cath lab) for the procedure?You may occasionally be given a sedative, either orally or through an intravenous line just before the procedure to help you relax. You will, however, still be awake during the procedure. The cath lab is a specialised X-ray suite where your coronary angiogram is performed by your interventional cardiologist, assisted by specialised cardiac scrub nurses. The puncture site (your wrist and /or groin) will be cleaned with an antiseptic solution and thereafter, a sterile drape will be used to cover you.
What can I expect during the procedure?The catheter will be passed to the coronaries in your heart via arteries in the arm, or via the aorta if the groin approach is taken. If your artery in your arm is considered to be small or tortuous, there is a chance that the groin approach will be taken rather than using the wrist as an access. In this situation, groin approach would be then converted from radial approach. It is generally a painless procedure, however, you may feel some discomfort in your arm while the catheters passes through. You will also notice that the X-ray machines be rotating around you during the procedure. This is to ensure the appropriate coronary images are taken during the study. When your Interventional Cardiologist positions the catheter at the origin of your coronary arteries, contrast (dye) will be injected into your arteries. Occasionally, due to differences in body sizes and shapes, different sized catheters have to be used (and exchanged at the sheath) to be able to position the catheter accurately at the origin of your coronaries. Moving images of Xray will then be taken as the dye “colours” your arteries. Your Interventional Cardiologist will then be able to identify the significant blockages affecting your coronary arteries. The whole procedure usually takes up to 30mins, but may be prolonged due to complexity of locating your coronary arteries. Your Interventional Cardiologist will inject local anaesthetic around the puncture site (wrist or groin). This puncture site is where catheters (long tube) will be inserted via a small tubing (sheath) after a small cut in the skin.
What can I expect after the procedure?Following the completion of the procedure, The sheath will be removed from your wrist or groin, and firm constant pressure at the puncture site will be applied to avoid bleeding. Occasionally, your Interventional Cardiologist may deploy a special device that will stop the bleeding. Your nurse will also monitor your blood pressure, heart rate and puncture site for bleeding closely. You can normally be discharged after 2 to 6 hours, after being observed in the recovery room. The nurse caring for you will instruct you to rest in bed for up to 4hrs depending on whether the wrist or the groin is used as the puncture site. You are encouraged to make prior arrangements for someone to send you home, especially if you have been given sedatives. Please do not drive for the next 24hrs post procedure if you have been given sedatives. What should I look out for when I reach home? On the night after the procedure, please rest with minimal walking if the groin procedure was done. Use your arm minimally with minimum wrist flexion for the next 24-48hrs if you have a wrist puncture. You are discouraged from lifting heavy weights for 7 days after the procedure. You can remove the plastic bandage dressing the day after the procedure. Drink lots of fluids. Please make an appointment to see either your Cardiologist or General Practitioner 1 week after your procedure to check on your puncture site. Please take note: If you notice that your puncture site (groin or wrist) becomes painful and develops a large lump, you are advised to lie down immediately and apply pressure on the puncture site with the help of someone. Please seek medical attention (calling an ambulance or proceed to nearest hospital) immediately as this could be due to bleeding from your artery.