Stress EchocardiogramLooking for angina
A stress echocardiogram is a type of stress test with higher sensitivity and accuracy
than a treadmill ECG. It may be performed on a treadmill or bike,
or more commonly by using a drug to trick the body into thinking it is exercising
Stress echocardiography (DSE) is a type of stress test used to help investigate pains in the chest or to look for ‘cardiac ischaemia’. This is when the heart suffers from an insufficient blood supply. This is most commonly caused by narrowing of the heart arteries. In other cases, this can be due to changes in the tiny arteries within the heart muscle. Patients who are or have been smokers, have diabetes or have raised cholesterol are more likely to have narrowing of heart arteries, and stress echocardiography can be a very sensitive way of detecting this.
“Stress echocardiography has been a mainstay in the UK for many years. Its a sensitive and accurate way of looking at the heart at rest and during stress. I look out for areas of the heart not working so well under stress. If we find this, this suggests there is a heart artery problem and coronary angiography is usually the next step.”
The cardiac stress can be invoked in two main ways. The first is to use exercise – you may be asked to run on a treadmill or to use an exercise bike. The second is to trick the heart into thinking you’re exercising by giving you a medicine called Dobutamine. The approach used will depend on your circumstances and your heart health.
The Test Procedure
The procedure involves taking pictures of the heart while you are lying on a couch using an ultrasound machine called an echocardiogram. Gel is placed on the chest and the technician will use the ultrasound probe to look at the heart, its function and its valves. The next stage is to increase your heart rate to mimic intense exercise. This is done by giving a medicine called Dobutamine through a controlled drip in the hand. Dobutamine will make the heart rate increase and ‘trick’ the body into thinking you are doing intense exercise. The dose of Dobutamine is slowly increased while your heart is continuously monitored. It can feel odd during the infusion. You will feel a strong and thumping heart beat and you may feel breathless. In some cases, you may develop a tightness across the chest. Once your peak heart rate is reached, the test will be drawn to an end. The Dobutamine medicine will very rapidly clear from your body and symptoms will quickly resolve.
In order to get the best result from the test, we recommend that you stop any beta-blocking medicine that you may be taking for 48 hours prior to the test. Beta-blockers include atenolol, bisoprolol, carvedilol and metoprolol. You can usually restart your medicine after the test.
Like all stress tests, there is a small element of risk when having the procedure. For the majority of people, this risk is 1/1000. The principle risk is that you may develop excessive side-effects from the dobutamine, including chest tightness and breathlessness. Some patients may develop low blood pressure and a feeling of faintness. There is also a very small chance of triggering a heart attack. This is most likely if your own heart arteries are very severely narrowed. Should any of these things happen, we would treat you straight away.
Getting the Results
The DSE is specialist test and I often discuss the findings with other expert Cardiologists who specialise specifically in this test. They will issue a report and then I will arrange an appointment in order to interpret the findings and explain them to you.
If the test shows that your heart responds well to stress, this can help to reassure you that there is no underlying cardiac ischaemia. Patients with a negative stress echocardiogram are known to have a better prognosis than those with a positive one.
If your test is positive for cardiac ischaemia, you may need an invasive angiogram to look at your heart arteries directly. If there is a narrowing of a coronary artery, this may be treatable by coronary angioplasty.