Written by Dimitrios Vrachatis, Specialist Cardiologist, PhD, National and Kapodistrian University of Athens.
What is stress echocardiography?
Stress echo is a functional test used to assess the likelihood of coronary artery disease or to evaluate valvular heart disease.
When, and for whom, is it needed?
A cardiologist may request the examination for:
- Initial assessment of suspected coronary artery disease.
- Assessment of known coronary artery disease to guide treatment.
- Follow-up of known coronary artery disease.
- Assessment of valvular disease, such as low-gradient aortic stenosis, mitral stenosis or mitral regurgitation.
What information does it provide?
When assessing possible coronary artery disease, stress echo examines the movement and thickening of different parts of the heart. Myocardial function is assessed at each stage and compared between stages to reach the diagnosis. In other cases, stress echo is used to evaluate the severity of valvular heart disease.
What else is monitored?
Alongside the ultrasound study, the ECG is monitored continuously, blood pressure is measured regularly and you are asked about symptoms such as chest pain, shortness of breath or feeling faint.
How is it performed?
It is an echocardiogram performed at rest and during progressively increasing stress.
Stress may be produced by physical exercise on a special examination bed with an exercise bicycle, or by administering medication, usually dobutamine.
An intravenous catheter is inserted beforehand to give:
- Medication, in a pharmacological stress echo.
- Ultrasound contrast agents, where needed, to make images clearer and therefore more reliable.
How long does the examination take?
The examination takes 20–30 minutes. Including preparation and monitoring afterwards, the total time is considerably longer.
Will I feel pain or discomfort?
Stress echo is painless. At the maximum heart rate, however, you may find the sensation uncomfortable, especially when medication has been used to produce the stress or rapid heart rate.
Stress echo, myocardial perfusion imaging or a treadmill stress test?
Functional tests that include imaging, such as stress echo or myocardial perfusion imaging, are preferred over a conventional exercise stress test.
When evaluating valvular heart disease, stress produced by physical exercise is preferred.
When will I receive the results?
Results are usually provided immediately after the examination. Although the test is relatively standardised, it still depends on the judgement of the cardiologist performing and interpreting it.
Ultrasound videos are recorded and can theoretically be reviewed by another clinician, but their large file size means they are not usually given to the patient.
Choose the centre carefully: when investigating coronary artery disease, the results may determine whether you undergo coronary angiography or a repeat angiogram.
Will I be exposed to radiation?
No. This is an advanced ultrasound examination and does not use ionising radiation.
Are there contraindications?
As with an exercise stress test, stress echo should not be performed when acute cardiac disease is suspected, such as an acute coronary event or myocarditis. There are also relative contraindications when complication risk is increased, for example severe aortic stenosis.
Are there risks?
Stress echo is a relatively safe, non-invasive examination, but it does place the heart under stress — precisely the response we want to study.
As with any functional test, rare but real risks exist, including an acute coronary event, recurrence of atrial fibrillation and, much more rarely, death. The small theoretical risk of a life-threatening complication (0.05%) is outweighed by the potential benefits.
For these reasons, the examination is performed in appropriately equipped facilities with staff experienced in managing emergencies.
Is preparation needed?
No special preparation is otherwise needed. Avoid food, smoking and related products for 2–3 hours beforehand, and caffeine and alcohol for 12 hours.
Your cardiologist will also advise you about stopping certain medicines, such as beta-blockers, 2–3 days beforehand.
What happens afterwards?
After the examination, the heart rate gradually returns to normal, either by itself or with medication. You remain under observation for about another 30 minutes, then can return to normal activities. It is advisable to avoid driving for a few hours.